---

import {
  AutoscaleInfo,
  CrosshairMode,
  IChartApi,
  IPrimitivePaneView,
  ISeriesApi,
  ISeriesPrimitive,
  ISeriesPrimitiveAxisView,
  Logical,
  PrimitiveHoveredItem,
  SeriesAttachedParameter,
  SeriesOptionsMap,
  SeriesType,
  Time,
} from 'lightweight-charts';
import { Observable, Subject, Subscription } from 'rxjs';

import { getPointerPoint as getPointerPointFromEvent } from '@core/Drawings/helpers';
import { AxisLabel, AxisSegment, Point, SeriesApi } from '@core/Drawings/types';

import { SettingsTab, SettingsValues } from '@src/types';

export interface DrawingInteraction {
  selected$: Observable<boolean>;
  locked$: Observable<boolean>;

  isSelected(): boolean;
  isLocked(): boolean;

  select(): void;
  deselect(): void;
}

export interface ISeriesDrawing extends ISeriesPrimitive<Time> {
  show(): void;
  hide(): void;
  rebind(series: ISeriesApi<SeriesType>): void;
  destroy(): void;

  waitTillReady(): Promise<void>;
  isCreationPending(): boolean;
  shouldShowInObjectTree(): boolean;

  getState(): unknown;
  setState(state: unknown): void;

  getSettings(): SettingsValues;
  getSettingsTabs(): SettingsTab[];
  updateSettings(settings: SettingsValues): void;

  subscribeSettings(callback: (settings: SettingsValues) => void): Subscription;

  getRenderData(): unknown;
}

interface SeriesDrawingBaseParams {
  container: HTMLElement;
  chart: IChartApi;
  series: SeriesApi;
  interaction: DrawingInteraction;
}

export abstract class SeriesDrawingBase<TSettings extends SettingsValues = SettingsValues> implements ISeriesDrawing {
  protected hidden = false;
  protected chart: IChartApi;
  protected series: SeriesApi;
  protected subscriptions = new Subscription();
  protected abstract mode: unknown; // todo: хочется иметь единый mode
  protected abstract settings: TSettings;
  protected readonly container: HTMLElement;
  protected isBound = false;

  private readonly interaction: DrawingInteraction;
  private readonly settingsSubject = new Subject<SettingsValues>();
  private isInteractionBound = false;

  protected readyPromise: Promise<void> | null = null;
  protected resolveReady: (() => void) | null = null;
  protected requestUpdate: (() => void) | null = null;

  constructor({ chart, series, container, interaction }: SeriesDrawingBaseParams) {
    this.chart = chart;
    this.series = series;
    this.container = container;
    this.interaction = interaction;
  }

  public subscribeSettings(callback: (settings: SettingsValues) => void): Subscription {
    callback(this.getSettings());

    return this.settingsSubject.subscribe(callback);
  }

  public show(): void {
    this.hidden = false;
    this.render();
  }

  public hide(): void {
    this.hidden = true;
    this.showCrosshair();
    this.render();
  }

  public rebind(series: SeriesApi): void {
    if (this.series === series) {
      return;
    }

    this.showCrosshair();
    this.unbindEvents();
    this.series.detachPrimitive(this as unknown as ISeriesPrimitive<Time>);

    this.series = series;
    this.requestUpdate = null;

    this.series.attachPrimitive(this as unknown as ISeriesPrimitive<Time>);
    this.render();
  }

  public destroy(): void {
    this.showCrosshair();
    this.unbindEvents();
    this.subscriptions.unsubscribe();
    this.settingsSubject.complete();
    this.series.detachPrimitive(this as unknown as ISeriesPrimitive<Time>);
    this.requestUpdate = null;
    this.resolveReady?.();
  }

  public waitTillReady(): Promise<void> {
    if (this.mode === 'ready') {
      return Promise.resolve();
    }

    if (!this.readyPromise) {
      this.readyPromise = new Promise((resolve) => {
        this.resolveReady = resolve;
      });
    }

    return this.readyPromise;
  }

  public shouldShowInObjectTree(): boolean {
    return this.mode !== 'idle';
  }

  public getSettings(): SettingsValues {
    return { ...this.settings };
  }

  public updateSettings(settings: SettingsValues): void {
    this.settings = {
      ...this.settings,
      ...settings,
    };

    this.settingsSubject.next(this.getSettings());
    this.render();
  }

  public attached(param: SeriesAttachedParameter<Time, keyof SeriesOptionsMap>): void {
    this.requestUpdate = param.requestUpdate;
    this.bindInteraction();
    this.bindEvents();
  }

  public detached(): void {
    this.showCrosshair();
    this.unbindEvents();
    this.requestUpdate = null;
  }

  public autoscaleInfo(_start: Logical, _end: Logical): AutoscaleInfo | null {
    return null;
  }

  public hitTest(x: number, y: number): PrimitiveHoveredItem | null {
    const hoveredItem = this.getHoveredItem(x, y);

    if (!hoveredItem || !this.isLocked()) {
      return hoveredItem;
    }

    return {
      ...hoveredItem,
      cursorStyle: 'pointer',
    };
  }

  public abstract getRenderData(): unknown; // todo: make proper type
  public abstract getState(): unknown;
  public abstract getSettingsTabs(): SettingsTab[];
  public abstract isCreationPending(): boolean;
  public abstract setState(state: unknown): void;
  public abstract updateAllViews(): void;
  public abstract paneViews(): readonly IPrimitivePaneView[];
  public abstract priceAxisPaneViews(): readonly IPrimitivePaneView[];
  public abstract priceAxisViews(): readonly ISeriesPrimitiveAxisView[];
  public abstract timeAxisPaneViews(): readonly IPrimitivePaneView[];
  public abstract timeAxisViews(): readonly ISeriesPrimitiveAxisView[];

  protected isSelected(): boolean {
    return this.interaction.isSelected();
  }

  protected isLocked(): boolean {
    return this.interaction.isLocked();
  }

  protected select(): void {
    this.interaction.select();
  }

  protected deselect(): void {
    this.interaction.deselect();
  }

  protected shouldShowHandles(): boolean {
    return !this.isLocked() && (this.isSelected() || this.isCreationPending());
  }

  protected render(): void {
    this.updateAllViews();
    this.requestUpdate?.();
  }

  protected hideCrosshair(): void {
    this.chart.applyOptions({
      crosshair: {
        mode: CrosshairMode.Hidden,
      },
    });
  }

  protected showCrosshair(): void {
    this.chart.applyOptions({
      crosshair: {
        mode: CrosshairMode.Normal,
      },
    });
  }

  protected getEventPoint(event: PointerEvent): Point {
    return getPointerPointFromEvent(this.container, event);
  }

  protected bindEvents(): void {
    if (this.isBound) {
      return;
    }

    this.isBound = true;

    this.container.addEventListener('dblclick', this.handleDoubleClick);
    this.container.addEventListener('pointerdown', this.handlePointerDownEvent);
    this.container.addEventListener('contextmenu', this.handleContextMenu);

    window.addEventListener('pointermove', this.handlePointerMove);
    window.addEventListener('pointerup', this.handlePointerUp);
    window.addEventListener('pointercancel', this.handlePointerUp);
  }

  protected unbindEvents(): void {
    if (!this.isBound) {
      return;
    }

    this.isBound = false;

    this.container.removeEventListener('dblclick', this.handleDoubleClick);
    this.container.removeEventListener('pointerdown', this.handlePointerDownEvent);
    this.container.removeEventListener('contextmenu', this.handleContextMenu);

    window.removeEventListener('pointermove', this.handlePointerMove);
    window.removeEventListener('pointerup', this.handlePointerUp);
    window.removeEventListener('pointercancel', this.handlePointerUp);
  }

  // todo: хочется общую реализацию для каждой кнопки
  protected handleContextMenu(event: MouseEvent): void {}
  protected handleDoubleClick(event: MouseEvent): void {}
  protected handlePointerDown(event: PointerEvent): void {}
  protected handlePointerMove(event: PointerEvent): void {}
  protected handlePointerUp(event: PointerEvent): void {}

  protected abstract getHoveredItem(x: number, y: number): PrimitiveHoveredItem | null;
  protected abstract getGeometry(): unknown; // todo: make proper type
  protected abstract getTimeAxisSegments(): AxisSegment[];
  protected abstract getPriceAxisSegments(): AxisSegment[];
  protected abstract getTimeAxisLabel(kind: string): AxisLabel | null;
  protected abstract getPriceAxisLabel(kind: string): AxisLabel | null;

  private bindInteraction(): void {
    if (this.isInteractionBound) {
      return;
    }

    this.isInteractionBound = true;

    this.subscriptions.add(
      this.interaction.selected$.subscribe(() => {
        this.render();
      }),
    );

    this.subscriptions.add(
      this.interaction.locked$.subscribe((isLocked) => {
        if (isLocked) {
          this.showCrosshair();
        }

        this.render();
      }),
    );
  }

  private handlePointerDownEvent = (event: PointerEvent): void => {
    if (!this.isLocked() || this.isCreationPending() || event.button !== 0) {
      this.handlePointerDown(event);

      return;
    }

    const point = this.getEventPoint(event);
    const isDrawingHit = this.getHoveredItem(point.x, point.y) !== null;

    if (isDrawingHit) {
      this.select();

      return;
    }

    if (this.isSelected()) {
      this.deselect();
    }
  };
}



import { IChartApi, IPrimitivePaneView, PrimitiveHoveredItem, UTCTimestamp } from 'lightweight-charts';
import { Observable } from 'rxjs';

import {
  CustomPriceAxisPaneView,
  CustomPriceAxisView,
  CustomTimeAxisPaneView,
  CustomTimeAxisView,
} from '@core/Drawings/axis';
import { SeriesDrawingBase } from '@core/Drawings/common';
import {
  getAnchorFromPoint,
  getPriceDelta as getPriceDeltaFromCoordinates,
  getPriceFromYCoordinate,
  getXCoordinateFromTime,
  getYCoordinateFromPrice,
  isNearPoint,
  shiftTimeByPixels,
} from '@core/Drawings/helpers';
import { updateViews } from '@core/Drawings/utils';

import { getThemeStore } from '@src/theme';
import { Defaults } from '@src/types/defaults';
import { formatPrice } from '@src/utils';
import { formatDate } from '@src/utils/formatter';

import { ParallelChannelPaneView } from './paneView';
import {
  createDefaultSettings,
  getParallelChannelSettingsTabs,
  ParallelChannelSettings,
  ParallelChannelStyle,
  ParallelChannelTextStyle,
} from './settings';

import type { DrawingInteraction, ISeriesDrawing } from '@core/Drawings/common';
import type { Anchor, AxisLabel, AxisSegment, Point, SeriesApi } from '@core/Drawings/types';
import type { ChartOptionsModel, SettingsTab } from '@src/types';

type ParallelChannelMode = 'idle' | 'drawing-line' | 'drawing-channel' | 'ready' | 'dragging';

type ParallelChannelDragTarget =
  | 'main-start'
  | 'main-middle'
  | 'main-end'
  | 'parallel-start'
  | 'parallel-middle'
  | 'parallel-end'
  | 'body';

type TimeLabelKind = 'start' | 'end';

type PriceLabelKind = 'main-start' | 'main-end' | 'parallel-start' | 'parallel-end';

interface ParallelChannelParams {
  container: HTMLElement;
  interaction: DrawingInteraction;
  formatObservable?: Observable<ChartOptionsModel>;
  openSettings?: () => void;
}

interface ParallelChannelState {
  hidden: boolean;
  mode: ParallelChannelMode;
  startAnchor: Anchor | null;
  endAnchor: Anchor | null;
  priceOffset: number | null;
  settings: ParallelChannelSettings;
}

interface ParallelChannelGeometry {
  startPoint: Point;
  mainMiddlePoint: Point;
  endPoint: Point;
  parallelStartPoint: Point;
  parallelMiddlePoint: Point;
  parallelEndPoint: Point;
  middleStartPoint: Point;
  middleEndPoint: Point;
  left: number;
  right: number;
  top: number;
  bottom: number;
}

export interface ParallelChannelRenderData
  extends ParallelChannelGeometry,
    ParallelChannelStyle,
    ParallelChannelTextStyle {
  showHandles: boolean;
}

const HANDLE_HIT_TOLERANCE = 8;
const LINE_HIT_TOLERANCE = 6;
const MIN_LINE_SIZE = 4;
const MIN_CHANNEL_WIDTH = 4;
const VERTICAL_LINE_TOLERANCE = 0.001;

export class ParallelChannel extends SeriesDrawingBase<ParallelChannelSettings> implements ISeriesDrawing {
  private openSettings?: () => void;

  protected settings: ParallelChannelSettings = createDefaultSettings();
  protected mode: ParallelChannelMode = 'idle';

  private startAnchor: Anchor | null = null;
  private endAnchor: Anchor | null = null;
  private priceOffset: number | null = null;

  private activeDragTarget: ParallelChannelDragTarget | null = null;
  private dragPointerId: number | null = null;
  private dragStartPoint: Point | null = null;
  private dragStateSnapshot: ParallelChannelState | null = null;

  private displayFormat: ChartOptionsModel = {
    dateFormat: Defaults.dateFormat,
    timeFormat: Defaults.timeFormat,
    showTime: Defaults.showTime,
  };

  private paneView: ParallelChannelPaneView;
  private timeAxisPaneView: CustomTimeAxisPaneView;
  private priceAxisPaneView: CustomPriceAxisPaneView;

  private startTimeAxisView: CustomTimeAxisView;
  private endTimeAxisView: CustomTimeAxisView;

  private mainStartPriceAxisView: CustomPriceAxisView;
  private mainEndPriceAxisView: CustomPriceAxisView;
  private parallelStartPriceAxisView: CustomPriceAxisView;
  private parallelEndPriceAxisView: CustomPriceAxisView;

  constructor(
    chart: IChartApi,
    series: SeriesApi,
    { container, interaction, formatObservable, openSettings }: ParallelChannelParams,
  ) {
    super({
      chart,
      series,
      container,
      interaction,
    });

    this.openSettings = openSettings;

    this.paneView = new ParallelChannelPaneView(this);

    this.timeAxisPaneView = new CustomTimeAxisPaneView({
      getAxisSegments: () => this.getTimeAxisSegments(),
    });

    this.priceAxisPaneView = new CustomPriceAxisPaneView({
      getAxisSegments: () => this.getPriceAxisSegments(),
    });

    this.startTimeAxisView = new CustomTimeAxisView({
      getAxisLabel: (kind) => this.getTimeAxisLabel(kind),
      labelKind: 'start',
    });

    this.endTimeAxisView = new CustomTimeAxisView({
      getAxisLabel: (kind) => this.getTimeAxisLabel(kind),
      labelKind: 'end',
    });

    this.mainStartPriceAxisView = new CustomPriceAxisView({
      getAxisLabel: (kind) => this.getPriceAxisLabel(kind),
      labelKind: 'main-start',
    });

    this.mainEndPriceAxisView = new CustomPriceAxisView({
      getAxisLabel: (kind) => this.getPriceAxisLabel(kind),
      labelKind: 'main-end',
    });

    this.parallelStartPriceAxisView = new CustomPriceAxisView({
      getAxisLabel: (kind) => this.getPriceAxisLabel(kind),
      labelKind: 'parallel-start',
    });

    this.parallelEndPriceAxisView = new CustomPriceAxisView({
      getAxisLabel: (kind) => this.getPriceAxisLabel(kind),
      labelKind: 'parallel-end',
    });

    if (formatObservable) {
      this.subscriptions.add(
        formatObservable.subscribe((format) => {
          this.displayFormat = format;
          this.render();
        }),
      );
    }

    this.series.attachPrimitive(this);
  }

  public isCreationPending(): boolean {
    return this.mode === 'idle' || this.mode === 'drawing-line' || this.mode === 'drawing-channel';
  }

  public getState(): ParallelChannelState {
    return {
      hidden: this.hidden,
      mode: this.mode,
      startAnchor: this.startAnchor,
      endAnchor: this.endAnchor,
      priceOffset: this.priceOffset,
      settings: { ...this.settings },
    };
  }

  public setState(state: unknown): void {
    if (!state || typeof state !== 'object') {
      return;
    }

    const nextState = state as Partial<ParallelChannelState>;

    if (typeof nextState.hidden === 'boolean') {
      this.hidden = nextState.hidden;
    }

    if (nextState.mode) {
      this.mode = nextState.mode === 'dragging' ? 'ready' : nextState.mode;
    }

    if ('startAnchor' in nextState) {
      this.startAnchor = nextState.startAnchor ?? null;
    }

    if ('endAnchor' in nextState) {
      this.endAnchor = nextState.endAnchor ?? null;
    }

    if ('priceOffset' in nextState) {
      this.priceOffset = nextState.priceOffset ?? null;
    }

    if (nextState.settings) {
      this.settings = {
        ...createDefaultSettings(),
        ...nextState.settings,
      };
    }

    this.render();
  }

  public getSettingsTabs(): SettingsTab[] {
    return getParallelChannelSettingsTabs(this.settings);
  }

  public updateAllViews(): void {
    updateViews([
      this.paneView,
      this.timeAxisPaneView,
      this.priceAxisPaneView,
      this.startTimeAxisView,
      this.endTimeAxisView,
      this.mainStartPriceAxisView,
      this.mainEndPriceAxisView,
      this.parallelStartPriceAxisView,
      this.parallelEndPriceAxisView,
    ]);
  }

  public paneViews(): readonly IPrimitivePaneView[] {
    return [this.paneView];
  }

  public timeAxisPaneViews(): readonly IPrimitivePaneView[] {
    return [this.timeAxisPaneView];
  }

  public priceAxisPaneViews(): readonly IPrimitivePaneView[] {
    return [this.priceAxisPaneView];
  }

  public timeAxisViews() {
    return [this.startTimeAxisView, this.endTimeAxisView];
  }

  public priceAxisViews() {
    return [
      this.mainStartPriceAxisView,
      this.mainEndPriceAxisView,
      this.parallelStartPriceAxisView,
      this.parallelEndPriceAxisView,
    ];
  }

  public getRenderData(): ParallelChannelRenderData | null {
    if (this.hidden) {
      return null;
    }

    const geometry = this.getGeometry();

    if (!geometry) {
      return null;
    }

    return {
      ...geometry,
      ...this.settings,
      showHandles: this.shouldShowHandles(),
    };
  }

  protected getHoveredItem(x: number, y: number): PrimitiveHoveredItem | null {
    if (this.hidden || this.mode !== 'ready') {
      return null;
    }

    const point = { x, y };
    const pointTarget = this.getPointTarget(point);
    const isChannelHit = this.isPointOnChannel(point);

    if (!pointTarget && !isChannelHit) {
      return null;
    }

    if (!this.isSelected()) {
      return {
        cursorStyle: 'pointer',
        externalId: 'parallel-channel',
        zOrder: 'top',
      };
    }

    return {
      cursorStyle: pointTarget ? 'move' : 'grab',
      externalId: 'parallel-channel',
      zOrder: 'top',
    };
  }

  protected getTimeAxisSegments(): AxisSegment[] {
    if (!this.isSelected() && !this.isCreationPending()) {
      return [];
    }

    const geometry = this.getGeometry();

    if (!geometry) {
      return [];
    }

    const { colors } = getThemeStore();

    return [
      {
        from: geometry.left,
        to: geometry.right,
        color: colors.axisMarkerAreaFill,
      },
    ];
  }

  protected getPriceAxisSegments(): AxisSegment[] {
    if (!this.isSelected() && !this.isCreationPending()) {
      return [];
    }

    const geometry = this.getGeometry();

    if (!geometry) {
      return [];
    }

    const { colors } = getThemeStore();

    return [
      {
        from: geometry.top,
        to: geometry.bottom,
        color: colors.axisMarkerAreaFill,
      },
    ];
  }

  protected getTimeAxisLabel(kind: string): AxisLabel | null {
    if ((!this.isSelected() && !this.isCreationPending()) || (kind !== 'start' && kind !== 'end')) {
      return null;
    }

    const anchor = kind === 'start' ? this.startAnchor : this.endAnchor;

    if (!anchor || typeof anchor.time !== 'number') {
      return null;
    }

    const coordinate = getXCoordinateFromTime(this.chart, anchor.time, this.series);

    if (coordinate === null) {
      return null;
    }

    const { colors } = getThemeStore();

    return {
      coordinate,
      text: formatDate(
        anchor.time as UTCTimestamp,
        this.displayFormat.dateFormat,
        this.displayFormat.timeFormat,
        this.displayFormat.showTime,
      ),
      textColor: colors.chartPriceLineText,
      backgroundColor: colors.axisMarkerLabelFill,
    };
  }

  protected getPriceAxisLabel(kind: string): AxisLabel | null {
    if ((!this.isSelected() && !this.isCreationPending()) || !isPriceLabelKind(kind)) {
      return null;
    }

    const price = this.getPriceLabelValue(kind);

    if (price === null) {
      return null;
    }

    const coordinate = getYCoordinateFromPrice(this.series, price);

    if (coordinate === null) {
      return null;
    }

    const { colors } = getThemeStore();

    return {
      coordinate,
      text: formatPrice(price) ?? '',
      textColor: colors.chartPriceLineText,
      backgroundColor: colors.axisMarkerLabelFill,
    };
  }

  protected handleDoubleClick = (event: MouseEvent): void => {
    if (this.hidden || this.mode !== 'ready' || !this.isSelected()) {
      return;
    }

    const point = this.getEventPoint(event as PointerEvent);

    if (!this.isPointOnChannel(point) && !this.getPointTarget(point)) {
      return;
    }

    event.preventDefault();
    event.stopPropagation();

    this.openSettings?.();
  };

  protected handlePointerDown = (event: PointerEvent): void => {
    if (this.hidden || event.button !== 0) {
      return;
    }

    const point = this.getEventPoint(event);

    if (this.mode === 'idle') {
      event.preventDefault();
      event.stopPropagation();

      this.startDrawing(point);
      return;
    }

    if (this.mode === 'drawing-line') {
      event.preventDefault();
      event.stopPropagation();

      this.setEndAnchor(point);

      if (!this.hasValidMainLine()) {
        this.render();
        return;
      }

      this.priceOffset = 0;
      this.mode = 'drawing-channel';

      this.render();
      return;
    }

    if (this.mode === 'drawing-channel') {
      event.preventDefault();
      event.stopPropagation();

      this.setPriceOffset(point);

      if (!this.hasValidChannelWidth()) {
        this.render();
        return;
      }

      this.finishDrawing();
      return;
    }

    if (this.mode !== 'ready') {
      return;
    }

    const pointTarget = this.getPointTarget(point);
    const isChannelHit = this.isPointOnChannel(point);
    const isDrawingHit = pointTarget !== null || isChannelHit;

    if (!this.isSelected()) {
      if (!isDrawingHit) {
        return;
      }

      event.preventDefault();
      event.stopPropagation();

      this.select();
      return;
    }

    if (pointTarget) {
      event.preventDefault();
      event.stopPropagation();

      this.startDragging(pointTarget, point, event.pointerId);

      return;
    }

    if (isChannelHit) {
      event.preventDefault();
      event.stopPropagation();

      this.startDragging('body', point, event.pointerId);

      return;
    }

    this.deselect();
  };

  protected handlePointerMove = (event: PointerEvent): void => {
    const point = this.getEventPoint(event);

    if (this.mode === 'drawing-line') {
      this.setEndAnchor(point);
      this.render();
      return;
    }

    if (this.mode === 'drawing-channel') {
      this.setPriceOffset(point);
      this.render();
      return;
    }

    if (this.mode !== 'dragging' || this.dragPointerId !== event.pointerId || !this.activeDragTarget) {
      return;
    }

    event.preventDefault();
    event.stopPropagation();

    this.applyDrag(point);
    this.render();
  };

  protected handlePointerUp = (event: PointerEvent): void => {
    if (this.mode !== 'dragging' || this.dragPointerId !== event.pointerId) {
      return;
    }

    this.finishDragging();
  };

  protected getGeometry(): ParallelChannelGeometry | null {
    if (!this.startAnchor || !this.endAnchor || this.priceOffset === null) {
      return null;
    }

    const startPoint = this.getAnchorPoint(this.startAnchor);
    const endPoint = this.getAnchorPoint(this.endAnchor);

    const parallelStartPoint = this.getAnchorPoint({
      time: this.startAnchor.time,
      price: this.startAnchor.price + this.priceOffset,
    });

    const parallelEndPoint = this.getAnchorPoint({
      time: this.endAnchor.time,
      price: this.endAnchor.price + this.priceOffset,
    });

    if (!startPoint || !endPoint || !parallelStartPoint || !parallelEndPoint) {
      return null;
    }

    const mainMiddlePoint = getMiddlePoint(startPoint, endPoint);

    const parallelMiddlePoint = getMiddlePoint(parallelStartPoint, parallelEndPoint);

    const middleStartPoint = getMiddlePoint(startPoint, parallelStartPoint);

    const middleEndPoint = getMiddlePoint(endPoint, parallelEndPoint);

    const points = [startPoint, endPoint, parallelStartPoint, parallelEndPoint];

    return {
      startPoint,
      mainMiddlePoint,
      endPoint,
      parallelStartPoint,
      parallelMiddlePoint,
      parallelEndPoint,
      middleStartPoint,
      middleEndPoint,
      left: Math.min(...points.map((point) => point.x)),
      right: Math.max(...points.map((point) => point.x)),
      top: Math.min(...points.map((point) => point.y)),
      bottom: Math.max(...points.map((point) => point.y)),
    };
  }

  private startDrawing(point: Point): void {
    const anchor = this.createAnchor(point);

    if (!anchor) {
      return;
    }

    this.startAnchor = anchor;
    this.endAnchor = anchor;
    this.priceOffset = 0;
    this.mode = 'drawing-line';

    this.render();
  }

  private finishDrawing(): void {
    this.mode = 'ready';
    this.resolveReady?.();

    this.render();
  }

  private startDragging(target: ParallelChannelDragTarget, point: Point, pointerId: number): void {
    this.mode = 'dragging';
    this.activeDragTarget = target;
    this.dragPointerId = pointerId;
    this.dragStartPoint = point;
    this.dragStateSnapshot = this.getState();

    this.hideCrosshair();
    this.render();
  }

  private finishDragging(): void {
    this.mode = 'ready';

    this.activeDragTarget = null;
    this.dragPointerId = null;
    this.dragStartPoint = null;
    this.dragStateSnapshot = null;

    this.showCrosshair();
    this.render();
  }

  private applyDrag(point: Point): void {
    switch (this.activeDragTarget) {
      case 'main-start':
        this.moveMainEdge('start', point);
        break;

      case 'main-middle':
        this.moveMainMiddle(point);
        break;

      case 'main-end':
        this.moveMainEdge('end', point);
        break;

      case 'parallel-start':
        this.moveParallelEdge('start', point);
        break;

      case 'parallel-middle':
        this.moveParallelMiddle(point);
        break;

      case 'parallel-end':
        this.moveParallelEdge('end', point);
        break;

      case 'body':
        this.moveBody(point);
        break;

      default:
        break;
    }
  }

  private moveMainEdge(kind: TimeLabelKind, point: Point): void {
    const anchor = this.createAnchor(point);

    if (!anchor) {
      return;
    }

    const previousAnchor = kind === 'start' ? this.startAnchor : this.endAnchor;

    if (kind === 'start') {
      this.startAnchor = anchor;
    } else {
      this.endAnchor = anchor;
    }

    if (this.hasValidMainLine()) {
      return;
    }

    if (kind === 'start') {
      this.startAnchor = previousAnchor;
    } else {
      this.endAnchor = previousAnchor;
    }
  }

  private moveParallelEdge(kind: TimeLabelKind, point: Point): void {
    const snapshot = this.dragStateSnapshot;
    const anchor = this.createAnchor(point);

    if (!snapshot || snapshot.priceOffset === null || !anchor) {
      return;
    }

    const previousAnchor = kind === 'start' ? this.startAnchor : this.endAnchor;

    const baseAnchor: Anchor = {
      time: anchor.time,
      price: anchor.price - snapshot.priceOffset,
    };

    if (kind === 'start') {
      this.startAnchor = baseAnchor;
    } else {
      this.endAnchor = baseAnchor;
    }

    if (this.hasValidMainLine()) {
      return;
    }

    if (kind === 'start') {
      this.startAnchor = previousAnchor;
    } else {
      this.endAnchor = previousAnchor;
    }
  }

  private moveMainMiddle(point: Point): void {
    const snapshot = this.dragStateSnapshot;

    if (!snapshot?.startAnchor || !snapshot.endAnchor || snapshot.priceOffset === null) {
      return;
    }

    const pointerPrice = getPriceFromYCoordinate(this.series, point.y);

    const linePrice = this.getLinePriceAtX(snapshot.startAnchor, snapshot.endAnchor, point.x);

    if (pointerPrice === null || linePrice === null) {
      return;
    }

    const priceDelta = pointerPrice - linePrice;

    this.startAnchor = {
      ...snapshot.startAnchor,
      price: snapshot.startAnchor.price + priceDelta,
    };

    this.endAnchor = {
      ...snapshot.endAnchor,
      price: snapshot.endAnchor.price + priceDelta,
    };

    this.priceOffset = snapshot.priceOffset - priceDelta;

    if (this.hasValidChannelWidth()) {
      return;
    }

    this.startAnchor = snapshot.startAnchor;
    this.endAnchor = snapshot.endAnchor;
    this.priceOffset = snapshot.priceOffset;
  }

  private moveParallelMiddle(point: Point): void {
    const previousOffset = this.priceOffset;

    this.setPriceOffset(point);

    if (this.hasValidChannelWidth()) {
      return;
    }

    this.priceOffset = previousOffset;
  }

  private moveBody(point: Point): void {
    const snapshot = this.dragStateSnapshot;

    if (!snapshot?.startAnchor || !snapshot.endAnchor || snapshot.priceOffset === null || !this.dragStartPoint) {
      return;
    }

    const offsetX = point.x - this.dragStartPoint.x;

    const priceDelta = getPriceDeltaFromCoordinates(this.series, this.dragStartPoint.y, point.y);

    const startTime = shiftTimeByPixels(this.chart, snapshot.startAnchor.time, offsetX, this.series);

    const endTime = shiftTimeByPixels(this.chart, snapshot.endAnchor.time, offsetX, this.series);

    if (startTime === null || endTime === null) {
      return;
    }

    this.startAnchor = {
      time: startTime,
      price: snapshot.startAnchor.price + priceDelta,
    };

    this.endAnchor = {
      time: endTime,
      price: snapshot.endAnchor.price + priceDelta,
    };

    this.priceOffset = snapshot.priceOffset;
  }

  private setEndAnchor(point: Point): void {
    const anchor = this.createAnchor(point);

    if (!anchor) {
      return;
    }

    this.endAnchor = anchor;
  }

  private setPriceOffset(point: Point): void {
    if (!this.startAnchor || !this.endAnchor) {
      return;
    }

    const pointerPrice = getPriceFromYCoordinate(this.series, point.y);

    const linePrice = this.getLinePriceAtX(this.startAnchor, this.endAnchor, point.x);

    if (pointerPrice === null || linePrice === null) {
      return;
    }

    this.priceOffset = pointerPrice - linePrice;
  }

  private getLinePriceAtX(startAnchor: Anchor, endAnchor: Anchor, x: number): number | null {
    const startPoint = this.getAnchorPoint(startAnchor);
    const endPoint = this.getAnchorPoint(endAnchor);

    if (!startPoint || !endPoint) {
      return null;
    }

    const deltaX = endPoint.x - startPoint.x;

    if (Math.abs(deltaX) <= VERTICAL_LINE_TOLERANCE) {
      return getPriceFromYCoordinate(this.series, (startPoint.y + endPoint.y) / 2);
    }

    const ratio = (x - startPoint.x) / deltaX;

    const y = startPoint.y + (endPoint.y - startPoint.y) * ratio;

    return getPriceFromYCoordinate(this.series, y);
  }

  private hasValidMainLine(): boolean {
    const geometry = this.getGeometry();

    if (!geometry) {
      return false;
    }

    return getDistance(geometry.startPoint, geometry.endPoint) >= MIN_LINE_SIZE;
  }

  private hasValidChannelWidth(): boolean {
    const geometry = this.getGeometry();

    if (!geometry) {
      return false;
    }

    return getDistance(geometry.startPoint, geometry.parallelStartPoint) >= MIN_CHANNEL_WIDTH;
  }

  private getPointTarget(point: Point): ParallelChannelDragTarget | null {
    const geometry = this.getGeometry();

    if (!geometry) {
      return null;
    }

    const targets: [ParallelChannelDragTarget, Point][] = [
      ['main-start', geometry.startPoint],
      ['main-middle', geometry.mainMiddlePoint],
      ['main-end', geometry.endPoint],
      ['parallel-start', geometry.parallelStartPoint],
      ['parallel-middle', geometry.parallelMiddlePoint],
      ['parallel-end', geometry.parallelEndPoint],
    ];

    for (const [target, targetPoint] of targets) {
      if (isNearPoint(point, targetPoint.x, targetPoint.y, HANDLE_HIT_TOLERANCE)) {
        return target;
      }
    }

    return null;
  }

  private isPointOnChannel(point: Point): boolean {
    const geometry = this.getGeometry();

    if (!geometry) {
      return false;
    }

    if (getDistanceToSegment(point, geometry.startPoint, geometry.endPoint) <= LINE_HIT_TOLERANCE) {
      return true;
    }

    if (getDistanceToSegment(point, geometry.parallelStartPoint, geometry.parallelEndPoint) <= LINE_HIT_TOLERANCE) {
      return true;
    }

    if (
      this.settings.showMiddleLine &&
      getDistanceToSegment(point, geometry.middleStartPoint, geometry.middleEndPoint) <= LINE_HIT_TOLERANCE
    ) {
      return true;
    }

    return isPointInPolygon(point, [
      geometry.startPoint,
      geometry.endPoint,
      geometry.parallelEndPoint,
      geometry.parallelStartPoint,
    ]);
  }

  private getPriceLabelValue(kind: PriceLabelKind): number | null {
    if (!this.startAnchor || !this.endAnchor || this.priceOffset === null) {
      return null;
    }

    switch (kind) {
      case 'main-start':
        return this.startAnchor.price;

      case 'main-end':
        return this.endAnchor.price;

      case 'parallel-start':
        return this.startAnchor.price + this.priceOffset;

      case 'parallel-end':
        return this.endAnchor.price + this.priceOffset;

      default:
        return null;
    }
  }

  private getAnchorPoint(anchor: Anchor): Point | null {
    const x = getXCoordinateFromTime(this.chart, anchor.time, this.series);

    const y = getYCoordinateFromPrice(this.series, anchor.price);

    if (x === null || y === null) {
      return null;
    }

    return {
      x: Number(x),
      y: Number(y),
    };
  }

  private createAnchor(point: Point): Anchor | null {
    return getAnchorFromPoint(this.chart, this.series, point);
  }
}

function isPriceLabelKind(kind: string): kind is PriceLabelKind {
  return kind === 'main-start' || kind === 'main-end' || kind === 'parallel-start' || kind === 'parallel-end';
}

function getMiddlePoint(startPoint: Point, endPoint: Point): Point {
  return {
    x: (startPoint.x + endPoint.x) / 2,
    y: (startPoint.y + endPoint.y) / 2,
  };
}

function getDistance(startPoint: Point, endPoint: Point): number {
  return Math.hypot(endPoint.x - startPoint.x, endPoint.y - startPoint.y);
}

function getDistanceToSegment(point: Point, startPoint: Point, endPoint: Point): number {
  const deltaX = endPoint.x - startPoint.x;
  const deltaY = endPoint.y - startPoint.y;

  if (deltaX === 0 && deltaY === 0) {
    return getDistance(point, startPoint);
  }

  const ratio = Math.max(
    0,
    Math.min(
      1,
      ((point.x - startPoint.x) * deltaX + (point.y - startPoint.y) * deltaY) / (deltaX * deltaX + deltaY * deltaY),
    ),
  );

  const projectionX = startPoint.x + ratio * deltaX;

  const projectionY = startPoint.y + ratio * deltaY;

  return Math.hypot(point.x - projectionX, point.y - projectionY);
}

function isPointInPolygon(point: Point, polygon: Point[]): boolean {
  let isInside = false;

  for (let index = 0, previousIndex = polygon.length - 1; index < polygon.length; previousIndex = index, index += 1) {
    const currentPoint = polygon[index];
    const previousPoint = polygon[previousIndex];

    const intersects =
      currentPoint.y > point.y !== previousPoint.y > point.y &&
      point.x <
        ((previousPoint.x - currentPoint.x) * (point.y - currentPoint.y)) / (previousPoint.y - currentPoint.y) +
          currentPoint.x;

    if (intersects) {
      isInside = !isInside;
    }
  }

  return isInside;
}



import { CanvasRenderingTarget2D } from 'fancy-canvas';
import { IPrimitivePaneRenderer } from 'lightweight-charts';

import { getThemeStore } from '@src/theme';

import type { ParallelChannel } from './parallelChannel';

import type { Point } from '@core/Drawings/types';

const UI = {
  lineWidth: 2,
  middleLineWidth: 1,
  middleLineDash: 6,
  middleLineGap: 4,
  handleRadius: 5,
  handleBorderWidth: 2,
  textLineHeightMultiplier: 1.2,
  textOffset: 5,
  textStartGap: 5,
};

export class ParallelChannelPaneRenderer implements IPrimitivePaneRenderer {
  private parallelChannel: ParallelChannel;

  constructor(parallelChannel: ParallelChannel) {
    this.parallelChannel = parallelChannel;
  }

  public draw(target: CanvasRenderingTarget2D): void {
    const data = this.parallelChannel.getRenderData();

    if (!data) {
      return;
    }

    target.useBitmapCoordinateSpace(({ context, horizontalPixelRatio, verticalPixelRatio }) => {
      const pixelRatio = Math.max(horizontalPixelRatio, verticalPixelRatio);

      const startPoint = scalePoint(data.startPoint, horizontalPixelRatio, verticalPixelRatio);
      const mainMiddlePoint = scalePoint(data.mainMiddlePoint, horizontalPixelRatio, verticalPixelRatio);
      const endPoint = scalePoint(data.endPoint, horizontalPixelRatio, verticalPixelRatio);

      const parallelStartPoint = scalePoint(data.parallelStartPoint, horizontalPixelRatio, verticalPixelRatio);
      const parallelMiddlePoint = scalePoint(data.parallelMiddlePoint, horizontalPixelRatio, verticalPixelRatio);
      const parallelEndPoint = scalePoint(data.parallelEndPoint, horizontalPixelRatio, verticalPixelRatio);

      const middleStartPoint = scalePoint(data.middleStartPoint, horizontalPixelRatio, verticalPixelRatio);
      const middleEndPoint = scalePoint(data.middleEndPoint, horizontalPixelRatio, verticalPixelRatio);

      context.save();

      drawChannelFill(context, [startPoint, endPoint, parallelEndPoint, parallelStartPoint], data.backgroundColor);

      context.strokeStyle = data.lineColor;
      context.lineWidth = UI.lineWidth * pixelRatio;

      drawLine(context, startPoint, endPoint);
      drawLine(context, parallelStartPoint, parallelEndPoint);

      if (data.showMiddleLine) {
        context.save();

        context.lineWidth = UI.middleLineWidth * pixelRatio;
        context.setLineDash([UI.middleLineDash * pixelRatio, UI.middleLineGap * pixelRatio]);

        drawLine(context, middleStartPoint, middleEndPoint);

        context.restore();
      }

      if (data.text.trim()) {
        const channelCenterPoint = getMiddlePoint(mainMiddlePoint, parallelMiddlePoint);
        const isMainLineAbove = mainMiddlePoint.y <= parallelMiddlePoint.y;

        drawTextAlongLine(context, {
          startPoint: isMainLineAbove ? startPoint : parallelStartPoint,
          endPoint: isMainLineAbove ? endPoint : parallelEndPoint,
          channelCenterPoint,
          text: data.text,
          fontSize: data.fontSize,
          isBold: data.isBold,
          isItalic: data.isItalic,
          textColor: data.textColor,
          pixelRatio,
          verticalPixelRatio,
        });
      }

      if (data.showHandles) {
        const { colors } = getThemeStore();

        context.fillStyle = colors.chartBackground;

        context.strokeStyle = colors.chartLineColor;

        context.lineWidth = UI.handleBorderWidth * pixelRatio;

        const radius = UI.handleRadius * pixelRatio;

        drawHandle(context, startPoint, radius);
        drawHandle(context, mainMiddlePoint, radius);
        drawHandle(context, endPoint, radius);
        drawHandle(context, parallelStartPoint, radius);
        drawHandle(context, parallelMiddlePoint, radius);
        drawHandle(context, parallelEndPoint, radius);
      }

      context.restore();
    });
  }
}

function scalePoint(point: Point, horizontalPixelRatio: number, verticalPixelRatio: number): Point {
  return {
    x: point.x * horizontalPixelRatio,
    y: point.y * verticalPixelRatio,
  };
}

function drawChannelFill(context: CanvasRenderingContext2D, points: Point[], color: string): void {
  const [startPoint, endPoint, parallelEndPoint, parallelStartPoint] = points;

  context.save();
  context.fillStyle = color;

  context.beginPath();
  context.moveTo(startPoint.x, startPoint.y);
  context.lineTo(endPoint.x, endPoint.y);
  context.lineTo(parallelEndPoint.x, parallelEndPoint.y);
  context.lineTo(parallelStartPoint.x, parallelStartPoint.y);
  context.closePath();
  context.fill();

  context.restore();
}

function drawLine(context: CanvasRenderingContext2D, startPoint: Point, endPoint: Point): void {
  context.beginPath();
  context.moveTo(startPoint.x, startPoint.y);
  context.lineTo(endPoint.x, endPoint.y);
  context.stroke();
}

function drawHandle(context: CanvasRenderingContext2D, point: Point, radius: number): void {
  context.beginPath();
  context.arc(point.x, point.y, radius, 0, Math.PI * 2);
  context.fill();
  context.stroke();
}

function drawTextAlongLine(
  context: CanvasRenderingContext2D,
  params: {
    startPoint: Point;
    endPoint: Point;
    channelCenterPoint: Point;
    text: string;
    fontSize: number;
    isBold: boolean;
    isItalic: boolean;
    textColor: string;
    pixelRatio: number;
    verticalPixelRatio: number;
  },
): void {
  const {
    startPoint,
    endPoint,
    channelCenterPoint,
    text,
    fontSize,
    isBold,
    isItalic,
    textColor,
    pixelRatio,
    verticalPixelRatio,
  } = params;

  let renderStartPoint = startPoint;
  let renderEndPoint = endPoint;

  let deltaX = renderEndPoint.x - renderStartPoint.x;
  let deltaY = renderEndPoint.y - renderStartPoint.y;
  let angle = Math.atan2(deltaY, deltaX);

  if (angle > Math.PI / 2 || angle < -Math.PI / 2) {
    renderStartPoint = endPoint;
    renderEndPoint = startPoint;

    deltaX = renderEndPoint.x - renderStartPoint.x;
    deltaY = renderEndPoint.y - renderStartPoint.y;
    angle = Math.atan2(deltaY, deltaX);
  }

  const lineLength = Math.hypot(deltaX, deltaY);

  if (!lineLength) {
    return;
  }

  const directionX = deltaX / lineLength;

  const directionY = deltaY / lineLength;

  const lineMiddlePoint = getMiddlePoint(startPoint, endPoint);

  const outwardX = lineMiddlePoint.x - channelCenterPoint.x;

  const outwardY = lineMiddlePoint.y - channelCenterPoint.y;

  const outwardLength = Math.hypot(outwardX, outwardY);

  const normalX = outwardLength ? outwardX / outwardLength : 0;

  const normalY = outwardLength ? outwardY / outwardLength : -1;

  const lines = text.split('\n');
  const safeFontSize = Math.max(1, fontSize);
  const fontSizePx = safeFontSize * verticalPixelRatio;
  const lineHeight = safeFontSize * UI.textLineHeightMultiplier * verticalPixelRatio;
  const fontWeight = isBold ? '700 ' : '';
  const fontStyle = isItalic ? 'italic ' : '';

  context.save();

  context.font = `${fontStyle}${fontWeight}${fontSizePx}px Inter, sans-serif`;

  const textWidth = lines.reduce((maxWidth, line) => {
    return Math.max(maxWidth, context.measureText(line || ' ').width);
  }, 0);

  const blockHeight = lines.length * lineHeight;

  const startPadding = (UI.handleRadius * 2 + UI.textStartGap) * pixelRatio;

  const desiredDistance = startPadding + textWidth / 2;
  const availableDistance = lineLength - textWidth / 2 - UI.textStartGap * pixelRatio;

  const distanceAlongLine = availableDistance >= desiredDistance ? desiredDistance : lineLength / 2;
  const outwardDistance = blockHeight / 2 + UI.textOffset * verticalPixelRatio;

  const textCenterX = renderStartPoint.x + directionX * distanceAlongLine + normalX * outwardDistance;
  const textCenterY = renderStartPoint.y + directionY * distanceAlongLine + normalY * outwardDistance;

  context.translate(textCenterX, textCenterY);
  context.rotate(angle);

  context.fillStyle = textColor;
  context.textAlign = 'center';
  context.textBaseline = 'middle';

  const firstLineY = (-(lines.length - 1) * lineHeight) / 2;

  lines.forEach((line, index) => {
    context.fillText(line, 0, firstLineY + index * lineHeight);
  });

  context.restore();
}

function getMiddlePoint(startPoint: Point, endPoint: Point): Point {
  return {
    x: (startPoint.x + endPoint.x) / 2,
    y: (startPoint.y + endPoint.y) / 2,
  };
}



import { getThemeStore } from '@src/theme';
import { t } from '@src/translations';

import { SettingField, SettingsTab, SettingsValues } from '@src/types';

export interface ParallelChannelStyle {
  lineColor: string;
  backgroundColor: string;
  showMiddleLine: boolean;
}

export interface ParallelChannelTextStyle {
  fontSize: number;
  text: string;
  isBold: boolean;
  isItalic: boolean;
  textColor: string;
}

export type ParallelChannelSettings = ParallelChannelStyle & ParallelChannelTextStyle & SettingsValues;

export function createDefaultSettings(): ParallelChannelSettings {
  const { colors } = getThemeStore();

  return {
    lineColor: colors.chartLineColor,
    backgroundColor: colors.axisMarkerAreaFill,
    showMiddleLine: true,
    fontSize: 14,
    text: '',
    isBold: false,
    isItalic: false,
    textColor: colors.chartLineColor,
  };
}

export function getParallelChannelSettingsTabs(settings: ParallelChannelSettings): SettingsTab[] {
  const styleFields: SettingField[] = [
    {
      key: 'lineColor',
      label: t('Line'),
      type: 'color',
      defaultValue: settings.lineColor,
      toolbar: {
        control: 'color',
        role: 'line',
      },
    },
    {
      key: 'backgroundColor',
      label: t('Background'),
      type: 'color',
      defaultValue: settings.backgroundColor,
      toolbar: {
        control: 'color',
        role: 'fill',
      },
    },
    {
      key: 'showMiddleLine',
      label: t('Middle line'),
      type: 'boolean',
      defaultValue: settings.showMiddleLine,
    },
  ];

  const textFields: SettingField[] = [
    {
      key: 'fontSize',
      label: t('Font size'),
      type: 'number',
      defaultValue: settings.fontSize,
      min: 8,
      max: 24,
    },
    {
      key: 'text',
      label: t('Text'),
      type: 'textarea',
      defaultValue: settings.text,
      placeholder: t('Enter text'),
    },
    {
      key: 'isBold',
      label: t('Bold'),
      type: 'boolean',
      defaultValue: settings.isBold,
    },
    {
      key: 'isItalic',
      label: t('Italic'),
      type: 'boolean',
      defaultValue: settings.isItalic,
    },
    {
      key: 'textColor',
      label: t('Text'),
      type: 'color',
      defaultValue: settings.textColor,
      toolbar: {
        control: 'color',
        role: 'text',
      },
    },
  ];

  return [
    {
      key: 'style',
      label: t('Style'),
      fields: styleFields,
    },
    {
      key: 'text',
      label: t('Text'),
      fields: textFields,
    },
  ];
}



import { clamp } from 'lodash-es';
import { Observable } from 'rxjs';

import {
  CustomPriceAxisPaneView,
  CustomPriceAxisView,
  CustomTimeAxisPaneView,
  CustomTimeAxisView,
} from '@core/Drawings/axis';
import { SeriesDrawingBase } from '@core/Drawings/common';
import {
  clampPointToContainer as clampPointToContainerInElement,
  getAnchorFromPoint,
  getContainerSize as getElementContainerSize,
  getPriceDelta as getPriceDeltaFromCoordinates,
  getPriceFromYCoordinate,
  getTimeFromXCoordinate,
  getXCoordinateFromTime,
  getYCoordinateFromPrice,
  isNearPoint,
  isPointInBounds,
  normalizeBounds,
  shiftTimeByPixels,
} from '@core/Drawings/helpers';
import { updateViews } from '@core/Drawings/utils';

import { getThemeStore } from '@src/theme';
import { Defaults } from '@src/types/defaults';
import { formatPrice } from '@src/utils';
import { formatDate } from '@src/utils/formatter';

import { RectanglePaneView } from './paneView';
import {
  createDefaultSettings,
  getRectangleSettingsTabs,
  RectangleSettings,
  RectangleStyle,
  RectangleTextStyle,
} from './settings';

import type { DrawingInteraction, ISeriesDrawing } from '@core/Drawings/common';
import type { AxisLabel, AxisSegment, Point, SeriesApi } from '@core/Drawings/types';
import type { ChartOptionsModel, SettingsTab } from '@src/types';
import type { IChartApi, IPrimitivePaneView, PrimitiveHoveredItem, Time, UTCTimestamp } from 'lightweight-charts';

type RectangleMode = 'idle' | 'drawing' | 'ready' | 'dragging';
type RectangleHandle = 'body' | 'nw' | 'n' | 'ne' | 'e' | 'se' | 's' | 'sw' | 'w' | null;
type RectangleHandleKey = Exclude<RectangleHandle, 'body' | null>;
type TimeLabelKind = 'left' | 'right';
type PriceLabelKind = 'top' | 'bottom';

interface RectangleParams {
  container: HTMLElement;
  interaction: DrawingInteraction;
  formatObservable?: Observable<ChartOptionsModel>;
  removeSelf?: () => void;
  openSettings?: () => void;
}

interface RectangleState {
  hidden: boolean;
  mode: RectangleMode;
  startTime: Time | null;
  endTime: Time | null;
  startPrice: number | null;
  endPrice: number | null;
  settings: RectangleSettings;
}

interface RectangleGeometry {
  left: number;
  right: number;
  top: number;
  bottom: number;
  width: number;
  height: number;
  handles: Record<RectangleHandleKey, Point>;
}

export interface RectangleRenderData extends RectangleGeometry, RectangleStyle, RectangleTextStyle {
  showFill: boolean;
  showHandles: boolean;
}

const HANDLE_HIT_TOLERANCE = 8;
const BODY_HIT_TOLERANCE = 6;
const MIN_RECTANGLE_SIZE = 6;

export class Rectangle extends SeriesDrawingBase<RectangleSettings> implements ISeriesDrawing {
  private removeSelf?: () => void;
  private openSettings?: () => void;

  protected settings: RectangleSettings = createDefaultSettings();

  protected mode: RectangleMode = 'idle';

  private startTime: Time | null = null;
  private endTime: Time | null = null;
  private startPrice: number | null = null;
  private endPrice: number | null = null;

  private activeDragTarget: RectangleHandle = null;
  private dragPointerId: number | null = null;
  private dragStartPoint: Point | null = null;
  private dragStateSnapshot: RectangleState | null = null;
  private dragGeometrySnapshot: RectangleGeometry | null = null;

  private displayFormat: ChartOptionsModel = {
    dateFormat: Defaults.dateFormat,
    timeFormat: Defaults.timeFormat,
    showTime: Defaults.showTime,
  };

  private readonly paneView: RectanglePaneView;
  private readonly timeAxisPaneView: CustomTimeAxisPaneView;
  private readonly priceAxisPaneView: CustomPriceAxisPaneView;
  private readonly leftTimeAxisView: CustomTimeAxisView;
  private readonly rightTimeAxisView: CustomTimeAxisView;
  private readonly topPriceAxisView: CustomPriceAxisView;
  private readonly bottomPriceAxisView: CustomPriceAxisView;

  constructor(
    chart: IChartApi,
    series: SeriesApi,
    { container, interaction, formatObservable, removeSelf, openSettings }: RectangleParams,
  ) {
    super({ chart, series, container, interaction });

    this.removeSelf = removeSelf;
    this.openSettings = openSettings;

    this.paneView = new RectanglePaneView(this);

    this.timeAxisPaneView = new CustomTimeAxisPaneView({
      getAxisSegments: () => this.getTimeAxisSegments(),
    });

    this.priceAxisPaneView = new CustomPriceAxisPaneView({
      getAxisSegments: () => this.getPriceAxisSegments(),
    });

    this.leftTimeAxisView = new CustomTimeAxisView({
      getAxisLabel: (kind) => this.getTimeAxisLabel(kind),
      labelKind: 'left',
    });

    this.rightTimeAxisView = new CustomTimeAxisView({
      getAxisLabel: (kind) => this.getTimeAxisLabel(kind),
      labelKind: 'right',
    });

    this.topPriceAxisView = new CustomPriceAxisView({
      getAxisLabel: (kind) => this.getPriceAxisLabel(kind),
      labelKind: 'top',
    });

    this.bottomPriceAxisView = new CustomPriceAxisView({
      getAxisLabel: (kind) => this.getPriceAxisLabel(kind),
      labelKind: 'bottom',
    });

    if (formatObservable) {
      this.subscriptions.add(
        formatObservable.subscribe((format) => {
          this.displayFormat = format;
          this.render();
        }),
      );
    }

    this.series.attachPrimitive(this);
  }

  public isCreationPending(): boolean {
    return this.mode === 'idle' || this.mode === 'drawing';
  }

  public getState(): RectangleState {
    return {
      hidden: this.hidden,
      mode: this.mode,
      startTime: this.startTime,
      endTime: this.endTime,
      startPrice: this.startPrice,
      endPrice: this.endPrice,
      settings: { ...this.settings },
    };
  }

  public setState(state: unknown): void {
    const nextState = state as Partial<RectangleState>;

    if ('hidden' in nextState && typeof nextState.hidden === 'boolean') {
      this.hidden = nextState.hidden;
    }

    if ('mode' in nextState && nextState.mode) {
      this.mode = nextState.mode;
    }

    if ('startTime' in nextState) {
      this.startTime = nextState.startTime ?? null;
    }

    if ('endTime' in nextState) {
      this.endTime = nextState.endTime ?? null;
    }

    if ('startPrice' in nextState) {
      this.startPrice = nextState.startPrice ?? null;
    }

    if ('endPrice' in nextState) {
      this.endPrice = nextState.endPrice ?? null;
    }

    if ('settings' in nextState && nextState.settings) {
      this.settings = {
        ...createDefaultSettings(),
        ...nextState.settings,
      };
    }

    this.render();
  }

  public getSettingsTabs(): SettingsTab[] {
    return getRectangleSettingsTabs(this.settings);
  }

  public updateAllViews(): void {
    updateViews([
      this.paneView,
      this.timeAxisPaneView,
      this.priceAxisPaneView,
      this.leftTimeAxisView,
      this.rightTimeAxisView,
      this.topPriceAxisView,
      this.bottomPriceAxisView,
    ]);
  }

  public paneViews(): readonly IPrimitivePaneView[] {
    return [this.paneView];
  }

  public timeAxisPaneViews(): readonly IPrimitivePaneView[] {
    return [this.timeAxisPaneView];
  }

  public priceAxisPaneViews(): readonly IPrimitivePaneView[] {
    return [this.priceAxisPaneView];
  }

  public timeAxisViews() {
    return [this.leftTimeAxisView, this.rightTimeAxisView];
  }

  public priceAxisViews() {
    return [this.topPriceAxisView, this.bottomPriceAxisView];
  }

  public getRenderData(): RectangleRenderData | null {
    if (this.hidden) {
      return null;
    }

    const geometry = this.getGeometry();

    if (!geometry) {
      return null;
    }

    return {
      ...geometry,
      showFill: true,
      showHandles: this.shouldShowHandles(),
      ...this.settings,
    };
  }

  protected getHoveredItem(x: number, y: number): PrimitiveHoveredItem | null {
    if (this.hidden || this.mode === 'idle' || this.mode === 'drawing') {
      return null;
    }

    const point = { x, y };

    if (!this.isSelected()) {
      if (!this.containsPoint(point)) {
        return null;
      }

      return {
        cursorStyle: 'pointer',
        externalId: 'rectangle-position',
        zOrder: 'top',
      };
    }

    const handleTarget = this.getHandleTarget(point);

    if (handleTarget) {
      return {
        cursorStyle: this.getCursorStyle(handleTarget),
        externalId: 'rectangle-position',
        zOrder: 'top',
      };
    }

    if (!this.containsPoint(point)) {
      return null;
    }

    return {
      cursorStyle: 'grab',
      externalId: 'rectangle-position',
      zOrder: 'top',
    };
  }

  protected getTimeAxisSegments(): AxisSegment[] {
    if (!this.isSelected() && !this.isCreationPending()) {
      return [];
    }

    const bounds = this.getTimeBounds();

    if (!bounds) {
      return [];
    }

    const { colors } = getThemeStore();

    return [
      {
        from: bounds.left,
        to: bounds.right,
        color: colors.axisMarkerAreaFill,
      },
    ];
  }

  protected getPriceAxisSegments(): AxisSegment[] {
    if (!this.isSelected() && !this.isCreationPending()) {
      return [];
    }

    const bounds = this.getPriceBounds();

    if (!bounds) {
      return [];
    }

    const { colors } = getThemeStore();

    return [
      {
        from: bounds.top,
        to: bounds.bottom,
        color: colors.axisMarkerAreaFill,
      },
    ];
  }

  protected getTimeAxisLabel(kind: string): AxisLabel | null {
    if ((!this.isSelected() && !this.isCreationPending()) || (kind !== 'left' && kind !== 'right')) {
      return null;
    }

    const labelKind = kind as TimeLabelKind;
    const coordinate = this.getTimeCoordinate(labelKind);
    const text = this.getTimeText(labelKind);

    if (coordinate === null || !text) {
      return null;
    }

    const { colors } = getThemeStore();

    return {
      coordinate,
      text,
      textColor: colors.chartPriceLineText,
      backgroundColor: colors.axisMarkerLabelFill,
    };
  }

  protected getPriceAxisLabel(kind: string): AxisLabel | null {
    if ((!this.isSelected() && !this.isCreationPending()) || (kind !== 'top' && kind !== 'bottom')) {
      return null;
    }

    const labelKind = kind as PriceLabelKind;
    const coordinate = this.getPriceCoordinate(labelKind);
    const text = this.getPriceText(labelKind);

    if (coordinate === null || !text) {
      return null;
    }

    const { colors } = getThemeStore();

    return {
      coordinate,
      text,
      textColor: colors.chartPriceLineText,
      backgroundColor: colors.axisMarkerLabelFill,
    };
  }

  protected handleDoubleClick = (event: MouseEvent): void => {
    if (this.hidden || this.mode !== 'ready') {
      return;
    }

    const rect = this.container.getBoundingClientRect();
    const point = {
      x: event.clientX - rect.left,
      y: event.clientY - rect.top,
    };

    if (!this.containsPoint(point) && !this.getHandleTarget(point)) {
      return;
    }

    event.preventDefault();
    event.stopPropagation();

    this.openSettings?.();
  };

  protected handlePointerDown = (event: PointerEvent): void => {
    if (this.hidden || event.button !== 0) {
      return;
    }

    const point = this.getEventPoint(event);

    if (this.mode === 'idle') {
      event.preventDefault();
      event.stopPropagation();

      this.startDrawing(point);
      return;
    }

    if (this.mode === 'drawing') {
      event.preventDefault();
      event.stopPropagation();

      this.updateDrawing(point);
      this.finishDrawing();
      return;
    }

    if (this.mode !== 'ready') {
      return;
    }

    if (!this.isSelected()) {
      if (!this.containsPoint(point)) {
        return;
      }

      event.preventDefault();
      event.stopPropagation();

      this.select();
      return;
    }

    const dragTarget = this.getDragTarget(point);

    if (!dragTarget) {
      this.deselect();
      return;
    }

    event.preventDefault();
    event.stopPropagation();

    this.startDragging(point, event.pointerId, dragTarget);
  };

  protected handlePointerMove = (event: PointerEvent): void => {
    const point = this.getEventPoint(event);

    if (this.mode === 'drawing') {
      this.updateDrawing(point);
      return;
    }

    if (this.mode !== 'dragging' || this.dragPointerId !== event.pointerId) {
      return;
    }

    event.preventDefault();

    if (this.activeDragTarget === 'body') {
      this.moveWhole(point);
      this.render();
      return;
    }

    this.resizeRectangle(point);
    this.render();
  };

  protected handlePointerUp = (event: PointerEvent): void => {
    if (this.mode !== 'dragging' || this.dragPointerId !== event.pointerId) {
      return;
    }

    this.finishDragging();
  };

  private startDrawing(point: Point): void {
    const anchor = this.createAnchor(point);

    if (!anchor) {
      return;
    }

    this.startTime = anchor.time;
    this.endTime = anchor.time;
    this.startPrice = anchor.price;
    this.endPrice = anchor.price;
    this.mode = 'drawing';

    this.render();
  }

  private updateDrawing(point: Point): void {
    const clampedPoint = this.clampPointToContainer(point);
    const anchor = this.createAnchor(clampedPoint);

    if (!anchor) {
      return;
    }

    this.endTime = anchor.time;
    this.endPrice = anchor.price;

    this.render();
  }

  private finishDrawing(): void {
    const geometry = this.getGeometry();

    if (!geometry || geometry.width < MIN_RECTANGLE_SIZE || geometry.height < MIN_RECTANGLE_SIZE) {
      if (this.removeSelf) {
        this.removeSelf();
        return;
      }

      this.resetToIdle();
      return;
    }

    this.mode = 'ready';
    this.resolveReady?.();

    this.render();
  }

  private startDragging(point: Point, pointerId: number, dragTarget: Exclude<RectangleHandle, null>): void {
    this.mode = 'dragging';

    this.activeDragTarget = dragTarget;
    this.dragPointerId = pointerId;
    this.dragStartPoint = point;
    this.dragStateSnapshot = this.getState();
    this.dragGeometrySnapshot = this.getGeometry();

    this.render();
  }

  private finishDragging(): void {
    this.mode = 'ready';
    this.resolveReady?.();

    this.clearInteractionState();
    this.render();
  }

  private clearInteractionState(): void {
    this.activeDragTarget = null;
    this.dragPointerId = null;
    this.dragStartPoint = null;
    this.dragStateSnapshot = null;
    this.dragGeometrySnapshot = null;
  }

  private resetToIdle(): void {
    this.hidden = false;
    this.mode = 'idle';

    this.startTime = null;
    this.endTime = null;
    this.startPrice = null;
    this.endPrice = null;

    this.clearInteractionState();
    this.render();
  }

  private getDragTarget(point: Point): Exclude<RectangleHandle, null> | null {
    const handleTarget = this.getHandleTarget(point);

    if (handleTarget) {
      return handleTarget;
    }

    if (this.containsPoint(point)) {
      return 'body';
    }

    return null;
  }

  private moveWhole(point: Point): void {
    const snapshot = this.dragStateSnapshot;
    const geometry = this.dragGeometrySnapshot;

    if (!snapshot || !geometry || !this.dragStartPoint) {
      return;
    }

    if (
      snapshot.startTime === null ||
      snapshot.endTime === null ||
      snapshot.startPrice === null ||
      snapshot.endPrice === null
    ) {
      return;
    }

    const containerSize = this.getContainerSize();

    const rawOffsetX = point.x - this.dragStartPoint.x;
    const rawOffsetY = point.y - this.dragStartPoint.y;

    const minOffsetX = -geometry.left;
    const maxOffsetX = containerSize.width - geometry.right;
    const clampedOffsetX = clamp(rawOffsetX, minOffsetX, maxOffsetX);

    const minOffsetY = -geometry.top;
    const maxOffsetY = containerSize.height - geometry.bottom;
    const clampedOffsetY = clamp(rawOffsetY, minOffsetY, maxOffsetY);

    const nextStartTime = this.shiftTime(snapshot.startTime, clampedOffsetX);
    const nextEndTime = this.shiftTime(snapshot.endTime, clampedOffsetX);

    if (nextStartTime === null || nextEndTime === null) {
      return;
    }

    const priceOffset = this.getPriceDelta(this.dragStartPoint.y, this.dragStartPoint.y + clampedOffsetY);

    this.startTime = nextStartTime;
    this.endTime = nextEndTime;
    this.startPrice = snapshot.startPrice + priceOffset;
    this.endPrice = snapshot.endPrice + priceOffset;
  }

  private resizeRectangle(point: Point): void {
    const geometry = this.dragGeometrySnapshot;

    if (!geometry || !this.activeDragTarget || this.activeDragTarget === 'body') {
      return;
    }

    const clampedPoint = this.clampPointToContainer(point);

    let { left } = geometry;
    let { right } = geometry;
    let { top } = geometry;
    let { bottom } = geometry;

    switch (this.activeDragTarget) {
      case 'nw':
        left = clampedPoint.x;
        top = clampedPoint.y;
        break;
      case 'n':
        top = clampedPoint.y;
        break;
      case 'ne':
        right = clampedPoint.x;
        top = clampedPoint.y;
        break;
      case 'e':
        right = clampedPoint.x;
        break;
      case 'se':
        right = clampedPoint.x;
        bottom = clampedPoint.y;
        break;
      case 's':
        bottom = clampedPoint.y;
        break;
      case 'sw':
        left = clampedPoint.x;
        bottom = clampedPoint.y;
        break;
      case 'w':
        left = clampedPoint.x;
        break;
      default:
        return;
    }

    this.setRectangleBounds(left, right, top, bottom);
  }

  private setRectangleBounds(left: number, right: number, top: number, bottom: number): boolean {
    const bounds = normalizeBounds(left, right, top, bottom, this.container);

    const startTime = getTimeFromXCoordinate(this.chart, bounds.left);
    const endTime = getTimeFromXCoordinate(this.chart, bounds.right);
    const startPrice = getPriceFromYCoordinate(this.series, bounds.top);
    const endPrice = getPriceFromYCoordinate(this.series, bounds.bottom);

    if (startTime === null || endTime === null || startPrice === null || endPrice === null) {
      return false;
    }

    this.startTime = startTime;
    this.endTime = endTime;
    this.startPrice = startPrice;
    this.endPrice = endPrice;

    return true;
  }

  private createAnchor(point: Point): { time: Time; price: number } | null {
    return getAnchorFromPoint(this.chart, this.series, point);
  }

  protected getGeometry(): RectangleGeometry | null {
    if (this.startTime === null || this.endTime === null || this.startPrice === null || this.endPrice === null) {
      return null;
    }

    const startX = getXCoordinateFromTime(this.chart, this.startTime, this.series);
    const endX = getXCoordinateFromTime(this.chart, this.endTime, this.series);
    const startY = getYCoordinateFromPrice(this.series, this.startPrice);
    const endY = getYCoordinateFromPrice(this.series, this.endPrice);

    if (startX === null || endX === null || startY === null || endY === null) {
      return null;
    }

    const left = Math.round(Math.min(Number(startX), Number(endX)));
    const right = Math.round(Math.max(Number(startX), Number(endX)));
    const top = Math.round(Math.min(Number(startY), Number(endY)));
    const bottom = Math.round(Math.max(Number(startY), Number(endY)));

    const centerX = (left + right) / 2;
    const centerY = (top + bottom) / 2;

    return {
      left,
      right,
      top,
      bottom,
      width: right - left,
      height: bottom - top,
      handles: {
        nw: { x: left, y: top },
        n: { x: centerX, y: top },
        ne: { x: right, y: top },
        e: { x: right, y: centerY },
        se: { x: right, y: bottom },
        s: { x: centerX, y: bottom },
        sw: { x: left, y: bottom },
        w: { x: left, y: centerY },
      },
    };
  }

  private getTimeBounds(): { left: number; right: number } | null {
    const geometry = this.getGeometry();

    if (!geometry) {
      return null;
    }

    return {
      left: geometry.left,
      right: geometry.right,
    };
  }

  private getPriceBounds(): { top: number; bottom: number } | null {
    const geometry = this.getGeometry();

    if (!geometry) {
      return null;
    }

    return {
      top: geometry.top,
      bottom: geometry.bottom,
    };
  }

  private getTimeCoordinate(kind: TimeLabelKind): number | null {
    const geometry = this.getGeometry();

    if (!geometry) {
      return null;
    }

    return kind === 'left' ? geometry.left : geometry.right;
  }

  private getPriceCoordinate(kind: PriceLabelKind): number | null {
    const geometry = this.getGeometry();

    if (!geometry) {
      return null;
    }

    return kind === 'top' ? geometry.top : geometry.bottom;
  }

  private getTimeText(kind: TimeLabelKind): string {
    const time = this.getTimeValueForLabel(kind);

    if (typeof time !== 'number') {
      return '';
    }

    return formatDate(
      time as UTCTimestamp,
      this.displayFormat.dateFormat,
      this.displayFormat.timeFormat,
      this.displayFormat.showTime,
    );
  }

  private getPriceText(kind: PriceLabelKind): string {
    const price = this.getPriceValueForLabel(kind);

    if (price === null) {
      return '';
    }

    return formatPrice(price) ?? '';
  }

  private getTimeValueForLabel(kind: TimeLabelKind): Time | null {
    if (this.startTime === null || this.endTime === null) {
      return null;
    }

    const startX = getXCoordinateFromTime(this.chart, this.startTime, this.series);
    const endX = getXCoordinateFromTime(this.chart, this.endTime, this.series);

    if (startX === null || endX === null) {
      return kind === 'left' ? this.startTime : this.endTime;
    }

    const startIsLeft = Number(startX) <= Number(endX);

    if (kind === 'left') {
      return startIsLeft ? this.startTime : this.endTime;
    }

    return startIsLeft ? this.endTime : this.startTime;
  }

  private getPriceValueForLabel(kind: PriceLabelKind): number | null {
    if (this.startPrice === null || this.endPrice === null) {
      return null;
    }

    const startY = getYCoordinateFromPrice(this.series, this.startPrice);
    const endY = getYCoordinateFromPrice(this.series, this.endPrice);

    if (startY === null || endY === null) {
      return kind === 'top' ? Math.max(this.startPrice, this.endPrice) : Math.min(this.startPrice, this.endPrice);
    }

    const startIsTop = Number(startY) <= Number(endY);

    if (kind === 'top') {
      return startIsTop ? this.startPrice : this.endPrice;
    }

    return startIsTop ? this.endPrice : this.startPrice;
  }

  private getHandleTarget(point: Point): RectangleHandleKey | null {
    const geometry = this.getGeometry();

    if (!geometry) {
      return null;
    }

    const handleOrder: RectangleHandleKey[] = ['nw', 'n', 'ne', 'e', 'se', 's', 'sw', 'w'];

    for (const handleName of handleOrder) {
      const handle = geometry.handles[handleName];

      if (isNearPoint(point, handle.x, handle.y, HANDLE_HIT_TOLERANCE)) {
        return handleName;
      }
    }

    return null;
  }

  private containsPoint(point: Point): boolean {
    const geometry = this.getGeometry();

    if (!geometry) {
      return false;
    }

    return isPointInBounds(point, geometry, BODY_HIT_TOLERANCE);
  }

  private getCursorStyle(handle: Exclude<RectangleHandle, null>): PrimitiveHoveredItem['cursorStyle'] {
    switch (handle) {
      case 'nw':
      case 'se':
        return 'nwse-resize';
      case 'ne':
      case 'sw':
        return 'nesw-resize';
      case 'n':
      case 's':
        return 'ns-resize';
      case 'e':
      case 'w':
        return 'ew-resize';
      case 'body':
        return 'grab';
      default:
        return 'default';
    }
  }

  private shiftTime(time: Time, offsetX: number): Time | null {
    return shiftTimeByPixels(this.chart, time, offsetX, this.series);
  }

  private getPriceDelta(fromY: number, toY: number): number {
    return getPriceDeltaFromCoordinates(this.series, fromY, toY);
  }

  private getContainerSize(): { width: number; height: number } {
    return getElementContainerSize(this.container);
  }

  private clampPointToContainer(point: Point): Point {
    return clampPointToContainerInElement(point, this.container);
  }
}



import { CanvasRenderingTarget2D } from 'fancy-canvas';
import { IPrimitivePaneRenderer } from 'lightweight-charts';

import { getThemeStore } from '@src/theme';

import { RegressionTrend } from './regressionTrend';

const UI = {
  lineWidth: 2,
  handleRadius: 5,
  handleBorderWidth: 2,
  textLineHeightMultiplier: 1.2,
  textOffset: 4,
};

export class RegressionTrendPaneRenderer implements IPrimitivePaneRenderer {
  private readonly regressionTrend: RegressionTrend;

  constructor(regressionTrend: RegressionTrend) {
    this.regressionTrend = regressionTrend;
  }

  public draw(target: CanvasRenderingTarget2D): void {
    const data = this.regressionTrend.getRenderData();

    if (!data) {
      return;
    }

    const { colors } = getThemeStore();

    target.useBitmapCoordinateSpace(({ context, horizontalPixelRatio, verticalPixelRatio }) => {
      const pixelRatio = Math.max(horizontalPixelRatio, verticalPixelRatio);

      const startX = data.startPoint.x * horizontalPixelRatio;
      const startY = data.startPoint.y * verticalPixelRatio;
      const endX = data.endPoint.x * horizontalPixelRatio;
      const endY = data.endPoint.y * verticalPixelRatio;

      context.save();

      context.lineWidth = UI.lineWidth * pixelRatio;
      context.strokeStyle = data.lineColor;

      context.beginPath();
      context.moveTo(startX, startY);
      context.lineTo(endX, endY);
      context.stroke();

      if (data.text.trim()) {
        drawTextAlongLine(context, {
          startX,
          startY,
          endX,
          endY,
          text: data.text,
          fontSize: data.fontSize,
          isBold: data.isBold,
          isItalic: data.isItalic,
          textColor: data.textColor,
          verticalPixelRatio,
        });
      }

      if (data.showHandles) {
        context.fillStyle = colors.chartBackground;
        context.strokeStyle = colors.chartLineColor;
        context.lineWidth = UI.handleBorderWidth * pixelRatio;

        drawHandle(context, startX, startY, UI.handleRadius * pixelRatio);

        drawHandle(context, endX, endY, UI.handleRadius * pixelRatio);
      }

      context.restore();
    });
  }
}

function drawHandle(context: CanvasRenderingContext2D, x: number, y: number, radius: number): void {
  context.beginPath();
  context.arc(x, y, radius, 0, Math.PI * 2);
  context.fill();
  context.stroke();
}

function drawTextAlongLine(
  context: CanvasRenderingContext2D,
  {
    startX,
    startY,
    endX,
    endY,
    text,
    fontSize,
    isBold,
    isItalic,
    textColor,
    verticalPixelRatio,
  }: {
    startX: number;
    startY: number;
    endX: number;
    endY: number;
    text: string;
    fontSize: number;
    isBold: boolean;
    isItalic: boolean;
    textColor: string;
    verticalPixelRatio: number;
  },
): void {
  const lines = text.split('\n');
  const safeFontSize = Math.max(1, fontSize);

  const fontSizePx = safeFontSize * verticalPixelRatio;

  const lineHeight = safeFontSize * UI.textLineHeightMultiplier * verticalPixelRatio;

  const dx = endX - startX;
  const dy = endY - startY;

  let angle = Math.atan2(dy, dx);

  if (angle > Math.PI / 2 || angle < -Math.PI / 2) {
    angle += Math.PI;
  }

  const centerX = (startX + endX) / 2;
  const centerY = (startY + endY) / 2;

  const fontWeight = isBold ? '700 ' : '';
  const fontStyle = isItalic ? 'italic ' : '';

  context.save();

  context.translate(centerX, centerY);
  context.rotate(angle);

  context.font = `${fontStyle}${fontWeight}${fontSizePx}px Inter, sans-serif`;

  context.fillStyle = textColor;
  context.textAlign = 'center';
  context.textBaseline = 'middle';

  const blockHeight = lines.length * lineHeight;
  const textOffset = UI.textOffset * verticalPixelRatio;
  const textCenterY = -(blockHeight / 2 + textOffset);
  const startLineY = textCenterY - blockHeight / 2 + lineHeight / 2;

  lines.forEach((line, index) => {
    context.fillText(line, 0, startLineY + index * lineHeight);
  });

  context.restore();
}



import { getThemeStore } from '@src/theme';
import { t } from '@src/translations';

import { SettingField, SettingsTab, SettingsValues } from '@src/types';

export interface RegressionTrendStyle {
  lineColor: string;
}

export interface RegressionTrendTextStyle {
  fontSize: number;
  text: string;
  isBold: boolean;
  isItalic: boolean;
  textColor: string;
}

export type RegressionTrendSettings = RegressionTrendStyle & RegressionTrendTextStyle & SettingsValues;

export function createDefaultSettings(): RegressionTrendSettings {
  const { colors } = getThemeStore();

  return {
    lineColor: colors.chartLineColor,
    fontSize: 14,
    text: '',
    isBold: false,
    isItalic: false,
    textColor: colors.chartLineColor,
  };
}

export function getRegressionTrendSettingsTabs(settings: RegressionTrendSettings): SettingsTab[] {
  const styleFields: SettingField[] = [
    {
      key: 'lineColor',
      label: t('Line'),
      type: 'color',
      defaultValue: settings.lineColor,
      toolbar: {
        control: 'color',
        role: 'line',
      },
    },
  ];

  const textFields: SettingField[] = [
    {
      key: 'fontSize',
      label: t('Font size'),
      type: 'number',
      defaultValue: settings.fontSize,
      min: 8,
      max: 24,
    },
    {
      key: 'text',
      label: t('Text'),
      type: 'textarea',
      defaultValue: settings.text,
      placeholder: t('Enter text'),
    },
    {
      key: 'isBold',
      label: t('Bold'),
      type: 'boolean',
      defaultValue: settings.isBold,
    },
    {
      key: 'isItalic',
      label: t('Italic'),
      type: 'boolean',
      defaultValue: settings.isItalic,
    },
    {
      key: 'textColor',
      label: t('Text'),
      type: 'color',
      defaultValue: settings.textColor,
      toolbar: {
        control: 'color',
        role: 'text',
      },
    },
  ];

  return [
    {
      key: 'style',
      label: t('Style'),
      fields: styleFields,
    },
    {
      key: 'text',
      label: t('Text'),
      fields: textFields,
    },
  ];
}