---

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

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

import { TrendLine } from './trendLine';

const UI = {
  lineWidth: 2,
  handleRadius: 5,
  handleBorderWidth: 2,
};

const { colors } = getThemeStore();

export class TrendLinePaneRenderer implements IPrimitivePaneRenderer {
  private readonly trendLine: TrendLine;

  constructor(trendLine: TrendLine) {
    this.trendLine = trendLine;
  }

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

    if (!data) {
      return;
    }

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

      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();
}



import { IPrimitivePaneRenderer, IPrimitivePaneView, PrimitivePaneViewZOrder } from 'lightweight-charts';

import { TrendLinePaneRenderer } from './paneRenderer';
import { TrendLine } from './trendLine';

export class TrendLinePaneView implements IPrimitivePaneView {
  private readonly trendLine: TrendLine;

  constructor(trendLine: TrendLine) {
    this.trendLine = trendLine;
  }

  public update(): void {}

  public renderer(): IPrimitivePaneRenderer {
    return new TrendLinePaneRenderer(this.trendLine);
  }

  public zOrder(): PrimitivePaneViewZOrder {
    return 'top';
  }
}


import {
  AutoscaleInfo,
  IChartApi,
  IPrimitivePaneView,
  Logical,
  PrimitiveHoveredItem,
  SeriesAttachedParameter,
  SeriesOptionsMap,
  Time,
  UTCTimestamp,
} from 'lightweight-charts';
import { Observable } from 'rxjs';

import {
  CustomPriceAxisPaneView,
  CustomPriceAxisView,
  CustomTimeAxisPaneView,
  CustomTimeAxisView,
} from '@core/Drawings/axis';
import {
  getAnchorFromPoint,
  getPointerPoint as getPointerPointFromEvent,
  getPriceDelta as getPriceDeltaFromCoordinates,
  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 { TrendLinePaneView } from './paneView';

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

type TrendLineMode = 'idle' | 'drawing' | 'ready' | 'dragging-start' | 'dragging-end' | 'dragging-body';
type TimeLabelKind = 'start' | 'end';
type PriceLabelKind = 'start' | 'end';

interface TrendLineParams {
  container: HTMLElement;
  formatObservable?: Observable<ChartOptionsModel>;
  removeSelf?: () => void;
}

interface TrendLineState {
  hidden: boolean;
  isActive: boolean;
  mode: TrendLineMode;
  startAnchor: Anchor | null;
  endAnchor: Anchor | null;
}

interface TrendLineGeometry {
  startPoint: Point;
  endPoint: Point;
  left: number;
  right: number;
  top: number;
  bottom: number;
}

export interface TrendLineRenderData extends TrendLineGeometry {
  showHandles: boolean;
}

const POINT_HIT_TOLERANCE = 8;
const LINE_HIT_TOLERANCE = 6;
const MIN_LINE_SIZE = 4;

const { colors } = getThemeStore();

export class TrendLine implements ISeriesDrawing {
  private chart: IChartApi;
  private series: SeriesApi;
  private container: HTMLElement;
  private removeSelf?: () => void;

  private requestUpdate: (() => void) | null = null;
  private isBound = false;

  private hidden = false;
  private isActive = false;
  private mode: TrendLineMode = 'idle';

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

  private dragPointerId: number | null = null;
  private dragStartPoint: Point | null = null;
  private dragGeometrySnapshot: TrendLineGeometry | null = null;
  private dragStateSnapshot: TrendLineState | null = null;

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

  private readonly paneView: TrendLinePaneView;
  private readonly timeAxisPaneView: CustomTimeAxisPaneView;
  private readonly priceAxisPaneView: CustomPriceAxisPaneView;
  private readonly startTimeAxisView: CustomTimeAxisView;
  private readonly endTimeAxisView: CustomTimeAxisView;
  private readonly startPriceAxisView: CustomPriceAxisView;
  private readonly endPriceAxisView: CustomPriceAxisView;

  constructor(chart: IChartApi, series: SeriesApi, { container, formatObservable, removeSelf }: TrendLineParams) {
    this.chart = chart;
    this.series = series;
    this.container = container;
    this.removeSelf = removeSelf;

    this.paneView = new TrendLinePaneView(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.startPriceAxisView = new CustomPriceAxisView({
      getAxisLabel: (kind) => this.getPriceAxisLabel(kind),
      labelKind: 'start',
    });

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

    formatObservable?.subscribe((format) => {
      this.displayFormat = format;
      this.render();
    });

    this.series.attachPrimitive(this);
  }

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

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

  public destroy(): void {
    this.unbindEvents();
    this.series.detachPrimitive(this);
    this.requestUpdate = null;
  }

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

    this.unbindEvents();
    this.series.detachPrimitive(this);

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

    this.series.attachPrimitive(this);
    this.render();
  }

  public getState(): TrendLineState {
    return {
      hidden: this.hidden,
      isActive: this.isActive,
      mode: this.mode,
      startAnchor: this.startAnchor,
      endAnchor: this.endAnchor,
    };
  }

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

    this.hidden = nextState.hidden ?? this.hidden;
    this.isActive = nextState.isActive ?? this.isActive;
    this.mode = nextState.mode ?? this.mode;
    this.startAnchor = nextState.startAnchor ?? this.startAnchor;
    this.endAnchor = nextState.endAnchor ?? this.endAnchor;

    this.render();
  }

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

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

  public updateAllViews(): void {
    updateViews([
      this.paneView,
      this.timeAxisPaneView,
      this.priceAxisPaneView,
      this.startTimeAxisView,
      this.endTimeAxisView,
      this.startPriceAxisView,
      this.endPriceAxisView,
    ]);
  }

  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.startPriceAxisView, this.endPriceAxisView];
  }

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

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

    const geometry = this.getGeometry();

    if (!geometry) {
      return null;
    }

    return {
      ...geometry,
      showHandles: this.isActive,
    };
  }

  public getTimeAxisSegments(): AxisSegment[] {
    if (!this.isActive) {
      return [];
    }

    const geometry = this.getGeometry();

    if (!geometry) {
      return [];
    }

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

  public getPriceAxisSegments(): AxisSegment[] {
    if (!this.isActive) {
      return [];
    }

    const geometry = this.getGeometry();

    if (!geometry) {
      return [];
    }

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

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

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

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

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

  public getPriceAxisLabel(kind: string): AxisLabel | null {
    if (!this.isActive || (kind !== 'start' && kind !== 'end')) {
      return null;
    }

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

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

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

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

    const point = { x, y };

    if (this.getPointTarget(point)) {
      return {
        cursorStyle: 'move',
        externalId: 'trend-line',
        zOrder: 'top',
      };
    }

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

    return {
      cursorStyle: 'grab',
      externalId: 'trend-line',
      zOrder: 'top',
    };
  }

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

    this.isBound = true;

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

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

    this.isBound = false;

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

  private 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;
    }

    const pointTarget = this.getPointTarget(point);

    if (!this.isActive) {
      if (!pointTarget && !this.isPointNearLine(point)) {
        return;
      }

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

      this.isActive = true;
      this.render();
      return;
    }

    if (pointTarget === 'start') {
      this.startDragging('dragging-start', point, event.pointerId);
      return;
    }

    if (pointTarget === 'end') {
      this.startDragging('dragging-end', point, event.pointerId);
      return;
    }

    if (this.isPointNearLine(point)) {
      this.startDragging('dragging-body', point, event.pointerId);
      return;
    }

    this.isActive = false;
    this.render();
  };

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

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

    if (this.dragPointerId !== event.pointerId) {
      return;
    }

    if (this.mode === 'dragging-start' || this.mode === 'dragging-end') {
      event.preventDefault();
      this.movePoint(point);
      this.render();
      return;
    }

    if (this.mode === 'dragging-body') {
      event.preventDefault();
      this.moveBody(point);
      this.render();
    }
  };

  private handlePointerUp = (event: PointerEvent): void => {
    if (this.dragPointerId !== event.pointerId) {
      return;
    }

    if (this.mode === 'dragging-start' || this.mode === 'dragging-end' || this.mode === 'dragging-body') {
      this.finishDragging();
    }
  };

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

    if (!anchor) {
      return;
    }

    this.startAnchor = anchor;
    this.endAnchor = anchor;
    this.isActive = true;
    this.mode = 'drawing';
    this.render();
  }

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

    if (!anchor) {
      return;
    }

    this.endAnchor = anchor;
    this.render();
  }

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

    if (!geometry || Math.hypot(geometry.endPoint.x - geometry.startPoint.x, geometry.endPoint.y - geometry.startPoint.y) < MIN_LINE_SIZE) {
      this.removeSelf?.();
      return;
    }

    this.mode = 'ready';
    this.render();
  }

  private startDragging(mode: TrendLineMode, point: Point, pointerId: number): void {
    this.mode = mode;
    this.dragPointerId = pointerId;
    this.dragStartPoint = point;
    this.dragGeometrySnapshot = this.getGeometry();
    this.dragStateSnapshot = this.getState();

    this.render();
  }

  private finishDragging(): void {
    this.mode = 'ready';
    this.dragPointerId = null;
    this.dragStartPoint = null;
    this.dragGeometrySnapshot = null;
    this.dragStateSnapshot = null;
    this.render();
  }

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

    if (!anchor) {
      return;
    }

    if (this.mode === 'dragging-start') {
      this.startAnchor = anchor;
    }

    if (this.mode === 'dragging-end') {
      this.endAnchor = anchor;
    }
  }

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

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

    const offsetX = point.x - this.dragStartPoint.x;
    const priceOffset = getPriceDeltaFromCoordinates(this.series, this.dragStartPoint.y, point.y);

    const nextStartTime = shiftTimeByPixels(this.chart, snapshot.startAnchor.time, offsetX);
    const nextEndTime = shiftTimeByPixels(this.chart, snapshot.endAnchor.time, offsetX);

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

    this.startAnchor = {
      time: nextStartTime,
      price: snapshot.startAnchor.price + priceOffset,
    };

    this.endAnchor = {
      time: nextEndTime,
      price: snapshot.endAnchor.price + priceOffset,
    };
  }

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

  private getGeometry(): TrendLineGeometry | null {
    if (!this.startAnchor || !this.endAnchor) {
      return null;
    }

    const startX = getXCoordinateFromTime(this.chart, this.startAnchor.time);
    const endX = getXCoordinateFromTime(this.chart, this.endAnchor.time);
    const startY = getYCoordinateFromPrice(this.series, this.startAnchor.price);
    const endY = getYCoordinateFromPrice(this.series, this.endAnchor.price);

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

    const startPoint = {
      x: Math.round(Number(startX)),
      y: Math.round(Number(startY)),
    };

    const endPoint = {
      x: Math.round(Number(endX)),
      y: Math.round(Number(endY)),
    };

    return {
      startPoint,
      endPoint,
      left: Math.min(startPoint.x, endPoint.x),
      right: Math.max(startPoint.x, endPoint.x),
      top: Math.min(startPoint.y, endPoint.y),
      bottom: Math.max(startPoint.y, endPoint.y),
    };
  }

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

    if (!geometry) {
      return null;
    }

    if (isNearPoint(point, geometry.startPoint.x, geometry.startPoint.y, POINT_HIT_TOLERANCE)) {
      return 'start';
    }

    if (isNearPoint(point, geometry.endPoint.x, geometry.endPoint.y, POINT_HIT_TOLERANCE)) {
      return 'end';
    }

    return null;
  }

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

    if (!geometry) {
      return false;
    }

    return this.getDistanceToSegment(point, geometry.startPoint, geometry.endPoint) <= LINE_HIT_TOLERANCE;
  }

  private getDistanceToSegment(point: Point, startPoint: Point, endPoint: Point): number {
    const dx = endPoint.x - startPoint.x;
    const dy = endPoint.y - startPoint.y;

    if (dx === 0 && dy === 0) {
      return Math.hypot(point.x - startPoint.x, point.y - startPoint.y);
    }

    const t = Math.max(
      0,
      Math.min(1, ((point.x - startPoint.x) * dx + (point.y - startPoint.y) * dy) / (dx * dx + dy * dy)),
    );

    const projectionX = startPoint.x + t * dx;
    const projectionY = startPoint.y + t * dy;

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

  private getTimeCoordinate(kind: TimeLabelKind): number | null {
    const anchor = kind === 'start' ? this.startAnchor : this.endAnchor;

    if (!anchor) {
      return null;
    }

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

    return coordinate === null ? null : Number(coordinate);
  }

  private getPriceCoordinate(kind: PriceLabelKind): number | null {
    const anchor = kind === 'start' ? this.startAnchor : this.endAnchor;

    if (!anchor) {
      return null;
    }

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

    return coordinate === null ? null : Number(coordinate);
  }

  private getTimeText(kind: TimeLabelKind): string {
    const anchor = kind === 'start' ? this.startAnchor : this.endAnchor;

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

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

  private getPriceText(kind: PriceLabelKind): string {
    const anchor = kind === 'start' ? this.startAnchor : this.endAnchor;

    if (!anchor) {
      return '';
    }

    return formatPrice(anchor.price) ?? '';
  }

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

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