---

import {
  IPriceLine,
  LogicalRange,
  MismatchDirection,
  PriceScaleMode,
} from 'lightweight-charts';
import { Observable, Subscription } from 'rxjs';

import { Indicator } from '@core/Indicator';
import { IndicatorsIds, MAIN_PANE_INDEX } from '@src/constants';
import { SeriesStrategies } from '@src/modules/series-strategies/SeriesFactory';
import { getThemeStore } from '@src/theme';
import { Direction } from '@src/types';
import {
  formatCompactNumber,
  formatPercent,
  formatPrice,
} from '@src/utils';
import { removeAlphaFromHex } from '@src/utils/removeAlphaFromHex';

import { PriceAxisLabelsPrimitive } from './primitive';
import { PRICE_AXIS_LABEL_HEIGHT, PriceAxisLabel } from './types';

type EntityCollection = 'compare' | 'indicator';
type SourceRole = 'main' | 'compare' | 'indicator' | 'volume';
type PriceAxisSide = Direction.Left | Direction.Right;

interface PriceAxisLabelsControllerOptions {
  mainSeries$: Observable<SeriesStrategies | null>;
  mainSymbol$: Observable<string>;
  compareEntities$: Observable<Indicator[]>;
  indicatorEntities$: Observable<Indicator[]>;
}

interface PriceLabelSource {
  id: string;
  role: SourceRole;
  series: SeriesStrategies;
  collisionGroup: string;
  priority: number;
}

interface SourceDefaults {
  lastValueVisible: boolean;
  priceLineVisible: boolean;
  title: string;
}

interface AxisLabelsGroup {
  paneIndex: number;
  side: PriceAxisSide;
  labels: PriceAxisLabel[];
}

interface AxisLayer {
  host: SeriesStrategies;
  primitive: PriceAxisLabelsPrimitive;
}

const SOURCE_PRIORITY: Record<SourceRole, number> = {
  main: 100,
  compare: 80,
  indicator: 50,
  volume: 30,
};

const CURRENT_PRICE_LABEL_GAP = 2;

function getDataPrice(data: unknown): number | null {
  if (!data || typeof data !== 'object') {
    return null;
  }

  if ('close' in data && typeof data.close === 'number') {
    return data.close;
  }

  if ('value' in data && typeof data.value === 'number') {
    return data.value;
  }

  return null;
}

function toOpaqueColor(color: string): string {
  return /^#[0-9a-fA-F]{8}$/.test(color)
    ? removeAlphaFromHex(color)
    : color;
}

function getSeriesColor(series: SeriesStrategies, data: unknown): string {
  if (
    data &&
    typeof data === 'object' &&
    'color' in data &&
    typeof data.color === 'string'
  ) {
    return toOpaqueColor(data.color);
  }

  const options = series.options() as unknown as Record<string, unknown>;

  if (
    data &&
    typeof data === 'object' &&
    'open' in data &&
    'close' in data &&
    typeof data.open === 'number' &&
    typeof data.close === 'number'
  ) {
    const candleColor =
      data.close >= data.open
        ? options.upColor
        : options.downColor;

    if (typeof candleColor === 'string') {
      return toOpaqueColor(candleColor);
    }
  }

  const color = [
    options.color,
    options.lineColor,
    options.topLineColor,
    options.bottomLineColor,
  ].find((value): value is string => typeof value === 'string');

  return color
    ? toOpaqueColor(color)
    : toOpaqueColor(getThemeStore().colors.chartLineColor);
}

function getContrastTextColor(color: string): string {
  const normalizedColor = toOpaqueColor(color)
    .replace('#', '')
    .slice(0, 6);

  if (normalizedColor.length !== 6) {
    return '#FFFFFF';
  }

  const red = Number.parseInt(normalizedColor.slice(0, 2), 16);
  const green = Number.parseInt(normalizedColor.slice(2, 4), 16);
  const blue = Number.parseInt(normalizedColor.slice(4, 6), 16);

  if (
    Number.isNaN(red) ||
    Number.isNaN(green) ||
    Number.isNaN(blue)
  ) {
    return '#FFFFFF';
  }

  const luminance =
    (red * 0.299 + green * 0.587 + blue * 0.114) / 255;

  return luminance > 0.6 ? '#000000' : '#FFFFFF';
}

function getShortSymbol(symbol: string): string {
  const parts = symbol.split(':');

  return parts[parts.length - 1] || symbol;
}

function getAxisSide(source: PriceLabelSource): PriceAxisSide {
  if (source.role === 'volume') {
    return Direction.Right;
  }

  return source.series.options().priceScaleId === Direction.Left
    ? Direction.Left
    : Direction.Right;
}

function getAxisKey(paneIndex: number, side: PriceAxisSide): string {
  return `${paneIndex}:${side}`;
}

function getEntityKey(
  collection: EntityCollection,
  entity: Indicator,
): string {
  return `${collection}:${entity.getId()}`;
}

function areSeriesListsEqual(
  currentSeries: readonly SeriesStrategies[] | undefined,
  nextSeries: readonly SeriesStrategies[],
): boolean {
  return (
    currentSeries?.length === nextSeries.length &&
    currentSeries.every(
      (series, index) => series === nextSeries[index],
    )
  );
}

export class PriceAxisLabelsController {
  private readonly subscriptions = new Subscription();

  private readonly entitySubscriptions = new Map<string, Subscription>();

  private readonly entitySeries = new Map<
    string,
    readonly SeriesStrategies[]
  >();

  private readonly sourceDefaults = new WeakMap<
    SeriesStrategies,
    SourceDefaults
  >();

  private readonly layers = new Map<string, AxisLayer>();

  private mainSeries: SeriesStrategies | null = null;

  private mainSeriesDataHandler: (() => void) | null = null;

  private compareEntities: Indicator[] = [];

  private indicatorEntities: Indicator[] = [];

  private visibleLogicalRange: LogicalRange | null = null;

  private currentPriceLine: IPriceLine | null = null;

  private currentPriceLineHost: SeriesStrategies | null = null;

  private mainSymbol = '';

  private isHistoryMode = false;

  private updateFrame: number | null = null;

  constructor({
    mainSeries$,
    mainSymbol$,
    compareEntities$,
    indicatorEntities$,
  }: PriceAxisLabelsControllerOptions) {
    this.subscriptions.add(
      mainSymbol$.subscribe((symbol) => {
        this.mainSymbol = getShortSymbol(symbol);

        this.applyDisplayMode();
        this.scheduleUpdate();
      }),
    );

    this.subscriptions.add(
      mainSeries$.subscribe((series) => {
        this.setMainSeries(series);
      }),
    );

    this.subscriptions.add(
      compareEntities$.subscribe((entities) => {
        this.setEntities('compare', entities);
      }),
    );

    this.subscriptions.add(
      indicatorEntities$.subscribe((entities) => {
        this.setEntities('indicator', entities);
      }),
    );
  }

  public setVisibleLogicalRange(
    logicalRange: LogicalRange | null,
  ): void {
    this.visibleLogicalRange = logicalRange;
    this.refreshHistoryMode();
    this.scheduleUpdate();
  }

  public invalidate(): void {
    this.scheduleUpdate();
  }

  public destroy(): void {
    if (
      this.updateFrame !== null &&
      typeof cancelAnimationFrame === 'function'
    ) {
      cancelAnimationFrame(this.updateFrame);
      this.updateFrame = null;
    }

    this.unsubscribeMainSeries();
    this.subscriptions.unsubscribe();

    this.entitySubscriptions.forEach((subscription) => {
      subscription.unsubscribe();
    });

    this.getSources().forEach((source) => {
      this.restoreSourceOptions(source.series);
    });

    this.entitySubscriptions.clear();
    this.entitySeries.clear();

    this.layers.forEach(({ host, primitive }) => {
      try {
        host.detachPrimitive(primitive);
      } catch {
        // Серия могла быть удалена раньше контроллера.
      }
    });

    this.layers.clear();
    this.removeCurrentPriceLine();
  }

  private setMainSeries(series: SeriesStrategies | null): void {
    if (this.mainSeries === series) {
      return;
    }

    const previousSeries = this.mainSeries;

    this.unsubscribeMainSeries();

    if (previousSeries) {
      this.restoreSourceOptions(previousSeries);
    }

    this.mainSeries = series;

    if (series) {
      this.ensureSourceDefaults(series);

      this.mainSeriesDataHandler = () => {
        this.refreshHistoryMode();
        this.scheduleUpdate();
      };

      series.subscribeDataChanged(this.mainSeriesDataHandler);
    }

    if (
      this.currentPriceLineHost &&
      this.currentPriceLineHost !== series
    ) {
      this.removeCurrentPriceLine();
    }

    this.refreshHistoryMode();
    this.applyDisplayMode();
    this.scheduleUpdate();
  }

  private unsubscribeMainSeries(): void {
    if (!this.mainSeries || !this.mainSeriesDataHandler) {
      this.mainSeriesDataHandler = null;

      return;
    }

    try {
      this.mainSeries.unsubscribeDataChanged(
        this.mainSeriesDataHandler,
      );
    } catch {
      // Серия могла быть удалена раньше контроллера.
    }

    this.mainSeriesDataHandler = null;
  }

  private setEntities(
    collection: EntityCollection,
    entities: Indicator[],
  ): void {
    if (collection === 'compare') {
      this.compareEntities = entities;
    } else {
      this.indicatorEntities = entities;
    }

    this.syncEntitySubscriptions(collection, entities);
    this.applyDisplayMode();
    this.scheduleUpdate();
  }

  private syncEntitySubscriptions(
    collection: EntityCollection,
    entities: Indicator[],
  ): void {
    const activeKeys = new Set(
      entities.map((entity) => getEntityKey(collection, entity)),
    );

    this.entitySubscriptions.forEach((subscription, key) => {
      if (
        !key.startsWith(`${collection}:`) ||
        activeKeys.has(key)
      ) {
        return;
      }

      const removedSeries = this.entitySeries.get(key);

      removedSeries?.forEach((series) => {
        this.restoreSourceOptions(series);
      });

      subscription.unsubscribe();
      this.entitySubscriptions.delete(key);
      this.entitySeries.delete(key);
    });

    entities.forEach((entity) => {
      const key = getEntityKey(collection, entity);

      const nextSeries = Array.from(
        entity.getSeriesMap().values(),
      );

      const currentSeries = this.entitySeries.get(key);

      if (!areSeriesListsEqual(currentSeries, nextSeries)) {
        currentSeries
          ?.filter((series) => !nextSeries.includes(series))
          .forEach((series) => {
            this.restoreSourceOptions(series);
          });

        this.entitySeries.set(key, nextSeries);

        this.applyDisplayModeToSources(
          this.getEntitySources(collection, entity),
        );
      }

      if (this.entitySubscriptions.has(key)) {
        return;
      }

      const subscription = entity.subscribeDataChange(() => {
        const updatedSeries = Array.from(
          entity.getSeriesMap().values(),
        );

        const registeredSeries = this.entitySeries.get(key);

        if (
          !areSeriesListsEqual(
            registeredSeries,
            updatedSeries,
          )
        ) {
          registeredSeries
            ?.filter(
              (series) => !updatedSeries.includes(series),
            )
            .forEach((series) => {
              this.restoreSourceOptions(series);
            });

          this.entitySeries.set(key, updatedSeries);

          this.applyDisplayModeToSources(
            this.getEntitySources(collection, entity),
          );
        }

        this.scheduleUpdate();
      });

      this.entitySubscriptions.set(key, subscription);
    });
  }

  private getSources(): PriceLabelSource[] {
    const sources: PriceLabelSource[] = [];

    if (this.mainSeries) {
      sources.push({
        id: 'main',
        role: 'main',
        series: this.mainSeries,
        collisionGroup: 'main',
        priority: SOURCE_PRIORITY.main,
      });
    }

    this.compareEntities.forEach((entity) => {
      sources.push(
        ...this.getEntitySources('compare', entity),
      );
    });

    this.indicatorEntities.forEach((entity) => {
      sources.push(
        ...this.getEntitySources('indicator', entity),
      );
    });

    return sources;
  }

  private getEntitySources(
    collection: EntityCollection,
    entity: Indicator,
  ): PriceLabelSource[] {
    const isVolume =
      collection === 'indicator' &&
      entity.getType() === IndicatorsIds.Volume;

    const role: SourceRole =
      collection === 'compare'
        ? 'compare'
        : isVolume
          ? 'volume'
          : 'indicator';

    const collisionGroup =
      role === 'volume'
        ? 'volume'
        : role === 'compare'
          ? `compare:${entity.getId()}`
          : `indicator:${entity.getId()}`;

    return Array.from(
      entity.getSeriesMap().entries(),
    ).map(([seriesId, series]) => ({
      id: `${collection}:${entity.getId()}:${seriesId}`,
      role,
      series,
      collisionGroup,
      priority: SOURCE_PRIORITY[role],
    }));
  }

  private ensureSourceDefaults(
    series: SeriesStrategies,
  ): SourceDefaults {
    const currentDefaults = this.sourceDefaults.get(series);

    if (currentDefaults) {
      return currentDefaults;
    }

    const options = series.options();

    const defaults: SourceDefaults = {
      lastValueVisible: options.lastValueVisible,
      priceLineVisible: options.priceLineVisible,
      title: options.title ?? '',
    };

    this.sourceDefaults.set(series, defaults);

    return defaults;
  }

  private restoreSourceOptions(series: SeriesStrategies): void {
    const defaults = this.sourceDefaults.get(series);

    if (!defaults) {
      return;
    }

    try {
      series.applyOptions(defaults);
    } catch {
      // Серия могла быть удалена раньше контроллера.
    }
  }

  private applyDisplayMode(): void {
    this.applyDisplayModeToSources(this.getSources());

    if (!this.isHistoryMode) {
      this.hideCurrentPriceLine();
    }
  }

  private applyDisplayModeToSources(
    sources: readonly PriceLabelSource[],
  ): void {
    sources.forEach((source) => {
      const defaults = this.ensureSourceDefaults(source.series);

      try {
        if (source.role === 'volume') {
          source.series.applyOptions({
            lastValueVisible: false,
            priceLineVisible: false,
            title: '',
          });

          return;
        }

        const normalTitle =
          source.role === 'main'
            ? this.mainSymbol
            : defaults.title;

        source.series.applyOptions({
          lastValueVisible: this.isHistoryMode
            ? false
            : defaults.lastValueVisible,
          title: this.isHistoryMode
            ? ''
            : normalTitle,
        });
      } catch {
        // Серия могла быть удалена раньше контроллера.
      }
    });
  }

  private getHistoryMode(
    logicalRange: LogicalRange | null,
  ): boolean {
    if (!logicalRange || !this.mainSeries) {
      return false;
    }

    const barsInfo = this.mainSeries.barsInLogicalRange(
      logicalRange,
    );

    return (barsInfo?.barsAfter ?? 0) > 0;
  }

  private refreshHistoryMode(): void {
    const nextHistoryMode = this.getHistoryMode(
      this.visibleLogicalRange,
    );

    if (this.isHistoryMode === nextHistoryMode) {
      return;
    }

    this.isHistoryMode = nextHistoryMode;
    this.applyDisplayMode();
  }

  private scheduleUpdate(): void {
    if (this.updateFrame !== null) {
      return;
    }

    if (typeof requestAnimationFrame !== 'function') {
      this.update();

      return;
    }

    this.updateFrame = requestAnimationFrame(() => {
      this.updateFrame = null;
      this.update();
    });
  }

  private update(): void {
    const sources = this.getSources();

    this.updateCurrentPriceLine(sources);

    this.updateAxisLayers(
      this.collectAxisGroups(sources),
      sources,
    );
  }

  private collectAxisGroups(
    sources: readonly PriceLabelSource[],
  ): Map<string, AxisLabelsGroup> {
    const groups = new Map<string, AxisLabelsGroup>();

    sources.forEach((source) => {
      if (!source.series.isVisible()) {
        return;
      }

      if (
        source.role !== 'volume' &&
        !this.isHistoryMode
      ) {
        return;
      }

      const label = this.createLabel(source);

      if (!label) {
        return;
      }

      const paneIndex = source.series
        .getPane()
        .paneIndex();

      const side = getAxisSide(source);
      const axisKey = getAxisKey(paneIndex, side);
      const group = groups.get(axisKey);

      if (group) {
        group.labels.push(label);

        return;
      }

      groups.set(axisKey, {
        paneIndex,
        side,
        labels: [label],
      });
    });

    return groups;
  }

  private createLabel(
    source: PriceLabelSource,
  ): PriceAxisLabel | null {
    const data = this.getSourceData(source);
    const price = getDataPrice(data);

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

    const coordinate = source.series.priceToCoordinate(price);

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

    let desiredCoordinate = coordinate;

    if (source.role === 'main') {
      const currentCoordinate =
        this.getCurrentMainPriceCoordinate();

      if (
        currentCoordinate !== null &&
        Math.abs(currentCoordinate - coordinate) <=
          PRICE_AXIS_LABEL_HEIGHT + CURRENT_PRICE_LABEL_GAP
      ) {
        desiredCoordinate -=
          PRICE_AXIS_LABEL_HEIGHT + CURRENT_PRICE_LABEL_GAP;
      }
    }

    const text =
      source.role === 'volume'
        ? formatCompactNumber(price)
        : this.formatValue(source.series, price);

    return {
      id: source.id,
      collisionGroup: source.collisionGroup,
      desiredCoordinate,
      text,
      color: getSeriesColor(source.series, data),
      style: this.isHistoryMode
        ? 'outlined'
        : 'filled',
      priority: source.priority,
      height: PRICE_AXIS_LABEL_HEIGHT,
    };
  }

  private getSourceData(source: PriceLabelSource): unknown {
    if (
      this.isHistoryMode &&
      this.visibleLogicalRange
    ) {
      return source.series.dataByIndex(
        Math.floor(this.visibleLogicalRange.to),
        MismatchDirection.NearestLeft,
      );
    }

    const data = source.series.data();

    return data.length > 0
      ? data[data.length - 1]
      : null;
  }

  private updateAxisLayers(
    groups: Map<string, AxisLabelsGroup>,
    sources: readonly PriceLabelSource[],
  ): void {
    const activeLayerKeys = new Set<string>();

    groups.forEach((group, axisKey) => {
      const host = this.getAxisHost(
        group.paneIndex,
        group.side,
        sources,
      );

      if (!host) {
        return;
      }

      activeLayerKeys.add(axisKey);

      this.getOrCreateLayer(
        axisKey,
        host,
      ).primitive.setLabels(group.labels);
    });

    this.layers.forEach((layer, axisKey) => {
      if (activeLayerKeys.has(axisKey)) {
        return;
      }

      try {
        layer.host.detachPrimitive(layer.primitive);
      } catch {
        // Серия могла быть удалена раньше контроллера.
      }

      this.layers.delete(axisKey);
    });
  }

  private getAxisHost(
    paneIndex: number,
    side: PriceAxisSide,
    sources: readonly PriceLabelSource[],
  ): SeriesStrategies | null {
    if (
      paneIndex === MAIN_PANE_INDEX &&
      side === Direction.Right &&
      this.mainSeries
    ) {
      return this.mainSeries;
    }

    const regularSource = sources.find(
      (source) =>
        source.role !== 'volume' &&
        source.series.getPane().paneIndex() === paneIndex &&
        getAxisSide(source) === side,
    );

    if (regularSource) {
      return regularSource.series;
    }

    const fallbackSource = sources.find(
      (source) =>
        source.series.getPane().paneIndex() === paneIndex &&
        getAxisSide(source) === side,
    );

    return fallbackSource?.series ?? null;
  }

  private getOrCreateLayer(
    axisKey: string,
    host: SeriesStrategies,
  ): AxisLayer {
    const currentLayer = this.layers.get(axisKey);

    if (currentLayer?.host === host) {
      return currentLayer;
    }

    if (currentLayer) {
      try {
        currentLayer.host.detachPrimitive(
          currentLayer.primitive,
        );
      } catch {
        // Серия могла быть удалена раньше контроллера.
      }
    }

    const primitive = new PriceAxisLabelsPrimitive();

    host.attachPrimitive(primitive);

    const nextLayer: AxisLayer = {
      host,
      primitive,
    };

    this.layers.set(axisKey, nextLayer);

    return nextLayer;
  }

  private updateCurrentPriceLine(
    sources: readonly PriceLabelSource[],
  ): void {
    const mainSource = sources.find(
      (source) => source.role === 'main',
    );

    if (
      !this.isHistoryMode ||
      !mainSource ||
      !mainSource.series.isVisible()
    ) {
      this.hideCurrentPriceLine();

      return;
    }

    const data = mainSource.series.data();

    const lastData =
      data.length > 0
        ? data[data.length - 1]
        : null;

    const price = getDataPrice(lastData);

    if (price === null) {
      this.hideCurrentPriceLine();

      return;
    }

    const color = getSeriesColor(
      mainSource.series,
      lastData,
    );

    const priceLine = this.getCurrentPriceLine(
      mainSource.series,
      color,
    );

    priceLine.applyOptions({
      price,
      color,
      lineVisible: false,
      axisLabelVisible: true,
      axisLabelColor: color,
      axisLabelTextColor: getContrastTextColor(color),
      title: this.mainSymbol,
    });
  }

  private getCurrentMainPriceCoordinate(): number | null {
    if (!this.mainSeries) {
      return null;
    }

    const data = this.mainSeries.data();

    const lastData =
      data.length > 0
        ? data[data.length - 1]
        : null;

    const price = getDataPrice(lastData);

    return price === null
      ? null
      : this.mainSeries.priceToCoordinate(price);
  }

  private getCurrentPriceLine(
    series: SeriesStrategies,
    color: string,
  ): IPriceLine {
    if (
      this.currentPriceLine &&
      this.currentPriceLineHost === series
    ) {
      return this.currentPriceLine;
    }

    this.removeCurrentPriceLine();

    this.currentPriceLine = series.createPriceLine({
      price: 0,
      color,
      lineVisible: false,
      axisLabelVisible: false,
      title: '',
    });

    this.currentPriceLineHost = series;

    return this.currentPriceLine;
  }

  private hideCurrentPriceLine(): void {
    this.currentPriceLine?.applyOptions({
      lineVisible: false,
      axisLabelVisible: false,
      title: '',
    });
  }

  private removeCurrentPriceLine(): void {
    if (
      this.currentPriceLine &&
      this.currentPriceLineHost
    ) {
      try {
        this.currentPriceLineHost.removePriceLine(
          this.currentPriceLine,
        );
      } catch {
        // Серия могла быть удалена раньше контроллера.
      }
    }

    this.currentPriceLine = null;
    this.currentPriceLineHost = null;
  }

  private formatValue(
    series: SeriesStrategies,
    price: number,
  ): string {
    const { mode } = series.priceScale().options();

    if (
      mode !== PriceScaleMode.Percentage &&
      mode !== PriceScaleMode.IndexedTo100
    ) {
      return (
        formatPrice(price) ??
        series.priceFormatter().format(price)
      );
    }

    const logicalRange = this.visibleLogicalRange;

    if (!logicalRange) {
      return (
        formatPrice(price) ??
        series.priceFormatter().format(price)
      );
    }

    const firstVisibleData = series.dataByIndex(
      Math.ceil(logicalRange.from),
      MismatchDirection.NearestRight,
    );

    const firstVisiblePrice = getDataPrice(
      firstVisibleData,
    );

    if (
      firstVisiblePrice === null ||
      firstVisiblePrice === 0
    ) {
      return (
        formatPrice(price) ??
        series.priceFormatter().format(price)
      );
    }

    if (mode === PriceScaleMode.Percentage) {
      const percentage =
        ((price - firstVisiblePrice) /
          firstVisiblePrice) *
        100;

      return formatPercent(percentage);
    }

    const indexedValue =
      (price / firstVisiblePrice) * 100;

    return (
      formatPrice(indexedValue) ??
      indexedValue.toString()
    );
  }
}