---

import { MismatchDirection, PriceScaleMode } from 'lightweight-charts';
import { 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 type { PriceAxisLabel } from './types';
import type { IPriceLine, LogicalRange } from 'lightweight-charts';
import type { Observable } from 'rxjs';

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;
  priority: number;
}

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

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

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

interface EntitySubscription {
  entity: Indicator;
  subscription: Subscription;
}

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

const SERIES_COLOR_OPTIONS = ['color', 'lineColor', 'topLineColor', 'bottomLineColor'];

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

  const close = Reflect.get(data, 'close');

  if (typeof close === 'number') {
    return close;
  }

  const value = Reflect.get(data, 'value');

  return typeof value === 'number' ? value : null;
}

function toOpaqueColor(color: string): string {
  return color.length === 9 ? removeAlphaFromHex(color) : color;
}

function getSeriesColor(series: SeriesStrategies, data: unknown): string {
  const options = series.options();

  if (data && typeof data === 'object') {
    const dataColor = Reflect.get(data, 'color');

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

    const open = Reflect.get(data, 'open');
    const close = Reflect.get(data, 'close');

    if (typeof open === 'number' && typeof close === 'number') {
      const candleColor = Reflect.get(options, close >= open ? 'upColor' : 'downColor');

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

  for (const option of SERIES_COLOR_OPTIONS) {
    const color = Reflect.get(options, option);

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

  return toOpaqueColor(getThemeStore().colors.chartLineColor);
}

function getContrastTextColor(color: string): string {
  const hex = toOpaqueColor(color).replace('#', '');
  const red = Number.parseInt(hex.slice(0, 2), 16);
  const green = Number.parseInt(hex.slice(2, 4), 16);
  const blue = Number.parseInt(hex.slice(4, 6), 16);
  const brightness = 0.199 * red + 0.687 * green + 0.114 * blue;

  return brightness > 160 ? '#000000' : '#FFFFFF';
}

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

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

export class PriceAxisLabelsController {
  private readonly subscriptions = new Subscription();
  private readonly entitySubscriptions = new Map<string, EntitySubscription>();
  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 = symbol.split(':').at(-1) || 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) {
      cancelAnimationFrame(this.updateFrame);
      this.updateFrame = null;
    }

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

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

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

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

    this.entitySubscriptions.clear();
    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;
    }

    const activeKeys = new Set(entities.map((entity) => `${collection}:${entity.getId()}`));

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

      entry.entity.getSeriesMap().forEach((series) => {
        this.restoreSourceOptions(series);
      });

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

    entities.forEach((entity) => {
      const key = `${collection}:${entity.getId()}`;
      const current = this.entitySubscriptions.get(key);

      if (current?.entity === entity) {
        return;
      }

      if (current) {
        current.entity.getSeriesMap().forEach((series) => {
          this.restoreSourceOptions(series);
        });

        current.subscription.unsubscribe();
      }

      const subscription = entity.subscribeDataChange(() => {
        this.applyDisplayModeToSources(this.getEntitySources(collection, entity));
        this.scheduleUpdate();
      });

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

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

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

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

    if (this.mainSeries) {
      sources.push({
        id: 'main',
        role: 'main',
        series: this.mainSeries,
        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[] {
    let role: SourceRole = 'indicator';

    if (collection === 'compare') {
      role = 'compare';
    } else if (entity.getType() === IndicatorsIds.Volume) {
      role = 'volume';
    }

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

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

    if (savedDefaults) {
      return savedDefaults;
    }

    const options = series.options();
    const defaults = {
      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,
          });
          return;
        }

        if (source.role === 'main') {
          source.series.applyOptions({
            lastValueVisible: this.isHistoryMode ? false : defaults.lastValueVisible,
            title: this.isHistoryMode ? '' : this.mainSymbol || defaults.title,
          });
          return;
        }

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

  private refreshHistoryMode(): void {
    const barsInfo =
      this.visibleLogicalRange && this.mainSeries
        ? this.mainSeries.barsInLogicalRange(this.visibleLogicalRange)
        : null;

    const nextHistoryMode = (barsInfo?.barsAfter ?? 0) > 0;

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

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

  private scheduleUpdate(): void {
    if (this.updateFrame !== null) {
      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() || (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 key = `${paneIndex}:${side}`;
      const group = groups.get(key);

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

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

    const mainSource = sources.find((source) => source.role === 'main');

    if (!mainSource) {
      return groups;
    }

    const showRealtimeLabel =
      this.isHistoryMode || this.ensureSourceDefaults(mainSource.series).lastValueVisible;

    if (!showRealtimeLabel) {
      return groups;
    }

    const reservedCoordinate = this.getCurrentMainPriceCoordinate();

    if (reservedCoordinate === null) {
      return groups;
    }

    const paneIndex = mainSource.series.getPane().paneIndex();
    const side = getAxisSide(mainSource);
    const group = groups.get(`${paneIndex}:${side}`);

    if (group) {
      group.reservedCoordinate = reservedCoordinate;
    }

    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;
    }

    return {
      id: source.id,
      desiredCoordinate: coordinate,
      text:
        source.role === 'volume'
          ? formatCompactNumber(price)
          : this.formatValue(source.series, price),
      color: getSeriesColor(source.series, data),
      style: this.isHistoryMode ? 'outlined' : 'filled',
      priority: source.priority,
    };
  }

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

    return source.series.data().at(-1) ?? null;
  }

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

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

      if (!host) {
        return;
      }

      activeKeys.add(key);
      this.getOrCreateLayer(key, host).primitive.setLabels(
        group.labels,
        group.reservedCoordinate,
      );
    });

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

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

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

  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;
    }

    return (
      sources.find(
        (source) =>
          source.series.getPane().paneIndex() === paneIndex &&
          getAxisSide(source) === side,
      )?.series ?? null
    );
  }

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

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

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

    const layer = {
      host,
      primitive: new PriceAxisLabelsPrimitive(),
    };

    host.attachPrimitive(layer.primitive);
    this.layers.set(key, layer);

    return layer;
  }

  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 lastData = mainSource.series.data().at(-1);
    const price = getDataPrice(lastData);

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

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

    this.getCurrentPriceLine(mainSource.series, color).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 price = getDataPrice(this.mainSeries.data().at(-1));

    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();
    const formattedPrice = formatPrice(price) ?? series.priceFormatter().format(price);

    if (mode !== PriceScaleMode.Percentage && mode !== PriceScaleMode.IndexedTo100) {
      return formattedPrice;
    }

    if (!this.visibleLogicalRange) {
      return formattedPrice;
    }

    const firstVisiblePrice = getDataPrice(
      series.dataByIndex(
        Math.ceil(this.visibleLogicalRange.from),
        MismatchDirection.NearestRight,
      ),
    );

    if (firstVisiblePrice === null || firstVisiblePrice === 0) {
      return formattedPrice;
    }

    if (mode === PriceScaleMode.Percentage) {
      return formatPercent(((price - firstVisiblePrice) / firstVisiblePrice) * 100);
    }

    const indexedValue = (price / firstVisiblePrice) * 100;

    return formatPrice(indexedValue) ?? String(indexedValue);
  }
}