class ConfluenceChart {
  constructor() {
    this.chart = null;
    this.candles = null;
    this.resizeObserver = null;
    this.levelSeries = new Map();
    this.bars = [];
    this.levels = [];
    this.onChartClick = null;
  }

  create(el) {
    this.chart = LightweightCharts.createChart(el, {
      autoSize: true,
      layout: {
        background: { color: getComputedStyle(document.documentElement).getPropertyValue('--chart-bg').trim() },
        textColor: getComputedStyle(document.documentElement).getPropertyValue('--muted').trim(),
      },
      grid: {
        vertLines: { color: 'rgba(128,128,128,.10)' },
        horzLines: { color: 'rgba(128,128,128,.10)' },
      },
      timeScale: { timeVisible: true, secondsVisible: false },
      rightPriceScale: { borderVisible: false },
    });
    this.candles = this.chart.addSeries(LightweightCharts.CandlestickSeries, {
      upColor: '#3fb984', downColor: '#e45757', borderVisible: false,
      wickUpColor: '#3fb984', wickDownColor: '#e45757',
    });
    this.resizeObserver = new ResizeObserver(() => {
      this.chart.applyOptions({ width: el.clientWidth, height: el.clientHeight });
    });
    this.resizeObserver.observe(el);
    this.chart.subscribeClick(param => {
      if (param.point && param.time && this.onChartClick) this.onChartClick(param);
    });
  }

  setBars(bars) {
    this.bars = bars;
    this.candles.setData(bars.map(this.toCandle));
    this.chart.timeScale().fitContent();
  }

  updateBar(bar) {
    this.candles.update(this.toCandle(bar));
    if (this.bars.length && this.bars[this.bars.length - 1].t === bar.t) this.bars[this.bars.length - 1] = bar;
    else this.bars.push(bar);
  }

  syncLevels(levels) {
    this.levels = levels;
    const wanted = new Set(levels.filter(level => !level.hidden).map(level => level.id));
    for (const [id, entry] of this.levelSeries) {
      if (!wanted.has(id)) {
        this.chart.removeSeries(entry.series);
        this.levelSeries.delete(id);
      }
    }
    for (const level of levels) {
      if (level.hidden) continue;
      let entry = this.levelSeries.get(level.id);
      const isMa = level.kind === 'ma';
      const options = {
        color: ConfluenceChart.tfColors[level.tf],
        lineWidth: level.tf === '1d' ? 2 : 1,
        lineType: isMa ? LightweightCharts.LineType.WithSteps : LightweightCharts.LineType.Simple,
        lineStyle: level.provisional ? LightweightCharts.LineStyle.Dashed : LightweightCharts.LineStyle.Solid,
        priceLineVisible: false,
        lastValueVisible: true,
        title: level.label,
      };
      if (!entry) {
        entry = { series: this.chart.addSeries(LightweightCharts.LineSeries, options) };
        this.levelSeries.set(level.id, entry);
      } else {
        entry.series.applyOptions(options);
      }
      let data;
      if (isMa) {
        data = (level.points || []).map(([time, value]) => ({ time, value }));
      } else {
        const first = this.bars[0]?.t || level.anchor_t;
        const last = this.bars[this.bars.length - 1]?.t || level.last_t;
        const extension = Math.max(60, Math.floor((last - first) * 0.2));
        const end = Math.max(last, level.last_t) + extension;
        data = [
          { time: level.anchor_t, value: level.anchor_p },
          { time: end, value: level.anchor_p + level.slope * (end - level.anchor_t) },
        ];
      }
      entry.series.setData(data);
    }
  }

  setClickHandler(handler) { this.onChartClick = handler; }

  pointFromClick(param, snap) {
    const rawPrice = this.candles.coordinateToPrice(param.point.y);
    let point = { t: Number(param.time), p: rawPrice, snappedSide: null };
    if (!snap || !this.bars.length) return point;
    const nearest = this.bars.reduce((best, bar) => Math.abs(bar.t - point.t) < Math.abs(best.t - point.t) ? bar : best);
    const candidates = [
      { p: nearest.h, side: 'resistance' },
      { p: nearest.l, side: 'support' },
    ];
    const snapped = candidates
      .map(value => ({ ...value, distance: Math.abs(this.candles.priceToCoordinate(value.p) - param.point.y) }))
      .sort((a, b) => a.distance - b.distance)[0];
    if (snapped.distance <= 8) point = { t: nearest.t, p: snapped.p, snappedSide: snapped.side };
    return point;
  }

  hitTest(param) {
    const t = Number(param.time);
    let best = null;
    for (const level of this.levels.filter(value => value.kind === 'manual')) {
      const price = level.anchor_p + level.slope * (t - level.anchor_t);
      const coordinate = this.candles.priceToCoordinate(price);
      const distance = Math.abs(coordinate - param.point.y);
      if (distance <= 6 && (!best || distance < best.distance)) best = { id: level.id, distance };
    }
    return best?.id || null;
  }

  toCandle(bar) {
    return { time: bar.t, open: bar.o, high: bar.h, low: bar.l, close: bar.c };
  }

  destroy() {
    if (this.resizeObserver) this.resizeObserver.disconnect();
    if (this.chart) this.chart.remove();
  }
}

ConfluenceChart.tfColors = {
  '1m':'#82909f', '2m':'#8a92df', '5m':'#65b7cf', '15m':'#45c39b',
  '30m':'#a8c85d', '1h':'#efb643', '4h':'#ec7b42', '1d':'#d96073',
};

window.ConfluenceChart = ConfluenceChart;