/** 轻量蜡烛图（无外部依赖），用于复盘四周期预览 */
(function () {
  function drawCandleChart(canvas, bars) {
    if (!canvas || !bars || !bars.length) return;
    const dpr = window.devicePixelRatio || 1;
    const cssW = canvas.clientWidth || 400;
    const cssH = canvas.clientHeight || 180;
    canvas.width = cssW * dpr;
    canvas.height = cssH * dpr;
    const ctx = canvas.getContext("2d");
    ctx.scale(dpr, dpr);

    const pad = 8;
    let min = Infinity, max = -Infinity;
    bars.forEach((b) => {
      min = Math.min(min, b.low);
      max = Math.max(max, b.high);
    });
    if (!(max > min)) {
      max = min + 1;
    }
    const w = cssW - pad * 2;
    const h = cssH - pad * 2;
    const n = bars.length;
    const slot = w / n;

    ctx.clearRect(0, 0, cssW, cssH);
    ctx.fillStyle = "#0e0e18";
    ctx.fillRect(0, 0, cssW, cssH);

    const yOf = (p) => pad + ((max - p) / (max - min)) * h;

    bars.forEach((b, i) => {
      const x = pad + i * slot + slot * 0.5;
      const up = b.close >= b.open;
      ctx.strokeStyle = up ? "#0ecb81" : "#f6465d";
      ctx.fillStyle = ctx.strokeStyle;
      ctx.beginPath();
      ctx.moveTo(x, yOf(b.high));
      ctx.lineTo(x, yOf(b.low));
      ctx.stroke();
      const y1 = yOf(b.open);
      const y2 = yOf(b.close);
      const top = Math.min(y1, y2);
      const bh = Math.max(1, Math.abs(y2 - y1));
      ctx.fillRect(x - Math.max(1, slot * 0.3), top, Math.max(2, slot * 0.6), bh);
    });
  }

  document.querySelectorAll("canvas.chart-canvas").forEach((el) => {
    try {
      const bars = JSON.parse(el.dataset.bars || "[]");
      drawCandleChart(el, bars);
    } catch (e) {
      console.warn(e);
    }
  });
})();