/** 复盘四周期：按「包含成交时刻」的 K 线落点，避免偏到下一根 */
(function () {
  var TF_MAX = { M1: 500, M5: 200, M15: 100, H1: 50 };
  var TF_SEC = { M1: 60, M5: 300, M15: 900, H1: 3600 };

  function num(v) {
    if (v == null || v === "") return null;
    var n = Number(v);
    return Number.isFinite(n) ? n : null;
  }

  /** 找到覆盖 ts 的那根 K 线：barOpen <= ts < barOpen+period（最后一根含右边界） */
  function barIndexAt(bars, ts, tf) {
    if (ts == null || !bars.length) return -1;
    var period = TF_SEC[tf] || 60;
    var t = Number(ts);
    var i;
    for (i = 0; i < bars.length; i++) {
      var open = Number(bars[i].ts);
      var end = open + period;
      var last = i === bars.length - 1;
      if (t >= open && (t < end || (last && t <= end))) {
        return i;
      }
    }
    // 落在首根之前 / 末根之后：夹到边界
    if (t < Number(bars[0].ts)) return 0;
    return bars.length - 1;
  }

  function cropBars(bars, markers, tf) {
    if (!bars.length) return bars;
    var maxN = TF_MAX[tf] || 100;
    if (bars.length <= maxN) return bars;

    var a = barIndexAt(bars, markers.openTs, tf);
    var b =
      markers.closeTs != null ? barIndexAt(bars, markers.closeTs, tf) : a;
    if (a < 0) a = Math.floor(bars.length / 2);
    if (b < 0) b = a;
    var lo = Math.min(a, b);
    var hi = Math.max(a, b);
    var span = hi - lo + 1;
    var pad = Math.max(4, Math.floor((maxN - span) / 2));
    var start = Math.max(0, lo - pad);
    var end = Math.min(bars.length, start + maxN);
    start = Math.max(0, end - maxN);
    return bars.slice(start, end);
  }

  function fmtBjt(ts) {
    if (ts == null) return "";
    var d = new Date(Number(ts) * 1000);
    // 用 UTC+8 显示，与复盘页北京时间一致
    var utc = d.getTime() + d.getTimezoneOffset() * 60000;
    var bjt = new Date(utc + 8 * 3600000);
    var hh = String(bjt.getHours()).padStart(2, "0");
    var mm = String(bjt.getMinutes()).padStart(2, "0");
    return hh + ":" + mm;
  }

  function drawCandleChart(canvas, bars, markers, tf) {
    if (!canvas || !bars || !bars.length) return;
    bars = cropBars(bars, markers || {}, tf);
    markers = markers || {};

    var dpr = window.devicePixelRatio || 1;
    var cssW = canvas.clientWidth || 400;
    var cssH = canvas.clientHeight || 220;
    canvas.width = cssW * dpr;
    canvas.height = cssH * dpr;
    var ctx = canvas.getContext("2d");
    ctx.setTransform(dpr, 0, 0, dpr, 0, 0);

    var padL = 4;
    var padR = 4;
    var padT = 4;
    var padB = 16; // 底部时间轴

    var min = Infinity;
    var max = -Infinity;
    bars.forEach(function (b) {
      min = Math.min(min, b.low);
      max = Math.max(max, b.high);
    });
    if (markers.openPrice != null) {
      min = Math.min(min, markers.openPrice);
      max = Math.max(max, markers.openPrice);
    }
    if (markers.closePrice != null) {
      min = Math.min(min, markers.closePrice);
      max = Math.max(max, markers.closePrice);
    }
    if (!(max > min)) max = min + 1;
    var padPrice = (max - min) * 0.06 || 0.5;
    min -= padPrice;
    max += padPrice;

    var w = cssW - padL - padR;
    var h = cssH - padT - padB;
    var n = bars.length;
    var slot = w / n;

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

    var yOf = function (p) {
      return padT + ((max - p) / (max - min)) * h;
    };
    var xOf = function (i) {
      return padL + i * slot + slot * 0.5;
    };

    var bodyW = Math.max(1, Math.min(6, slot * 0.6));
    bars.forEach(function (b, i) {
      var x = xOf(i);
      var up = b.close >= b.open;
      ctx.strokeStyle = up ? "#0ecb81" : "#f6465d";
      ctx.fillStyle = ctx.strokeStyle;
      ctx.lineWidth = 1;
      ctx.beginPath();
      ctx.moveTo(x, yOf(b.high));
      ctx.lineTo(x, yOf(b.low));
      ctx.stroke();
      var y1 = yOf(b.open);
      var y2 = yOf(b.close);
      var top = Math.min(y1, y2);
      var bh = Math.max(1, Math.abs(y2 - y1));
      ctx.fillRect(x - bodyW / 2, top, bodyW, bh);
    });

    // 底部左右时间（北京时间），方便对照成交时刻
    ctx.fillStyle = "#888899";
    ctx.font = "10px Microsoft YaHei UI, sans-serif";
    ctx.textBaseline = "top";
    ctx.textAlign = "left";
    ctx.fillText(fmtBjt(bars[0].ts), padL, cssH - padB + 2);
    ctx.textAlign = "right";
    ctx.fillText(fmtBjt(bars[n - 1].ts), cssW - padR, cssH - padB + 2);

    var entryColor = "#4cc2ff";
    var exitColor = "#f0b429";
    var entryIdx = barIndexAt(bars, markers.openTs, tf);
    var exitIdx =
      markers.closeTs != null ? barIndexAt(bars, markers.closeTs, tf) : -1;
    var hasExit =
      markers.closeTs != null &&
      markers.closePrice != null &&
      exitIdx >= 0;

    function drawDot(i, price, color) {
      if (i < 0 || price == null) return { x: 0, y: 0 };
      var x = xOf(i);
      var y = yOf(price);
      ctx.beginPath();
      ctx.arc(x, y, 4.5, 0, Math.PI * 2);
      ctx.fillStyle = color;
      ctx.fill();
      ctx.lineWidth = 1.5;
      ctx.strokeStyle = "#ffffff";
      ctx.stroke();
      return { x: x, y: y };
    }

    var pe = null;
    var px = null;
    if (entryIdx >= 0 && markers.openPrice != null) {
      pe = drawDot(entryIdx, markers.openPrice, entryColor);
    }
    if (hasExit) {
      if (Math.abs(exitIdx - entryIdx) <= 1) {
        var x = xOf(exitIdx) + Math.max(6, slot * 0.8);
        var y = yOf(markers.closePrice);
        if (pe && Math.abs(y - pe.y) < 6) {
          y = pe.y - 8;
        }
        ctx.beginPath();
        ctx.arc(x, y, 4.5, 0, Math.PI * 2);
        ctx.fillStyle = exitColor;
        ctx.fill();
        ctx.lineWidth = 1.5;
        ctx.strokeStyle = "#ffffff";
        ctx.stroke();
        px = { x: x, y: y };
      } else {
        px = drawDot(exitIdx, markers.closePrice, exitColor);
      }
    }

    ctx.font = "bold 10px Microsoft YaHei UI, sans-serif";
    if (pe) {
      ctx.fillStyle = entryColor;
      ctx.textAlign = "center";
      ctx.textBaseline = "bottom";
      ctx.fillText("入", pe.x, pe.y - 6);
    }
    if (px) {
      ctx.fillStyle = exitColor;
      ctx.textAlign = "center";
      ctx.textBaseline = "bottom";
      ctx.fillText("出", px.x, px.y - 6);
    }

    var meta = canvas.parentElement && canvas.parentElement.querySelector(".chart-meta");
    if (meta) {
      meta.textContent =
        bars.length +
        " 根 · " +
        fmtBjt(bars[0].ts) +
        "–" +
        fmtBjt(bars[n - 1].ts) +
        " 北京时间";
    }
  }

  function readMarkers(el) {
    return {
      openTs: num(el.dataset.openTs),
      closeTs: num(el.dataset.closeTs),
      openPrice: num(el.dataset.openPrice),
      closePrice: num(el.dataset.closePrice),
      side: el.dataset.side || "",
    };
  }

  function paintAll() {
    document.querySelectorAll("canvas.chart-canvas").forEach(function (el) {
      try {
        var bars = JSON.parse(el.dataset.bars || "[]");
        var tf = el.dataset.tf || "M1";
        drawCandleChart(el, bars, readMarkers(el), tf);
      } catch (e) {
        console.warn(e);
      }
    });
  }

  paintAll();
  window.addEventListener("resize", paintAll);
})();