// chart.js
export function drawChart(canvas, history) {
    if (!canvas || !history?.length)
        return;
    const rect = canvas.getBoundingClientRect();
    const displayHeight = rect.height || 200;
    const displayWidth = rect.width || 800;
    canvas.width = displayWidth;
    canvas.height = displayHeight;
    const ctx = canvas.getContext("2d");
    if (!ctx)
        return;
    const w = canvas.width;
    const h = canvas.height;
    const padLeft = 45;
    const padRight = 15;
    const padTop = 10;
    const padBottom = 25;
    const plotW = w - padLeft - padRight;
    const plotH = h - padTop - padBottom;
    // Фон
    ctx.fillStyle = "#0a0f0a";
    ctx.fillRect(0, 0, w, h);
    // Сетка
    const maxVal = 63;
    const gridLines = 4;
    ctx.strokeStyle = "#0d2a0d";
    ctx.lineWidth = 0.5;
    ctx.setLineDash([4, 4]);
    for (let i = 0; i <= gridLines; i++) {
        const val = (maxVal / gridLines) * i;
        const y = padTop + plotH - (val / maxVal) * plotH;
        ctx.beginPath();
        ctx.moveTo(padLeft, y);
        ctx.lineTo(w - padRight, y);
        ctx.stroke();
        ctx.fillStyle = "#00ff88";
        ctx.font = "11px monospace";
        ctx.textAlign = "right";
        ctx.fillText(Math.round(val).toString(), padLeft - 8, y + 4);
    }
    ctx.setLineDash([]);
    // Подписи осей
    ctx.fillStyle = "#00ff88";
    ctx.font = "bold 11px monospace";
    ctx.save();
    ctx.translate(12, padTop + plotH / 2);
    ctx.rotate(-Math.PI / 2);
    ctx.textAlign = "center";
    ctx.fillText("ЗНАЧЕНИЕ", 0, 0);
    ctx.restore();
    ctx.textAlign = "center";
    ctx.fillText("БУФЕР ПРИНЯТЫХ ДАННЫХ", padLeft + plotW / 2, h - 4);
    const hasSignal = history.some(v => v > 0);
    if (!hasSignal) {
        ctx.fillStyle = "#ff4444";
        ctx.font = "14px monospace";
        ctx.textAlign = "center";
        ctx.fillText("Ожидание сигнала...", w / 2, h / 2);
        return;
    }
    let plotData = history;
    if (history.length > plotW) {
        const step = history.length / plotW;
        plotData = [];
        for (let i = 0; i < plotW; i++) {
            const idx = Math.floor(i * step);
            plotData.push(history[idx]);
        }
    }
    ctx.strokeStyle = "#e6852d";
    ctx.lineWidth = 1.5;
    ctx.shadowColor = "#e6852d";
    ctx.shadowBlur = 3;
    ctx.beginPath();
    const stepX = plotW / Math.max(plotData.length - 1, 1);
    for (let i = 0; i < plotData.length; i++) {
        const x = padLeft + i * stepX;
        const y = padTop + plotH - (plotData[i] / maxVal) * plotH;
        if (i === 0)
            ctx.moveTo(x, y);
        else
            ctx.lineTo(x, y);
    }
    ctx.stroke();
    ctx.shadowBlur = 0;
    if (history.length > 0) {
        const lastVal = history[history.length - 1];
        const lastX = padLeft + (plotData.length - 1) * stepX;
        const lastY = padTop + plotH - (lastVal / maxVal) * plotH;
        ctx.fillStyle = "#c46b1f";
        ctx.beginPath();
        ctx.arc(lastX, lastY, 4, 0, Math.PI * 2);
        ctx.fill();
        const labelText = `${lastVal}`;
        const labelWidth = ctx.measureText(labelText).width;
        ctx.fillStyle = "rgba(0,0,0,0.8)";
        ctx.fillRect(lastX - labelWidth / 2 - 4, lastY - 22, labelWidth + 8, 18);
        ctx.fillStyle = "#00ff88";
        ctx.font = "bold 12px monospace";
        ctx.textAlign = "center";
        ctx.fillText(labelText, lastX, lastY - 8);
        const peak = Math.max(...history);
        const min = Math.min(...history);
        ctx.fillStyle = "rgba(0,0,0,0.7)";
        ctx.fillRect(w - 120, padTop, 110, 42);
        ctx.fillStyle = "#00ff88";
        ctx.font = "10px monospace";
        ctx.textAlign = "left";
        ctx.fillText(`Пик: ${peak}`, w - 110, padTop + 14);
        ctx.fillText(`Мин: ${min}`, w - 110, padTop + 28);
        ctx.fillText(`Точек: ${history.length}`, w - 110, padTop + 42);
    }
}