import { qs } from "./dom.js";

export function renderTrend(events = []) {
  const days = Array.from({ length: 7 }, (_, index) => {
    const date = new Date();
    date.setDate(date.getDate() - (6 - index));
    return {
      key: date.toISOString().slice(0, 10),
      label: `${date.getMonth() + 1}/${date.getDate()}`,
      fire: 0,
      smoke: 0,
    };
  });
  events.forEach((event) => {
    const classes = event.classes || [];
    const day = days.find((item) => item.key === String(event.created_at).slice(0, 10));
    if (!day) return;
    if (classes.includes("fire")) day.fire += 1;
    if (classes.includes("smoke")) day.smoke += 1;
  });
  const width = 720;
  const height = 225;
  const padding = { left: 34, right: 12, top: 14, bottom: 28 };
  const maxValue = Math.max(3, ...days.flatMap((day) => [day.fire, day.smoke]));
  const x = (index) => padding.left + index * ((width - padding.left - padding.right) / 6);
  const y = (value) => height - padding.bottom - value * ((height - padding.top - padding.bottom) / maxValue);
  const path = (key) => days.map((day, index) => `${index ? "L" : "M"}${x(index)},${y(day[key])}`).join(" ");
  const gridValues = [0, Math.ceil(maxValue / 2), maxValue];
  qs("#trendChart").innerHTML = `<svg viewBox="0 0 ${width} ${height}" preserveAspectRatio="none"><title>最近七天火焰与烟雾告警趋势</title>${gridValues.map((value) => `<line class="chart-grid" x1="${padding.left}" x2="${width - padding.right}" y1="${y(value)}" y2="${y(value)}"></line><text class="chart-axis-label" x="4" y="${y(value) + 3}">${value}</text>`).join("")}<path class="chart-fire" d="${path("fire")}"></path><path class="chart-smoke" d="${path("smoke")}"></path>${days.map((day, index) => `<circle class="chart-point-fire" cx="${x(index)}" cy="${y(day.fire)}" r="3"></circle><circle class="chart-point-smoke" cx="${x(index)}" cy="${y(day.smoke)}" r="3"></circle><text class="chart-axis-label" text-anchor="middle" x="${x(index)}" y="${height - 8}">${day.label}</text>`).join("")}</svg>`;
}