import { PLATFORMS } from "./sites.js";

export function analyzeKidsTrend(history) {
  const platformTrends = PLATFORMS.map((platform) => platformTrend(history, platform.id));
  const valued = platformTrends.filter((item) => item.latest_status === "ok");
  const growing = valued.filter((item) => Number.isFinite(item.delta) && item.delta > 0);
  const bestDelta = growing.length ? Math.max(...growing.map((item) => item.delta)) : 0;
  const bestGrowthRate = growing.length ? Math.max(...growing.map((item) => item.growth_rate || 0)) : 0;

  let verdict = "no_data";
  let label = "暂无数值";
  let recommendation = "先不关注";

  if (valued.length > 0 && growing.length === 0) {
    verdict = "new_signal";
    label = "新有数值";
    recommendation = "再采一次";
  }
  if (growing.length > 0) {
    verdict = "rising";
    label = "在增长";
    recommendation = "继续观察";
  }
  if (growing.length >= 2 || bestGrowthRate >= 0.3 || bestDelta >= 300) {
    verdict = "strong_growth";
    label = "强增长";
    recommendation = "重点跟踪";
  }
  if (valued.length >= 2 && verdict === "new_signal") {
    verdict = "multi_platform";
    label = "多平台有数";
    recommendation = "值得观察";
  }

  return {
    name: history?.name || "",
    verdict,
    label,
    recommendation,
    platforms_with_value: valued.length,
    growing_platforms: growing.length,
    best_delta: bestDelta,
    best_growth_rate: bestGrowthRate,
    platform_trends: Object.fromEntries(platformTrends.map((item) => [item.platform, item])),
  };
}

function platformTrend(history, platformId) {
  const row = history?.platforms?.[platformId] || {};
  const runs = [...(history?.runs || [])].sort().reverse();
  const values = [];

  for (const run of runs) {
    const value = row.values?.[run];
    if (value?.status !== "ok") continue;
    const number = Number(value.number);
    if (!Number.isFinite(number)) continue;
    values.push({
      run,
      raw: value.raw || String(value.number || ""),
      number,
    });
    if (values.length >= 2) break;
  }

  const latest = values[0] || null;
  const previous = values[1] || null;
  const delta = latest && previous ? latest.number - previous.number : null;
  const growthRate = Number.isFinite(delta) && previous?.number
    ? delta / previous.number
    : null;

  return {
    platform: platformId,
    latest_status: latest ? "ok" : "missing",
    latest_raw: latest?.raw || "",
    latest_number: latest?.number || "",
    latest_run: latest?.run || "",
    previous_raw: previous?.raw || "",
    previous_number: previous?.number || "",
    previous_run: previous?.run || "",
    delta,
    growth_rate: growthRate,
  };
}