import { Hono } from 'hono';
import mileagePool from '../../mileage-db.js';

const app = new Hono();

interface DayRow {
  date: string;
  daily_km: string | number | null;
  source: string | null;
}

function fmt(d: Date): string {
  const y = d.getFullYear();
  const m = String(d.getMonth() + 1).padStart(2, '0');
  const dd = String(d.getDate()).padStart(2, '0');
  return `${y}-${m}-${dd}`;
}

function parseYmd(s: string): Date | null {
  const m = /^(\d{4})-(\d{2})-(\d{2})$/.exec(s);
  if (!m) return null;
  const d = new Date(Number(m[1]), Number(m[2]) - 1, Number(m[3]));
  d.setHours(0, 0, 0, 0);
  return Number.isFinite(d.getTime()) ? d : null;
}

const MAX_DAYS = 366;

app.get('/:plate/recent', async (c) => {
  const plate = c.req.param('plate');
  if (!plate) return c.json({ plate: '', days: [] }, 400);

  const today = new Date();
  today.setHours(0, 0, 0, 0);

  // 区间参数：优先 start/end；否则回退 days（兼容旧调用）
  const startQ = c.req.query('start');
  const endQ = c.req.query('end');
  let start: Date;
  let end: Date;
  if (startQ) {
    const ps = parseYmd(startQ);
    if (!ps) return c.json({ plate, days: [] }, 400);
    start = ps;
    end = endQ ? (parseYmd(endQ) ?? today) : today;
  } else {
    const days = Math.min(Math.max(Number(c.req.query('days')) || 15, 1), MAX_DAYS);
    end = today;
    start = new Date(today);
    start.setDate(today.getDate() - (days - 1));
  }
  if (start > end) [start, end] = [end, start];
  // 限制区间长度
  const span = Math.round((end.getTime() - start.getTime()) / 86400000) + 1;
  if (span > MAX_DAYS) {
    start = new Date(end);
    start.setDate(end.getDate() - (MAX_DAYS - 1));
  }

  try {
    const [rows] = await mileagePool.execute(
      `SELECT DATE_FORMAT(stat_date, '%Y-%m-%d') AS date, daily_km, source
       FROM v_vehicle_daily_stats
       WHERE plate = ? AND stat_date >= ? AND stat_date <= ?
       ORDER BY stat_date`,
      [plate, fmt(start), fmt(end)]
    ) as [DayRow[], unknown];

    // 同一 plate 同一天可能有多个数据源，取最大 daily_km
    const map = new Map<string, { dailyKm: number; source: string }>();
    for (const r of rows) {
      const km = Number(r.daily_km) || 0;
      const src = r.source || 'NONE';
      const existing = map.get(r.date);
      if (!existing || km > existing.dailyKm) {
        map.set(r.date, { dailyKm: km, source: src });
      }
    }

    // 补全：从 start 到 end 每天一条
    const result: { date: string; dailyKm: number; isDataSynced: boolean }[] = [];
    const cursor = new Date(start);
    while (cursor <= end) {
      const key = fmt(cursor);
      const hit = map.get(key);
      result.push({
        date: key,
        dailyKm: hit?.dailyKm ?? 0,
        isDataSynced: !!hit && hit.source !== 'NONE',
      });
      cursor.setDate(cursor.getDate() + 1);
    }

    return c.json({ plate, start: fmt(start), end: fmt(end), days: result });
  } catch (e: unknown) {
    console.error('vehicle recent error:', e);
    return c.json({ plate, days: [] }, 500);
  }
});

export default app;