import { Hono } from 'hono';
import { fetchOneOsMileageDates } from './oneos-api.js';
import {
  parseMileageSourcePriority,
  protocolsForSourcePriority,
  sourceCategoryFromProtocol,
} from './source-policy.js';

const app = new Hono();

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 sourcePriority = parseMileageSourcePriority(c.req.query('sourcePriority'));
  const protocolPriority = protocolsForSourcePriority(sourcePriority);

  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 dates: string[] = [];
    const dateCursor = new Date(start);
    while (dateCursor <= end) {
      dates.push(fmt(dateCursor));
      dateCursor.setDate(dateCursor.getDate() + 1);
    }
    const rowsByDate = await fetchOneOsMileageDates(dates, [plate], protocolPriority);

    // 补全：从 start 到 end 每天一条
    const result: {
      date: string;
      dailyKm: number;
      isDataSynced: boolean;
      sourceProtocol: 'GB32960' | 'MQTT' | 'JT808' | null;
      sourceCategory: 'INSTRUMENT' | 'GPS' | null;
    }[] = [];
    const cursor = new Date(start);
    while (cursor <= end) {
      const key = fmt(cursor);
      const hit = (rowsByDate.get(key) || []).find(row => row.plateNumber === plate);
      result.push({
        date: key,
        dailyKm: hit?.status === 'NORMAL' ? (hit.dailyMileageKm || 0) : 0,
        isDataSynced: hit?.status === 'NORMAL',
        sourceProtocol: hit?.sourceProtocol || null,
        sourceCategory: sourceCategoryFromProtocol(hit?.sourceProtocol || null),
      });
      cursor.setDate(cursor.getDate() + 1);
    }

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

export default app;