import { Hono } from 'hono';
import { getCache, queryDateMileage, queryRangeMileage, buildDateFilters } from './cache.js';
import { filterByPermission, maskCustomerNames } from '../../auth/permissions.js';
import type { AuthUser } from '../../auth/types.js';
import type { CachedVehicle, MonitoringFilters, MonitoringResponse } from './types.js';
import {
  DEFAULT_MILEAGE_SOURCE_PRIORITY,
  parseMileageSourcePriority,
  protocolsForSourcePriority,
} from './source-policy.js';
import {
  isMonitoringCacheEligible,
  isMonitoringSnapshotScope,
  shanghaiDate,
} from './monitoring-cache-policy.js';
import {
  getManualMonitoringSnapshot,
  storeManualMonitoringSnapshot,
} from './manual-snapshot.js';
import { sumMileageKm } from './precision.js';

const app = new Hono();

const EMPTY_RESPONSE: MonitoringResponse = {
  vehicles: [],
  stats: { totalToday: 0, totalAll: 0, vehicleCount: 0, yesterdayTotal: 0 },
  filters: { departments: [], customers: [], plates: [], projects: [], entities: [], rentStatuses: [], platePrefixes: [], targetNames: [], regions: [], brands: [] },
  total: 0,
  page: 1,
  totalPages: 1,
  updatedAt: new Date().toISOString(),
  sourcePriority: [...DEFAULT_MILEAGE_SOURCE_PRIORITY],
};

function applyFilters(vehicles: CachedVehicle[], params: {
  search: string; dept: string; customer: string; project: string;
  entity: string; rentStatus: string; plate: string; platePrefix: string;
  targetNames: string[]; region: string; mileageMin: string; mileageMax: string;
  brands: string[];
}): CachedVehicle[] {
  let result = vehicles;

  if (params.search) {
    const q = params.search.toLowerCase();
    result = result.filter(v =>
      v.plate.toLowerCase().includes(q) ||
      v.vin.toLowerCase().includes(q) ||
      (v.customer || '').toLowerCase().includes(q) ||
      (v.project || '').toLowerCase().includes(q)
    );
  }
  if (params.dept) result = result.filter(v => params.dept === '__EMPTY__' ? !v.department : v.department === params.dept);
  if (params.customer) result = result.filter(v => params.customer === '__EMPTY__' ? !v.customer : (v.customer || '').toLowerCase().includes(params.customer.toLowerCase()));
  if (params.project) result = result.filter(v => v.project === params.project);
  if (params.entity) result = result.filter(v => v.entity === params.entity);
  if (params.rentStatus) result = result.filter(v => v.rentStatus === params.rentStatus);
  if (params.plate) {
    const wanted = new Set(params.plate.split(',').map(s => s.trim()).filter(Boolean));
    if (wanted.size > 0) result = result.filter(v => wanted.has(v.plate));
  }
  if (params.platePrefix) result = result.filter(v => v.plate.startsWith(params.platePrefix));
  if (params.region) result = result.filter(v => v.region === params.region);
  if (params.targetNames.length > 0) {
    const selectedTargets = new Set(params.targetNames);
    result = result.filter(v => v.targetNames.some(targetName => selectedTargets.has(targetName)));
  }
  if (params.brands.length > 0) {
    const selectedBrands = new Set(params.brands);
    result = result.filter(v => v.brand != null && selectedBrands.has(v.brand));
  }
  if (params.mileageMin) result = result.filter(v => v.dailyKm >= Number(params.mileageMin));
  if (params.mileageMax) result = result.filter(v => v.dailyKm <= Number(params.mileageMax));

  return result;
}

function parseTargetNames(reqUrl: string): string[] {
  const params = new URL(reqUrl).searchParams;
  const raw = [
    ...params.getAll('targetName'),
    ...params.getAll('targetNames'),
  ];
  const names = raw.flatMap(item => item.split(','))
    .map(item => item.trim())
    .filter(Boolean);
  return Array.from(new Set(names));
}

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

function fmtYmd(date: Date): string {
  return `${date.getFullYear()}-${String(date.getMonth() + 1).padStart(2, '0')}-${String(date.getDate()).padStart(2, '0')}`;
}

function normalizeRange(startQuery: string, endQuery: string): { start: string; end: string } | null {
  if (!startQuery && !endQuery) return null;
  const start = parseYmd(startQuery || endQuery);
  const end = parseYmd(endQuery || startQuery);
  if (!start || !end) return null;
  const a = start <= end ? start : end;
  let b = start <= end ? end : start;
  const span = Math.round((b.getTime() - a.getTime()) / 86400000) + 1;
  if (span > 366) {
    b = new Date(a);
    b.setDate(a.getDate() + 365);
  }
  return { start: fmtYmd(a), end: fmtYmd(b) };
}

app.get('/', async (c) => {
  const requestedSortBy = c.req.query('sortBy');
  const sortBy = requestedSortBy === 'total' || requestedSortBy === 'statisticTime'
    ? requestedSortBy
    : 'today';
  const sortOrder = c.req.query('sortOrder') === 'asc' ? 'asc' : 'desc';
  const limit = Number(c.req.query('limit')) || 50;
  const page = Number(c.req.query('page')) || 1;
  const date = c.req.query('date') || '';
  const range = normalizeRange(c.req.query('startDate') || '', c.req.query('endDate') || '');
  const sourcePriority = parseMileageSourcePriority(c.req.query('sourcePriority'));
  const protocolPriority = protocolsForSourcePriority(sourcePriority);
  const force = c.req.query('force') === '1';

  const filterParams = {
    search: c.req.query('search') || '',
    dept: c.req.query('dept') || '',
    customer: c.req.query('customer') || '',
    project: c.req.query('project') || '',
    entity: c.req.query('entity') || '',
    rentStatus: c.req.query('rentStatus') || '',
    plate: c.req.query('plate') || '',
    platePrefix: c.req.query('platePrefix') || '',
    targetNames: parseTargetNames(c.req.url),
    region: c.req.query('region') || '',
    mileageMin: c.req.query('mileageMin') || '',
    mileageMax: c.req.query('mileageMax') || '',
    brands: c.req.queries('brand') || [],
  };

  let allVehicles: CachedVehicle[];
  let filters: MonitoringFilters;
  let rangeDailyTotals: { date: string; totalKm: number }[] | undefined;
  let dateRange: { start: string; end: string } | undefined;
  let dataUpdatedAt: string | undefined;
  let cacheStatus: 'hit' | 'manual-hit' | 'refresh' | 'miss' | 'bypass' = 'bypass';

  if (range) {
    const cache = getCache();
    const today = shanghaiDate();
    const snapshotScope = isMonitoringSnapshotScope({
      startDate: range.start,
      endDate: range.end,
      today,
      sourcePriority,
    });
    const cacheEligible = isMonitoringCacheEligible({
      startDate: range.start,
      endDate: range.end,
      today,
      sourcePriority,
      force,
    });
    const manualSnapshot = cacheEligible
      ? getManualMonitoringSnapshot(range.start, range.end)
      : null;
    if (manualSnapshot) {
      cacheStatus = 'manual-hit';
      allVehicles = manualSnapshot.result.vehicles;
      rangeDailyTotals = manualSnapshot.result.dailyTotals;
      dateRange = { start: manualSnapshot.result.start, end: manualSnapshot.result.end };
      dataUpdatedAt = manualSnapshot.updatedAt;
      filters = buildDateFilters(allVehicles);
    } else if (cacheEligible && cache) {
      cacheStatus = 'hit';
      allVehicles = cache.vehicles.map(vehicle => ({
        ...vehicle,
        dailyMileage: { [range.start]: vehicle.dailyKm },
        dailySourceProtocols: { [range.start]: vehicle.sourceProtocol },
      }));
      rangeDailyTotals = [{
        date: range.start,
        totalKm: Math.round(allVehicles.reduce((sum, vehicle) => sum + vehicle.dailyKm, 0)),
      }];
      dateRange = { ...range };
      dataUpdatedAt = cache.updatedAt;
      filters = cache.filters;
    } else {
      cacheStatus = cacheEligible ? 'miss' : 'bypass';
      try {
        const result = await queryRangeMileage(range.start, range.end, protocolPriority);
        allVehicles = result.vehicles;
        rangeDailyTotals = result.dailyTotals;
        dateRange = { start: result.start, end: result.end };
        filters = buildDateFilters(allVehicles);
        if (force && snapshotScope) {
          const stored = storeManualMonitoringSnapshot(result);
          cacheStatus = 'refresh';
          dataUpdatedAt = stored.updatedAt;
        }
      } catch (e: unknown) {
        console.error('monitoring range query error:', e);
        return c.json(EMPTY_RESPONSE, 500);
      }
    }
  } else if (date) {
    try {
      allVehicles = await queryDateMileage(date, protocolPriority);
      filters = buildDateFilters(allVehicles);
    } catch (e: unknown) {
      console.error('monitoring date query error:', e);
      return c.json(EMPTY_RESPONSE, 500);
    }
  } else {
    const cache = getCache();
    if (!cache) return c.json(EMPTY_RESPONSE);
    allVehicles = cache.vehicles;
    filters = cache.filters;
  }

  // 权限过滤
  const user = (c as any).get('user') as AuthUser | undefined;
  if (user) {
    allVehicles = filterByPermission(allVehicles, user);
    filters = buildDateFilters(allVehicles); // 重算筛选选项以匹配权限范围
  }

  // 区域级联：选中运营区域时，下游筛选选项（车牌等）只展示该区域车辆
  if (filterParams.region) {
    const regionScope = allVehicles.filter(v => v.region === filterParams.region);
    filters = buildDateFilters(regionScope);
  }

  const filtered = applyFilters(allVehicles, filterParams);
  if (rangeDailyTotals && filtered.length !== allVehicles.length) {
    rangeDailyTotals = rangeDailyTotals.map(item => ({
      ...item,
      totalKm: Math.round(filtered.reduce((sum, vehicle) => sum + (vehicle.dailyMileage?.[item.date] || 0), 0)),
    }));
  }

  const stats = {
    totalToday: Math.round(filtered.reduce((sum, v) => sum + v.dailyKm, 0)),
    totalAll: sumMileageKm(filtered.map(v => v.totalKm || 0)),
    vehicleCount: filtered.length,
    yesterdayTotal: sumMileageKm(filtered.map(v => v.yesterdayKm)),
  };

  const sorted = [...filtered].sort((a, b) => {
    if (sortBy === 'statisticTime') {
      const rawTimeA = a.dataTime || a.updatedAt || a.calculatedAt;
      const rawTimeB = b.dataTime || b.updatedAt || b.calculatedAt;
      const parsedTimeA = rawTimeA ? Date.parse(rawTimeA) : Number.NaN;
      const parsedTimeB = rawTimeB ? Date.parse(rawTimeB) : Number.NaN;
      const timeA = Number.isFinite(parsedTimeA) ? parsedTimeA : null;
      const timeB = Number.isFinite(parsedTimeB) ? parsedTimeB : null;

      // Missing/invalid statistic times always stay at the end for both directions.
      if (timeA == null && timeB == null) return a.plate.localeCompare(b.plate, 'zh-CN');
      if (timeA == null) return 1;
      if (timeB == null) return -1;
      const timeDiff = sortOrder === 'desc' ? timeB - timeA : timeA - timeB;
      return timeDiff || a.plate.localeCompare(b.plate, 'zh-CN');
    }

    const valA = sortBy === 'today' ? a.dailyKm : (a.totalKm || 0);
    const valB = sortBy === 'today' ? b.dailyKm : (b.totalKm || 0);
    const mileageDiff = sortOrder === 'desc' ? valB - valA : valA - valB;
    return mileageDiff || a.plate.localeCompare(b.plate, 'zh-CN');
  });

  const offset = (page - 1) * limit;
  const paged = sorted.slice(offset, offset + limit);
  const total = filtered.length;

  c.header('X-Mileage-Cache', cacheStatus);
  return c.json({
    vehicles: maskCustomerNames(paged),
    stats,
    filters,
    rangeDailyTotals,
    dateRange,
    total,
    page,
    totalPages: Math.ceil(total / limit),
    updatedAt: dataUpdatedAt || dateRange?.end || date || getCache()?.updatedAt || new Date().toISOString(),
    sourcePriority,
  });
});

export default app;