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';

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: [] },
  total: 0,
  page: 1,
  totalPages: 1,
  updatedAt: new Date().toISOString(),
};

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;
}): CachedVehicle[] {
  let result = vehicles;

  if (params.search) {
    const q = params.search.toLowerCase();
    result = result.filter(v =>
      v.plate.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 === params.customer);
  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.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 sortBy = c.req.query('sortBy') || 'today';
  const sortOrder = c.req.query('sortOrder') || '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 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') || '',
  };

  let allVehicles: CachedVehicle[];
  let filters: MonitoringFilters;
  let rangeDailyTotals: { date: string; totalKm: number }[] | undefined;
  let dateRange: { start: string; end: string } | undefined;

  if (range) {
    try {
      const result = await queryRangeMileage(range.start, range.end);
      allVehicles = result.vehicles;
      rangeDailyTotals = result.dailyTotals;
      dateRange = { start: result.start, end: result.end };
      filters = buildDateFilters(allVehicles);
    } catch (e: unknown) {
      console.error('monitoring range query error:', e);
      return c.json(EMPTY_RESPONSE, 500);
    }
  } else if (date) {
    try {
      allVehicles = await queryDateMileage(date);
      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: filtered.reduce((sum, vehicle) => sum + (vehicle.dailyMileage?.[item.date] || 0), 0),
    }));
  }

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

  const sorted = [...filtered].sort((a, b) => {
    const valA = sortBy === 'today' ? a.dailyKm : (a.totalKm || 0);
    const valB = sortBy === 'today' ? b.dailyKm : (b.totalKm || 0);
    return sortOrder === 'desc' ? valB - valA : valA - valB;
  });

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

  return c.json({
    vehicles: maskCustomerNames(paged),
    stats,
    filters,
    rangeDailyTotals,
    dateRange,
    total,
    page,
    totalPages: Math.ceil(total / limit),
    updatedAt: dateRange?.end || date || getCache()?.updatedAt || new Date().toISOString(),
  });
});

export default app;