import type {
  SummaryData,
  TypeSummary,
  VehicleListItem,
  DeptGroup,
  RegionGroup,
  CustomerStats,
  RegionalInventoryStats,
} from './types';

const BASE = '/api/vehicles';

async function fetchJson<T>(url: string): Promise<T> {
  const res = await fetch(url);
  if (!res.ok) throw new Error(`API error: ${res.status} ${res.statusText}`);
  return res.json();
}

export async function fetchSummary(): Promise<SummaryData> {
  return fetchJson<SummaryData>(`${BASE}/summary`);
}

export async function fetchByType(): Promise<TypeSummary[]> {
  return fetchJson<TypeSummary[]>(`${BASE}/by-type`);
}

export async function fetchVehicleList(params: {
  batch?: string;
  model?: string;
  location?: string;
  status?: string;
  category?: string;
  vehicleType?: string;
  manager?: string;
  customer?: string;
  isColdChain?: string;
  isTrailer?: string;
  department?: string;
  attendance?: string;
}): Promise<VehicleListItem[]> {
  const query = new URLSearchParams();
  if (params.batch) query.set('batch', params.batch);
  if (params.model) query.set('model', params.model);
  if (params.location) query.set('location', params.location);
  if (params.status) query.set('status', params.status);
  if (params.category) query.set('category', params.category);
  if (params.vehicleType) query.set('vehicleType', params.vehicleType);
  if (params.manager) query.set('manager', params.manager);
  if (params.customer) query.set('customer', params.customer);
  if (params.isColdChain) query.set('isColdChain', params.isColdChain);
  if (params.isTrailer) query.set('isTrailer', params.isTrailer);
  if (params.department) query.set('department', params.department);
  if (params.attendance) query.set('attendance', params.attendance);
  return fetchJson<VehicleListItem[]>(`${BASE}/list?${query.toString()}`);
}

export interface WeeklyDetailItem {
  truck_id: number;
  plate_number: string;
  handover_date: string | null;
  contract_type: string | null;
  customer_name: string | null;
}

export async function fetchDeptStats(): Promise<DeptGroup[]> {
  return fetchJson<DeptGroup[]>(`${BASE}/dept-stats`);
}

export async function fetchRegionStats(params?: { customer?: string; city?: string; region?: string }): Promise<RegionGroup[]> {
  const query = new URLSearchParams();
  if (params?.customer) query.set('customer', params.customer);
  if (params?.city) query.set('city', params.city);
  if (params?.region) query.set('region', params.region);
  const qs = query.toString();
  return fetchJson<RegionGroup[]>(`${BASE}/region-stats${qs ? `?${qs}` : ''}`);
}

export async function fetchCustomerStats(): Promise<CustomerStats[]> {
  return fetchJson<CustomerStats[]>(`${BASE}/customer-stats`);
}

export async function fetchInventoryStats(): Promise<RegionalInventoryStats[]> {
  return fetchJson<RegionalInventoryStats[]>(`${BASE}/inventory-stats`);
}

export async function fetchRegionChart(groupBy: string, top = 8, source = 'realtime'): Promise<{ name: string; value: number }[]> {
  return fetchJson<{ name: string; value: number }[]>(`${BASE}/region-chart?groupBy=${groupBy}&top=${top}&source=${source}`);
}

export async function fetchWeeklyDetail(type: string): Promise<WeeklyDetailItem[]> {
  return fetchJson<WeeklyDetailItem[]>(`${BASE}/weekly-detail?type=${type}`);
}