import type { PaginatedResponse } from '@edr/types';

import { api as apiClient } from '../auth/http';

import { URL_CONSTANTS } from '@/constants/URLS';

export type LocomotiveType = 'DIESEL' | 'ELECTRIC';
export type LocomotiveStatus =
  | 'AVAILABLE'
  | 'UNAVAILABLE'
  | 'IMPORT_READY'
  | 'EXPORT_READY'
  | 'MAINTENANCE'
  | 'ASSIGNED'
  | 'OUT_OF_SERVICE';

export interface LocomotiveListFilters {
  status?: LocomotiveStatus;
  currentYardId?: string;
  /** Drop locos already coupled to a built train (train-builder picker). */
  excludeCoupled?: boolean;
  /** With excludeCoupled: keep THIS train's own coupled locos in the list. */
  excludeTrainId?: string;
  /** Free-text over code + name — only honoured by `getPaged`. */
  search?: string;
  /** Registration day range (YYYY-MM-DD), both ends inclusive. */
  createdFrom?: string;
  createdTo?: string;
  /** Only read by `getPaged`. */
  page?: number;
  pageSize?: number;
}

const locomotiveListQuery = (filters: LocomotiveListFilters): string => {
  const params = new URLSearchParams();
  if (filters.status) params.set('status', filters.status);
  if (filters.currentYardId) params.set('currentYardId', filters.currentYardId);
  if (filters.excludeCoupled) params.set('excludeCoupled', 'true');
  if (filters.excludeTrainId) params.set('excludeTrainId', filters.excludeTrainId);
  if (filters.search?.trim()) params.set('search', filters.search.trim());
  if (filters.createdFrom) params.set('createdFrom', filters.createdFrom);
  if (filters.createdTo) params.set('createdTo', filters.createdTo);
  if (filters.page) params.set('page', String(filters.page));
  if (filters.pageSize) params.set('pageSize', String(filters.pageSize));
  const qs = params.toString();
  return qs ? `?${qs}` : '';
};

export interface Locomotive {
  id: string;
  code: string;
  name?: string | null;
  locomotiveType: LocomotiveType;
  status: LocomotiveStatus;
  currentYardId: string | null;
  currentYard?: { id: string; label?: string; code?: string } | null;
  maxPullWeightTons: number;
  maxTrainLengthMeters: number;
  /** Tons a train may exceed maxPullWeightTons by before scheduling blocks it. */
  overageToleranceTons?: number | null;
  /** Metres a train may exceed maxTrainLengthMeters by before scheduling blocks it. */
  overageToleranceMeters?: number | null;
  createdAt: string;
  updatedAt: string;
}

export type SaveLocomotivePayload = Omit<
  Locomotive,
  'id' | 'createdAt' | 'updatedAt'
>;

export const locomotivesService = {
  getAll: (filters: LocomotiveListFilters = {}) =>
    apiClient.get<Locomotive[]>(
      `${URL_CONSTANTS.LOCOMOTIVES.BASE}${locomotiveListQuery(filters)}`,
    ),
  /** Same filters as `getAll` plus search, server-paginated ({items, meta}). */
  getPaged: (filters: LocomotiveListFilters = {}) =>
    apiClient.get<PaginatedResponse<Locomotive>>(
      `${URL_CONSTANTS.LOCOMOTIVES.BASE}/paged${locomotiveListQuery(filters)}`,
    ),
  getById: (id: string) => apiClient.get<Locomotive>(URL_CONSTANTS.LOCOMOTIVES.BY_ID(id)),
  create: (data: Partial<SaveLocomotivePayload>) =>
    apiClient.post(URL_CONSTANTS.LOCOMOTIVES.BASE, data),
  update: (id: string, data: Partial<SaveLocomotivePayload>) =>
    apiClient.patch(URL_CONSTANTS.LOCOMOTIVES.BY_ID(id), data),
  decommission: (id: string) => apiClient.post(URL_CONSTANTS.LOCOMOTIVES.DECOMMISSION(id), {}),
  /** Irreversible purge — the API refuses it while any train references the loco. */
  purge: (id: string) =>
    apiClient.delete(`${URL_CONSTANTS.LOCOMOTIVES.BY_ID(id)}/permanent`),
};