import { Body, Controller, Get, Param, Patch, Post, Query, ParseIntPipe, UseGuards } from '@nestjs/common';
import { ApiTags, ApiOperation, ApiBearerAuth, ApiParam, ApiQuery, ApiResponse } from '@nestjs/swagger';
import { SchedulesService } from './schedules.service';
import { CreateScheduleDto, CreateFareRuleDto, UpdateScheduleStatusDto, UpdateStopTimeDto, ListSchedulesDto } from './schedules.dto';
import { JwtGuard } from '../../common/jwt.guard';
import { TripStatus } from '@prisma/client';

@ApiTags('Schedule')
@Controller('schedules')
export class SchedulesController {
  constructor(private service: SchedulesService) {}

  @Post()
  @UseGuards(JwtGuard) @ApiBearerAuth('JWT-auth')
  @ApiOperation({
    summary: 'Create a train schedule from a route template',
    description: `Creates a schedule by referencing a Route (routeId).
Stops are automatically copied from the route's RouteStop definitions.
You supply the actual planned arrival/departure times per stop sequence.
Origin and destination are derived from the first and last route stop — no need to specify them manually.`,
  })
  @ApiResponse({ status: 201, description: 'Schedule created with stops copied from route template' })
  @ApiResponse({ status: 400, description: 'Invalid times, inactive route, or missing planned times for some stops' })
  @ApiResponse({ status: 404, description: 'Train or route not found' })
  createSchedule(@Body() dto: CreateScheduleDto) { return this.service.createSchedule(dto); }

  @Get()
  @ApiOperation({ summary: 'List schedules with optional filters' })
  @ApiQuery({ name: 'date', required: false, example: '2026-06-15', description: 'Departure date (YYYY-MM-DD). Returns all schedules departing on this calendar day.' })
  @ApiQuery({ name: 'routeId', required: false, description: 'Filter by route UUID' })
  @ApiQuery({ name: 'trainId', required: false, description: 'Filter by train UUID' })
  @ApiQuery({ name: 'status', required: false, enum: TripStatus, description: 'Filter by schedule status' })
  @ApiResponse({ status: 200, description: 'Array of schedules ordered by departureAt, each with train, origin/destination, stops, and booking/assignment counts' })
  listSchedules(
    @Query('date') date?: string,
    @Query('routeId') routeId?: string,
    @Query('trainId') trainId?: string,
    @Query('status') status?: TripStatus,
  ) {
    return this.service.listSchedules({ date, routeId, trainId, status });
  }

  // Static routes before parameterised ones
  @Post('fares')
  @UseGuards(JwtGuard) @ApiBearerAuth('JWT-auth')
  @ApiOperation({ summary: 'Create a fare rule scoped to a schedule or route code' })
  @ApiResponse({ status: 201, description: 'Fare rule created' })
  createFareRule(@Body() dto: CreateFareRuleDto) { return this.service.createFareRule(dto); }

  @Get(':id')
  @ApiOperation({ summary: 'Get schedule with train, coaches, seats, and stop timeline' })
  @ApiParam({ name: 'id', description: 'TrainSchedule UUID' })
  @ApiResponse({ status: 200, description: 'Full schedule detail including route stops with station info' })
  @ApiResponse({ status: 404, description: 'Schedule not found' })
  getSchedule(@Param('id') id: string) { return this.service.getSchedule(id); }

  @Patch(':id/status')
  @UseGuards(JwtGuard) @ApiBearerAuth('JWT-auth')
  @ApiOperation({ summary: 'Update schedule status (SCHEDULED → BOARDING → EN_ROUTE → ARRIVED)' })
  @ApiParam({ name: 'id', description: 'TrainSchedule UUID' })
  @ApiResponse({ status: 200, description: 'Status updated' })
  @ApiResponse({ status: 404, description: 'Schedule not found' })
  updateStatus(@Param('id') id: string, @Body() dto: UpdateScheduleStatusDto) {
    return this.service.updateScheduleStatus(id, dto);
  }

  // ── Stop Times ─────────────────────────────────────────────────────────────

  @Get(':id/stops')
  @ApiOperation({ summary: 'List all stops for a schedule ordered by sequence' })
  @ApiParam({ name: 'id', description: 'TrainSchedule UUID' })
  @ApiResponse({ status: 200, description: 'Ordered stop list with station details and planned/actual times' })
  @ApiResponse({ status: 404, description: 'Schedule not found' })
  getStops(@Param('id') id: string) { return this.service.getStops(id); }

  @Patch(':id/stops/:sequence')
  @UseGuards(JwtGuard) @ApiBearerAuth('JWT-auth')
  @ApiOperation({ summary: 'Update planned times or live status of a specific stop' })
  @ApiParam({ name: 'id', description: 'TrainSchedule UUID' })
  @ApiParam({ name: 'sequence', description: 'Stop sequence number' })
  @ApiResponse({ status: 200, description: 'Stop updated' })
  @ApiResponse({ status: 404, description: 'Stop not found on schedule' })
  updateStop(
    @Param('id') id: string,
    @Param('sequence', ParseIntPipe) sequence: number,
    @Body() dto: UpdateStopTimeDto,
  ) { return this.service.updateStop(id, sequence, dto); }

  // ── Fares ──────────────────────────────────────────────────────────────────

  @Get(':scheduleId/fares')
  @ApiOperation({ summary: 'Get fare for a schedule and seat class from the fare engine' })
  @ApiParam({ name: 'scheduleId', description: 'TrainSchedule UUID' })
  @ApiQuery({ name: 'seatClassId', required: true, description: 'SeatClass UUID' })
  @ApiQuery({ name: 'nationality', required: false, description: 'Passenger nationality — determines billing currency (Ethiopian→ETB, Djiboutian→DJF, other→USD)' })
  @ApiResponse({ status: 200, description: 'Live fare breakdown from fare engine' })
  @ApiResponse({ status: 400, description: 'Schedule has no route or missing distanceKm on stops' })
  @ApiResponse({ status: 404, description: 'Schedule or seat class not found' })
  getFare(
    @Param('scheduleId') scheduleId: string,
    @Query('seatClassId') seatClassId: string,
    @Query('nationality') nationality?: string,
  ) {
    return this.service.getFareFromEngine(scheduleId, seatClassId, nationality);
  }

  @Get(':scheduleId/fares/all')
  @ApiOperation({ summary: 'Get fares for all active seat classes on a schedule' })
  @ApiParam({ name: 'scheduleId', description: 'TrainSchedule UUID' })
  @ApiQuery({ name: 'nationality', required: false, description: 'Passenger nationality — determines billing currency' })
  @ApiResponse({ status: 200, description: 'Array of fare breakdowns for every active seat class, ordered by price ascending' })
  @ApiResponse({ status: 400, description: 'Schedule has no route or missing distanceKm on stops' })
  @ApiResponse({ status: 404, description: 'Schedule not found' })
  getAllFares(
    @Param('scheduleId') scheduleId: string,
    @Query('nationality') nationality?: string,
  ) {
    return this.service.getAllFaresFromEngine(scheduleId, nationality);
  }

  @Post(':id/fares/sync')
  @ApiOperation({
    summary: 'Sync fares from fare engine',
    description: 'Recalculates fares for all active seat classes using the fare engine (km × ratePerKm + tax) and upserts them as FareRule records scoped to this schedule. Previous active rules are expired.',
  })
  @ApiParam({ name: 'id', description: 'TrainSchedule UUID' })
  @ApiResponse({ status: 201, description: 'Fares synced — returns count of synced rules and any errors' })
  @ApiResponse({ status: 400, description: 'Schedule has no associated route or missing distanceKm on stops' })
  @ApiResponse({ status: 404, description: 'Schedule not found' })
  syncFares(@Param('id') id: string) {
    return this.service.syncFaresFromEngine(id);
  }
}