import { Body, Controller, Delete, Get, Param, Patch, Post, Put, Query, ParseIntPipe } from '@nestjs/common';
import { ApiTags, ApiOperation, ApiBearerAuth, ApiParam, ApiQuery, ApiResponse } from '@nestjs/swagger';
import { RoutesService } from './routes.service';
import { CreateRouteDto, AddRouteStopDto, UpdateRouteDto, SetRouteCoachTemplateDto } from './routes.dto';
import { PassengerAdmin, PassengerStaff } from '../../common/passenger-guards';
import { PASSENGER_PERMS } from '../../seed/passenger-permissions.registry';

@ApiTags('Routes')
@Controller('routes')
export class RoutesController {
  constructor(private service: RoutesService) {}

  // ── Routes ─────────────────────────────────────────────────────────────────

  @Post()
  @PassengerStaff([PASSENGER_PERMS.routes.manage, PASSENGER_PERMS.admin]) @ApiBearerAuth('IAM-auth')
  @ApiOperation({
    summary: 'Create a reusable route with its ordered stops',
    description: `Define the physical corridor once (e.g. ADD→ADM→AWS→DDW→AYS→DJI).
Schedules reference this route via routeId and supply actual planned times per stop.
Route stops carry distanceKm for fare-by-distance calculations.`,
  })
  @ApiResponse({ status: 201, description: 'Route created with stops' })
  @ApiResponse({ status: 409, description: 'Route code already exists or duplicate sequences' })
  @ApiResponse({ status: 400, description: 'Fewer than 2 stops or invalid station IDs' })
  createRoute(@Body() dto: CreateRouteDto) { return this.service.createRoute(dto); }

  @Get()
  @ApiOperation({ summary: 'List all routes' })
  @ApiQuery({ name: 'activeOnly', required: false, type: Boolean, description: 'Filter to active routes only' })
  @ApiResponse({ status: 200, description: 'Array of routes with stop count' })
  listRoutes(@Query('activeOnly') activeOnly?: string) {
    return this.service.listRoutes(activeOnly === 'true');
  }

  @Get(':id')
  @ApiOperation({ summary: 'Get route with all stops and station details' })
  @ApiParam({ name: 'id', description: 'Route UUID' })
  @ApiResponse({ status: 200, description: 'Route with enriched stop list (station name, code, city)' })
  @ApiResponse({ status: 404, description: 'Route not found' })
  getRoute(@Param('id') id: string) { return this.service.getRoute(id); }

  @Patch(':id')
  @PassengerStaff([PASSENGER_PERMS.routes.manage, PASSENGER_PERMS.admin]) @ApiBearerAuth('IAM-auth')
  @ApiOperation({ summary: 'Update route metadata (name, description, active flag, effectiveFrom, effectiveUntil)' })
  @ApiParam({ name: 'id', description: 'Route UUID' })
  @ApiResponse({ status: 200, description: 'Route updated' })
  @ApiResponse({ status: 404, description: 'Route not found' })
  updateRoute(@Param('id') id: string, @Body() dto: UpdateRouteDto) { return this.service.updateRoute(id, dto); }

  @Delete(':id')
  @PassengerAdmin()
  @ApiBearerAuth('IAM-auth')
  @ApiOperation({ summary: 'Delete a route' })
  @ApiParam({ name: 'id', description: 'Route UUID' })
  @ApiQuery({ name: 'cascade', required: false, type: Boolean, description: 'Force delete with all related data' })
  @ApiResponse({ status: 200, description: 'Route deleted' })
  @ApiResponse({ status: 404, description: 'Route not found' })
  deleteRoute(@Param('id') id: string, @Query('cascade') cascade?: string) { return this.service.deleteRoute(id, cascade === 'true'); }

  // ── Route Stops ────────────────────────────────────────────────────────────

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

  @Post(':id/stops')
  @PassengerStaff([PASSENGER_PERMS.routes.manage, PASSENGER_PERMS.admin]) @ApiBearerAuth('IAM-auth')
  @ApiOperation({ summary: 'Add a stop to an existing route' })
  @ApiParam({ name: 'id', description: 'Route UUID' })
  @ApiResponse({ status: 201, description: 'Stop added' })
  @ApiResponse({ status: 409, description: 'Sequence already exists on this route' })
  @ApiResponse({ status: 404, description: 'Route or station not found' })
  addStop(@Param('id') id: string, @Body() dto: AddRouteStopDto) { return this.service.addStop(id, dto); }

  @Delete(':id/stops/:sequence')
  @PassengerAdmin()
  @ApiBearerAuth('IAM-auth')
  @ApiOperation({ summary: 'Remove a stop from a route by sequence number' })
  @ApiParam({ name: 'id', description: 'Route UUID' })
  @ApiParam({ name: 'sequence', description: 'Stop sequence number to remove' })
  @ApiResponse({ status: 200, description: 'Stop removed' })
  @ApiResponse({ status: 400, description: 'Cannot remove — route would have fewer than 2 stops' })
  @ApiResponse({ status: 404, description: 'Stop not found' })
  removeStop(@Param('id') id: string, @Param('sequence', ParseIntPipe) sequence: number) {
    return this.service.removeStop(id, sequence);
  }

  // ── Schedules for a Route ──────────────────────────────────────────────────

  @Get(':id/schedules')
  @ApiOperation({ summary: 'List all train schedules that use this route' })
  @ApiParam({ name: 'id', description: 'Route UUID' })
  @ApiResponse({ status: 200, description: 'Schedules with train and terminal station details' })
  @ApiResponse({ status: 404, description: 'Route not found' })
  getSchedules(@Param('id') id: string) { return this.service.getSchedulesForRoute(id); }

  // ── Route Coach Template ───────────────────────────────────────────────────

  @Get(':id/coaches')
  @ApiOperation({ summary: 'Get the default coach lineup for this route' })
  @ApiParam({ name: 'id', description: 'Route UUID' })
  @ApiResponse({ status: 200, description: 'Ordered coach template with coach and coach type details' })
  @ApiResponse({ status: 404, description: 'Route not found' })
  getCoachTemplate(@Param('id') id: string) { return this.service.getRouteCoachTemplate(id); }

  @Put(':id/coaches')
  @PassengerStaff([PASSENGER_PERMS.routes.manage, PASSENGER_PERMS.admin]) @ApiBearerAuth('IAM-auth')
  @ApiOperation({
    summary: 'Set the default coach lineup for this route',
    description: 'Replaces the entire coach template. Coaches are auto-assigned in this order when a new schedule is created for this route.',
  })
  @ApiParam({ name: 'id', description: 'Route UUID' })
  @ApiResponse({ status: 200, description: 'Updated coach template' })
  @ApiResponse({ status: 400, description: 'Duplicate positions or inactive coach' })
  @ApiResponse({ status: 404, description: 'Route or coach not found' })
  setCoachTemplate(@Param('id') id: string, @Body() dto: SetRouteCoachTemplateDto) {
    return this.service.setRouteCoachTemplate(id, dto);
  }

  @Delete(':id/coaches')
  @PassengerAdmin()
  @ApiBearerAuth('IAM-auth')
  @ApiOperation({ summary: 'Clear the default coach lineup for this route' })
  @ApiParam({ name: 'id', description: 'Route UUID' })
  @ApiResponse({ status: 200, description: 'Template cleared' })
  @ApiResponse({ status: 404, description: 'Route not found' })
  clearCoachTemplate(@Param('id') id: string) { return this.service.removeRouteCoachTemplate(id); }
}