/**
 * @ai-summary Business logic for vehicles feature
 * @ai-context Handles VIN decoding, caching, and business rules
 */

import { VehiclesRepository } from '../data/vehicles.repository';
import {
  Vehicle,
  CreateVehicleRequest,
  UpdateVehicleRequest,
  VehicleResponse
} from './vehicles.types';
import { logger } from '../../../core/logging/logger';
import { cacheService } from '../../../core/config/redis';
import { isValidVIN } from '../../../shared-minimal/utils/validators';
import { normalizeMakeName, normalizeModelName } from './name-normalizer';
import { getVehicleDataService, getPool } from '../../platform';

export class VehiclesService {
  private readonly cachePrefix = 'vehicles';
  private readonly listCacheTTL = 300; // 5 minutes

  constructor(private repository: VehiclesRepository) {
    // VIN decode service is now provided by platform feature
  }
  
  async createVehicle(data: CreateVehicleRequest, userId: string): Promise<VehicleResponse> {
    logger.info('Creating vehicle', { userId, vin: data.vin, licensePlate: (data as any).licensePlate });

    if (data.vin) {
      // Validate VIN if provided
      if (!isValidVIN(data.vin)) {
        throw new Error('Invalid VIN format');
      }
      // Duplicate check only when VIN is present
      const existing = await this.repository.findByUserAndVIN(userId, data.vin);
      if (existing) {
        throw new Error('Vehicle with this VIN already exists');
      }
    }

    // Create vehicle with user-provided data
    const vehicle = await this.repository.create({
      ...data,
      userId,
      make: data.make ? normalizeMakeName(data.make) : undefined,
      model: data.model ? normalizeModelName(data.model) : undefined,
    });

    // Invalidate user's vehicle list cache
    await this.invalidateUserCache(userId);

    return this.toResponse(vehicle);
  }
  
  async getUserVehicles(userId: string): Promise<VehicleResponse[]> {
    const cacheKey = `${this.cachePrefix}:user:${userId}`;
    
    // Check cache
    const cached = await cacheService.get<VehicleResponse[]>(cacheKey);
    if (cached) {
      logger.debug('Vehicle list cache hit', { userId });
      return cached;
    }
    
    // Get from database
    const vehicles = await this.repository.findByUserId(userId);
    const response = vehicles.map((v: Vehicle) => this.toResponse(v));
    
    // Cache result
    await cacheService.set(cacheKey, response, this.listCacheTTL);
    
    return response;
  }
  
  async getVehicle(id: string, userId: string): Promise<VehicleResponse> {
    const vehicle = await this.repository.findById(id);
    
    if (!vehicle) {
      throw new Error('Vehicle not found');
    }
    
    if (vehicle.userId !== userId) {
      throw new Error('Unauthorized');
    }
    
    return this.toResponse(vehicle);
  }
  
  async updateVehicle(
    id: string, 
    data: UpdateVehicleRequest, 
    userId: string
  ): Promise<VehicleResponse> {
    // Verify ownership
    const existing = await this.repository.findById(id);
    if (!existing) {
      throw new Error('Vehicle not found');
    }
    if (existing.userId !== userId) {
      throw new Error('Unauthorized');
    }
    
    // Normalize any provided name fields
    const normalized: UpdateVehicleRequest = { ...data } as any;
    if (data.make !== undefined) {
      (normalized as any).make = normalizeMakeName(data.make);
    }
    if (data.model !== undefined) {
      (normalized as any).model = normalizeModelName(data.model);
    }

    // Update vehicle
    const updated = await this.repository.update(id, normalized);
    if (!updated) {
      throw new Error('Update failed');
    }
    
    // Invalidate cache
    await this.invalidateUserCache(userId);
    
    return this.toResponse(updated);
  }
  
  async deleteVehicle(id: string, userId: string): Promise<void> {
    // Verify ownership
    const existing = await this.repository.findById(id);
    if (!existing) {
      throw new Error('Vehicle not found');
    }
    if (existing.userId !== userId) {
      throw new Error('Unauthorized');
    }
    
    // Soft delete
    await this.repository.softDelete(id);
    
    // Invalidate cache
    await this.invalidateUserCache(userId);
  }
  
  private async invalidateUserCache(userId: string): Promise<void> {
    const cacheKey = `${this.cachePrefix}:user:${userId}`;
    await cacheService.del(cacheKey);
  }
  
  async getDropdownMakes(year: number): Promise<string[]> {
    const vehicleDataService = getVehicleDataService();
    const pool = getPool();

    logger.info('Fetching dropdown makes via platform module', { year });
    return vehicleDataService.getMakes(pool, year);
  }

  async getDropdownModels(year: number, make: string): Promise<string[]> {
    const vehicleDataService = getVehicleDataService();
    const pool = getPool();

    logger.info('Fetching dropdown models via platform module', { year, make });
    return vehicleDataService.getModels(pool, year, make);
  }

  async getDropdownTransmissions(year: number, make: string, model: string, trim: string): Promise<string[]> {
    const vehicleDataService = getVehicleDataService();
    const pool = getPool();

    logger.info('Fetching dropdown transmissions via platform module', { year, make, model, trim });
    return vehicleDataService.getTransmissionsForTrim(pool, year, make, model, trim);
  }

  async getDropdownEngines(year: number, make: string, model: string, trim: string): Promise<string[]> {
    const vehicleDataService = getVehicleDataService();
    const pool = getPool();

    logger.info('Fetching dropdown engines via platform module', { year, make, model, trim });
    return vehicleDataService.getEngines(pool, year, make, model, trim);
  }

  async getDropdownTrims(year: number, make: string, model: string): Promise<string[]> {
    const vehicleDataService = getVehicleDataService();
    const pool = getPool();

    logger.info('Fetching dropdown trims via platform module', { year, make, model });
    return vehicleDataService.getTrims(pool, year, make, model);
  }

  async getDropdownOptions(
    year: number,
    make: string,
    model: string,
    trim: string,
    engine?: string,
    transmission?: string
  ): Promise<{ engines: string[]; transmissions: string[] }> {
    const vehicleDataService = getVehicleDataService();
    const pool = getPool();

    logger.info('Fetching dropdown options via platform module', { year, make, model, trim, engine, transmission });
    return vehicleDataService.getOptions(pool, year, make, model, trim, engine, transmission);
  }

  async getDropdownYears(): Promise<number[]> {
    const vehicleDataService = getVehicleDataService();
    const pool = getPool();

    logger.info('Fetching dropdown years via platform module');
    return vehicleDataService.getYears(pool);
  }

  private toResponse(vehicle: Vehicle): VehicleResponse {
    return {
      id: vehicle.id,
      userId: vehicle.userId,
      vin: vehicle.vin,
      make: vehicle.make,
      model: vehicle.model,
      year: vehicle.year,
      engine: vehicle.engine,
      transmission: vehicle.transmission,
      trimLevel: vehicle.trimLevel,
      driveType: vehicle.driveType,
      fuelType: vehicle.fuelType,
      nickname: vehicle.nickname,
      color: vehicle.color,
      licensePlate: vehicle.licensePlate,
      odometerReading: vehicle.odometerReading,
      isActive: vehicle.isActive,
      createdAt: vehicle.createdAt.toISOString(),
      updatedAt: vehicle.updatedAt.toISOString(),
    };
  }
}