import { Module, Logger as NestLogger } from '@nestjs/common';
import { ConfigModule, ConfigService } from '@nestjs/config';
import { APP_FILTER, APP_GUARD, APP_INTERCEPTOR } from '@nestjs/core';
import { ThrottlerModule, ThrottlerGuard } from '@nestjs/throttler';
import { CacheModule } from '@nestjs/cache-manager';
import { redisStore } from 'cache-manager-redis-yet';
import { LoggerModule } from 'nestjs-pino';
import {
  I18nModule,
  AcceptLanguageResolver,
  HeaderResolver,
  QueryResolver,
} from 'nestjs-i18n';
import * as path from 'path';
import { ServeStaticModule } from '@nestjs/serve-static';

// Config
import {
  appConfig,
  databaseConfig,
  jwtConfig,
  redisConfig,
  i18nConfig,
  featuresConfig,
  throttleConfig,
} from './config/configuration';
import { geminiConfig } from './modules/gemini/gemini.config';
import { validateEnv } from './config/env.validation';

// Common
import { GlobalExceptionFilter } from './common/filters/global-exception.filter';
import { ResponseInterceptor } from './common/interceptors/response.interceptor';

// Database
import { DatabaseModule } from './database/database.module';

// Modules
import { AuthModule } from './modules/auth/auth.module';
import { UsersModule } from './modules/users/users.module';
import { AdminModule } from './modules/admin/admin.module';
import { HealthModule } from './modules/health/health.module';
import { GeminiModule } from './modules/gemini/gemini.module';
import { CmsModule } from './modules/cms/cms.module';
import { MailModule } from './modules/mail/mail.module';

// Guards
import {
  JwtAuthGuard,
  RolesGuard,
  PermissionsGuard,
} from './modules/auth/guards';

@Module({
  imports: [
    // Configuration
    ConfigModule.forRoot({
      isGlobal: true,
      validate: validateEnv,
      load: [
        appConfig,
        databaseConfig,
        jwtConfig,
        redisConfig,
        i18nConfig,
        featuresConfig,
        throttleConfig,
        geminiConfig,
      ],
    }),

    // Logger (Structured Logging with Pino)
    LoggerModule.forRootAsync({
      imports: [ConfigModule],
      inject: [ConfigService],
      useFactory: (configService: ConfigService) => {
        return {
          pinoHttp: {
            level: configService.get('app.isDevelopment') ? 'debug' : 'info',
            transport: configService.get('app.isDevelopment')
              ? {
                target: 'pino-pretty',
                options: {
                  singleLine: true,
                },
              }
              : undefined,
          },
        };
      },
    }),

    // i18n
    I18nModule.forRootAsync({
      useFactory: (configService: ConfigService) => ({
        fallbackLanguage: configService.get('i18n.fallbackLanguage', 'en'),
        loaderOptions: {
          path: path.join(__dirname, '/i18n/'),
          watch: configService.get('app.isDevelopment', true),
        },
      }),
      resolvers: [
        new HeaderResolver(['x-lang', 'accept-language']),
        new QueryResolver(['lang']),
        AcceptLanguageResolver,
      ],
      inject: [ConfigService],
    }),

    // Throttling
    ThrottlerModule.forRootAsync({
      inject: [ConfigService],
      useFactory: (configService: ConfigService) => [
        {
          ttl: configService.get('throttle.ttl', 60000),
          limit: configService.get('throttle.limit', 100),
        },
      ],
    }),

    // Caching (Redis with in-memory fallback)
    CacheModule.registerAsync({
      isGlobal: true,
      imports: [ConfigModule],
      useFactory: async (configService: ConfigService) => {
        const logger = new NestLogger('CacheModule');
        const useRedis = configService.get('REDIS_ENABLED', 'false') === 'true';

        if (useRedis) {
          try {
            const store = await redisStore({
              socket: {
                host: configService.get('redis.host', 'localhost'),
                port: configService.get('redis.port', 6379),
              },
              ttl: 60 * 1000, // 1 minute default
            });
            logger.log('✅ Redis cache connected');
            return {
              store: store as unknown as any,
              ttl: 60 * 1000,
            };
          } catch {
            logger.warn('⚠️ Redis connection failed, using in-memory cache');
          }
        }

        // Fallback to in-memory cache
        logger.log('📦 Using in-memory cache');
        return {
          ttl: 60 * 1000,
        };
      },
      inject: [ConfigService],
    }),

    // Database
    DatabaseModule,

    // Core Modules
    AuthModule,
    UsersModule,
    AdminModule,

    // Optional Modules (controlled by env variables)
    GeminiModule,
    HealthModule,

    // CMS Module
    CmsModule,

    // Mail Module
    MailModule,

    // Serve uploaded files
    ServeStaticModule.forRoot({
      rootPath: path.join(__dirname, '..', 'uploads'),
      serveRoot: '/uploads',
    }),
  ],
  providers: [
    // Global Exception Filter
    {
      provide: APP_FILTER,
      useClass: GlobalExceptionFilter,
    },

    // Global Response Interceptor
    {
      provide: APP_INTERCEPTOR,
      useClass: ResponseInterceptor,
    },

    // Global Rate Limiting
    {
      provide: APP_GUARD,
      useClass: ThrottlerGuard,
    },

    // Global JWT Auth Guard
    {
      provide: APP_GUARD,
      useClass: JwtAuthGuard,
    },

    // Global Roles Guard
    {
      provide: APP_GUARD,
      useClass: RolesGuard,
    },

    // Global Permissions Guard
    {
      provide: APP_GUARD,
      useClass: PermissionsGuard,
    },
  ],
})
export class AppModule {
  private readonly logger = new NestLogger(AppModule.name);

  constructor() {
    this.logger.log('AppModule initialized');
  }
}