import cors from 'cors';
import express, { Router, type ErrorRequestHandler, type RequestHandler } from 'express';
import type { Pool } from 'pg';
import { ZodError } from 'zod';
import type { AppConfig } from './config/env.js';
import { ApiError } from './http/api-error.js';
import { createDomesticVocRouter, type DomesticSnapshotProvider } from './modules/domestic-voc/routes.js';
import { SyncJobRepository, type SyncJobStore } from './modules/domestic-voc/repositories/sync-job.repository.js';
import { SnapshotService } from './modules/domestic-voc/services/snapshot.service.js';
import { SyncService } from './modules/domestic-voc/services/sync.service.js';
import { createAuthenticationMiddleware, createAuthenticator, WorkspaceAccessService } from './modules/saas-platform/auth.js';
import type { PlatformRepository } from './modules/saas-platform/domain.js';
import { PostgresPlatformRepository } from './modules/saas-platform/postgres-platform.repository.js';
import { createSaasPlatformRouter } from './modules/saas-platform/routes.js';
import { FmodeAiClient } from './modules/ai-gateway/client.js';
import { createAiGatewayRouter } from './modules/ai-gateway/routes.js';
import type { AiPromptConfigStore } from './modules/ai-gateway/prompt-config.repository.js';
import { createProductKnowledgeRouter } from './modules/product-knowledge/routes.js';
import type { ProductKnowledgeStore } from './modules/product-knowledge/product-knowledge.store.js';
import { InMemoryListingAiRepository } from './modules/listing-ai/repositories/in-memory-listing-ai.repository.js';
import { FmodeJdVocAiScoringProvider, FmodeListingAiScoringProvider, ListingAiService } from './modules/listing-ai/listing-ai.service.js';
import { FmodeGeminiImageReviewProvider } from './modules/listing-ai/image-review/gemini-image-review.provider.js';
import { createListingAiRouter } from './modules/listing-ai/routes.js';
import type { ListingAiRepository } from './modules/listing-ai/domain.js';
import type { CompetitorListingMonitorService } from './modules/competitor-listing-monitor/competitor-listing-monitor.service.js';
import { createCompetitorListingMonitorRouter } from './modules/competitor-listing-monitor/routes.js';
import { createCloudFunctionRouter, dispatchThroughRouter } from './cloud-functions/router.js';
import { createSpecialActionHandler } from './cloud-functions/special-actions.js';
import { FmodeVocEcommerceClient } from './modules/domestic-voc/upstream/fmode-client.js';

export function createApp(input: {
  config: AppConfig;
  pool?: Pool;
  parseApp?: RequestHandler;
  platformRepository?: PlatformRepository;
  jobs?: SyncJobStore;
  snapshot?: DomesticSnapshotProvider;
  healthCheck?: () => Promise<{ ready: boolean; missingObjects: string[] }>;
  aiPromptConfigs?: AiPromptConfigStore;
  productKnowledge?: ProductKnowledgeStore;
  listingAiRepository?: ListingAiRepository;
  listingAiService?: ListingAiService;
  competitorListingMonitor?: CompetitorListingMonitorService;
}) {
  const app = express();
  app.disable('x-powered-by');
  app.use(cors({
    origin(origin, callback) {
      if (!origin || input.config.corsOrigins.includes(origin)) return callback(null, true);
      return callback(new Error('Origin is not allowed'));
    },
    credentials: true,
  }));
  app.use(express.json({ limit: '1mb' }));

  app.get('/health', async (_request, response) => {
    try {
      if (input.healthCheck) {
        const readiness = await input.healthCheck();
        if (!readiness.ready) {
          response.status(503).json({
            service: 'saas-voc-server',
            status: 'unavailable',
            database: readiness.missingObjects.length ? 'migration_required' : 'unavailable',
            missingTables: readiness.missingObjects,
            storage: input.config.storageDriver,
            timestamp: new Date().toISOString(),
          });
          return;
        }
        response.json({
          service: 'saas-voc-server',
          status: 'ok',
          database: 'ready',
          storage: input.config.storageDriver,
          timestamp: new Date().toISOString(),
        });
        return;
      }
      if (!input.pool) throw new Error('Database pool is not configured');
      const result = await input.pool.query<Record<string, string | null>>(`
        SELECT
          to_regclass('voc.workspace')::text AS workspace,
          to_regclass('voc.product')::text AS product,
          to_regclass('voc.review')::text AS review,
          to_regclass('voc.sync_job')::text AS sync_job,
          to_regclass('voc.workspace_member')::text AS workspace_member,
          to_regclass('voc.analysis_run')::text AS analysis_run,
          to_regclass('voc.action_item')::text AS action_item,
          to_regclass('voc.alert')::text AS alert,
          to_regclass('voc.audit_log')::text AS audit_log
          ,to_regclass('voc.listing_source_snapshot')::text AS listing_source_snapshot
          ,to_regclass('voc.listing_score_job')::text AS listing_score_job
          ,to_regclass('voc.listing_score_item')::text AS listing_score_item
          ,to_regclass('voc.listing_current_score')::text AS listing_current_score
          ,to_regclass('voc.listing_version')::text AS listing_version
      `);
      const readiness = result.rows[0] ?? {};
      const missingTables = Object.entries(readiness)
        .filter((entry) => !entry[1])
        .map((entry) => `voc.${entry[0]}`);
      if (missingTables.length) {
        response.status(503).json({
          service: 'saas-voc-server',
          status: 'unavailable',
          database: 'migration_required',
          missingTables,
          timestamp: new Date().toISOString(),
        });
        return;
      }
      response.json({
        service: 'saas-voc-server',
        status: 'ok',
        database: 'ready',
        timestamp: new Date().toISOString(),
      });
    } catch {
      response.status(503).json({
        service: 'saas-voc-server',
        status: 'unavailable',
        database: 'unavailable',
        timestamp: new Date().toISOString(),
      });
    }
  });

  if (input.parseApp) app.use('/parse', input.parseApp);

  if (!input.platformRepository && !input.pool) throw new Error('Platform repository is not configured');
  const platform = input.platformRepository ?? new PostgresPlatformRepository(input.pool!);
  const access = new WorkspaceAccessService(platform);
  const businessRouter = Router();
  const authenticationMiddleware = createAuthenticationMiddleware(createAuthenticator(input.config));
  app.use('/api', authenticationMiddleware);
  const aiClient = new FmodeAiClient(input.config.ai);
  const domesticGateway = new FmodeVocEcommerceClient(input.config.fmode);
  businessRouter.use('/ai', createAiGatewayRouter(aiClient, input.aiPromptConfigs));

  const jobs = input.jobs ?? new SyncJobRepository(input.pool!);
  const sync = new SyncService(jobs);
  const snapshot = input.snapshot ?? new SnapshotService(input.pool!);
  businessRouter.use('/domestic-voc', createDomesticVocRouter({
    jobs,
    sync,
    snapshot,
    catalog: platform,
    access,
    defaultWorkspaceId: input.config.auth.defaultWorkspaceId,
  }));
  businessRouter.use('/saas', createSaasPlatformRouter({ repository: platform, access }));
  const listingAi = input.listingAiService ?? new ListingAiService(
    input.listingAiRepository ?? new InMemoryListingAiRepository(),
    new FmodeListingAiScoringProvider(aiClient, input.config.listingAi.model),
    () => new Date(),
    input.config.listingAi.concurrency,
    input.config.listingAi.maxAiItemsPerJob,
    input.config.listingAi.jdVocAiEnabled ? new FmodeJdVocAiScoringProvider(aiClient, input.config.listingAi.jdVocAiModel) : undefined,
    input.config.listingAi.jdVocImageShadowEnabled ? new FmodeGeminiImageReviewProvider({ baseUrl: process.env.FMODE_LLM_BASE_URL ?? input.config.ai.baseUrl, token: process.env.FMODE_LLM_API_KEY ?? input.config.ai.token, timeoutMs: 45_000 }) : undefined,
    input.config.listingAi.jdVocDisplayDefault,
    input.config.listingAi.jdVocEnabled,
  );
  businessRouter.use('/listing-ai', createListingAiRouter({
    service: listingAi,
    access,
    audit: platform,
    defaultWorkspaceId: input.config.auth.defaultWorkspaceId,
  }));
  queueMicrotask(() => {
    void listingAi.resumePendingJobs(input.config.auth.defaultWorkspaceId).catch((error: unknown) => {
      console.error('[listing-ai] failed to resume persisted score jobs', error);
    });
  });
  if (input.productKnowledge) {
    businessRouter.use('/knowledge', createProductKnowledgeRouter({
      store: input.productKnowledge,
      repository: platform,
      access,
      defaultWorkspaceId: input.config.auth.defaultWorkspaceId,
    }));
  }
  if (input.competitorListingMonitor) {
    businessRouter.use('/competitor-listings', createCompetitorListingMonitorRouter({
      service: input.competitorListingMonitor,
      access,
      defaultWorkspaceId: input.config.auth.defaultWorkspaceId,
    }));
  }

  app.use('/api', businessRouter);
  const localCloudFunctionRouter = createCloudFunctionRouter({
    defaultWorkspaceId: input.config.auth.defaultWorkspaceId,
    specialAction: createSpecialActionHandler({ ai: aiClient, domestic: domesticGateway }),
    dispatch: (request, response, actionPath, method, body, requestId) =>
      dispatchThroughRouter(businessRouter, request, response, actionPath, method, body, requestId),
  });
  app.use('/api/functions', localCloudFunctionRouter);
  // Parse REST storage has no embedded Parse Server. This compatibility mount
  // lets the browser's Parse SDK keep calling /parse/functions/* while the
  // request is still dispatched through the same allow-listed Cloud actions.
  if (!input.parseApp) app.use('/parse/functions', authenticationMiddleware, localCloudFunctionRouter);

  app.use((_request, response) => {
    response.status(404).json({ error: 'not_found' });
  });

  const errorHandler: ErrorRequestHandler = (error, _request, response, _next) => {
    if (error instanceof ApiError) {
      response.status(error.status).json({ error: error.code });
      return;
    }
    if (error instanceof ZodError) {
      response.status(400).json({
        error: 'invalid_request',
        issues: error.issues.map((issue) => ({ path: issue.path.join('.'), message: issue.message })),
      });
      return;
    }
    console.error('[http] unhandled request error', error);
    response.status(500).json({ error: 'internal_error' });
  };
  app.use(errorHandler);

  return app;
}