import Fastify from 'fastify';
import cors from '@fastify/cors';
import { Client as PgClient } from 'pg';
import { createClient as createRedisClient } from 'redis';
import { DbService } from './services/db.service.js';
import { JobService } from './services/job.service.js';
import { SearchService } from './services/search.service.js';
import libraryRoutes from './routes/library.routes.js';
import searchRoutes from './routes/search.routes.js';
import adminRoutes from './routes/admin.routes.js';
import vibeRoutes from './routes/vibe.routes.js';
import historyRoutes from './routes/history.routes.js';
import streamRoutes from './routes/stream.routes.js';
import quarantineRoutes from './routes/quarantine.routes.js';
import settingsRoutes from './routes/settings.routes.js';
import graphRoutes from './routes/graph.routes.js';
import { SessionDirector } from './services/session-director.service.js';
import v2Routes from './routes/v2.routes.js';
import discoveryRoutes from './routes/discovery.routes.js';
import imagesRoutes from './routes/images.routes.js';

export interface AppConfig {
  port: number;
  searchHost: string;
  searchPort: number;
  searchApiKey: string;
}

export async function buildApp(config: AppConfig) {
  const fastify = Fastify({ logger: true });

  await fastify.register(cors, {
    origin: process.env.CORS_ORIGIN?.split(',') || ['http://localhost:5173', 'http://localhost:5174'],
  });

  const pgClient = new PgClient({
    connectionString: process.env.DATABASE_URL,
  });
  await pgClient.connect();

  const redisClient = createRedisClient({
    url: process.env.REDIS_URL,
  });
  await redisClient.connect();

  const jobService = new JobService({ redisUrl: process.env.REDIS_URL! });
  const searchService = new SearchService({
    host: config.searchHost,
    port: config.searchPort,
    protocol: 'http',
    apiKey: config.searchApiKey,
  });
  const dbService = new DbService(pgClient, searchService);

  // Apply the idempotent schema on boot so tables added after the initial DB
  // volume was created (e.g. play_history, feedback) exist. The init-time
  // docker-entrypoint mount only runs on first init, so older volumes miss them.
  await dbService.ensureSchema();
  await dbService.runMigrations();

  // Keep the claim_fusion materialised view fresh. The trigger on
  // `claims` fires NOTIFY on every change; rather than maintain a
  // LISTEN consumer (separate long-lived connection), we refresh on a
  // short interval. 10s staleness is well below any user-facing
  // latency for a homelab music player.
  const FUSION_REFRESH_MS = 10_000;
  const fusionTimer = setInterval(() => {
    dbService.refreshClaimFusion().catch(() => {});
  }, FUSION_REFRESH_MS);

  // Daily belief decay (spec §B.4). Runs hourly; the SQL only touches
  // beliefs whose last_decayed_at is >1h old, so frequent runs are safe.
  const DECAY_INTERVAL_MS = 60 * 60 * 1000;
  const decayTimer = setInterval(() => {
    dbService.decayBeliefs().catch((e) => console.error('[DB] belief decay failed:', e));
  }, DECAY_INTERVAL_MS);

  // Nightly 'forgotten' profile derivation (spec §B.2).
  const FORGOTTEN_INTERVAL_MS = 24 * 60 * 60 * 1000;
  const forgottenTimer = setInterval(() => {
    dbService.deriveForgottenProfile().catch((e) =>
      console.error('[DB] forgotten derivation failed:', e)
    );
  }, FORGOTTEN_INTERVAL_MS);

  // Run both once at boot so the first session benefits.
  dbService.decayBeliefs().catch(() => {});
  dbService.deriveForgottenProfile().catch(() => {});

  // Ensure the Typesense 'tracks' collection schema exists on boot so that
  // the first search request doesn't hit a 404.
  await searchService.ensureCollection();

  // Health check route

  fastify.get('/api/health', async (request, reply) => {
    const status = {
      postgres: 'unknown',
      redis: 'unknown',
    };

    try {
      await pgClient.query('SELECT 1');
      status.postgres = 'ok';
    } catch (err) {
      status.postgres = 'error';
      fastify.log.error(err);
    }

    try {
      const redisRes = await redisClient.ping();
      if (redisRes === 'PONG') {
        status.redis = 'ok';
      }
    } catch (err) {
      status.redis = 'error';
      fastify.log.error(err);
    }

    const isHealthy = status.postgres === 'ok' && status.redis === 'ok';
    
    if (isHealthy) {
      return reply.code(200).send(status);
    } else {
      return reply.code(503).send(status);
    }
  });

  fastify.register(imagesRoutes, { prefix: '/api' });
  fastify.register(libraryRoutes, { prefix: '/api', dbService });
  fastify.register(searchRoutes, { prefix: '/api', dbService });
  fastify.register(adminRoutes, { prefix: '/api/admin', jobService, dbService });
  fastify.register(vibeRoutes, { prefix: '/api/vibe', dbService });
  fastify.register(historyRoutes, { prefix: '/api', dbService });
  fastify.register(streamRoutes, { prefix: '/api', dbService });
  fastify.register(quarantineRoutes, { prefix: '/api', dbService });
  fastify.register(settingsRoutes, { prefix: '/api', dbService });
  fastify.register(graphRoutes, { prefix: '/api', dbService });

  const sessionDirector = new SessionDirector(dbService);

  fastify.register(v2Routes, { prefix: '/api', dbService, sessionDirector });
  fastify.register(discoveryRoutes, { prefix: '/api', dbService });
  fastify.post('/api/test/enqueue-job', async (request, reply) => {
    const { jobType, trackId, payload } = request.body as any;
    try {
      if (jobType === 'metadataRefresh') {
        await jobService.enqueueMetadataRefresh(trackId, payload.type);
      } else if (jobType === 'audioAnalysis') {
        await jobService.enqueueAudioAnalysis(trackId, payload.features);
      } else if (jobType === 'cleanup') {
        await jobService.enqueueCleanup(payload.reason, payload.targetFiles);
      } else {
        return reply.code(400).send({ error: 'Unknown job type' });
      }
      await reply.send({ message: 'Job enqueued' });
    } catch (error) {
      request.log.error(error);
      await reply.status(500).send({ error: 'Internal server error' });
    }
  });

  // Register hooks to close connections on shutdown
  fastify.addHook('onClose', async () => {
    try {
      clearInterval(fusionTimer);
      clearInterval(decayTimer);
      clearInterval(forgottenTimer);
    } catch (err) {
      fastify.log.error(err);
    }
    try {
      await pgClient.end();
    } catch (err) {
      fastify.log.error(err);
    }
    try {
      await redisClient.quit();
    } catch (err) {
      fastify.log.error(err);
    }
    try {
      await jobService.close();
    } catch (err) {
      fastify.log.error(err);
    }
  });

  return { fastify, pgClient, redisClient };
}