import { resolve, dirname } from 'node:path';
import { fileURLToPath } from 'node:url';
import { existsSync } from 'node:fs';
import Fastify from 'fastify';
import fastifyWebsocket from '@fastify/websocket';
import fastifyStatic from '@fastify/static';

const __filename = fileURLToPath(import.meta.url);
const __dirname = dirname(__filename);
import { loadConfig } from './config.js';
import { getSql, applySchema, pingDb, closeDb } from './db.js';
import { startMcpServer } from './services/mcp-server.js';
// v2.0.0 Phase 2B: workspace dependency on @boocode/server — reuse the
// inference loop, broker, and tool registry without duplication.
import { createInferenceRunner } from '@boocode/server/inference';
import { createBroker } from '@boocode/server/broker';
import { appendMcpTools, ALL_TOOLS } from '@boocode/server/tools';
import type { Config as ServerConfig } from '@boocode/server/config';
import type { WsFrame } from '@boocode/server/ws-frames';
// v2.0.0 Phase 2C: write tools + adapter for BooChat ToolDef compatibility.
import { WRITE_TOOLS } from './services/tools/index.js';
import { adaptWriteTool } from './services/tools/adapter.js';
import { setInferenceContext, clearInferenceContext } from './services/tools/inference_context.js';
// Routes
import { registerMessageRoutes } from './routes/messages.js';
import { registerPendingRoutes } from './routes/pending.js';
import { registerTaskRoutes } from './routes/tasks.js';
import { registerInboxRoutes } from './routes/inbox.js';
import { registerStatsRoutes } from './routes/stats.js';
import { registerArenaRoutes } from './routes/arena.js';
import { registerProviderRoutes } from './routes/providers.js';
import { registerWebSocket } from './routes/ws.js';
// Phase 4: dispatcher + agent probe
import { createDispatcher } from './services/dispatcher.js';
import { probeAgents } from './services/agent-probe.js';

async function main() {
  // MCP mode: stdio transport, no HTTP server
  if (process.argv.includes('--mcp')) {
    const config = loadConfig();
    const sql = getSql(config);
    await applySchema(sql);
    await startMcpServer(sql);
    return;
  }

  const config = loadConfig();

  const app = Fastify({
    logger: { level: config.LOG_LEVEL },
  });

  // Allow empty JSON bodies (same pattern as apps/server).
  app.removeContentTypeParser(['application/json']);
  app.addContentTypeParser('application/json', { parseAs: 'string' }, (_req, body, done) => {
    const str = (body as string) ?? '';
    if (str.trim().length === 0) {
      done(null, {});
      return;
    }
    try {
      done(null, JSON.parse(str));
    } catch (err) {
      done(err as Error, undefined);
    }
  });

  const sql = getSql(config);
  await applySchema(sql);
  app.log.info('database schema applied');

  // Broker: in-memory pub/sub for session + user channel streaming.
  const broker = createBroker(app.log);

  // --- Tool registry extension ---
  // Append BooCoder write tools (adapted to BooChat's ToolDef interface) to
  // the shared ALL_TOOLS registry. appendMcpTools re-sorts and rebuilds
  // TOOLS_BY_NAME so tool-phase.ts dispatch sees the full set.
  const adaptedWriteTools = WRITE_TOOLS.map((t) => adaptWriteTool(t));
  appendMcpTools(adaptedWriteTools);
  app.log.info(`tool registry: ${ALL_TOOLS.length} tools loaded (${WRITE_TOOLS.length} write tools)`);

  // Inference runner: same engine as BooChat, uses ALL_TOOLS (which includes
  // the appended write tools) for tool dispatch.
  const inference = createInferenceRunner(
    {
      sql,
      config: config as unknown as ServerConfig,
      log: app.log,
      publish: (sessionId, frame) => {
        broker.publishFrame(sessionId, frame as unknown as WsFrame);
      },
      broker,
    },
    (user, frame) => {
      broker.publishUserFrame(user, frame as unknown as WsFrame);
    }
  );

  // Wrap the inference runner to set/clear the write-tool context around each run.
  // The inference runner calls enqueue() which fires asynchronously — we hook
  // into the enqueue to set context before the run starts.
  const inferenceApi = {
    enqueue: (sessionId: string, chatId: string, assistantId: string, user: string) => {
      // Set the inference context so write tools can access sql + sessionId.
      // The context persists for the duration of the inference run. Since
      // BooCoder is single-user and runs one inference at a time per session,
      // this module-level state is safe.
      setInferenceContext({ sql, sessionId, taskId: null });
      inference.enqueue(sessionId, chatId, assistantId, user);
    },
    cancel: async (sessionId: string, chatId: string) => {
      const result = await inference.cancel(sessionId, chatId);
      clearInferenceContext();
      return result;
    },
    hasActive: (chatId: string) => inference.hasActive(chatId),
  };

  // Register WebSocket support
  await app.register(fastifyWebsocket);

  // Health endpoint
  app.get('/api/health', async (_req, reply) => {
    const dbOk = await pingDb(sql);
    const status = dbOk ? 200 : 503;
    return reply.status(status).send({
      ok: dbOk,
      db: dbOk,
      tools: ALL_TOOLS.length,
    });
  });

  // Phase 4: probe available agents on startup
  await probeAgents(sql, app.log);

  // Phase 4: dispatcher — polls tasks table and runs inference
  const dispatcher = createDispatcher({ sql, inference: inferenceApi, broker, log: app.log, config });
  dispatcher.start();
  app.addHook('onClose', () => dispatcher.stop());

  // Register routes
  registerMessageRoutes(app, sql, broker, inferenceApi);
  registerPendingRoutes(app, sql);
  registerTaskRoutes(app, sql, inferenceApi);
  registerInboxRoutes(app, sql);
  registerStatsRoutes(app, sql);
  registerArenaRoutes(app, sql);
  registerProviderRoutes(app, sql, config);
  registerWebSocket(app, sql, broker);

  // Serve static frontend (built web app). In production, the dist/ is
  // copied to ../web relative to the dist/ directory at /app/web. In dev,
  // check adjacent to the source.
  const webRoot = resolve(__dirname, '../web');
  if (existsSync(webRoot)) {
    await app.register(fastifyStatic, {
      root: webRoot,
      prefix: '/',
      // Don't intercept /api routes — static only serves files that exist.
      wildcard: false,
    });
    // SPA fallback: serve index.html for non-API routes that don't match a file.
    app.setNotFoundHandler(async (req, reply) => {
      if (req.url.startsWith('/api')) {
        reply.code(404);
        return { error: 'not found' };
      }
      return reply.sendFile('index.html');
    });
    app.log.info(`serving frontend from ${webRoot}`);
  }

  // Graceful shutdown
  const shutdown = async () => {
    app.log.info('shutting down');
    await app.close();
    await closeDb();
    process.exit(0);
  };
  process.on('SIGTERM', shutdown);
  process.on('SIGINT', shutdown);

  await app.listen({ port: config.PORT, host: config.HOST });
  app.log.info(`BooCoder listening on ${config.HOST}:${config.PORT}`);
}

main().catch((err) => {
  console.error('fatal:', err);
  process.exit(1);
});