process.env.TZ = 'UTC';

import compress from '@fastify/compress';
import cookie from '@fastify/cookie';
import cors, { type FastifyCorsOptions } from '@fastify/cors';
import {
  decodeSessionToken,
  EMPTY_SESSION,
  type SessionValidationResult,
  validateSessionToken,
} from '@openpanel/auth';
import { generateId } from '@openpanel/common';
import {
  type IServiceClientWithProject,
  runWithAlsSession,
} from '@openpanel/db';
import { getRedisPub } from '@openpanel/redis';
import type { AppRouter } from '@openpanel/trpc';
import { appRouter, createContext } from '@openpanel/trpc';
import type { FastifyTRPCPluginOptions } from '@trpc/server/adapters/fastify';
import { fastifyTRPCPlugin } from '@trpc/server/adapters/fastify';
import type { FastifyBaseLogger, FastifyRequest } from 'fastify';
import Fastify from 'fastify';
import metricsPlugin from 'fastify-metrics';
import sourceMapSupport from 'source-map-support';
import {
  healthcheck,
  liveness,
  readiness,
} from './controllers/healthcheck.controller';
import { ipHook } from './hooks/ip.hook';
import { requestIdHook } from './hooks/request-id.hook';
import { requestLoggingHook } from './hooks/request-logging.hook';
import { timestampHook } from './hooks/timestamp.hook';
import aiRouter from './routes/ai.router';
import eventRouter from './routes/event.router';
import exportRouter from './routes/export.router';
import importRouter from './routes/import.router';
import insightsRouter from './routes/insights.router';
import liveRouter from './routes/live.router';
import manageRouter from './routes/manage.router';
import miscRouter from './routes/misc.router';
import oauthRouter from './routes/oauth-callback.router';
import profileRouter from './routes/profile.router';
import trackRouter from './routes/track.router';
import webhookRouter from './routes/webhook.router';
import { HttpError } from './utils/errors';
import { shutdown } from './utils/graceful-shutdown';
import { logger } from './utils/logger';

sourceMapSupport.install();

declare module 'fastify' {
  interface FastifyRequest {
    client: IServiceClientWithProject | null;
    clientIp: string;
    clientIpHeader: string;
    timestamp?: number;
    session: SessionValidationResult;
  }
}

const port = Number.parseInt(process.env.API_PORT || '3000', 10);
const host =
  process.env.API_HOST ||
  (process.env.NODE_ENV === 'production' ? '0.0.0.0' : 'localhost');

const startServer = async () => {
  logger.info('Starting server');
  try {
    const fastify = Fastify({
      maxParamLength: 15_000,
      bodyLimit: 1_048_576 * 500, // 500MB
      loggerInstance: logger as unknown as FastifyBaseLogger,
      disableRequestLogging: true,
      genReqId: (req) =>
        req.headers['request-id']
          ? String(req.headers['request-id'])
          : generateId(),
    });

    fastify.register(cors, () => {
      return (
        req: FastifyRequest,
        callback: (error: Error | null, options: FastifyCorsOptions) => void
      ) => {
        // TODO: set prefix on dashboard routes
        const corsPaths = [
          '/trpc',
          '/live',
          '/webhook',
          '/oauth',
          '/misc',
          '/ai',
        ];

        const isPrivatePath = corsPaths.some((path) =>
          req.url.startsWith(path)
        );

        if (isPrivatePath) {
          // Allow multiple dashboard domains
          const allowedOrigins = [
            process.env.DASHBOARD_URL || process.env.NEXT_PUBLIC_DASHBOARD_URL,
            ...(process.env.API_CORS_ORIGINS?.split(',') ?? []),
          ].filter(Boolean);

          const origin = req.headers.origin;
          const isAllowed = origin && allowedOrigins.includes(origin);

          return callback(null, {
            origin: isAllowed ? origin : false,
            credentials: true,
          });
        }

        return callback(null, {
          origin: '*',
          maxAge: 86_400 * 7, // cache preflight for 7 days
        });
      };
    });

    await fastify.register(import('fastify-raw-body'), {
      global: false,
    });

    fastify.addHook('onRequest', requestIdHook);
    fastify.addHook('onRequest', timestampHook);
    fastify.addHook('onRequest', ipHook);
    fastify.addHook('onResponse', requestLoggingHook);

    fastify.register(compress, {
      global: false,
      encodings: ['gzip', 'deflate'],
    });

    // Dashboard API
    fastify.register(async (instance) => {
      instance.register(cookie, {
        secret: process.env.COOKIE_SECRET ?? '',
        hook: 'onRequest',
        parseOptions: {},
      });

      instance.addHook('onRequest', async (req) => {
        if (req.cookies?.session) {
          try {
            const sessionId = decodeSessionToken(req.cookies?.session);
            const session = await runWithAlsSession(sessionId, () =>
              validateSessionToken(req.cookies.session)
            );
            req.session = session;
          } catch (e) {
            req.session = EMPTY_SESSION;
          }
        } else if (process.env.DEMO_USER_ID) {
          try {
            const session = await runWithAlsSession('1', () =>
              validateSessionToken(null)
            );
            req.session = session;
          } catch (e) {
            req.session = EMPTY_SESSION;
          }
        } else {
          req.session = EMPTY_SESSION;
        }
      });

      instance.register(fastifyTRPCPlugin, {
        prefix: '/trpc',
        trpcOptions: {
          router: appRouter,
          createContext,
          onError(ctx) {
            if (
              ctx.error.code === 'UNAUTHORIZED' &&
              ctx.path === 'organization.list'
            ) {
              return;
            }
            ctx.req.log.error('trpc error', {
              error: ctx.error,
              path: ctx.path,
              input: ctx.input,
              type: ctx.type,
              session: ctx.ctx?.session,
            });
          },
        } satisfies FastifyTRPCPluginOptions<AppRouter>['trpcOptions'],
      });
      instance.register(liveRouter, { prefix: '/live' });
      instance.register(webhookRouter, { prefix: '/webhook' });
      instance.register(oauthRouter, { prefix: '/oauth' });
      instance.register(miscRouter, { prefix: '/misc' });
      instance.register(aiRouter, { prefix: '/ai' });
    });

    // Public API
    fastify.register(async (instance) => {
      instance.register(metricsPlugin, { endpoint: '/metrics' });
      instance.register(eventRouter, { prefix: '/event' });
      instance.register(profileRouter, { prefix: '/profile' });
      instance.register(exportRouter, { prefix: '/export' });
      instance.register(importRouter, { prefix: '/import' });
      instance.register(insightsRouter, { prefix: '/insights' });
      instance.register(trackRouter, { prefix: '/track' });
      instance.register(manageRouter, { prefix: '/manage' });
      // Keep existing endpoints for backward compatibility
      instance.get('/healthcheck', healthcheck);
      // New Kubernetes-style health endpoints
      instance.get('/healthz/live', liveness);
      instance.get('/healthz/ready', readiness);
      instance.get('/', (_request, reply) =>
        reply.send({
          status: 'ok',
          message: 'Successfully running OpenPanel.dev API',
        })
      );
    });

    fastify.setErrorHandler((error, request, reply) => {
      if (error instanceof HttpError) {
        request.log.error(`${error.message}`, error);
        if (process.env.NODE_ENV === 'production' && error.status === 500) {
          request.log.error('request error', { error });
          reply.status(500).send('Internal server error');
        } else {
          reply.status(error.status).send({
            status: error.status,
            error: error.error,
            message: error.message,
          });
        }
      } else if (error.statusCode === 429) {
        reply.status(429).send({
          status: 429,
          error: 'Too Many Requests',
          message: 'You have exceeded the rate limit for this endpoint.',
        });
      } else if (error.statusCode === 400) {
        reply.status(400).send({
          status: 400,
          error,
          message: 'The request was invalid.',
        });
      } else {
        request.log.error('request error', { error });
        reply.status(500).send('Internal server error');
      }
    });

    if (process.env.NODE_ENV === 'production') {
      logger.info('Registering graceful shutdown handlers');
      process.on('SIGTERM', async () => await shutdown(fastify, 'SIGTERM', 0));
      process.on('SIGINT', async () => await shutdown(fastify, 'SIGINT', 0));
      process.on('uncaughtException', async (error) => {
        logger.error('Uncaught exception', error);
        await shutdown(fastify, 'uncaughtException', 1);
      });
      process.on('unhandledRejection', async (reason, promise) => {
        logger.error('Unhandled rejection', { reason, promise });
        await shutdown(fastify, 'unhandledRejection', 1);
      });
    }

    await fastify.listen({ host, port });

    try {
      // Notify when keys expires
      await getRedisPub().config('SET', 'notify-keyspace-events', 'Ex');
    } catch (error) {
      logger.warn('Failed to set redis notify-keyspace-events', error);
      logger.warn(
        'If you use a managed Redis service, you may need to set this manually.'
      );
      logger.warn('Otherwise some functions may not work as expected.');
    }
  } catch (error) {
    logger.error('Failed to start server', error);
  }
};

startServer();