import fs from "fs";
import fastify from "fastify";
import cookie from "@fastify/cookie";
import cors from "@fastify/cors";
import jwt from "@fastify/jwt";
import fastifyStatic from "@fastify/static";
import { migrate, db } from "./db.js";
import { log, enableLogPersistence, flushLogs } from "./logger.js";
import * as store from "./store.js";
import { createRegistry } from "./registry.js";
import { addApiAuthGuard, COOKIE } from "./src/api/auth.js";
import authPlugin from "./src/api/auth.js";
import usersPlugin from "./src/api/users.js";
import scriptsPluginFactory from "./src/api/scripts.js";
import workflowsPluginFactory from "./src/api/workflows.js";
import runsPlugin from "./src/api/runs.js";
import { queryRunsFromRequest } from "./src/api/run-query.js";
import dashboardPluginFactory from "./src/api/dashboard.js";
import secretsPlugin from "./src/api/secrets.js";
import kvPlugin from "./src/api/kv.js";
import variablesPlugin from "./src/api/variables.js";
import httpPagesPlugin from "./src/api/http-pages.js";
import httpAuthsPlugin from "./src/api/http-auths.js";
import { WEB_DIST } from "./paths.js";
import { resolveSecretsKeyMaterial } from "./secrets.js";
import {
  closeRedis,
  createWorkflowQueue,
  createWorkflowWorker,
  getRedisUrlForLog,
} from "./workflow-queue.js";
import { purgeExpiredTrash } from "./workflow-trash.js";
import {
  getConfigGeneration,
  startHeartbeatLoop,
  subscribeReload,
} from "./control-bus.js";

/**
 * @param {{
 *   role?: string,
 *   migrate?: boolean,
 *   serveStaticUi?: boolean,
 * }} [opts]
 */
export async function startApp(opts = {}) {
  const role = (opts.role || process.env.JFLOW_ROLE || "all").toLowerCase();
  const shouldMigrate = opts.migrate ?? role === "all";
  const serveStaticUi = opts.serveStaticUi ?? (role === "all" || role === "api");

  if (shouldMigrate) {
    await migrate();
    try {
      const purged = await purgeExpiredTrash();
      if (purged > 0) {
        log.info({ purged }, "purged expired workflow trash");
      }
    } catch (err) {
      log.warn({ err }, "workflow trash purge failed");
    }
  }
  enableLogPersistence();

  const jwtSecret =
    process.env.JFLOW_JWT_SECRET ??
    (process.env.NODE_ENV === "production" ? "" : "jflow-dev-secret");

  if (!jwtSecret) {
    log.error("JFLOW_JWT_SECRET is required in production");
    process.exit(1);
  }

  try {
    resolveSecretsKeyMaterial();
  } catch (err) {
    log.error(err instanceof Error ? err.message : String(err));
    process.exit(1);
  }

  const runApi = role === "all" || role === "api";
  const runWorker = role === "all" || role === "worker";

  log.info(
    {
      redis: getRedisUrlForLog(),
      role,
      generation: getConfigGeneration(),
      migrate: shouldMigrate,
    },
    "starting jerapah-flow",
  );

  const workflowQueue = createWorkflowQueue();
  try {
    await workflowQueue.waitUntilReady();
  } catch (err) {
    log.error({ err, redis: getRedisUrlForLog() }, "failed to connect to Redis");
    process.exit(1);
  }

  const server = fastify({ loggerInstance: log });

  await server.register(cookie);
  await server.register(jwt, {
    secret: jwtSecret,
    cookie: {
      cookieName: COOKIE,
      signed: false,
    },
  });
  await server.register(cors, {
    origin: process.env.JFLOW_CORS_ORIGIN ?? "http://localhost:8500",
    credentials: true,
  });

  server.decorate("authenticate", async function authenticate(req, reply) {
    try {
      await req.jwtVerify();
    } catch {
      return reply.code(401).send({ error: "unauthorized" });
    }
  });

  server.decorate("requireAdmin", async function requireAdmin(req, reply) {
    if (req.user?.role !== "admin") {
      return reply.code(403).send({ error: "forbidden" });
    }
  });

  const registry = createRegistry(server, {
    queue: workflowQueue,
    // Cron + HTTP triggers enqueue jobs; only the API process may own them.
    enableTriggers: runApi,
  });
  registry.registerWorkflows();
  if (runApi) {
    registry.registerHttpTriggers();
    registry.registerCronTriggers();
    registry.registerPruneJob();
  }

  /** @type {import("bullmq").Worker | null} */
  let workflowWorker = null;
  if (runWorker) {
    workflowWorker = createWorkflowWorker(async (job) => {
      const data = /** @type {{ runId?: string, key?: string, depth?: number }} */ (
        job.data ?? {}
      );
      if (typeof data.runId !== "string" || typeof data.key !== "string") {
        throw new Error("invalid workflow job payload");
      }
      const result = await registry.executeQueuedRun({
        runId: data.runId,
        key: data.key,
        depth: data.depth ?? 0,
      });
      if (result.status === "failed") {
        throw new Error(result.error || "workflow failed");
      }
      return result;
    });
  }

  if (runApi) {
    await server.register(
      async (api) => {
        addApiAuthGuard(api, server);
        await api.register(authPlugin);
        await api.register(usersPlugin);
        await api.register(secretsPlugin);
        await api.register(variablesPlugin);
        await api.register(kvPlugin);
        await api.register(httpPagesPlugin);
        await api.register(httpAuthsPlugin);
        await api.register(scriptsPluginFactory(registry));
        await api.register(workflowsPluginFactory(registry));
        await api.register(runsPlugin);
        await api.register(dashboardPluginFactory(registry));
      },
      { prefix: "/api" },
    );

    server.post(
      "/admin/workflows/reregister",
      { onRequest: [server.authenticate] },
      async (_req, reply) => {
        registry.reregister();
        try {
          const { publishReload } = await import("./control-bus.js");
          await publishReload({ type: "workflows" });
        } catch {
          // ignore
        }
        return reply.send({ message: "Workflows refreshed" });
      },
    );

    server.get(
      "/admin/runs",
      { onRequest: [server.authenticate] },
      async (req, reply) => {
        const q = /** @type {Record<string, string | undefined>} */ (req.query ?? {});
        return reply.send(await queryRunsFromRequest(q));
      },
    );

    server.get(
      "/admin/runs/:id",
      { onRequest: [server.authenticate] },
      async (req, reply) => {
        const { id } = /** @type {{ id: string }} */ (req.params);
        const run = await store.getRun(id);
        if (!run) {
          return reply.code(404).send({ error: "run not found" });
        }
        return reply.send(run);
      },
    );

    if (serveStaticUi && fs.existsSync(WEB_DIST)) {
      await server.register(fastifyStatic, {
        root: WEB_DIST,
        wildcard: false,
      });
      server.setNotFoundHandler((req, reply) => {
        const url = req.raw.url ?? "";
        if (
          url.startsWith("/api") ||
          url.startsWith("/u/") ||
          url.startsWith("/admin") ||
          url.startsWith("/ops")
        ) {
          return reply.code(404).send({ error: "not found" });
        }
        return reply.sendFile("index.html");
      });
    }
  }

  const stopHeartbeat = startHeartbeatLoop(runApi && runWorker ? "all" : runApi ? "api" : "worker");

  const reloadSub = await subscribeReload(async () => {
    log.info("received reload signal");
    registry.reregister();
  });

  async function shutdown() {
    try {
      stopHeartbeat();
      await reloadSub.stop();
      if (workflowWorker) {
        await workflowWorker.close();
      }
      await workflowQueue.close();
      await closeRedis();
      await flushLogs();
      await db.destroy();
    } catch (err) {
      log.error({ err }, "shutdown error");
    }
    process.exit(0);
  }

  process.on("SIGINT", shutdown);
  process.on("SIGTERM", shutdown);

  const port = Number(process.env.PORT ?? 8700);

  if (runApi) {
    try {
      await server.listen({ host: "0.0.0.0", port });
      log.info(`Server is running on port ${port}`);
    } catch (err) {
      log.error({ err }, "failed to start server");
      process.exit(1);
    }
  } else {
    log.info("worker-only mode; HTTP server not started");
  }

  return {
    role,
    server,
    workflowQueue,
    workflowWorker,
    registry,
    shutdown,
  };
}