import Fastify from "fastify";
import config from "@/lib/config";
import { accessSync, constants as fsConst } from "node:fs";
import staticStream from "@fastify/static";
import { styleText } from "node:util";
import Routes from "@/routes";
import Database from "@/lib/db";
import Logger from "@/lib/logger";
import AccessLog from "@/lib/access";
import Authorization from "@/lib/auth";
import { RequestContext } from "@mikro-orm/core";
import { DatabaseError, ErrorBase } from "@/errors";
import { ConfigEntity } from "@/modules/entities/Config";

process.title = "LynqChat";

const logger = new Logger("Core");
logger.info("Process started...");

if (process.env.NODE_ENV !== "production") {
  process.title = "LynqChat backend";
  logger.warn(styleText(["red", "bold", "bgYellow"], "Development environment avaiable!!"));
}

const fastify = Fastify({
  logger: false,
  trustProxy: config.server.trustProxy,
  bodyLimit: 1024 * 100,
});

try {
	fastify.setErrorHandler((err, req, res) => {
    res.header("Content-Type", "application/json");

    const customLogger = new Logger("Unknown(Error handler)");
    customLogger.error("Unknown error:", err);

    return res.status(500).send(ErrorBase({
      bad: "server",
      code: "unknown_error",
      message: "不明なエラーが発生しました。",
    }));
  });

  if (process.env.NODE_ENV === "production") {
    try {
      accessSync(`${import.meta.dirname}/../../frontend/dist/index.html`, fsConst.R_OK);

      await fastify.register(staticStream, {
        root: `${import.meta.dirname}/../../frontend/dist`,
        index: "/",
      });
    } catch (err) {
      logger.error("It's in production but the frontend dist is not found.");
      process.exit(1);
    }
  }

  fastify.setNotFoundHandler((req, res) => {
    if (req.url.startsWith("/api")) {
      res.header("Content-Type", "application/json");

      return res.code(404).send(ErrorBase({
        bad: "client",
        code: "endpoint_not_found",
        message: "エンドポイントが見つかりませんでした。",
      }));
    }

    if (process.env.NODE_ENV === "production") {
      return res.sendFile("index.html");
    }

    return res.code(500).send();
  });

  await fastify.register(Database);
  
  fastify.addHook("onRequest", (req, res, done) => {
    RequestContext.create(fastify.orm.em, done);
  });

	fastify.addHook("onRequest", async (req, res) => {
    if (
			req.url.startsWith("/api") &&
			!req.url.startsWith("/api/setup")
		) {
			try {
				const configCount = await fastify.orm.em.count(ConfigEntity);

				if (configCount === 0) {
					return res.code(409).send(ErrorBase({
						bad: "client",
						code: "yet_initialization",
						message: "初期設定が行われていません。",
					}));
				}
			} catch (err) {
        const customLogger = new Logger("Check already initialized hook");
				customLogger.error("Database error: Could not check if already initialization:", err);

				return res.code(500).send(DatabaseError());
			}
		}
	});

  await fastify.register(AccessLog);
  await fastify.register(Authorization);

  fastify.removeAllContentTypeParsers();

  fastify.addContentTypeParser("application/json", { parseAs: "string" }, (req, body, done) => {
    try {
      const json = JSON.parse(
        typeof body === "string"
          ? body
          : body.toString("utf-8")
      );

      done(null, json);
    } catch (err) {
      done(null, {});
    }
  });

  await fastify.register(Routes, {
    prefix: "/api",
  });

  const addr = await fastify.listen({
    port: config.server.port,
    host: config.server.host,
  });

  if (process.env.NODE_ENV === "production") {
    logger.info(`Listening at ${addr}`);
  } else {
    logger.info(`Backend listening at ${addr}`);
  }
} catch (err) {
  logger.error(err);
  process.exit(1);
}

const shutdown = async () => {
  try {
    await fastify.close();
    logger.log("Server downed.");
    process.exit(0);
  } catch (err) {
    logger.error("Server down failed", err);
    process.exit(1);
  }
};

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