import { mkdirSync } from "node:fs";

import type { RuntimeMode } from "../shared/api";
import type { ResolvedConfig, ResolvedLoggingConfig } from "./config/types";
import type { Logger } from "./logger";
import type { StartServerOptions } from "./server";

import { loadServerConfig } from "./config";
import { createConsoleFallback, createRuntimeLogger } from "./logger";
import { startServer } from "./server";

export interface BootstrapDependencies {
  createLogger?: (config: ResolvedLoggingConfig, mode: string, version?: string) => Promise<Logger>;
  exit?: (code: number) => never;
  loadConfig?: (configPath: string) => Promise<ResolvedConfig>;
  onSignal?: (signal: "SIGINT" | "SIGTERM", handler: () => void) => void;
  startServer?: (options: StartServerOptions) => unknown;
}

export interface BootstrapOptions {
  configPath: string;
  mode: RuntimeMode;
  staticAssets?: StartServerOptions["staticAssets"];
  version?: string;
}

export async function bootstrap(options: BootstrapOptions, dependencies: BootstrapDependencies = {}): Promise<void> {
  const load = dependencies.loadConfig ?? loadServerConfig;
  const buildLogger = dependencies.createLogger ?? createRuntimeLogger;
  const serve = dependencies.startServer ?? startServer;
  const onSignal =
    dependencies.onSignal ??
    ((signal: "SIGINT" | "SIGTERM", handler: () => void) => {
      process.on(signal, handler);
    });
  const exit = dependencies.exit ?? ((code: number) => process.exit(code));

  const createFallback = (): Logger => createConsoleFallback();

  let logger: Logger | undefined;

  try {
    const config = await load(options.configPath);

    try {
      logger = await buildLogger(config.logging, options.mode, options.version);
    } catch (logInitError) {
      createFallback().fatal(
        `日志初始化失败: ${logInitError instanceof Error ? logInitError.message : String(logInitError)}`,
      );
      exit(1);
    }

    logger!.info(
      { configDir: config.configDir, configPath: options.configPath, mode: options.mode, version: options.version },
      "配置加载成功",
    );

    mkdirSync(config.dataDir, { recursive: true });
    logger!.info({ dataDir: config.dataDir }, "数据目录就绪");

    const shutdown = () => {
      logger?.info("收到退出信号，开始优雅关闭");
      logger?.flush();
      exit(0);
    };
    onSignal("SIGINT", shutdown);
    onSignal("SIGTERM", shutdown);

    serve({
      config: { host: config.host, port: config.port },
      logger: logger!.child({ component: "server" }),
      mode: options.mode,
      staticAssets: options.staticAssets,
      version: options.version,
    });
  } catch (error) {
    if (logger) {
      logger.fatal({ error: error instanceof Error ? error.message : String(error) }, "启动失败");
      logger.flush();
    } else {
      createFallback().fatal(`启动失败: ${error instanceof Error ? error.message : String(error)}`);
    }
    exit(1);
  }
}