import { spawn, execSync, type ChildProcess } from "child_process";
import { BLOG_ROOT } from "./config";

class HugoManager {
  private process: ChildProcess | null = null;
  private ready = false;
  private starting = false;
  private healthTimer: NodeJS.Timeout | null = null;

  async start(): Promise<{ ok: boolean; alreadyRunning?: boolean }> {
    if (this.process && this.ready) {
      return { ok: true, alreadyRunning: true };
    }
    if (this.starting) {
      return { ok: false };
    }

    this.starting = true;
    this.ready = false;

    this.process = spawn("hugo", ["server", "--bind", "0.0.0.0", "--port", "1313", "--disableFastRender", "--noHTTPCache"], {
      cwd: BLOG_ROOT,
      shell: true,
      stdio: "pipe",
      windowsHide: true,
    });

    this.process.stdout?.on("data", (d: Buffer) => process.stdout.write(`[hugo] ${d}`));
    this.process.stderr?.on("data", (d: Buffer) => process.stderr.write(`[hugo] ${d}`));

    this.process.on("exit", (code) => {
      console.log(`[hugo] exited ${code}`);
      this.process = null;
      this.ready = false;
      this.starting = false;
    });

    // 等待 Hugo 就绪（最多 15 秒）
    const ok = await this.waitForReady(15000);
    this.starting = false;
    if (ok) {
      this.ready = true;
      this.startHealthCheck();
      console.log("[hugo] ready on 0.0.0.0:1313");
    }
    return { ok };
  }

  stop(): void {
    this.stopHealthCheck();
    if (!this.process) return;
    try {
      const pid = this.process.pid;
      if (process.platform === "win32" && pid) {
        execSync(`taskkill /PID ${pid} /T /F`, { stdio: "ignore" });
      } else {
        this.process.kill();
      }
    } catch (_e) { /* nothing to kill */ }
    this.process = null;
    this.ready = false;
    this.starting = false;
  }

  status(): { running: boolean; starting: boolean } {
    return { running: !!(this.process && this.ready), starting: this.starting };
  }

  async ensureRunning(): Promise<boolean> {
    if (this.process && this.ready) return true;
    const result = await this.start();
    return result.ok;
  }

  private async waitForReady(timeoutMs: number): Promise<boolean> {
    const start = Date.now();
    while (Date.now() - start < timeoutMs) {
      if (await this.ping()) return true;
      await new Promise((r) => setTimeout(r, 1500));
    }
    return false;
  }

  private async ping(): Promise<boolean> {
    try {
      const res = await fetch("http://127.0.0.1:1313", { signal: AbortSignal.timeout(1500) });
      return res.ok || res.status < 500;
    } catch (_e) {
      return false;
    }
  }

  private startHealthCheck(): void {
    this.stopHealthCheck();
    this.healthTimer = setInterval(async () => {
      if (!this.process) return;
      const alive = await this.ping();
      if (!alive) {
        console.warn("[hugo] health check failed, marking as not ready");
        this.ready = false;
        this.stopHealthCheck();
      }
    }, 30_000);
  }

  private stopHealthCheck(): void {
    if (this.healthTimer) {
      clearInterval(this.healthTimer);
      this.healthTimer = null;
    }
  }
}

export const hugo = new HugoManager();