import fs from "fs";
import path from "path";
import { spawn } from "child_process";

// ============================================================
// 版本更新模块
// 用于检查远程仓库版本并执行 Docker 容器更新
// ============================================================

/** .version JSON 文件结构 */
export interface VersionFile {
  version: string;
  release_date: string;
  changelog: string;
}

/** 版本信息（API 返回给前端） */
export interface VersionInfo {
  current: VersionFile;
  latest: VersionFile | null;
  hasUpdate: boolean;
  currentCommit?: string;
  latestCommit?: string;
  /** 状态消息，如 "远程仓库未包含 .version 文件" */
  message?: string;
}

/** 默认版本文件 */
const DEFAULT_VERSION: VersionFile = {
  version: "0.0.0",
  release_date: "",
  changelog: "",
};

/** 更新配置 */
interface UpdateConfig {
  remoteUrl: string;
  accessToken: string;
}

/** 更新日志回调 */
export type LogCallback = (message: string) => void;

/** 空回调 */
const noopLog: LogCallback = () => {};

/** 带时间戳的控制台日志 */
function consoleLog(tag: string, msg: string): void {
  const t = new Date().toISOString().slice(0, 19).replace("T", " ");
  console.log(`[${t}] [更新:${tag}] ${msg}`);
}

/** 带时间戳的控制台错误 */
function consoleErr(tag: string, msg: string): void {
  const t = new Date().toISOString().slice(0, 19).replace("T", " ");
  console.error(`[${t}] [更新:${tag}] ${msg}`);
}

/**
 * 异步执行命令，实时流式输出（不阻塞事件循环）
 * @param command 可执行文件
 * @param args 参数列表
 * @param tag 日志标签
 * @param options.onLine 每行输出回调（用于 SSE 推送到前端）
 */
function execAsync(
  command: string,
  args: string[],
  tag: string,
  options?: {
    timeout?: number;
    cwd?: string;
    onLine?: (line: string) => void;
  }
): Promise<void> {
  return new Promise((resolve, reject) => {
    const desc = `${command} ${args.join(" ")}`;
    consoleLog(tag, `执行: ${desc}`);

    const child = spawn(command, args, {
      cwd: options?.cwd,
      timeout: options?.timeout,
      stdio: ["ignore", "pipe", "pipe"],
      windowsHide: true,
    });

    let timedOut = false;
    if (options?.timeout) {
      const timer = setTimeout(() => {
        timedOut = true;
        child.kill();
        reject(new Error(`命令超时 (${options.timeout}ms): ${desc}`));
      }, options.timeout);
      child.on("close", () => clearTimeout(timer));
    }

    const handleData = (data: Buffer, isStderr: boolean) => {
      const str = data.toString();
      const lines = str.split("\n").filter(Boolean);
      for (const raw of lines) {
        const line = raw.trimEnd();
        if (!line) continue;
        if (isStderr) {
          consoleErr(tag, `  │ ${line.slice(0, 2000)}`);
        } else {
          consoleLog(tag, `  │ ${line.slice(0, 2000)}`);
        }
        options?.onLine?.(line);
      }
    };

    child.stdout?.on("data", (data: Buffer) => handleData(data, false));
    child.stderr?.on("data", (data: Buffer) => handleData(data, true));

    child.on("close", (code) => {
      if (timedOut) return;
      if (code === 0) {
        consoleLog(tag, `✓ 完成`);
        resolve();
      } else {
        consoleErr(tag, `失败 (exit=${code})`);
        reject(new Error(`Command failed with exit code ${code}: ${desc}`));
      }
    });

    child.on("error", (err) => {
      if (timedOut) return;
      consoleErr(tag, `异常: ${err.message}`);
      reject(err);
    });
  });
}

/**
 * 读取并解析本地的 .version 文件
 */
export function readLocalVersionFile(): VersionFile {
  try {
    const versionPath = path.join(process.cwd(), ".version");
    const content = fs.readFileSync(versionPath, "utf-8").trim();
    return JSON.parse(content) as VersionFile;
  } catch {
    return DEFAULT_VERSION;
  }
}

/**
 * 获取更新配置
 */
function getUpdateConfig(): UpdateConfig {
  return {
    remoteUrl:
      process.env.GIT_REMOTE_URL || "https://git.hanhan.ltd/recipe_tool.git",
    accessToken: process.env.ONEDEV_ACCESS_TOKEN || "",
  };
}

/**
 * 构建带认证的远程 URL
 */
function getAuthenticatedRemoteUrl(): string {
  const config = getUpdateConfig();
  if (!config.accessToken) return config.remoteUrl;
  const url = new URL(config.remoteUrl);
  url.username = "access-token";
  url.password = config.accessToken;
  return url.toString();
}

/**
 * 通过 git ls-remote 获取远程最新 commit hash
 */
export async function getRemoteCommitHash(): Promise<string | null> {
  try {
    const url = getAuthenticatedRemoteUrl();
    let stdout = "";
    await execAsync("git", ["ls-remote", url, "HEAD"], "git-ls-remote", {
      timeout: 15000,
      onLine: (line) => { stdout += line + "\n"; },
    });
    const match = stdout.match(/^([a-f0-9]+)\s+HEAD/m);
    return match?.[1] || null;
  } catch {
    return null;
  }
}

/**
 * 获取远程 .version 文件内容并解析为 VersionFile
 */
export async function getRemoteVersionFile(): Promise<VersionFile | null> {
  // 尝试方式1: git archive
  try {
    const url = getAuthenticatedRemoteUrl();
    let stdout = "";
    await execAsync("git", ["archive", `--remote=${url}`, "HEAD:.version"], "git-archive", {
      timeout: 15000,
      onLine: (line) => { stdout += line; },
    });
    const parsed = JSON.parse(stdout.trim()) as VersionFile;
    if (parsed.version) return parsed;
  } catch {
    // fall through
  }

  // 尝试方式2: 浅克隆
  return getRemoteVersionByClone();
}

/**
 * 通过浅克隆获取远程 .version 文件（备选方案）
 * OneDev 不支持 git archive --remote，改用完整浅克隆
 */
async function getRemoteVersionByClone(): Promise<VersionFile | null> {
  const tmpDir = path.join(
    process.env.TEMP || "/tmp",
    `recipe_tool_version_${Date.now()}`
  );
  try {
    const url = getAuthenticatedRemoteUrl();
    await execAsync("git", ["clone", "--depth", "1", url, tmpDir], "git-clone", {
      timeout: 60000,
    });
    const versionPath = path.join(tmpDir, ".version");
    if (fs.existsSync(versionPath)) {
      const content = fs.readFileSync(versionPath, "utf-8").trim();
      return JSON.parse(content) as VersionFile;
    }
    return null;
  } catch {
    return null;
  } finally {
    try {
      fs.rmSync(tmpDir, { recursive: true, force: true });
    } catch {
      // ignore cleanup errors
    }
  }
}

/**
 * 比较两个语义化版本号
 * 返回: 1 = v1 > v2, -1 = v1 < v2, 0 = equal
 */
export function compareVersions(v1: string, v2: string): number {
  const parts1 = v1.split(".").map(Number);
  const parts2 = v2.split(".").map(Number);

  for (let i = 0; i < Math.max(parts1.length, parts2.length); i++) {
    const p1 = parts1[i] || 0;
    const p2 = parts2[i] || 0;
    if (p1 > p2) return 1;
    if (p1 < p2) return -1;
  }
  return 0;
}

/**
 * 检查是否有可用更新
 */
export async function checkForUpdate(): Promise<VersionInfo> {
  consoleLog("检查", "开始检查版本更新");

  const current = readLocalVersionFile();
  consoleLog("检查", `当前版本: v${current.version} (${current.release_date || "无日期"})`);

  const remoteCommit = await getRemoteCommitHash();

  if (!remoteCommit) {
    consoleErr("检查", "无法连接到远程仓库");
    return {
      current,
      latest: null,
      hasUpdate: false,
      message: "无法连接到远程仓库，请检查网络和 ONEDEV_ACCESS_TOKEN 配置",
    };
  }

  consoleLog("检查", `远程 HEAD: ${remoteCommit}`);
  const remoteVersionFile = await getRemoteVersionFile();

  if (remoteVersionFile) {
    const cmp = compareVersions(remoteVersionFile.version, current.version);
    consoleLog(
      "检查",
      `远程版本: v${remoteVersionFile.version} → ${cmp > 0 ? "有新版本" : "已是最新"}`
    );
    return {
      current,
      latest: remoteVersionFile,
      hasUpdate: cmp > 0,
      latestCommit: remoteCommit,
    };
  }

  consoleErr("检查", "远程仓库中未找到 .version 文件");
  return {
    current,
    latest: null,
    hasUpdate: false,
    latestCommit: remoteCommit,
    message:
      "远程仓库中未找到 .version 文件。\n" +
      "请确保 .version 文件已提交并推送到远程仓库：\n" +
      "  git add .version && git commit -m \"add version file\" && git push",
  };
}

/**
 * 检查 Docker 是否可用
 */
async function checkDockerAvailable(): Promise<{ ok: boolean; message: string }> {
  consoleLog("Docker", "检查 Docker 守护进程...");
  try {
    await execAsync("docker", ["info"], "Docker");
    consoleLog("Docker", "✓ Docker 正常");
    return { ok: true, message: "" };
  } catch {
    consoleErr("Docker", "✗ Docker 不可用");
    return {
      ok: false,
      message:
        "Docker 守护进程不可用。\n" +
        "更新功能需要在 Docker 容器内运行，当前环境不支持。\n" +
        "如需测试，请使用 Docker 部署后访问容器内的页面：\n" +
        "  docker compose -p recipe_tool up -d\n" +
        "然后访问 http://localhost:8011/settings/update",
    };
  }
}

/**
 * 执行 Docker 容器更新
 * @param onLog 日志回调
 */
const REGISTRY_IMAGE = "git.hanhan.ltd/recipe_tool/recipe_tool:latest";

export async function executeUpdate(
  onLog: LogCallback = noopLog
): Promise<{ success: boolean; message: string }> {
  const cwd = process.cwd(); // /app（容器内工作目录，含 docker-compose.yml）
  const token = process.env.ONEDEV_ACCESS_TOKEN || "";

  consoleLog("执行", "=== 开始执行更新 ===");
  consoleLog("执行", `工作目录: ${cwd}, 镜像: ${REGISTRY_IMAGE}`);

  const logLine = (line: string) => onLog(line);

  try {
    onLog("开始更新流程");

    // 0. 检查 Docker 是否可用
    onLog("[0/4] 检查 Docker 环境");
    consoleLog("执行", "步骤 0/4 — 检查 Docker 环境");
    const dockerCheck = await checkDockerAvailable();
    if (!dockerCheck.ok) {
      onLog(`✗ ${dockerCheck.message}`);
      consoleErr("执行", "Docker 检查未通过，更新终止");
      return { success: false, message: dockerCheck.message };
    }
    onLog("✓ Docker 环境正常");

    // 1. 登录 OneDev 镜像仓库并拉取最新镜像
    onLog("[1/4] 登录镜像仓库");
    consoleLog("执行", "步骤 1/4 — 登录 OneDev 镜像仓库");
    if (token) {
      await execAsync(
        "sh",
        ["-c", `echo "${token}" | docker login git.hanhan.ltd -u access-token --password-stdin`],
        "docker-login",
        { timeout: 15000, onLine: logLine }
      );
    } else {
      onLog("⚠ 未配置 ONEDEV_ACCESS_TOKEN，尝试匿名拉取");
      consoleLog("执行", "未配置 access token，尝试匿名拉取");
    }

    onLog("[1/4] 拉取新镜像");
    consoleLog("执行", "步骤 1/4 — 拉取镜像");
    await execAsync("docker", ["pull", REGISTRY_IMAGE], "docker-pull", {
      timeout: 300000,
      onLine: logLine,
    });
    onLog("✓ 镜像拉取完成");

    // 2. 生成 .env 配置文件（供 docker-compose 解析 ${VAR}）
    onLog("[2/4] 准备环境变量");
    consoleLog("执行", "步骤 2/4 — 准备环境变量");
    const envContent = [
      `DB_HOST=${process.env.DB_HOST || "127.0.0.1"}`,
      `DB_PORT=${process.env.DB_PORT || "3306"}`,
      `DB_USER=${process.env.DB_USER || "root"}`,
      `DB_PASSWORD=${process.env.DB_PASSWORD || ""}`,
      `DB_NAME=${process.env.DB_NAME || "recipe_tools"}`,
      `AI_API_KEY=${process.env.AI_API_KEY || ""}`,
      `AI_BASE_URL=${process.env.AI_BASE_URL || "https://api.openai.com/v1"}`,
      `AI_MODEL=${process.env.AI_MODEL || "gpt-3.5-turbo"}`,
      `ONEDEV_ACCESS_TOKEN=${token}`,
      `GIT_REMOTE_URL=${process.env.GIT_REMOTE_URL || "https://git.hanhan.ltd/recipe_tool.git"}`,
    ].join("\n");
    fs.writeFileSync(path.join(cwd, ".env"), envContent, "utf-8");
    consoleLog("执行", `.env 已写入 ${envContent.split("\n").length} 行`);
    onLog("✓ 环境变量已准备");

    // 3. 停止旧容器（释放端口），忽略失败
    onLog("[3/4] 停止旧容器");
    consoleLog("执行", "步骤 3/4 — 停止旧容器");
    try {
      await execAsync("docker-compose", ["-p", "recipe_tool", "down", "--remove-orphans"], "docker-down", {
        cwd,
        timeout: 30000,
        onLine: logLine,
      });
    } catch {
      consoleLog("执行", "旧容器停止（可能不存在，忽略）");
    }
    onLog("✓ 旧容器已停止");

    // 4. 启动新容器（使用拉取的镜像）
    onLog("[4/4] 启动新容器");
    consoleLog("执行", "步骤 4/4 — 启动新容器");
    await execAsync("docker-compose", ["-p", "recipe_tool", "up", "-d"], "docker-up", {
      cwd,
      timeout: 60000,
      onLine: logLine,
    });
    onLog("✓ 新容器已启动");

    consoleLog("执行", "=== 更新成功 ===");
    return { success: true, message: "更新完成" };
  } catch (error) {
    const errMsg = error instanceof Error ? error.message : "未知错误";
    consoleErr("执行", `=== 更新失败: ${errMsg} ===`);
    onLog(`✗ 更新失败: ${errMsg}`);
    return { success: false, message: errMsg };
  }
}