/**
 * 版本管理模块
 * @module update/version
 */

import type { VersionInfo } from "../types.js";
import { createLogger } from "../utils/logger.js";

const MODULE = "update:version";

/**
 * 当前版本（从 package.json 读取）
 */
let CURRENT_VERSION = "1.0.0";

/**
 * 设置当前版本
 */
export function setCurrentVersion(version: string): void {
  CURRENT_VERSION = version;
}

/**
 * 检查更新
 */
export async function checkUpdate(): Promise<VersionInfo> {
  const log = createLogger(MODULE);

  try {
    // TODO: 从 npm registry 或 GitHub releases 获取最新版本
    // 这里简化处理
    const latestVersion = "1.0.0";
    
    return {
      version: CURRENT_VERSION,
      latestVersion,
      hasUpdate: compareVersions(CURRENT_VERSION, latestVersion) < 0,
    };
  } catch (error) {
    log.error("Failed to check update", error);
    return {
      version: CURRENT_VERSION,
      hasUpdate: false,
    };
  }
}

/**
 * 比较版本号
 * @returns -1: v1 < v2, 0: v1 == v2, 1: v1 > v2
 */
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;
}

/**
 * 解析版本号
 */
export function parseVersion(version: string): {
  major: number;
  minor: number;
  patch: number;
  prerelease?: string;
  build?: string;
} {
  const match = version.match(
    /^(\\d+)\\.(\\d+)\\.(\\d+)(?:-([a-zA-Z0-9.-]+))?(?:\\+([a-zA-Z0-9.-]+))?$/
  );

  if (!match) {
    throw new Error(`Invalid version: ${version}`);
  }

  return {
    major: parseInt(match[1], 10),
    minor: parseInt(match[2], 10),
    patch: parseInt(match[3], 10),
    prerelease: match[4],
    build: match[5],
  };
}