package repo

import (
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
	"strings"

	"skillmgr/internal/config"
)

// URLToPathName 将 URL 转换为缓存目录名
// 例如: https://github.com/user/repo.git -> github.com_user_repo
func URLToPathName(url string) string {
	clean := strings.TrimPrefix(url, "https://")
	clean = strings.TrimPrefix(clean, "http://")
	clean = strings.TrimSuffix(clean, ".git")
	clean = strings.ReplaceAll(clean, "/", "_")
	return clean
}

// CloneOrPull 克隆或更新仓库
// 如果仓库不存在则 clone，存在则 pull
func CloneOrPull(url, branch string) (string, error) {
	cachePath, err := config.GetCachePath()
	if err != nil {
		return "", err
	}

	repoPath := filepath.Join(cachePath, URLToPathName(url))

	// 检查是否已存在
	if _, err := os.Stat(filepath.Join(repoPath, ".git")); err == nil {
		// 已存在，执行 pull
		return repoPath, pullRepo(repoPath, branch)
	}

	// 不存在，执行 clone
	return repoPath, cloneRepo(url, branch, repoPath)
}

// cloneRepo 克隆仓库
func cloneRepo(url, branch, dest string) error {
	args := []string{"clone", "--depth", "1"}
	if branch != "" {
		args = append(args, "--branch", branch)
	}
	args = append(args, url, dest)

	cmd := exec.Command("git", args...)
	output, err := cmd.CombinedOutput()
	if err != nil {
		return fmt.Errorf("git clone 失败: %w\n%s", err, output)
	}
	return nil
}

// pullRepo 更新仓库
func pullRepo(path, branch string) error {
	// 先 fetch
	fetchCmd := exec.Command("git", "-C", path, "fetch", "origin")
	if output, err := fetchCmd.CombinedOutput(); err != nil {
		return fmt.Errorf("git fetch 失败: %w\n%s", err, output)
	}

	// 然后 pull
	pullArgs := []string{"-C", path, "pull", "origin"}
	if branch != "" {
		pullArgs = append(pullArgs, branch)
	}
	pullCmd := exec.Command("git", pullArgs...)
	output, err := pullCmd.CombinedOutput()
	if err != nil {
		return fmt.Errorf("git pull 失败: %w\n%s", err, output)
	}
	return nil
}

// GetRepoPath 获取仓库缓存路径
func GetRepoPath(url string) (string, error) {
	cachePath, err := config.GetCachePath()
	if err != nil {
		return "", err
	}
	return filepath.Join(cachePath, URLToPathName(url)), nil
}

// CloneTemporary 克隆临时仓库到临时目录
// 返回临时目录路径和清理函数
func CloneTemporary(url, branch string) (repoPath string, cleanup func(), err error) {
	// 创建临时目录
	tmpDir, err := os.MkdirTemp("", "skillmgr-temp-*")
	if err != nil {
		return "", nil, fmt.Errorf("创建临时目录失败: %w", err)
	}

	cleanup = func() {
		os.RemoveAll(tmpDir)
	}

	// 克隆到临时目录
	if err := cloneRepo(url, branch, tmpDir); err != nil {
		cleanup()
		return "", nil, err
	}

	return tmpDir, cleanup, nil
}