package installer

import (
	"fmt"
	"os"
	"path/filepath"
	"time"

	"skillmgr/internal/adapter"
	"skillmgr/internal/config"
	"skillmgr/internal/prompt"
	"skillmgr/internal/repo"
	"skillmgr/internal/types"
)

// InstallSkill 安装 skill
func InstallSkill(name string, platform types.Platform, scope types.Scope) error {
	return InstallSkillFrom(name, platform, scope, "")
}

// InstallSkillFrom 从指定源安装 skill
// fromURL 为空时从已配置的仓库安装，否则从临时仓库安装
func InstallSkillFrom(name string, platform types.Platform, scope types.Scope, fromURL string) error {
	var skillPath string
	var repoName string
	var cleanup func()

	if fromURL != "" {
		// 从临时仓库安装
		tmpRepo, cleanupFunc, err := repo.CloneTemporary(fromURL, "")
		if err != nil {
			return fmt.Errorf("克隆临时仓库失败: %w", err)
		}
		cleanup = cleanupFunc
		defer cleanup()

		// 检查 skill 是否存在
		sp := filepath.Join(tmpRepo, "skills", name)
		if _, err := os.Stat(filepath.Join(sp, "SKILL.md")); err != nil {
			return fmt.Errorf("skill '%s' 未在临时仓库中找到", name)
		}
		skillPath = sp
		repoName = "(临时)"
	} else {
		// 从已配置的仓库安装
		_, sp, rn, err := repo.FindSkill(name)
		if err != nil {
			// 列出可用的 skills
			skills, _ := repo.ListAvailableSkills()
			if len(skills) > 0 {
				fmt.Println("\n可用的 skills:")
				for _, s := range skills {
					fmt.Printf("  - %s (from %s)\n", s.Name, s.SourceRepo)
				}
			}
			return err
		}
		skillPath = sp
		repoName = rn
	}

	// 2. 获取适配器
	adp, err := adapter.GetAdapter(platform)
	if err != nil {
		return err
	}

	// 3. 确定安装路径
	installPath, err := adp.GetSkillInstallPath(scope, name)
	if err != nil {
		return err
	}

	// 4. 检查是否已存在
	if err := checkExistingInstallation(types.ItemTypeSkill, name, platform, scope, installPath); err != nil {
		return err
	}

	// 5. 适配文件映射
	fileMap, err := adp.AdaptSkill(skillPath, installPath)
	if err != nil {
		return err
	}

	// 6. 事务性安装
	tx, err := NewTransaction(installPath, fileMap)
	if err != nil {
		return err
	}
	defer tx.Rollback() // 确保失败时清理

	if err := tx.Stage(); err != nil {
		return fmt.Errorf("staging 失败: %w", err)
	}

	if err := tx.Commit(); err != nil {
		return fmt.Errorf("commit 失败: %w", err)
	}

	// 7. 记录安装
	record := types.InstallRecord{
		Type:        types.ItemTypeSkill,
		Name:        name,
		SourceRepo:  repoName,
		Platform:    platform,
		Scope:       scope,
		InstallPath: installPath,
		InstalledAt: time.Now(),
		UpdatedAt:   time.Now(),
	}

	// 先移除旧记录（如果存在）
	config.RemoveInstallRecord(types.ItemTypeSkill, name, platform, scope)

	if err := config.AddInstallRecord(record); err != nil {
		return fmt.Errorf("保存安装记录失败: %w", err)
	}

	fmt.Printf("✓ Skill '%s' 已安装到 %s\n", name, installPath)
	return nil
}

// InstallCommand 安装 command
func InstallCommand(name string, platform types.Platform, scope types.Scope) error {
	return InstallCommandFrom(name, platform, scope, "")
}

// InstallCommandFrom 从指定源安装 command
// fromURL 为空时从已配置的仓库安装，否则从临时仓库安装
func InstallCommandFrom(name string, platform types.Platform, scope types.Scope, fromURL string) error {
	var commandPath string
	var repoName string
	var cleanup func()

	if fromURL != "" {
		// 从临时仓库安装
		tmpRepo, cleanupFunc, err := repo.CloneTemporary(fromURL, "")
		if err != nil {
			return fmt.Errorf("克隆临时仓库失败: %w", err)
		}
		cleanup = cleanupFunc
		defer cleanup()

		// 检查 command 是否存在
		cp := filepath.Join(tmpRepo, "commands", name)
		if info, err := os.Stat(cp); err != nil || !info.IsDir() {
			return fmt.Errorf("command '%s' 未在临时仓库中找到", name)
		}

		// 检查是否包含 .md 文件
		files, _ := filepath.Glob(filepath.Join(cp, "*.md"))
		if len(files) == 0 {
			return fmt.Errorf("command group '%s' 不包含任何命令文件", name)
		}

		commandPath = cp
		repoName = "(临时)"
	} else {
		// 从已配置的仓库安装
		_, cp, rn, err := repo.FindCommand(name)
		if err != nil {
			// 列出可用的 commands
			commands, _ := repo.ListAvailableCommands()
			if len(commands) > 0 {
				fmt.Println("\n可用的 commands:")
				for _, c := range commands {
					fmt.Printf("  - %s (from %s)\n", c.Name, c.SourceRepo)
				}
			}
			return err
		}
		commandPath = cp
		repoName = rn
	}

	// 2. 获取适配器
	adp, err := adapter.GetAdapter(platform)
	if err != nil {
		return err
	}

	// 3. 确定安装路径
	installPath, err := adp.GetCommandInstallPath(scope, name)
	if err != nil {
		return err
	}

	// 4. 检查是否已存在
	if err := checkExistingInstallation(types.ItemTypeCommand, name, platform, scope, installPath); err != nil {
		return err
	}

	// 5. 适配文件映射
	fileMap, err := adp.AdaptCommand(commandPath, installPath, name)
	if err != nil {
		return err
	}

	// 6. 事务性安装
	tx, err := NewTransaction(installPath, fileMap)
	if err != nil {
		return err
	}
	defer tx.Rollback()

	if err := tx.Stage(); err != nil {
		return fmt.Errorf("staging 失败: %w", err)
	}

	if err := tx.Commit(); err != nil {
		return fmt.Errorf("commit 失败: %w", err)
	}

	// 7. 记录安装
	record := types.InstallRecord{
		Type:        types.ItemTypeCommand,
		Name:        name,
		SourceRepo:  repoName,
		Platform:    platform,
		Scope:       scope,
		InstallPath: installPath,
		InstalledAt: time.Now(),
		UpdatedAt:   time.Now(),
	}

	// 先移除旧记录（如果存在）
	config.RemoveInstallRecord(types.ItemTypeCommand, name, platform, scope)

	if err := config.AddInstallRecord(record); err != nil {
		return fmt.Errorf("保存安装记录失败: %w", err)
	}

	fmt.Printf("✓ Command '%s' 已安装到 %s\n", name, installPath)
	return nil
}

// checkExistingInstallation 检查现有安装
func checkExistingInstallation(itemType types.ItemType, name string, platform types.Platform, scope types.Scope, installPath string) error {
	// 检查 install.json 中是否有记录
	record, err := config.FindInstallRecord(itemType, name, platform, scope)
	if err != nil {
		return err
	}

	// 检查目录是否实际存在
	_, dirErr := os.Stat(installPath)
	dirExists := dirErr == nil

	if record != nil && dirExists {
		// 已安装，询问是否覆盖
		if !prompt.Confirm(fmt.Sprintf("%s '%s' 已安装。是否覆盖?", itemType, name)) {
			return fmt.Errorf("用户取消安装")
		}
	} else if record == nil && dirExists {
		// 目录存在但没有记录，询问是否覆盖
		if !prompt.Confirm(fmt.Sprintf("目录 %s 已存在但不是由 skillmgr 管理。是否覆盖?", installPath)) {
			return fmt.Errorf("用户取消安装")
		}
	}

	return nil
}

// UpdateSkill 更新 skill
func UpdateSkill(name string, platform types.Platform, scope types.Scope) error {
	// 查找记录
	record, err := config.FindInstallRecord(types.ItemTypeSkill, name, platform, scope)
	if err != nil {
		return err
	}
	if record == nil {
		return fmt.Errorf("未找到 skill '%s' 的安装记录", name)
	}

	// 重新安装
	if err := InstallSkill(name, platform, scope); err != nil {
		return err
	}

	// 更新记录时间
	record.UpdatedAt = time.Now()
	return config.UpdateInstallRecord(*record)
}

// UpdateCommand 更新 command
func UpdateCommand(name string, platform types.Platform, scope types.Scope) error {
	// 查找记录
	record, err := config.FindInstallRecord(types.ItemTypeCommand, name, platform, scope)
	if err != nil {
		return err
	}
	if record == nil {
		return fmt.Errorf("未找到 command '%s' 的安装记录", name)
	}

	// 重新安装
	if err := InstallCommand(name, platform, scope); err != nil {
		return err
	}

	// 更新记录时间
	record.UpdatedAt = time.Now()
	return config.UpdateInstallRecord(*record)
}