package config

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

// ValidationError 表示配置验证错误
type ValidationError struct {
	Field   string
	Message string
}

// ValidationResult 表示配置验证结果
type ValidationResult struct {
	Valid  bool
	Errors []ValidationError
}

// String 返回验证结果的字符串表示
func (vr ValidationResult) String() string {
	if vr.Valid {
		return "配置验证通过"
	}

	var sb strings.Builder
	sb.WriteString(fmt.Sprintf("配置验证失败，共有 %d 个错误：\n", len(vr.Errors)))
	for i, err := range vr.Errors {
		sb.WriteString(fmt.Sprintf("%d. %s: %s\n", i+1, err.Field, err.Message))
	}
	return sb.String()
}

// Validate 验证配置是否有效
func (c *Config) Validate(strict bool) ValidationResult {
	result := ValidationResult{
		Valid:  true,
		Errors: []ValidationError{},
	}

	// 验证基本信息
	if c.Name == "" {
		result.Valid = false
		result.Errors = append(result.Errors, ValidationError{
			Field:   "name",
			Message: "安装包名称不能为空",
		})
	}

	if c.Version == "" {
		result.Valid = false
		result.Errors = append(result.Errors, ValidationError{
			Field:   "version",
			Message: "安装包版本不能为空",
		})
	}

	// 验证构建设置
	if len(c.Build.Targets) == 0 {
		result.Valid = false
		result.Errors = append(result.Errors, ValidationError{
			Field:   "build.targets",
			Message: "至少需要指定一个目标平台",
		})
	}

	if len(c.Build.Formats) == 0 {
		result.Valid = false
		result.Errors = append(result.Errors, ValidationError{
			Field:   "build.formats",
			Message: "至少需要指定一个输出格式",
		})
	}

	// 验证文件和目录
	for i, file := range c.Contents.Files {
		if file.Source == "" {
			result.Valid = false
			result.Errors = append(result.Errors, ValidationError{
				Field:   fmt.Sprintf("contents.files[%d].source", i),
				Message: "源文件路径不能为空",
			})
		} else if strict {
			// 在严格模式下，验证源文件是否存在
			if _, err := os.Stat(file.Source); os.IsNotExist(err) {
				result.Valid = false
				result.Errors = append(result.Errors, ValidationError{
					Field:   fmt.Sprintf("contents.files[%d].source", i),
					Message: fmt.Sprintf("源文件 '%s' 不存在", file.Source),
				})
			}
		}

		if file.Destination == "" {
			result.Valid = false
			result.Errors = append(result.Errors, ValidationError{
				Field:   fmt.Sprintf("contents.files[%d].destination", i),
				Message: "目标路径不能为空",
			})
		}
	}

	// 验证脚本
	for i, script := range c.Contents.Scripts {
		if script.Type == "" {
			result.Valid = false
			result.Errors = append(result.Errors, ValidationError{
				Field:   fmt.Sprintf("contents.scripts[%d].type", i),
				Message: "脚本类型不能为空",
			})
		} else if !isValidScriptType(script.Type) {
			result.Valid = false
			result.Errors = append(result.Errors, ValidationError{
				Field:   fmt.Sprintf("contents.scripts[%d].type", i),
				Message: fmt.Sprintf("无效的脚本类型: %s", script.Type),
			})
		}

		if script.Content == "" && script.Source == "" {
			result.Valid = false
			result.Errors = append(result.Errors, ValidationError{
				Field:   fmt.Sprintf("contents.scripts[%d]", i),
				Message: "脚本内容和源文件路径不能同时为空",
			})
		}

		if script.Source != "" && strict {
			// 在严格模式下，验证脚本源文件是否存在
			if _, err := os.Stat(script.Source); os.IsNotExist(err) {
				result.Valid = false
				result.Errors = append(result.Errors, ValidationError{
					Field:   fmt.Sprintf("contents.scripts[%d].source", i),
					Message: fmt.Sprintf("脚本源文件 '%s' 不存在", script.Source),
				})
			}
		}
	}

	// 验证符号链接
	for i, symlink := range c.Contents.Symlinks {
		if symlink.Source == "" {
			result.Valid = false
			result.Errors = append(result.Errors, ValidationError{
				Field:   fmt.Sprintf("contents.symlinks[%d].source", i),
				Message: "符号链接源路径不能为空",
			})
		}

		if symlink.Destination == "" {
			result.Valid = false
			result.Errors = append(result.Errors, ValidationError{
				Field:   fmt.Sprintf("contents.symlinks[%d].destination", i),
				Message: "符号链接目标路径不能为空",
			})
		}
	}

	// 验证平台特定配置
	for _, target := range c.Build.Targets {
		switch target {
		case "windows":
			// 验证Windows MSI配置
			if containsFormat(c.Build.Formats, "msi") {
				if c.Platforms.Windows.Msi.UpgradeCode == "" && strict {
					result.Valid = false
					result.Errors = append(result.Errors, ValidationError{
						Field:   "platforms.windows.msi.upgradeCode",
						Message: "MSI升级代码不能为空",
					})
				}
			}
		case "linux":
			// 验证Linux DEB配置
			if containsFormat(c.Build.Formats, "deb") {
				// 可以添加更多DEB特定的验证
			}

			// 验证Linux RPM配置
			if containsFormat(c.Build.Formats, "rpm") {
				// 可以添加更多RPM特定的验证
			}
		}
	}

	return result
}

// 检查是否为有效的脚本类型
func isValidScriptType(scriptType string) bool {
	validTypes := []string{
		"preinstall",
		"postinstall",
		"preuninstall",
		"postuninstall",
	}

	for _, validType := range validTypes {
		if scriptType == validType {
			return true
		}
	}

	return false
}

// 检查格式列表是否包含指定格式
func containsFormat(formats []string, format string) bool {
	for _, f := range formats {
		if f == format {
			return true
		}
	}
	return false
}

// ValidateConfigFile 验证指定路径的配置文件
func ValidateConfigFile(path string, strict bool) (ValidationResult, error) {
	config, err := LoadConfig(path)
	if err != nil {
		return ValidationResult{
			Valid: false,
			Errors: []ValidationError{
				{
					Field:   "file",
					Message: err.Error(),
				},
			},
		}, err
	}

	// 设置工作目录为配置文件所在目录，以便相对路径的验证
	if strict {
		oldWd, err := os.Getwd()
		if err != nil {
			return ValidationResult{}, err
		}
		defer os.Chdir(oldWd)

		configDir := filepath.Dir(path)
		if err := os.Chdir(configDir); err != nil {
			return ValidationResult{}, err
		}
	}

	return config.Validate(strict), nil
}