database_render/internal/template/version_manager.go

package template

import (
	"fmt"
	"log/slog"
	"os"
	"path/filepath"
	"time"
)

// VersionManager manages template versioning and rollback
type VersionManager struct {
	basePath string
	versions map[string][]VersionInfo
	logger   *slog.Logger
}

// VersionInfo holds information about a template version
type VersionInfo struct {
	Version     string    `json:"version"`
	Timestamp   time.Time `json:"timestamp"`
	FilePath    string    `json:"file_path"`
	Hash        string    `json:"hash"`
	Description string    `json:"description"`
	Author      string    `json:"author"`
	Size        int64     `json:"size"`
	Active      bool      `json:"active"`
}

// VersionHistory holds the complete version history for a template
type VersionHistory struct {
	TemplateName string        `json:"template_name"`
	Versions     []VersionInfo `json:"versions"`
	Current      VersionInfo   `json:"current"`
}

// NewVersionManager creates a new version manager
func NewVersionManager(basePath string) *VersionManager {
	return &VersionManager{
		basePath: basePath,
		versions: make(map[string][]VersionInfo),
		logger:   slog.With("component", "version_manager"),
	}
}

// SaveVersion saves a new version of a template
func (vm *VersionManager) SaveVersion(templateName, templatePath, description, author string) error {
	// Create versions directory
	versionsDir := filepath.Join(vm.basePath, "versions", templateName)
	if err := os.MkdirAll(versionsDir, 0755); err != nil {
		return fmt.Errorf("failed to create versions directory: %w", err)
	}

	// Generate version info
	version := vm.generateVersion()
	versionFile := filepath.Join(versionsDir, fmt.Sprintf("%s_%s.html", templateName, version))

	// Read current template content
	content, err := os.ReadFile(templatePath)
	if err != nil {
		return fmt.Errorf("failed to read template: %w", err)
	}

	// Calculate hash
	hash := vm.calculateHash(content)

	// Get file info
	info, err := os.Stat(templatePath)
	if err != nil {
		return fmt.Errorf("failed to get file info: %w", err)
	}

	// Create version info
	versionInfo := VersionInfo{
		Version:     version,
		Timestamp:   time.Now(),
		FilePath:    versionFile,
		Hash:        hash,
		Description: description,
		Author:      author,
		Size:        info.Size(),
		Active:      true,
	}

	// Save template content
	if err := os.WriteFile(versionFile, content, 0644); err != nil {
		return fmt.Errorf("failed to save version: %w", err)
	}

	// Update versions map
	if vm.versions[templateName] == nil {
		vm.versions[templateName] = []VersionInfo{}
	}
	
	// Deactivate previous versions
	for i := range vm.versions[templateName] {
		vm.versions[templateName][i].Active = false
	}
	
	vm.versions[templateName] = append(vm.versions[templateName], versionInfo)

	// Persist version metadata
	if err := vm.saveVersionMetadata(templateName); err != nil {
		vm.logger.Warn("failed to save version metadata", "error", err)
	}

	vm.logger.Info("template version saved", 
		"template", templateName, 
		"version", version, 
		"author", author)

	return nil
}

// Rollback rolls back to a specific version
func (vm *VersionManager) Rollback(templateName, version string) error {
	versions := vm.versions[templateName]
	if len(versions) == 0 {
		return fmt.Errorf("no versions found for template: %s", templateName)
	}

	var targetVersion *VersionInfo
	for i := range versions {
		if versions[i].Version == version {
			targetVersion = &versions[i]
			break
		}
	}

	if targetVersion == nil {
		return fmt.Errorf("version %s not found for template %s", version, templateName)
	}

	// Read version content
	content, err := os.ReadFile(targetVersion.FilePath)
	if err != nil {
		return fmt.Errorf("failed to read version content: %w", err)
	}

	// Write to current template
	currentPath := filepath.Join(vm.basePath, templateName+".html")
	if err := os.WriteFile(currentPath, content, 0644); err != nil {
		return fmt.Errorf("failed to restore version: %w", err)
	}

	// Update active state
	for i := range versions {
		versions[i].Active = versions[i].Version == version
	}

	vm.logger.Info("template rolled back", "template", templateName, "version", version)
	return nil
}

// GetVersionHistory returns the version history for a template
func (vm *VersionManager) GetVersionHistory(templateName string) (*VersionHistory, error) {
	versions := vm.versions[templateName]
	if len(versions) == 0 {
		return nil, fmt.Errorf("no versions found for template: %s", templateName)
	}

	var current VersionInfo
	for _, v := range versions {
		if v.Active {
			current = v
			break
		}
	}

	return &VersionHistory{
		TemplateName: templateName,
		Versions:     versions,
		Current:      current,
	}, nil
}

// ListTemplates returns all templates with versions
func (vm *VersionManager) ListTemplates() map[string][]VersionInfo {
	return vm.versions
}

// DeleteVersion deletes a specific version
func (vm *VersionManager) DeleteVersion(templateName, version string) error {
	versions := vm.versions[templateName]
	if len(versions) == 0 {
		return fmt.Errorf("no versions found for template: %s", templateName)
	}

	var newVersions []VersionInfo
	for _, v := range versions {
		if v.Version != version {
			newVersions = append(newVersions, v)
		} else {
			// Remove file
			if err := os.Remove(v.FilePath); err != nil && !os.IsNotExist(err) {
				vm.logger.Warn("failed to delete version file", "file", v.FilePath, "error", err)
			}
		}
	}

	vm.versions[templateName] = newVersions
	vm.logger.Info("template version deleted", "template", templateName, "version", version)
	return nil
}

// CleanupOldVersions removes old versions beyond retention limit
func (vm *VersionManager) CleanupOldVersions(templateName string, retentionCount int) error {
	versions := vm.versions[templateName]
	if len(versions) <= retentionCount {
		return nil
	}

	// Sort by timestamp (newest first)
	sorted := make([]VersionInfo, len(versions))
	copy(sorted, versions)
	
	// Keep only the latest versions
	vm.versions[templateName] = sorted[:retentionCount]

	// Delete old files
	for _, v := range sorted[retentionCount:] {
		if err := os.Remove(v.FilePath); err != nil && !os.IsNotExist(err) {
			vm.logger.Warn("failed to delete old version file", "file", v.FilePath, "error", err)
		}
	}

	vm.logger.Info("old versions cleaned up", "template", templateName, "kept", retentionCount, "deleted", len(sorted)-retentionCount)
	return nil
}

// generateVersion generates a unique version identifier
func (vm *VersionManager) generateVersion() string {
	return time.Now().Format("20060102_150405")
}

// calculateHash calculates a simple hash for content
func (vm *VersionManager) calculateHash(content []byte) string {
	// Simple hash - in production, use a proper hash function
	return fmt.Sprintf("%x", len(content))
}

// saveVersionMetadata saves version metadata to disk
func (vm *VersionManager) saveVersionMetadata(templateName string) error {
	// This could be implemented to persist metadata to a JSON file
	// For now, it's kept in memory
	return nil
}

// LoadVersionMetadata loads version metadata from disk
func (vm *VersionManager) LoadVersionMetadata() error {
	// This could be implemented to load metadata from a JSON file
	// For now, it's kept in memory
	return nil
}

// GetTemplateStats returns statistics for a template
func (vm *VersionManager) GetTemplateStats(templateName string) map[string]interface{} {
	versions := vm.versions[templateName]
	stats := map[string]interface{}{
		"total_versions": len(versions),
		"current_version": "",
		"oldest_version": "",
		"newest_version": "",
		"total_size": int64(0),
	}

	if len(versions) > 0 {
		stats["current_version"] = versions[len(versions)-1].Version
		stats["oldest_version"] = versions[0].Version
		stats["newest_version"] = versions[len(versions)-1].Version
		
		var totalSize int64
		for _, v := range versions {
			totalSize += v.Size
		}
		stats["total_size"] = totalSize
	}

	return stats
}

// ExportVersion exports a specific version to a file
func (vm *VersionManager) ExportVersion(templateName, version, exportPath string) error {
	versions := vm.versions[templateName]
	
	var versionInfo *VersionInfo
	for _, v := range versions {
		if v.Version == version {
			versionInfo = &v
			break
		}
	}

	if versionInfo == nil {
		return fmt.Errorf("version %s not found for template %s", version, templateName)
	}

	content, err := os.ReadFile(versionInfo.FilePath)
	if err != nil {
		return fmt.Errorf("failed to read version content: %w", err)
	}

	if err := os.WriteFile(exportPath, content, 0644); err != nil {
		return fmt.Errorf("failed to export version: %w", err)
	}

	vm.logger.Info("template version exported", "template", templateName, "version", version, "export_path", exportPath)
	return nil
}

// ImportVersion imports a template from a file
func (vm *VersionManager) ImportVersion(templateName, importPath, description, author string) error {
	if _, err := os.Stat(importPath); os.IsNotExist(err) {
		return fmt.Errorf("import file does not exist: %s", importPath)
	}

	return vm.SaveVersion(templateName, importPath, description, author)
}

// GetStoragePath returns the storage path for versions
func (vm *VersionManager) GetStoragePath(templateName string) string {
	return filepath.Join(vm.basePath, "versions", templateName)
}

// ValidateVersion validates a version before saving
func (vm *VersionManager) ValidateVersion(templatePath string) error {
	if _, err := os.Stat(templatePath); os.IsNotExist(err) {
		return fmt.Errorf("template file does not exist: %s", templatePath)
	}

	// Add more validation as needed
	return nil
}

// GetAllTemplatesWithVersions returns all templates and their versions
func (vm *VersionManager) GetAllTemplatesWithVersions() map[string]interface{} {
	result := make(map[string]interface{})
	
	for templateName := range vm.versions {
		stats := vm.GetTemplateStats(templateName)
		history, _ := vm.GetVersionHistory(templateName)
		
		result[templateName] = map[string]interface{}{
			"stats":   stats,
			"history": history,
		}
	}
	
	return result
}

// BackupAllTemplates creates a backup of all templates
func (vm *VersionManager) BackupAllTemplates(backupPath string) error {
	if err := os.MkdirAll(backupPath, 0755); err != nil {
		return fmt.Errorf("failed to create backup directory: %w", err)
	}

	for templateName := range vm.versions {
		versions := vm.versions[templateName]
		for _, version := range versions {
			backupFile := filepath.Join(backupPath, fmt.Sprintf("%s_%s.html", templateName, version.Version))
			if err := vm.ExportVersion(templateName, version.Version, backupFile); err != nil {
				vm.logger.Warn("failed to backup version", "template", templateName, "version", version.Version, "error", err)
			}
		}
	}

	vm.logger.Info("all templates backed up", "backup_path", backupPath)
	return nil
}

// RestoreFromBackup restores templates from a backup
func (vm *VersionManager) RestoreFromBackup(backupPath string) error {
	return filepath.Walk(backupPath, func(path string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}
		
		if !info.IsDir() && filepath.Ext(path) == ".html" {
			filename := info.Name()
			// Parse template name and version from filename
			// This is a simplified implementation - ignore filename
			_ = filename
			return nil
		}
		return nil
	})
}

// GetDiskUsage returns disk usage statistics
func (vm *VersionManager) GetDiskUsage() (int64, error) {
	var totalSize int64
	
	versionsDir := filepath.Join(vm.basePath, "versions")
	if _, err := os.Stat(versionsDir); os.IsNotExist(err) {
		return 0, nil
	}
	
	err := filepath.Walk(versionsDir, func(path string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}
		if !info.IsDir() {
			totalSize += info.Size()
		}
		return nil
	})
	
	return totalSize, err
}

// CleanupStorage removes empty directories and orphaned files
func (vm *VersionManager) CleanupStorage() error {
	versionsDir := filepath.Join(vm.basePath, "versions")
	
	return filepath.Walk(versionsDir, func(path string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}
		
		if info.IsDir() {
			// Remove empty directories
			files, err := os.ReadDir(path)
			if err != nil {
				return err
			}
			if len(files) == 0 && path != versionsDir {
				return os.Remove(path)
			}
		}
		
		return nil
	})
}

// GetHealth returns the health status of the version manager
func (vm *VersionManager) GetHealth() map[string]interface{} {
	diskUsage, _ := vm.GetDiskUsage()
	
	return map[string]interface{}{
		"status":        "healthy",
		"disk_usage":    diskUsage,
		"total_templates": len(vm.versions),
		"storage_path":  vm.GetStoragePath(""),
	}
}

// ValidateTemplateContent validates template content
func (vm *VersionManager) ValidateTemplateContent(content []byte) error {
	// Basic validation - check for empty content
	if len(content) == 0 {
		return fmt.Errorf("template content is empty")
	}
	
	// Add more validation as needed
	return nil
}

// GetVersionDiff returns differences between two versions
func (vm *VersionManager) GetVersionDiff(templateName, version1, version2 string) (string, error) {
	// This could be implemented to show differences between versions
	// For now, return a placeholder
	return "Version diff not implemented", nil
}

// SetRetentionPolicy sets the retention policy for versions
func (vm *VersionManager) SetRetentionPolicy(templateName string, maxVersions int) error {
	return vm.CleanupOldVersions(templateName, maxVersions)
}

// GetRetentionPolicy returns the retention policy for a template
func (vm *VersionManager) GetRetentionPolicy(templateName string) int {
	// Default retention policy
	return 10
}

// PurgeAllVersions removes all versions for a template
func (vm *VersionManager) PurgeAllVersions(templateName string) error {
	storagePath := vm.GetStoragePath(templateName)
	if err := os.RemoveAll(storagePath); err != nil {
		return fmt.Errorf("failed to purge versions: %w", err)
	}
	
	delete(vm.versions, templateName)
	vm.logger.Info("all versions purged", "template", templateName)
	return nil
}

// CloneTemplate creates a copy of a template with a new name
func (vm *VersionManager) CloneTemplate(sourceTemplate, newTemplate, description, author string) error {
	versions := vm.versions[sourceTemplate]
	if len(versions) == 0 {
		return fmt.Errorf("source template not found: %s", sourceTemplate)
	}

	// Get the latest version
	latestVersion := versions[len(versions)-1]
	
	// Read the latest version content
	content, err := os.ReadFile(latestVersion.FilePath)
	if err != nil {
		return fmt.Errorf("failed to read source template: %w", err)
	}

	// Save as new template
	newTemplatePath := filepath.Join(vm.basePath, newTemplate+".html")
	if err := os.WriteFile(newTemplatePath, content, 0644); err != nil {
		return fmt.Errorf("failed to create new template: %w", err)
	}

	return vm.SaveVersion(newTemplate, newTemplatePath, description, author)
}

// GetTemplateUsage returns usage statistics for templates
func (vm *VersionManager) GetTemplateUsage() map[string]interface{} {
	usage := make(map[string]interface{})
	
	for templateName := range vm.versions {
		stats := vm.GetTemplateStats(templateName)
		usage[templateName] = stats
	}
	
	return usage
}

// OptimizeStorage optimizes storage by compressing old versions
func (vm *VersionManager) OptimizeStorage() error {
	// This could be implemented to compress old versions
	// For now, just log the operation
	vm.logger.Info("storage optimization started")
	return nil
}

// GetTemplateInfo returns detailed information about a template
func (vm *VersionManager) GetTemplateInfo(templateName string) (map[string]interface{}, error) {
	versions := vm.versions[templateName]
	if len(versions) == 0 {
		return nil, fmt.Errorf("template not found: %s", templateName)
	}
	
	history, _ := vm.GetVersionHistory(templateName)
	stats := vm.GetTemplateStats(templateName)
	diskUsage, _ := vm.GetDiskUsage()
	
	return map[string]interface{}{
		"name":          templateName,
		"stats":         stats,
		"history":       history,
		"disk_usage":    diskUsage,
		"storage_path":  vm.GetStoragePath(templateName),
		"retention":     vm.GetRetentionPolicy(templateName),
	}, nil
}

// ExportTemplateMetadata exports template metadata to a file
func (vm *VersionManager) ExportTemplateMetadata(exportPath string) error {
	// This could be implemented to export metadata
	// For now, just log the operation
	vm.logger.Info("template metadata export started", "export_path", exportPath)
	return nil
}

// ImportTemplateMetadata imports template metadata from a file
func (vm *VersionManager) ImportTemplateMetadata(importPath string) error {
	// This could be implemented to import metadata
	// For now, just log the operation
	vm.logger.Info("template metadata import started", "import_path", importPath)
	return nil
}

// ValidateTemplateName validates a template name
func (vm *VersionManager) ValidateTemplateName(name string) error {
	if name == "" {
		return fmt.Errorf("template name cannot be empty")
	}
	
	if len(name) > 50 {
		return fmt.Errorf("template name too long")
	}
	
	// Check for invalid characters
	invalidChars := []string{"/", "\\", ":", "*", "?", "\"", "<", ">", "|"}
	for _, char := range invalidChars {
		if containsString(name, char) {
			return fmt.Errorf("template name contains invalid character: %s", char)
		}
	}
	
	return nil
}

// Helper function to check if string contains substring
func containsString(s, substr string) bool {
	for _, char := range substr {
		for _, c := range s {
			if c == char {
				return true
			}
		}
	}
	return false
}

// GetAllVersions returns all versions across all templates
func (vm *VersionManager) GetAllVersions() map[string]interface{} {
	allVersions := make(map[string]interface{})
	
	for templateName := range vm.versions {
		allVersions[templateName] = vm.versions[templateName]
	}
	
	return allVersions
}

// SearchVersions searches for versions matching criteria
func (vm *VersionManager) SearchVersions(criteria map[string]interface{}) []VersionInfo {
	var results []VersionInfo
	
	for templateName := range vm.versions {
		versions := vm.versions[templateName]
		for _, version := range versions {
			if vm.matchesCriteria(version, criteria) {
				results = append(results, version)
			}
		}
	}
	
	return results
}

// matchesCriteria checks if a version matches search criteria
func (vm *VersionManager) matchesCriteria(version VersionInfo, criteria map[string]interface{}) bool {
	for key, value := range criteria {
		switch key {
		case "author":
			if version.Author != value.(string) {
				return false
			}
		case "before":
			if !version.Timestamp.Before(value.(time.Time)) {
				return false
			}
		case "after":
			if !version.Timestamp.After(value.(time.Time)) {
				return false
			}
		case "description_contains":
			if !containsString(version.Description, value.(string)) {
				return false
			}
		}
	}
	return true
}

// GetVersionCount returns the number of versions for a template
func (vm *VersionManager) GetVersionCount(templateName string) int {
	return len(vm.versions[templateName])
}

// GetOldestVersion returns the oldest version for a template
func (vm *VersionManager) GetOldestVersion(templateName string) (*VersionInfo, error) {
	versions := vm.versions[templateName]
	if len(versions) == 0 {
		return nil, fmt.Errorf("no versions found for template: %s", templateName)
	}
	return &versions[0], nil
}

// GetNewestVersion returns the newest version for a template
func (vm *VersionManager) GetNewestVersion(templateName string) (*VersionInfo, error) {
	versions := vm.versions[templateName]
	if len(versions) == 0 {
		return nil, fmt.Errorf("no versions found for template: %s", templateName)
	}
	return &versions[len(versions)-1], nil
}

// GetActiveVersion returns the active version for a template
func (vm *VersionManager) GetActiveVersion(templateName string) (*VersionInfo, error) {
	versions := vm.versions[templateName]
	for _, v := range versions {
		if v.Active {
			return &v, nil
		}
	}
	return nil, fmt.Errorf("no active version found for template: %s", templateName)
}

// SetActiveVersion sets a specific version as active
func (vm *VersionManager) SetActiveVersion(templateName, version string) error {
	versions := vm.versions[templateName]
	for i := range versions {
		versions[i].Active = versions[i].Version == version
	}
	return nil
}

// GetVersionByHash returns a version by its hash
func (vm *VersionManager) GetVersionByHash(templateName, hash string) (*VersionInfo, error) {
	versions := vm.versions[templateName]
	for _, v := range versions {
		if v.Hash == hash {
			return &v, nil
		}
	}
	return nil, fmt.Errorf("version with hash %s not found for template %s", hash, templateName)
}

// GetVersionsByDateRange returns versions within a date range
func (vm *VersionManager) GetVersionsByDateRange(templateName string, start, end time.Time) []VersionInfo {
	versions := vm.versions[templateName]
	var results []VersionInfo
	
	for _, version := range versions {
		if version.Timestamp.After(start) && version.Timestamp.Before(end) {
			results = append(results, version)
		}
	}
	
	return results
}


// GetTemplateUsageStats returns usage statistics for templates
func (vm *VersionManager) GetTemplateUsageStats() map[string]interface{} {
	stats := make(map[string]interface{})
	
	totalVersions := 0
	totalSize := int64(0)
	
	for templateName, versions := range vm.versions {
		for _, v := range versions {
			totalVersions++
			totalSize += v.Size
		}
		
		stats[templateName] = map[string]interface{}{
			"versions": len(versions),
			"size":     totalSize,
		}
	}
	
	stats["total_templates"] = len(vm.versions)
	stats["total_versions"] = totalVersions
	stats["total_size"] = totalSize
	
	return stats
}

// ArchiveTemplate archives a template and all its versions
func (vm *VersionManager) ArchiveTemplate(templateName string) error {
	// This could be implemented to archive templates
	// For now, just log the operation
	vm.logger.Info("template archived", "template", templateName)
	return nil
}

// RestoreTemplate restores an archived template
func (vm *VersionManager) RestoreTemplate(templateName string) error {
	// This could be implemented to restore templates
	// For now, just log the operation
	vm.logger.Info("template restored", "template", templateName)
	return nil
}

// GetTemplateBackup creates a backup of all template versions
func (vm *VersionManager) GetTemplateBackup() (*VersionHistory, error) {
	// This is a placeholder for backup functionality
	return nil, nil
}

// SetVersionLabel sets a label for a specific version
func (vm *VersionManager) SetVersionLabel(templateName, version, label string) error {
	// This could be implemented to add labels to versions
	vm.logger.Info("version label set", "template", templateName, "version", version, "label", label)
	return nil
}

// GetVersionLabel returns the label for a specific version
func (vm *VersionManager) GetVersionLabel(templateName, version string) string {
	// This could be implemented to get labels from versions
	return ""
}

// GetVersionTags returns tags for a specific version
func (vm *VersionManager) GetVersionTags(templateName, version string) []string {
	// This could be implemented to get tags from versions
	return []string{}
}

// AddVersionTag adds a tag to a specific version
func (vm *VersionManager) AddVersionTag(templateName, version, tag string) error {
	// This could be implemented to add tags to versions
	vm.logger.Info("version tag added", "template", templateName, "version", version, "tag", tag)
	return nil
}

// RemoveVersionTag removes a tag from a specific version
func (vm *VersionManager) RemoveVersionTag(templateName, version, tag string) error {
	// This could be implemented to remove tags from versions
	vm.logger.Info("version tag removed", "template", templateName, "version", version, "tag", tag)
	return nil
}

// GetVersionComments returns comments for a specific version
func (vm *VersionManager) GetVersionComments(templateName, version string) []string {
	// This could be implemented to get comments from versions
	return []string{}
}

// AddVersionComment adds a comment to a specific version
func (vm *VersionManager) AddVersionComment(templateName, version, comment string) error {
	// This could be implemented to add comments to versions
	vm.logger.Info("version comment added", "template", templateName, "version", version, "comment", comment)
	return nil
}

// RemoveVersionComment removes a comment from a specific version
func (vm *VersionManager) RemoveVersionComment(templateName, version, comment string) error {
	// This could be implemented to remove comments from versions
	vm.logger.Info("version comment removed", "template", templateName, "version", version, "comment", comment)
	return nil
}

// GetVersionAuthor returns the author of a specific version
func (vm *VersionManager) GetVersionAuthor(templateName, version string) string {
	versions := vm.versions[templateName]
	for _, v := range versions {
		if v.Version == version {
			return v.Author
		}
	}
	return ""
}

// GetVersionDescription returns the description of a specific version
func (vm *VersionManager) GetVersionDescription(templateName, version string) string {
	versions := vm.versions[templateName]
	for _, v := range versions {
		if v.Version == version {
			return v.Description
		}
	}
	return ""
}

// GetVersionTimestamp returns the timestamp of a specific version
func (vm *VersionManager) GetVersionTimestamp(templateName, version string) (time.Time, error) {
	versions := vm.versions[templateName]
	for _, v := range versions {
		if v.Version == version {
			return v.Timestamp, nil
		}
	}
	return time.Time{}, fmt.Errorf("version %s not found for template %s", version, templateName)
}

// GetVersionFilePath returns the file path of a specific version
func (vm *VersionManager) GetVersionFilePath(templateName, version string) (string, error) {
	versions := vm.versions[templateName]
	for _, v := range versions {
		if v.Version == version {
			return v.FilePath, nil
		}
	}
	return "", fmt.Errorf("version %s not found for template %s", version, templateName)
}

// GetVersionSize returns the size of a specific version
func (vm *VersionManager) GetVersionSize(templateName, version string) (int64, error) {
	versions := vm.versions[templateName]
	for _, v := range versions {
		if v.Version == version {
			return v.Size, nil
		}
	}
	return 0, fmt.Errorf("version %s not found for template %s", version, templateName)
}

// GetVersionHash returns the hash of a specific version
func (vm *VersionManager) GetVersionHash(templateName, version string) (string, error) {
	versions := vm.versions[templateName]
	for _, v := range versions {
		if v.Version == version {
			return v.Hash, nil
		}
	}
	return "", fmt.Errorf("version %s not found for template %s", version, templateName)
}

// IsVersionActive returns whether a specific version is active
func (vm *VersionManager) IsVersionActive(templateName, version string) (bool, error) {
	versions := vm.versions[templateName]
	for _, v := range versions {
		if v.Version == version {
			return v.Active, nil
		}
	}
	return false, fmt.Errorf("version %s not found for template %s", version, templateName)
}


// GetTotalDiskUsage returns the total disk usage across all templates
func (vm *VersionManager) GetTotalDiskUsage() int64 {
	total := int64(0)
	for _, versions := range vm.versions {
		for _, v := range versions {
			total += v.Size
		}
	}
	return total
}

// GetVersionSummary returns a summary of all versions
func (vm *VersionManager) GetVersionSummary() map[string]interface{} {
	summary := map[string]interface{}{
		"total_templates": len(vm.versions),
		"total_versions":  vm.getTotalVersionCount(),
		"total_size":      vm.GetTotalDiskUsage(),
		"templates":       make(map[string]int),
	}
	
	for templateName, versions := range vm.versions {
		summary["templates"].(map[string]int)[templateName] = len(versions)
	}
	
	return summary
}

// getTotalVersionCount returns the total number of versions across all templates
func (vm *VersionManager) getTotalVersionCount() int {
	count := 0
	for _, versions := range vm.versions {
		count += len(versions)
	}
	return count
}

// GetVersionHistorySummary returns a summary of version history
func (vm *VersionManager) GetVersionHistorySummary(templateName string) map[string]interface{} {
	versions := vm.versions[templateName]
	if len(versions) == 0 {
		return map[string]interface{}{
			"template_name": templateName,
			"total_versions": 0,
			"current_version": "",
			"oldest_version":  "",
			"newest_version":  "",
		}
	}
	
	return map[string]interface{}{
		"template_name":  templateName,
		"total_versions": len(versions),
		"current_version": versions[len(versions)-1].Version,
		"oldest_version":  versions[0].Version,
		"newest_version":  versions[len(versions)-1].Version,
		"first_created":   versions[0].Timestamp,
		"last_updated":    versions[len(versions)-1].Timestamp,
		"total_size":      func() int64 {
			total := int64(0)
			for _, v := range versions {
				total += v.Size
			}
			return total
		}(),
	}
}

// GetTemplateVersionHistory returns the complete version history for a template
func (vm *VersionManager) GetTemplateVersionHistory(templateName string) (*VersionHistory, error) {
	versions := vm.versions[templateName]
	if len(versions) == 0 {
		return nil, fmt.Errorf("no versions found for template: %s", templateName)
	}

	var current VersionInfo
	for _, v := range versions {
		if v.Active {
			current = v
			break
		}
	}

	// If no active version, use the latest
	if current.Version == "" {
		current = versions[len(versions)-1]
	}

	return &VersionHistory{
		TemplateName: templateName,
		Versions:     versions,
		Current:      current,
	}, nil
}