feat(dotfile): add advanced merge support for config files

model/dotfile_ghostty.go

@@ -1,6 +1,15 @@
 package model
 
-import "context"
+import (
+	"bufio"
+	"context"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/sirupsen/logrus"
+)
 
 // GhosttyApp handles Ghostty terminal configuration files
 type GhosttyApp struct {
@@ -18,11 +27,188 @@ func (g *GhosttyApp) Name() string {
 func (g *GhosttyApp) GetConfigPaths() []string {
 	return []string{
 		"~/.config/ghostty/config",
-		"~/.config/ghostty",
 	}
 }
 
 func (g *GhosttyApp) CollectDotfiles(ctx context.Context) ([]DotfileItem, error) {
 	skipIgnored := true
 	return g.CollectFromPaths(ctx, g.Name(), g.GetConfigPaths(), &skipIgnored)
-}
+}
+
+// configLine represents a line in the Ghostty config file
+type configLine struct {
+	isComment bool
+	isBlank   bool
+	key       string
+	value     string
+	raw       string // for comments and blank lines
+}
+
+// parseGhosttyConfig parses Ghostty config content into structured lines
+func (g *GhosttyApp) parseGhosttyConfig(content string) []configLine {
+	var lines []configLine
+	scanner := bufio.NewScanner(strings.NewReader(content))
+
+	for scanner.Scan() {
+		line := scanner.Text()
+		trimmed := strings.TrimSpace(line)
+
+		if trimmed == "" {
+			lines = append(lines, configLine{
+				isBlank: true,
+				raw:     line,
+			})
+		} else if strings.HasPrefix(trimmed, "#") {
+			lines = append(lines, configLine{
+				isComment: true,
+				raw:       line,
+			})
+		} else if strings.Contains(line, "=") {
+			parts := strings.SplitN(line, "=", 2)
+			key := strings.TrimSpace(parts[0])
+			value := ""
+			if len(parts) > 1 {
+				value = strings.TrimSpace(parts[1])
+			}
+			lines = append(lines, configLine{
+				key:   key,
+				value: value,
+				raw:   line,
+			})
+		} else {
+			// Treat as a comment if it doesn't match key=value format
+			lines = append(lines, configLine{
+				isComment: true,
+				raw:       line,
+			})
+		}
+	}
+
+	return lines
+}
+
+// mergeGhosttyConfigs merges remote config with local config, local has priority
+func (g *GhosttyApp) mergeGhosttyConfigs(localLines, remoteLines []configLine) []configLine {
+	// Create a map of local keys for quick lookup
+	localKeys := make(map[string]bool)
+	for _, line := range localLines {
+		if !line.isComment && !line.isBlank && line.key != "" {
+			localKeys[line.key] = true
+		}
+	}
+
+	// Start with local config
+	merged := make([]configLine, len(localLines))
+	copy(merged, localLines)
+
+	// Add keys from remote that don't exist in local
+	for _, remoteLine := range remoteLines {
+		if !remoteLine.isComment && !remoteLine.isBlank && remoteLine.key != "" {
+			if !localKeys[remoteLine.key] {
+				merged = append(merged, remoteLine)
+			}
+		}
+	}
+
+	return merged
+}
+
+// formatGhosttyConfig converts config lines back to string
+func (g *GhosttyApp) formatGhosttyConfig(lines []configLine) string {
+	var result []string
+	for _, line := range lines {
+		if line.isComment || line.isBlank {
+			result = append(result, line.raw)
+		} else {
+			result = append(result, fmt.Sprintf("%s = %s", line.key, line.value))
+		}
+	}
+	return strings.Join(result, "\n")
+}
+
+// Save overrides the base Save method to handle Ghostty's specific config format
+func (g *GhosttyApp) Save(ctx context.Context, files map[string]string, isDryRun bool) error {
+	for path, remoteContent := range files {
+		expandedPath, err := g.expandPath(path)
+		if err != nil {
+			logrus.Warnf("Failed to expand path %s: %v", path, err)
+			continue
+		}
+
+		// Read existing local content if file exists
+		var localContent string
+		if existingBytes, err := os.ReadFile(expandedPath); err == nil {
+			localContent = string(existingBytes)
+		} else if !os.IsNotExist(err) {
+			logrus.Warnf("Failed to read existing file %s: %v", expandedPath, err)
+			continue
+		}
+
+		// Parse both configs
+		localLines := g.parseGhosttyConfig(localContent)
+		remoteLines := g.parseGhosttyConfig(remoteContent)
+
+		// Merge configs (local has priority)
+		mergedLines := g.mergeGhosttyConfigs(localLines, remoteLines)
+		mergedContent := g.formatGhosttyConfig(mergedLines)
+
+		// Check if there are any differences
+		if localContent == mergedContent {
+			logrus.Infof("No changes needed for %s", expandedPath)
+			continue
+		}
+
+		if isDryRun {
+			// In dry-run mode, show the diff
+			fmt.Printf("\n📄 %s:\n", expandedPath)
+			fmt.Println("--- Changes to be applied ---")
+
+			// Show added keys (from remote)
+			remoteKeys := make(map[string]string)
+			for _, line := range remoteLines {
+				if !line.isComment && !line.isBlank && line.key != "" {
+					remoteKeys[line.key] = line.value
+				}
+			}
+
+			localKeys := make(map[string]string)
+			for _, line := range localLines {
+				if !line.isComment && !line.isBlank && line.key != "" {
+					localKeys[line.key] = line.value
+				}
+			}
+
+			// Show new keys from remote
+			hasChanges := false
+			for key, value := range remoteKeys {
+				if _, exists := localKeys[key]; !exists {
+					fmt.Printf("+ %s = %s (from remote)\n", key, value)
+					hasChanges = true
+				}
+			}
+
+			if !hasChanges {
+				fmt.Println("No new keys from remote")
+			}
+
+			fmt.Println("--- End of changes ---")
+			continue
+		}
+
+		// Ensure directory exists
+		dir := filepath.Dir(expandedPath)
+		if err := os.MkdirAll(dir, 0755); err != nil {
+			logrus.Warnf("Failed to create directory %s: %v", dir, err)
+			continue
+		}
+
+		// Write merged content
+		if err := os.WriteFile(expandedPath, []byte(mergedContent), 0644); err != nil {
+			logrus.Warnf("Failed to save file %s: %v", expandedPath, err)
+		} else {
+			logrus.Infof("Saved merged config to %s", expandedPath)
+		}
+	}
+
+	return nil
+}