feat(ai): add color-coded diff formatting with progress bar

- Added a new `FormatDiff` function to format git diff output with color-coded lines and a progress bar.
- Added a `createProgressBar` function to generate a visual progress bar for diff statistics.
- Simplified the `diff` command in the UI by delegating diff formatting to the new `FormatDiff` function.
- Removed redundant code for manually highlighting diff lines in the UI.

Signed-off-by: codiing-hui <wecoding@yeah.net>

Author: coding-hui

internal/git/git.go

@@ -241,3 +241,72 @@ func (c *Command) commit(val string) *exec.Cmd {
 		args...,
 	)
 }
+
+// FormatDiff formats git diff output with color and stats
+func (c *Command) FormatDiff(diffOutput string) string {
+	lines := strings.Split(diffOutput, "\n")
+	var formattedLines []string
+	var stats struct {
+		added   int
+		removed int
+		total   int
+	}
+
+	// First pass to calculate stats
+	for _, line := range lines {
+		switch {
+		case strings.HasPrefix(line, "+"):
+			stats.added++
+			stats.total++
+		case strings.HasPrefix(line, "-"):
+			stats.removed++
+			stats.total++
+		case strings.HasPrefix(line, "@@"):
+			stats.total++
+		}
+	}
+
+	// Create progress bar
+	progress := c.createProgressBar(stats.added, stats.removed, stats.total)
+
+	// Second pass to format lines
+	for _, line := range lines {
+		switch {
+		case strings.HasPrefix(line, "+"):
+			formattedLines = append(formattedLines,
+				fmt.Sprintf("\x1b[32m%s\x1b[0m", line)) // Green for additions
+		case strings.HasPrefix(line, "-"):
+			formattedLines = append(formattedLines,
+				fmt.Sprintf("\x1b[31m%s\x1b[0m", line)) // Red for deletions
+		case strings.HasPrefix(line, "@@"):
+			formattedLines = append(formattedLines,
+				fmt.Sprintf("\x1b[33m%s\x1b[0m", line)) // Yellow for headers
+		default:
+			formattedLines = append(formattedLines, line)
+		}
+	}
+
+	// Add header with stats
+	header := fmt.Sprintf("Changes (%d added, %d removed):\n%s\n",
+		stats.added, stats.removed, progress)
+
+	return header + strings.Join(formattedLines, "\n")
+}
+
+// createProgressBar generates a visual progress bar for diff stats
+func (c *Command) createProgressBar(added, removed, total int) string {
+	const barWidth = 30
+	if total == 0 {
+		return ""
+	}
+
+	addedBlocks := int(float64(added) / float64(total) * barWidth)
+	removedBlocks := int(float64(removed) / float64(total) * barWidth)
+	unchangedBlocks := barWidth - addedBlocks - removedBlocks
+
+	bar := strings.Repeat("█", addedBlocks) +
+		strings.Repeat("░", removedBlocks) +
+		strings.Repeat(" ", unchangedBlocks)
+
+	return fmt.Sprintf("[%s] %d changes", bar, total)
+}

internal/ui/coders/commands.go

@@ -351,27 +351,14 @@ func (c *CommandExecutor) diff(ctx context.Context, _ ...string) error {
 		return errbook.Wrap("Failed to get diff", err)
 	}
 
-	// Split and highlight diff lines
-	lines := strings.Split(diffOutput, "\n")
-	var highlightedLines []string
-
-	for _, line := range lines {
-		switch {
-		case strings.HasPrefix(line, "+"):
-			highlightedLines = append(highlightedLines, console.StdoutStyles().CommitSuccess.Render(line))
-		case strings.HasPrefix(line, "-"):
-			highlightedLines = append(highlightedLines, console.StdoutStyles().InlineCode.Render(line))
-		case strings.HasPrefix(line, "@@"):
-			highlightedLines = append(highlightedLines, console.StdoutStyles().Flag.Render(line))
-		default:
-			highlightedLines = append(highlightedLines, line)
-		}
-	}
-
-	console.Render("Changes:\n%s", strings.Join(highlightedLines, "\n"))
+	// Process and format the diff
+	formattedDiff := c.coder.repo.FormatDiff(diffOutput)
+	console.Render("Changes:\n%s", formattedDiff)
 	return nil
 }
 
+
+
 func (c *CommandExecutor) exit(_ context.Context, _ ...string) error {
 	fmt.Println("Bye!")
 	os.Exit(0)