finished, also added cobra cli

cmd/root.go

@@ -0,0 +1,116 @@
+package cmd
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/spf13/cobra"
+
+	"dirmd/internal/config"
+	"dirmd/internal/renderer"
+	"dirmd/internal/walker"
+)
+
+var (
+	rootCmd = &cobra.Command{
+		Use:   "dirmd [flags] <directory>",
+		Short: "Generate markdown documentation from directory structure",
+		Long: `dirmd walks a directory and generates a markdown file with:
+
+- Directory tree structure  
+- All readable text files with their contents
+
+Examples:
+
+  # Create new documentation
+  dirmd -o output.md ~/repos/myproject
+
+  # Append a single file  
+  dirmd -a -i README.md -o existing.md
+
+  # Append another directory
+  dirmd -a -o existing.md ~/repos/anotherproject`,
+		RunE: run,
+	}
+
+	outputPath     string
+	appendMode     bool
+	singleFile     string
+	maxSize        int64
+	maxDepth       int
+	ignorePatterns []string
+	extensions     []string
+)
+
+func Execute() {
+	if err := rootCmd.Execute(); err != nil {
+		os.Exit(1)
+	}
+}
+
+func init() {
+	rootCmd.PersistentFlags().StringVarP(&outputPath, "output", "o", "", "output markdown file path (required)")
+	rootCmd.Flags().BoolVarP(&appendMode, "append", "a", false, "append to existing output file")
+	rootCmd.Flags().StringVarP(&singleFile, "input-file", "i", "", "single file input (append mode only)")
+	rootCmd.Flags().Int64Var(&maxSize, "max-size", config.DefaultMaxSize, "max file size in bytes")
+	rootCmd.Flags().IntVar(&maxDepth, "max-depth", config.DefaultMaxDepth, "max directory recursion depth")
+	rootCmd.Flags().StringArrayVar(&ignorePatterns, "ignore", nil, "additional ignore patterns (glob)")
+	rootCmd.Flags().StringArrayVar(&extensions, "extensions", nil, "additional file extensions to skip (repeatable)")
+
+	rootCmd.MarkPersistentFlagRequired("output")
+}
+
+func run(cmd *cobra.Command, args []string) error {
+	cfg := &config.Config{
+		OutputPath: outputPath,
+		AppendMode: appendMode,
+		MaxSize:    maxSize,
+		MaxDepth:   maxDepth,
+		Ignores:    append(config.DefaultIgnores, ignorePatterns...),
+		Extensions: append(config.DefaultExts, extensions...),
+	}
+
+	if singleFile != "" {
+		cfg.InputPath = singleFile
+		cfg.SingleFile = true
+		if !appendMode {
+			return fmt.Errorf("single file input (-i) requires append mode (-a)")
+		}
+	} else {
+		if len(args) < 1 {
+			return fmt.Errorf("directory argument is required when -i is not used")
+		}
+		cfg.InputPath = args[0]
+	}
+
+	abs, err := filepath.Abs(cfg.InputPath)
+	if err != nil {
+		return fmt.Errorf("failed to resolve absolute path: %w", err)
+	}
+	cfg.AbsRoot = abs
+
+	// Non-append mode: output must not exist
+	if !appendMode {
+		if _, err := os.Stat(outputPath); err == nil {
+			return fmt.Errorf("output file %s already exists (use -a to append)", outputPath)
+		}
+	}
+
+	result, err := walker.Run(cfg)
+	if err != nil {
+		return err
+	}
+
+	if len(result.Entries) == 0 {
+		return fmt.Errorf("no readable text files found in %s", cfg.AbsRoot)
+	}
+
+	if err := renderer.Write(result, outputPath, appendMode, cfg.SingleFile); err != nil {
+		return err
+	}
+
+	fmt.Fprintf(os.Stderr, "wrote %d entries to %s\n", len(result.Entries), outputPath)
+	return nil
+}
+