finished, also added cobra cli

internal/walker/walker.go

@@ -0,0 +1,123 @@
+package walker
+
+import (
+	"fmt"
+	"io/fs"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"dirmd/internal/config"
+	"dirmd/internal/filter"
+)
+
+type Entry struct {
+	RelPath string
+	Size    int64
+}
+
+type Result struct {
+	Entries    []Entry
+	AbsRoot    string
+	SingleFile bool
+}
+
+func Run(cfg *config.Config) (*Result, error) {
+	if cfg.SingleFile {
+		return processSingleFile(cfg)
+	}
+	return walkDirectory(cfg)
+}
+
+func processSingleFile(cfg *config.Config) (*Result, error) {
+	info, err := os.Stat(cfg.AbsRoot)
+	if err != nil {
+		return nil, fmt.Errorf("cannot access %s: %w", cfg.AbsRoot, err)
+	}
+
+	if info.IsDir() {
+		return walkDirectory(cfg)
+	}
+
+	flt := &filter.Filter{
+		MaxSize:    cfg.MaxSize,
+		Extensions: cfg.Extensions,
+		Ignores:    cfg.Ignores,
+	}
+
+	if flt.ShouldSkipFile(cfg.AbsRoot, filepath.Base(cfg.AbsRoot), info) {
+		return nil, fmt.Errorf("file %s filtered out", cfg.AbsRoot)
+	}
+
+	return &Result{
+		Entries:    []Entry{{RelPath: filepath.Base(cfg.AbsRoot), Size: info.Size()}},
+		AbsRoot:    filepath.Dir(cfg.AbsRoot),
+		SingleFile: true,
+	}, nil
+
+}
+
+func walkDirectory(cfg *config.Config) (*Result, error) {
+	flt := &filter.Filter{
+		MaxSize:    cfg.MaxSize,
+		Extensions: cfg.Extensions,
+		Ignores:    cfg.Ignores,
+	}
+
+	result := &Result{AbsRoot: cfg.AbsRoot}
+
+	err := filepath.WalkDir(cfg.AbsRoot, func(path string, d fs.DirEntry, err error) error {
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "warning: %v\n", err)
+			return nil
+		}
+
+		rel, err := filepath.Rel(cfg.AbsRoot, path)
+		if err != nil {
+			return nil
+		}
+
+		depth := strings.Count(rel, string(filepath.Separator))
+		if rel != "." {
+			depth++
+		}
+
+		if depth > cfg.MaxDepth {
+			if d.IsDir() {
+				return filepath.SkipDir
+			}
+			return nil
+		}
+
+		if filter.IsSymlink(path) {
+			if d.IsDir() {
+				return filepath.SkipDir
+			}
+			return nil
+		}
+
+		base := filepath.Base(path)
+
+		if d.IsDir() {
+			if rel != "." && flt.ShouldSkipDir(base) {
+				return filepath.SkipDir
+			}
+			return nil
+		}
+
+		info, err := d.Info()
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "warning: cannot stat %s: %v\n", rel, err)
+			return nil
+		}
+
+		if flt.ShouldSkipFile(path, base, info) {
+			return nil
+		}
+
+		result.Entries = append(result.Entries, Entry{RelPath: rel, Size: info.Size()})
+		return nil
+	})
+
+	return result, err
+}