package archive

import (
	"archive/tar"
	"errors"
	"fmt"
	"io"
	"io/fs"
	"path/filepath"

	"code.icb4dc0.de/buildr/buildr/internal/ignore"
)

var ErrEmptyArchive = errors.New("no files were added to the archive")

type Tar struct {
	Ignorer *ignore.Ignorer
	root    *archiveNode
}

func (t *Tar) Write(writer io.Writer) error {
	if t.root == nil {
		return ErrEmptyArchive
	}
	tarWriter := tar.NewWriter(writer)

	if err := t.root.writeToTar(tarWriter, t.Ignorer, ""); err != nil {
		return err
	}

	return tarWriter.Close()
}

func (t *Tar) Remove(path string) bool {
	if t.root == nil {
		return false
	}

	return t.root.remove(path)
}

func (t *Tar) Add(srcPath, destPath string) error {
	if t.root == nil {
		t.root = newNode()
	}

	info, err := t.Ignorer.Stat(srcPath)
	if err != nil {
		return fmt.Errorf("failed to get file information for %s: %w", srcPath, err)
	}

	if info.IsDir() {
		return t.addDir(srcPath, destPath)
	}

	t.addFile(srcPath, destPath)
	return nil
}

func (t *Tar) addFile(srcPath, destPath string) {
	if t.root == nil {
		t.root = newNode()
	}

	t.root.addFile(srcPath, destPath)
}

func (t *Tar) addDir(srcPath, destPath string) error {
	if t.root == nil {
		t.root = newNode()
	}

	err := t.Ignorer.WalkDir(srcPath, func(path string, d fs.DirEntry, err error) error {
		if err != nil {
			return err
		}

		relativeToSource, err := filepath.Rel(srcPath, path)
		if err != nil {
			return fmt.Errorf("failed to determine relative path for %s: %w", path, err)
		}

		if d.IsDir() {
			t.root.addDir(filepath.Join(destPath, relativeToSource))
		} else {
			t.root.addFile(path, filepath.Join(destPath, relativeToSource))
		}

		return nil
	})
	if err != nil {
		return fmt.Errorf("failed to add dir %s recursively: %w", srcPath, err)
	}

	return nil
}