package services

import (
	"errors"
	"fmt"
	"os"
	"path/filepath"
	"strings"

	"github.com/klauspost/compress/zstd"

	"code.icb4dc0.de/prskr/searcherside/core/ports"
	"code.icb4dc0.de/prskr/searcherside/internal/archive"
)

var _ ports.Archiver = (*TarZSTIndexArchiver)(nil)

type TarZSTIndexArchiver struct {
	DataDirectory string
}

func (a TarZSTIndexArchiver) ArchiveIndex(req ports.ArchiveIndexRequest) (err error) {
	archiveFile, err := os.Create(filepath.Join(a.DataDirectory, strings.Join([]string{req.Hash, req.Type.String(), "tar.zst"}, ".")))
	if err != nil {
		return fmt.Errorf("failed to create archive file: %w", err)
	}

	defer func() {
		err = errors.Join(err, archiveFile.Close())
	}()

	encoder, err := zstd.NewWriter(archiveFile, zstd.WithEncoderLevel(zstd.SpeedBestCompression))
	if err != nil {
		return fmt.Errorf("failed to create zst encoder: %w", err)
	}

	defer func() {
		err = errors.Join(err, encoder.Close())
	}()

	relativePath, err := filepath.Rel(a.DataDirectory, req.Path)
	if err != nil {
		return fmt.Errorf("failed to get relative path: %w", err)
	}

	return archive.TarDirectory(
		os.DirFS(a.DataDirectory),
		filepath.ToSlash(relativePath),
		archiveFile,
	)
}