package bundle

import (
	"archive/zip"
	"context"
	"io"
	"os"
	"path/filepath"
	"strings"

	"github.com/pkg/errors"
	"gitlab.com/wpetit/goweb/logger"
)

type ZipBundle struct {
	reader *zip.Reader
}

func (b *ZipBundle) File(filename string) (io.ReadCloser, os.FileInfo, error) {
	ctx := logger.With(
		context.Background(),
		logger.F("filename", filename),
	)

	logger.Debug(ctx, "opening file")

	f, err := b.reader.Open(filename)
	if err != nil {
		return nil, nil, errors.WithStack(err)
	}

	stat, err := f.Stat()
	if err != nil {
		return nil, nil, errors.WithStack(err)
	}

	return f, stat, nil
}

func (b *ZipBundle) Dir(dirname string) ([]os.FileInfo, error) {
	files := make([]os.FileInfo, 0)
	ctx := context.Background()

	for _, f := range b.reader.File {
		if !strings.HasPrefix(f.Name, dirname) {
			continue
		}

		relPath, err := filepath.Rel(dirname, f.Name)
		if err != nil {
			return nil, errors.Wrap(err, "could not get relative path")
		}

		logger.Debug(
			ctx, "checking file prefix",
			logger.F("dirname", dirname),
			logger.F("filename", f.Name),
			logger.F("relpath", relPath),
		)

		if relPath == filepath.Base(f.Name) {
			files = append(files, f.FileInfo())
		}
	}

	return files, nil
}

func NewZipBundleFromReader(reader io.ReaderAt, size int64) (*ZipBundle, error) {
	zipReader, err := zip.NewReader(reader, size)
	if err != nil {
		return nil, errors.WithStack(err)
	}

	return &ZipBundle{
		reader: zipReader,
	}, nil
}

func NewZipBundleFromPath(filename string) (*ZipBundle, error) {
	file, err := os.Open(filename)
	if err != nil {
		return nil, errors.WithStack(err)
	}

	stat, err := file.Stat()
	if err != nil {
		return nil, errors.WithStack(err)
	}

	return NewZipBundleFromReader(file, stat.Size())
}

func Must(bundle Bundle, err error) Bundle {
	if err != nil {
		panic(errors.WithStack(err))
	}

	return bundle
}