package main

import (
	"archive/zip"
	"errors"
	"io"
	"log"
	"os"
	"path"
)

type archiveFileCreator interface {
	Create(name string) (io.Writer, error)
	Close() error
}

type filesCloser []io.Closer

func (fds filesCloser) Close() error {
	log.Println("Closing fd..")
	for _, fd := range fds {
		err := fd.Close()
		if err != nil {
			return err
		}
	}

	return nil
}

func init() {
	OutputFormats["archive"] = func(args ...string) (func(string) (io.WriteCloser, error), io.Closer, error) {
		if len(args) != 1 {
			return nil, nil, errors.New("archive has 1 required argument: [destination-file]")
		}

		fd, err := os.Create(args[0])
		if err != nil {
			return nil, nil, err
		}

		var w archiveFileCreator
		if path.Ext(args[0]) == ".zip" {
			w = zip.NewWriter(fd)
		} else {
			return nil, nil, errors.New("destination file has to have .zip extension")
		}

		return func(dest string) (io.WriteCloser, error) {
			fw, err := w.Create(dest)
			if err != nil {
				return nil, err
			}

			return NopCloser(fw), nil
		}, filesCloser{w, fd}, nil
	}
}