// Copyright 2024 Matthew Rich <matthewrich.conf@gmail.com>. All rights reserved.

package source

import (
_	"context"
_	"encoding/json"
_	"fmt"
_	"gopkg.in/yaml.v3"
	"net/url"
	"path/filepath"
	"decl/internal/resource"
	"decl/internal/transport"
	"compress/gzip"
	"archive/tar"
	"regexp"
_	"os"
	"io"
)

type Tar struct {
	Path string `yaml:"path" json:"path"`
	transport *transport.Reader `yaml:"-" json:"-"`
}

func NewTar() *Tar {
	return &Tar{}
}

func init() {
	SourceTypes.Register([]string{"tar"}, func(u *url.URL) DocSource {
		t := NewTar()
		t.Path,_ = filepath.Abs(filepath.Join(u.Hostname(), u.Path))
		t.transport,_ = transport.NewReader(u)
		return t
	})

	SourceTypes.Register([]string{"tar.gz", "tgz"}, func(u *url.URL) DocSource {
		t := NewTar()
		if u.Scheme == "file" {
			fileAbsolutePath, _ := filepath.Abs(filepath.Join(u.Hostname(), u.Path))
			t.Path = fileAbsolutePath
		} else {
			t.Path = filepath.Join(u.Hostname(), u.Path)
		}
		t.transport,_ = transport.NewReader(u)
		return t
	})

}


func (t *Tar) Type() string { return "tar" }

func (t *Tar) ExtractResources(filter ResourceSelector) ([]*resource.Document, error) {
	documents := make([]*resource.Document, 0, 100)
	d := resource.NewDocument()
	documents = append(documents, d)

	TarGzipFileName := regexp.MustCompile(`^.*\.(tar\.gz|tgz)$`)
	TarFileName := regexp.MustCompile(`^.*\.tar$`)

	defer t.transport.Close()

	var gzipReader io.Reader
	switch t.Path {
	case TarGzipFileName.FindString(t.Path):
		zr, err := gzip.NewReader(t.transport)
		if err != nil {
			return documents, err
		}
		gzipReader = zr
		fallthrough
	case TarFileName.FindString(t.Path):
		var fileReader io.Reader
		if gzipReader == nil {
			fileReader = t.transport
		} else {
			fileReader = gzipReader
		}
		tarReader := tar.NewReader(fileReader)
		for {
			hdr, err := tarReader.Next()
			if err == io.EOF {
				break
			}
			if err != nil {
				return documents, err
			}
			f := resource.NewFile()
			f.Path = hdr.Name
			if fiErr := f.UpdateAttributesFromFileInfo(hdr.FileInfo()); fiErr != nil {
				return documents, fiErr
			}
			readErr := f.SetContent(tarReader)
			if readErr != nil {
				return documents, readErr
			}
			d.AddResourceDeclaration("file", f)
		}
	}
	return documents, nil
}