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

package fan

import (
_	"context"
_	"encoding/json"
	"fmt"
_	"gopkg.in/yaml.v3"
	"net/url"
	"decl/internal/transport"
	"decl/internal/data"
	"decl/internal/folio"
	"archive/tar"
_	"regexp"
	"io"
	"io/fs"
	"log"
	"log/slog"
	"path/filepath"
)

type Tar struct {
	Uri folio.URI `yaml:"uri" json:"uri"`
	parsedURI *url.URL `yaml:"-" json:"-"`
	emitResource data.Resource `yaml:"-" json:"-"`
	reader io.ReadCloser `yaml:"-" json:"-"`
	writer io.WriteCloser `yaml:"-" json:"-"`
	targetArchive *tar.Writer `yaml:"-" json:"-"`
}

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

func init() {
	folio.DocumentRegistry.ConverterTypes.Register([]string{"tar"}, func(u *url.URL) data.Converter {
		t := NewTar()
		t.SetURI(u)
		return t
	})

	folio.DocumentRegistry.ConverterTypes.RegisterContentType([]string{"tar", "tar.gz", "tgz"}, func(u *url.URL) data.Converter {
		t := NewTar()
		t.SetURI(u)
		return t
	})

}

func (t *Tar) Type() data.TypeName { return "tar" }

func (t *Tar) SetURI(u *url.URL) {
	slog.Info("Tar.SetURI()", "tar", t)
	u.Scheme = "file"
	if u.Path == "" || u.Path == "-" {
	} else {
		fileAbsolutePath, _ := filepath.Abs(filepath.Join(u.Hostname(), u.Path))
		u.Path = fileAbsolutePath
	}
	t.Uri.SetURL(u)
	t.parsedURI = u
/*
	exttype, fileext := t.Uri.Extension()
	if exttype == "tgz" || fileext == "tgz" {
		q := u.Query()
		q.Set("gzip", string("true"))
		u.RawQuery = q.Encode()
	}
*/
}

func (t *Tar) targetResource() (target data.Resource, err error) {
	if t.emitResource == nil {

		if t.emitResource, err = t.Uri.NewResource(nil); err != nil {
			return nil, err
		}

		var tarTargetFile data.FileResource = t.emitResource.(data.FileResource)
		tarTargetFile.SetContentSourceRef(t.Uri.String())
		tarTargetFile.SetGzipContent(true)

		t.writer, err = tarTargetFile.(data.ContentReadWriter).ContentWriterStream()
		if err == io.EOF {
			slog.Info("Tar.targetResource() ContentWriterStream", "target", tarTargetFile, "tar", t.writer.(*transport.Writer), "error", err)
			panic(err)
		}
		t.targetArchive = tar.NewWriter(t.writer)
		slog.Info("Tar.targetResource() SetContentSourceRef", "target", tarTargetFile, "uri", t.Uri.String(), "tar", t.targetArchive, "error", err)

	}
	target = t.emitResource
	return 
}

// Convert a document of file resources to a tar file resource
func (t *Tar) Emit(document data.Document, filter data.ElementSelector) (resourceTarget data.Resource, err error) {

	resourceTarget, err = t.targetResource()
	
	slog.Info("Tar.Emit()", "writer", t.writer.(*transport.Writer), "error", err)

	for _,res := range document.Filter(func(d data.Declaration) bool {
		return d.ResourceType() == "file"
	}) {

		var f data.FileResource = res.(*folio.Declaration).Attributes.(data.FileResource)

		//f.PathNormalization(true)
		//err = f.NormalizePath()

		fileInfo := f.FileInfo()
		slog.Info("Tar.Emit() FileInfo", "fileinfo", fileInfo, "size", fileInfo.Size(), "file", f)
		if fileInfo.Size() < 1 {
			if len(f.GetContentSourceRef()) > 0 {
				rs, _ := f.(data.ContentReader).ContentReaderStream()
				info, _ := rs.Stat()
				err = f.SetFileInfo(info)
				slog.Info("Tar.Emit() Set FileInfo from ContentSourceRef", "fileinfo", f.FileInfo(), "file", f)
				rs.Close()
			} else {
				if err = f.(data.Info).ReadStat(); err != nil {
					return
				}
			}
		}

		slog.Info("Tar.Emit", "file", f, "size", fileInfo.Size(),  "error", err)
		hdr, fiErr := tar.FileInfoHeader(fileInfo, "")

		if fileInfo.Mode() & fs.ModeSymlink != 0 {
			hdr.Linkname = f.GetTarget()
		}

		slog.Info("Tar.Emit", "header", hdr, "size", fileInfo.Size(), "err", fiErr)
		if err := t.targetArchive.WriteHeader(hdr); err != nil {
			slog.Error("Tar.Emit() WriteHeader", "target", t.targetArchive, "header", hdr, "resource", f, "fileinfo", fileInfo, "error", err)
			log.Fatal(err)
		}

		if fileInfo.IsDir() {
			continue
		}

		slog.Info("Tar.Emit - writing resource to target archive", "target", t.targetArchive, "resource", f, "err", err)
		if _, err := f.GetContent(t.targetArchive); err != nil {
			slog.Error("Tar.Emit() Content", "target", t.targetArchive, "resource", f, "fileinfo", fileInfo, "error", err)
			log.Fatal(err)
		}
		slog.Info("Tar.Emit - wrote", "resource", f, "err", err)
	}
	
	return
}

// Convert a tar file resource to a document of file resources
func (t *Tar) Extract(resourceSource data.Resource, filter data.ElementSelector) (document data.Document, err error) {
	document = folio.DocumentRegistry.NewDocument("")
	var tarSourceFile data.FileResource = resourceSource.(data.FileResource)
	//tarSourceFile := resourceSource.(*resource.File)

	tarSourceFile.SetGzipContent(true)
	t.reader, err = tarSourceFile.GetContent(nil)
	sourceArchive := tar.NewReader(t.reader)

	defer t.reader.Close()

	for {
		var hdr *tar.Header
		hdr, err = sourceArchive.Next()
		if err == io.EOF {
			slog.Info("Tar.Extract() EOF", "source", sourceArchive)
			err = nil
			break
		}
		if err != nil {
			slog.Info("Tar.Extract() ERROR", "source", sourceArchive, "error", err)
			return
		}

		var fileResource data.Resource
		uri := fmt.Sprintf("file://%s", hdr.Name)
		if fileResource, err = document.(*folio.Document).NewResource(uri); err != nil {
			return
		}
		var f data.FileResource = fileResource.(data.FileResource)

		if err = f.SetFileInfo(hdr.FileInfo()); err != nil {
			return
		}
		err = f.SetContent(sourceArchive)
		if err != nil {
			return
		}
	}
	return
}

func (t *Tar) Close() (err error) {
	if t.reader != nil {
		if err = t.reader.Close(); err != nil {
			return
		}
	}
	if err = t.targetArchive.Close(); err == nil {
		if t.writer != nil {
			err = t.writer.Close()
		}
	}
	return
}