Goit

// Copyright (C) 2023, Jakob Wakeling

// All rights reserved.

package repo

import (

	"archive/zip"

	"errors"

	"fmt"

	"io"

	"log"

	"net/http"

	"path/filepath"

	"strings"

	"github.com/Jamozed/Goit/src/goit"

	"github.com/Jamozed/Goit/src/util"

	"github.com/go-chi/chi/v5"

	"github.com/go-git/go-git/v5"

	"github.com/go-git/go-git/v5/plumbing"

	"github.com/go-git/go-git/v5/plumbing/object"

)

func HandleDownload(w http.ResponseWriter, r *http.Request) {

	auth, user, err := goit.Auth(w, r, true)

	if err != nil {

		log.Println("[repo/download]", err.Error())

		goit.HttpError(w, http.StatusInternalServerError)

		return

	}

	tpath := chi.URLParam(r, "*")

	repo, err := goit.GetRepoByName(chi.URLParam(r, "repo"))

	if err != nil {

		goit.HttpError(w, http.StatusInternalServerError)

		return

	} else if repo == nil || !goit.IsVisible(repo, auth, user) {

		goit.HttpError(w, http.StatusNotFound)

		return

	}

	gr, err := git.PlainOpen(goit.RepoPath(repo.Name, true))

	if err != nil {

		log.Println("[/repo/download]", err.Error())

		goit.HttpError(w, http.StatusInternalServerError)

		return

	}

	ref, err := gr.Head()

	if errors.Is(err, plumbing.ErrReferenceNotFound) {

		goit.HttpError(w, http.StatusNotFound)

		return

	} else if err != nil {

		log.Println("[/repo/download]", err.Error())

		goit.HttpError(w, http.StatusInternalServerError)

		return

	}

	commit, err := gr.CommitObject(ref.Hash())

	if err != nil {

		log.Println("[/repo/download]", err.Error())

		goit.HttpError(w, http.StatusInternalServerError)

		return

	}

	file, err := commit.File(tpath)

	if errors.Is(err, object.ErrFileNotFound) {

		/* Possibly a directory, search file tree for prefix */

		var files []string

		var zSize uint64

		iter, err := commit.Files()

		if err != nil {

			log.Println("[/repo/download]", err.Error())

			goit.HttpError(w, http.StatusInternalServerError)

			return

		}

		iter.ForEach(func(f *object.File) error {

			if tpath == "" || strings.HasPrefix(f.Name, tpath+"/") {

				files = append(files, f.Name)

				zSize += uint64(f.Size)

			}

			return nil

		})

		if len(files) == 0 {

			goit.HttpError(w, http.StatusNotFound)

			return

		}

		/* Build and write ZIP of directory */

		w.Header().Set(

			"Content-Disposition", "attachment; filename="+util.If(tpath == "", repo.Name, filepath.Base(tpath))+".zip",

		)

		// w.Header().Set("Content-Length", fmt.Sprint(zSize))

		z := zip.NewWriter(w)

		for _, f := range files {

			zh := zip.FileHeader{Name: f, Method: zip.Store}

			zf, err := z.CreateHeader(&zh)

			if err != nil {

				log.Println("[/repo/download]", err.Error())

				goit.HttpError(w, http.StatusInternalServerError)

			}

			if file, err := commit.File(f); err != nil {

				log.Println("[/repo/download]", err.Error())

				goit.HttpError(w, http.StatusInternalServerError)

				return

			} else if rc, err := file.Blob.Reader(); err != nil {

				log.Println("[/repo/download]", err.Error())

				goit.HttpError(w, http.StatusInternalServerError)

				return

			} else {

				if _, err := io.Copy(zf, rc); err != nil {

					log.Println("[/repo/download]", err.Error())

				}

				rc.Close()

			}

		}

		z.Close()

		return

	} else if err != nil {

		log.Println("[/repo/download]", err.Error())

		goit.HttpError(w, http.StatusInternalServerError)

		return

	}

	if rc, err := file.Blob.Reader(); err != nil {

		log.Println("[/repo/download]", err.Error())

		goit.HttpError(w, http.StatusInternalServerError)

		return

	} else {

		w.Header().Set("Content-Disposition", "attachement; filename="+filepath.Base(tpath))

		w.Header().Set("Content-Length", fmt.Sprint(file.Size))

		if _, err := io.Copy(w, rc); err != nil {

			log.Println("[/repo/download]", err.Error())

		}

		rc.Close()

	}

}