package main

import (

	"fmt"
	"io"

	"net/http"

	"github.com/go-git/go-billy/v5/osfs"
	"github.com/go-git/go-git/v5/plumbing/format/pktline"
	"github.com/go-git/go-git/v5/plumbing/transport"
	"github.com/go-git/go-git/v5/plumbing/transport/server"

	"os/exec"

)

func handle_repo_info(w http.ResponseWriter, r *http.Request, params map[string]any) (err error) {
	group_name, repo_name := params["group_name"].(string), params["repo_name"].(string)
	var repo_path string
	err = database.QueryRow(r.Context(), "SELECT r.filesystem_path FROM repos r JOIN groups g ON r.group_id = g.id WHERE g.name = $1 AND r.name = $2;", group_name, repo_name).Scan(&repo_path)
	if err != nil {
		return err
	}

	endpoint, err := transport.NewEndpoint("/")

	w.Header().Set("Content-Type", "application/x-git-upload-pack-advertisement")
	w.WriteHeader(http.StatusOK)

	cmd := exec.Command("git", "upload-pack", "--stateless-rpc", "--advertise-refs", repo_path)

	stdout, err := cmd.StdoutPipe()

	if err != nil {
		return err
	}

	billy_fs := osfs.New(repo_path)
	fs_loader := server.NewFilesystemLoader(billy_fs)
	transport := server.NewServer(fs_loader)
	upload_pack_session, err := transport.NewUploadPackSession(endpoint, nil)

	cmd.Stderr = cmd.Stdout
	defer func() {
		_ = stdout.Close()
	}()

	err = cmd.Start()
	if err != nil {
		return err
	}

	err = pack_line(w, "# service=git-upload-pack\n")

	if err != nil {
		return err
	}

	advertised_references, err := upload_pack_session.AdvertisedReferencesContext(r.Context())

	err = pack_flush(w)
	if err != nil {
		return
	}

	_, err = io.Copy(w, stdout)

	if err != nil {
		return err
	}

	advertised_references.Prefix = [][]byte{[]byte("# service=git-upload-pack"), pktline.Flush}
	w.Header().Set("content-type", "application/x-git-upload-pack-advertisement")
	err = advertised_references.Encode(w)

	err = cmd.Wait()

	if err != nil {
		return err
	}

	return nil
}

// Taken from https://github.com/icyphox/legit, MIT license
func pack_line(w io.Writer, s string) error {
	_, err := fmt.Fprintf(w, "%04x%s", len(s)+4, s)
	return err
}

// Taken from https://github.com/icyphox/legit, MIT license
func pack_flush(w io.Writer) error {
	_, err := fmt.Fprint(w, "0000")
	return err
}

package main

import (

	"io"

	"net/http"

	"github.com/go-git/go-billy/v5/osfs"
	"github.com/go-git/go-git/v5/plumbing/protocol/packp"
	"github.com/go-git/go-git/v5/plumbing/transport"
	"github.com/go-git/go-git/v5/plumbing/transport/server"

	"os/exec"

)

func handle_upload_pack(w http.ResponseWriter, r *http.Request, params map[string]any) (err error) {
	group_name, repo_name := params["group_name"].(string), params["repo_name"].(string)
	var repo_path string
	err = database.QueryRow(r.Context(), "SELECT r.filesystem_path FROM repos r JOIN groups g ON r.group_id = g.id WHERE g.name = $1 AND r.name = $2;", group_name, repo_name).Scan(&repo_path)
	if err != nil {
		return err
	}

	endpoint, err := transport.NewEndpoint("/")

	w.Header().Set("Content-Type", "application/x-git-upload-pack-result")
	w.Header().Set("Connection", "Keep-Alive")
	w.Header().Set("Transfer-Encoding", "chunked")
	w.WriteHeader(http.StatusOK)

	cmd := exec.Command("git", "upload-pack", "--stateless-rpc", repo_path)
	stdout, err := cmd.StdoutPipe()
	if err != nil {
		return err
	}
	cmd.Stderr = cmd.Stdout
	defer func() {
		_ = stdout.Close()
	}()

	stdin, err := cmd.StdinPipe()
	if err != nil {
		return err
	}
	defer func() {
		_ = stdin.Close()
	}()

	err = cmd.Start()

	if err != nil {
		return err
	}

	billy_fs := osfs.New(repo_path)
	fs_loader := server.NewFilesystemLoader(billy_fs)
	transport := server.NewServer(fs_loader)
	upload_pack_session, err := transport.NewUploadPackSession(endpoint, nil)

	_, err = io.Copy(stdin, r.Body)

	if err != nil {
		return err
	}

	w.Header().Set("Content-Type", "application/x-git-upload-pack-result")
	reference_update_request := packp.NewUploadPackRequest()
	err = reference_update_request.Decode(r.Body)

	err = stdin.Close()

	if err != nil {
		return err
	}

	report_status, err := upload_pack_session.UploadPack(r.Context(), reference_update_request)

	_, err = io.Copy(w, stdout)

	if err != nil {
		return err
	}

	err = report_status.Encode(w)

	err = cmd.Wait()

	if err != nil {
		return err
	}

	return nil
}