package main

import (
	"bytes"
	"encoding/binary"
	"errors"
	"fmt"
	"net"
	"os"

	"path/filepath"

	"syscall"
)

var (

	err_get_fd       = errors.New("Unable to get file descriptor")
	err_get_ucred    = errors.New("Failed getsockopt")

	err_get_fd    = errors.New("Unable to get file descriptor")
	err_get_ucred = errors.New("Failed getsockopt")

)

func hooks_handle_connection(conn net.Conn) {
	defer conn.Close()

	ucred, err := get_ucred(conn)
	if err != nil {
		conn.Write([]byte{1})
		fmt.Fprintln(conn, "Unable to get peer credentials:", err.Error())
		return
	}
	if ucred.Uid != uint32(os.Getuid()) {
		conn.Write([]byte{1})
		fmt.Fprintln(conn, "UID mismatch")
		return
	}

	cookie := make([]byte, 64)
	_, err = conn.Read(cookie)
	if err != nil {
		conn.Write([]byte{1})
		fmt.Fprintln(conn, "Failed to read cookie:", err.Error())
		return
	}

	deployer_chan, ok := hooks_cookie_deployer.Load(string(cookie))

	pack_to_hook, ok := pack_to_hook_by_cookie.Load(string(cookie))

	if !ok {
		conn.Write([]byte{1})

		fmt.Fprintln(conn, "Invalid cookie")

		fmt.Fprintln(conn, "Invalid handler cookie")

		return
	}

	var argc64 uint64
	err = binary.Read(conn, binary.NativeEndian, &argc64)
	if err != nil {
		conn.Write([]byte{1})
		fmt.Fprintln(conn, "Failed to read argc:", err.Error())
		return
	}
	var args []string
	for i := uint64(0); i < argc64; i++ {
		var arg bytes.Buffer
		for {
			b := make([]byte, 1)
			n, err := conn.Read(b)
			if err != nil || n != 1 {
				conn.Write([]byte{1})
				fmt.Fprintln(conn, "Failed to read arg:", err.Error())
				return
			}
			if b[0] == 0 {
				break
			}
			arg.WriteByte(b[0])
		}
		args = append(args, arg.String())
	}

	callback := make(chan struct{})

	deployer_chan <- hooks_cookie_deployer_return{
		args:     args,
		callback: callback,
		conn:     conn,

	switch filepath.Base(args[0]) {
	case "pre-receive":
		if pack_to_hook.direct_access {
			conn.Write([]byte{0})
		} else {
			conn.Write([]byte{1})
			fmt.Fprintln(conn, "Non-maintainer push access not implemented yet")
		}
	default:
		conn.Write([]byte{1})
		fmt.Fprintln(conn, "Invalid hook:", args[0])

	}

	<-callback

}

func serve_git_hooks(listener net.Listener) error {
	for {
		conn, err := listener.Accept()
		if err != nil {
			return err
		}
		go hooks_handle_connection(conn)
	}
}

func get_ucred(conn net.Conn) (*syscall.Ucred, error) {
	unix_conn := conn.(*net.UnixConn)
	fd, err := unix_conn.File()
	if err != nil {
		return nil, err_get_fd
	}
	defer fd.Close()

	ucred, err := syscall.GetsockoptUcred(int(fd.Fd()), syscall.SOL_SOCKET, syscall.SO_PEERCRED)
	if err != nil {
		return nil, err_get_ucred
	}
	return ucred, nil
}

package main

import (
	"crypto/rand"
	"errors"
	"fmt"

	"net"

	"os"
	"os/exec"

	glider_ssh "github.com/gliderlabs/ssh"
	"go.lindenii.runxiyu.org/lindenii-common/cmap"
)

var err_unauthorized_push = errors.New("You are not authorized to push to this repository")

type hooks_cookie_deployer_return struct {
	args     []string
	callback chan struct{}
	conn     net.Conn

type pack_to_hook_t struct {
	session       *glider_ssh.Session
	pubkey        string
	direct_access bool
	repo_path     string

}

var hooks_cookie_deployer = cmap.ComparableMap[string, chan hooks_cookie_deployer_return]{}

var pack_to_hook_by_cookie = cmap.Map[string, pack_to_hook_t]{}

func ssh_handle_receive_pack(session glider_ssh.Session, pubkey string, repo_identifier string) (err error) {
	repo_path, access, err := get_repo_path_perms_from_ssh_path_pubkey(session.Context(), repo_identifier, pubkey)
	if err != nil {
		return err
	}

	cookie, err := random_urlsafe_string(16)
	if err != nil {
		fmt.Fprintln(session.Stderr(), "Error while generating cookie:", err)
	}

	deployer_channel := make(chan hooks_cookie_deployer_return)
	hooks_cookie_deployer.Store(cookie, deployer_channel)
	defer hooks_cookie_deployer.Delete(cookie)

	pack_to_hook_by_cookie.Store(cookie, pack_to_hook_t{
		session:       &session,
		pubkey:        pubkey,
		direct_access: access,
		repo_path:     repo_path,
	})
	defer pack_to_hook_by_cookie.Delete(cookie)

	proc := exec.CommandContext(session.Context(), "git-receive-pack", repo_path)
	proc.Env = append(os.Environ(),
		"LINDENII_FORGE_HOOKS_SOCKET_PATH="+config.Hooks.Socket,
		"LINDENII_FORGE_HOOKS_COOKIE="+cookie,
	)
	proc.Stdin = session
	proc.Stdout = session
	proc.Stderr = session.Stderr()

	err = proc.Start()
	if err != nil {
		fmt.Fprintln(session.Stderr(), "Error while starting process:", err)
		return err
	}

	deployer := <-deployer_channel

	if access {
		deployer.conn.Write([]byte{0})
	} else {
		deployer.conn.Write([]byte{1})
		fmt.Fprintln(deployer.conn, "Hi! We don't support pushing from non-authorized users yet. This will be implemented soon.")
	}

	deployer.callback <- struct{}{}

	err = proc.Wait()
	if exitError, ok := err.(*exec.ExitError); ok {
		fmt.Fprintln(session.Stderr(), "Process exited with error", exitError.ExitCode())
	} else if err != nil {
		fmt.Fprintln(session.Stderr(), "Error while waiting for process:", err)
	}

	return err
}

func random_string(sz int) (string, error) {
	r := make([]byte, sz)
	_, err := rand.Read(r)
	return string(r), err
}