#!/usr/bin/env perl

use strict;
use warnings;
use utf8;
use FindBin;
use lib "$FindBin::Bin/../lib";
use lib "$FindBin::Bin/../extlib/lib/perl5";
use Gitprep;

my $debug = 0;

# Project name pattern
my $project_re = qr/[a-zA-Z0-9_\-\.]+$/;

# User
my $session_user = shift;
die "User not specifed" unless defined $session_user;

# Application
my $app = Gitprep->new;

# Git
my $git = $app->git;

# DBI
my $dbi = $app->dbi;

# SSH connection
my $ssh_connection = $ENV{SSH_CONNECTION};
warn "ssh_connection: $ssh_connection" if $debug;
die "who the *heck* are you?\n" unless defined $ssh_connection;

# SSH original command
my $ssh_original_command = $ENV{SSH_ORIGINAL_COMMAND} || '';
warn "ssh_original_command: $ssh_original_command" if $debug;

# IP address
my $ip = $ssh_connection || '(no-IP)';
warn "ip: $ip" if $debug;
$ip =~ s/ .*//;

# Check new line of SSH original command
my $ssh_original_command_tmp = $ssh_original_command;
$ssh_original_command_tmp =~ s/[\n\r]+/<<newline>>/g;
die "I don't like newlines in the command: $ssh_original_command\n"
  if $ssh_original_command ne $ssh_original_command_tmp;

# Project
my ($verb, $user, $project) = parse_ssh_original_command($ssh_original_command);
sanity($project);

# Can access
my $can_access;
if ($session_user eq $user) {
  $can_access = 1;
}
else {
  my $row = $app->dbi->model('collaboration')->select(
    id => [$user, $project, $session_user]
  )->one;
  
  $can_access = $row ? 1 : 0;
}
die qq|User "$session_user" can't access repository "$user/$project.git"\n|
  unless $can_access; 

# Command
my $rep_home = $git->rep_home;
my $repository = "'$rep_home/$user/$project.git'";
my @git_shell_cmd = ("git", "shell", "-c", "$verb $repository");
warn "@git_shell_cmd" if $debug;
unless ($debug) {
  system(@git_shell_cmd) == 0
    or die "Can't execute command: @git_shell_cmd\n" ;
}

sub parse_ssh_original_command {
  my $ssh_original_command = shift;

  $ssh_original_command ||= '';

  my $git_commands = "git-upload-pack|git-receive-pack|git-upload-archive";
  if ($ssh_original_command =~ m(^($git_commands) '.*/([a-zA-Z1-9_]+)/([^\/]+?)\.git'$)) {
    my ($verb, $user, $project) = ($1, $2, $3);
    warn "User:$user, Project:$project" if $debug;
    die "invalid repo name: '$project'\n" if $project !~ $project_re;
    return ($verb, $user, $project);
  }
  else {
    die "Invalid command: $ssh_original_command\n";
  }
}

sub sanity {
  my $project = shift;
  die "'$project' contains bad characters\n" if $project !~ $project_re;
  die "'$project' ends with a '/'\n"         if $project =~ m(/$);
  die "'$project' contains '..'\n"           if $project =~ m(\.\.);
}

=head1 NAME

gitprep-shell - AuthorizedKeysCommand for sshd

=head1 USAGE

  ./gitprep-shell kimoto

This command return user public_key