<?php
/**
*
* @package phpBB3
* @copyright (c) 2011 phpBB Group
* @license http://opensource.org/licenses/gpl-license.php GNU Public License
*
*/

if ($argc < 2)
{
	show_usage();
}

if (file_exists('.git'))
{
	echo "[error] git repository already exists\n";
	exit(1);
}

function show_usage()
{
	$filename = basename(__FILE__);

	echo "$filename adds repositories of a github network as remotes to a local git repository.\n";
	echo "\n";

	echo "Usage: php $filename -s collaborators|organisation|contributors|network [OPTIONS]\n";
	echo "\n";

	echo "Scopes:\n";
	echo "  collaborators                 Repositories of people who have push access to the specified repository\n";
	echo "  contributors                  Repositories of people who have contributed to the specified repository\n";
	echo "  organisation                  Repositories of members of the organisation at github\n";
	echo "  network                       All repositories of the whole github network\n";
	echo "\n";

	echo "Options:\n";
	echo " -s scope                       See description above (mandatory)\n";
	echo " -u github_username             Overwrites the github username (optional)\n";
	echo " -r repository_name             Overwrites the repository name (optional)\n";
	echo " -m your_github_username        Sets up ssh:// instead of git:// for pushable repositories (optional)\n";

	exit(1);
}

// Handle arguments
$opts			= getopt('s:u:r:m:');
$scope			= get_arg($opts, 's', '');
$username		= get_arg($opts, 'u', 'phpbb');
$repository 	= get_arg($opts, 'r', 'phpbb3');
$developer		= get_arg($opts, 'm', '');

// Get some basic data
$network		= get_network($username, $repository);
$collaborators	= get_collaborators($username, $repository);

// Clone the blessed repository
clone_repository($username, $repository, isset($collaborators[$developer]));

switch ($scope)
{
	case 'collaborators':
		$remotes = array_intersect_key($network, $collaborators);
	break;

	case 'organisation':
		$remotes = array_intersect_key($network, get_organisation_members($username));
	break;

	case 'contributors':
		$remotes = array_intersect_key($network, get_contributors($username, $repository));
	break;

	case 'network':
		$remotes = $network;
	break;

	default:
		show_usage();
}

foreach ($remotes as $remote)
{
	if ($remote['username'] == $username)
	{
		// Skip blessed repository.
		continue;
	}

	add_remote($remote['username'], $remote['repository'], $remote['username'] == $developer);
}

run('git remote update');

function clone_repository($username, $repository, $pushable = false)
{
	$url = get_repository_url($username, $repository, false);
	run("git clone $url ./");

	if ($pushable)
	{
		$ssh_url = get_repository_url($username, $repository, true);
		run("git remote set-url --push origin $ssh_url");
	}
}

function add_remote($username, $repository, $pushable = false)
{
	$url = get_repository_url($username, $repository, false);
	run("git remote add $username $url");

	if ($pushable)
	{
		$ssh_url = get_repository_url($username, $repository, true);
		run("git remote set-url --push $username $ssh_url");
	}
}

function get_repository_url($username, $repository, $ssh = false)
{
	$url_base = ($ssh) ? 'git@github.com:' : 'git://github.com/';

	return $url_base . $username . '/' . $repository . '.git';
}

function api_request($query)
{
	return json_decode(file_get_contents("http://github.com/api/v2/json/$query"));
}

function get_contributors($username, $repository)
{
	$request = api_request("repos/show/$username/$repository/contributors");

	$usernames = array();
	foreach ($request->contributors as $contributor)
	{
		$usernames[$contributor->login] = $contributor->login;
	}

	return $usernames;
}

function get_organisation_members($username)
{
	$request = api_request("organizations/$username/public_members");

	$usernames = array();
	foreach ($request->users as $member)
	{
		$usernames[$member->login] = $member->login;
	}

	return $usernames;
}

function get_collaborators($username, $repository)
{
	$request = api_request("repos/show/$username/$repository/collaborators");

	$usernames = array();
	foreach ($request->collaborators as $collaborator)
	{
		$usernames[$collaborator] = $collaborator;
	}

	return $usernames;
}

function get_network($username, $repository)
{
	$request = api_request("repos/show/$username/$repository/network");

	$usernames = array();
	foreach ($request->network as $network)
	{
		$usernames[$network->owner] = array(
			'username'		=> $network->owner,
			'repository'	=> $network->name,
		);
	}

	return $usernames;
}

function get_arg($array, $index, $default)
{
	return isset($array[$index]) ? $array[$index] : $default;
}

function run($cmd)
{
	passthru(escapeshellcmd($cmd));
}