<?php
// Merge requests

require_once($INC . "/util.inc.php");
require_once($INC . "/sql.inc.php");
require_once($INC . '/user.inc.php');
require_once($INC . "/events.inc.php");

$rg_mr_env_q = getenv("ROCKETGIT_MR_QUEUE");
if (empty($rg_mr_env_q))
	$rg_mr_queue = $rg_state_dir . "/q_merge_requests";
else
	$rg_mr_queue = $rg_mr_env_q;

$rg_mr_error = "";

function rg_mr_set_error($str)
{
	global $rg_mr_error;
	$rg_mr_error = $str;
	rg_log($str);
}

function rg_mr_error()
{
	global $rg_mr_error;
	return $rg_mr_error;
}


/*
 * Event functions
 */
$rg_mr_functions = array(
	'mr_event_new' => 'rg_mr_event_new',
	'mr_event_add_to_db' => 'rg_mr_event_add_to_db',
	'mr_merge' => 'rg_mr_event_merge'
);
rg_event_register_functions($rg_mr_functions);

/*
 * This is called when the user press "Merge" button
 */
function rg_mr_event_merge($db, $ev)
{
	$ret = array();

	// TODO: we should send the error messages only at last try! Anywhere! Really?!
	// TODO: care! we should not send the mail before doing the merge!
	// TODO: check also all the other events.
	// do the merge

	$r = rg_git_merge($ev['repo_path'], $ev['merge_against'],
		$ev['mri']['new_rev'], $ev['merge_ff'], $ev['merge_msg']);
	if ($r === FALSE) {
		rg_log('Merge failed: ' . rg_git_error());
		// TODO: notify ui['uid'] that the merge failed
		rg_mail_template('repo/mail/merge_failed', $ev);
		return $ret;
	}

	$r = rg_mr_merge_set_status($db, $ev['ri']['repo_id'],
		$ev['mri']['id'], time());
	if ($r === FALSE)
		return FALSE;

	// notify the requester (if not anonymous)
	// TODO: notify the watchers?
	// TODO: notify the users who commented on the pull request?
	// TODO: notify users who watch the pull request?

	return $ret;
}

/*
 * This is called when a new pull request is done
 */
function rg_mr_event_new($db, $ev)
{
	$ret = array();

	// Insert it into database
	$ret[] = array_merge($ev,
		array('category' => 'mr_event_add_to_db', 'prio' => 100));

	// TODO: Notify admins of the repo

	// TODO: Call a webhook

	return $ret;
}

/*
 * Add a merge request file to database
 */
function rg_mr_event_add_to_db($db, $a)
{
	rg_prof_start('mr_event_add_to_db');
	rg_log_enter('mr_add_to_db: a: ' . rg_array2string($a));

	$now = time();

	$ret = FALSE;
	$rollback = 0;
	while (1) {
		if (rg_sql_begin($db) !== TRUE) {
			rg_mr_set_error('start transaction failed');
			break;
		}

		$rollback = 1;

		$id = rg_repo_next_id($db, 'mr', $a['repo_id']);
		if ($id === FALSE) {
			rg_mr_set_error('cannot get next id');
			break;
		}

		// TODO: git may fail to update the reference after this hook;
		// the mr code should check if the update was done.
		$mr = 'refs/mr/' . $id;
		$reason = $a['ui']['username'] . ' pushed a merge request'
			. ' for ref ' . $a['refname']
			. ' into ' . $mr;
		$r = rg_git_update_ref($a['repo_path'], $mr, '', $a['new_rev'], $reason);
		if ($r !== TRUE) {
			rg_mr_set_error('cannot update-ref: ' . rg_git_error());
			break;
		}

		$a['id'] = $id;
		$a['who'] = $a['ui']['uid'];
		$sql = 'INSERT INTO merge_requests (repo_id, id, itime'
			. ', namespace, refname, old_rev, new_rev, done, ip'
			. ', who)'
			. ' VALUES (@@repo_id@@, @@id@@, @@itime@@'
			. ', @@namespace@@, @@refname@@, @@old_rev@@'
			. ', @@new_rev@@, 0, @@ip@@, @@who@@)';
		$res = rg_sql_query_params($db, $sql, $a);
		if ($res === FALSE) {
			rg_mr_set_error('cannot insert merge request');
			break;
		}
		rg_sql_free_result($res);

		if (rg_sql_commit($db) !== TRUE) {
			rg_mr_set_error('cannot commit');
			break;
		}

		$rollback = 0;

		$ret = array();
		break;
	}

	if ($rollback)
		rg_sql_rollback($db);

	rg_log_exit();
	rg_prof_end('mr_event_add_to_db');
	return $ret;
}

/*
 * Loads info from a merge request file
 */
function rg_mr_queue_load_file($file)
{
	global $php_errormsg;

	$ret = array();
	$ret['ok'] = 0;

	$c = @file_get_contents($file);
	if ($c === FALSE) {
		rg_mr_set_error("cannot load a merge request from $file ($php_errormsg)");
		return $ret;
	}

	$tokens = explode(" ", trim($c));
	foreach ($tokens as $token) {
		$p = explode("=", $token);
		$ret[$p[0]] = $p[1];
	}

	$ret['ok'] = 1;
	return $ret;
}

/*
 * Process merge requests queue
 */
function rg_mr_queue_process($db)
{
	global $php_errormsg;
	global $rg_mr_queue;

	rg_prof_start("mr_queue_process");

	$ret = TRUE;
	$dir = @opendir($rg_mr_queue);
	if ($dir === FALSE) {
		rg_mr_set_error("cannot open dir $rg_mr_queue ($php_errormsg)!");
		return FALSE;
	}

	while (($file = readdir($dir))) {
		if (strncmp($file, "mr-", 3) != 0)
			continue;

		$path = $rg_mr_queue . "/" . $file;
		rg_log("Loading merge request from $path...");
		$d = rg_mr_queue_load_file($path);
		if ($d['ok'] != 1) {
			$ret = FALSE;
			break;
		}

		$r = rg_mr_create($db, $d['repo_id'], $d['namespace'],
			$d['old_rev'], $d['new_rev'], $d['refname'], $d['ip']);
		if ($r != TRUE) {
			rename($path, $rg_mr_queue . "/BAD-" . $file);
		} else {
			if (@unlink($path) !== TRUE)
				rg_log("Warn: Cannot unlink file $path!");
			// TODO: Verify it exists in database
		}
	}
	closedir($dir);

	rg_prof_end("mr_queue_process");
	return $ret;
}

/*
 * Helper to cosmetic mr data
 */
function rg_mr_cosmetic($db, &$row)
{
	$row['date_utc'] = gmdate("Y-m-d H:i", $row['itime']);
	$row['old_rev_short'] = substr($row['old_rev'], 0, 7);
	$row['new_rev_short'] = substr($row['new_rev'], 0, 7);

	if (!isset($row['who_nice'])) {
		if ($row['who'] == 0) {
			$row['who_nice'] = 'anonymous';
		} else {
			$ui = rg_user_info($db, $row['who'], '', '');
			if ($ui['exists'] == 1)
				$row['who_nice'] = $ui['username'];
			else
				$row['who_nice'] = 'n/a';
		}
	}
	$row['done_nice'] = gmdate("Y-m-d H:i", $row['done']);
}

/*
 * Loads merge requests
 * @type - 'pending' or 'closed'
 * @limit = 0 => no limit
 */
function rg_mr_load($db, $repo_id, $type, $limit)
{
	rg_log("mr_load: repo_id=$repo_id type=$type limit=$limit");

	if (strcmp($type, 'pending') == 0)
		$add = ' AND done = 0';
	else
		$add = ' AND done > 1000'; // first values are for different status

	$params = array('repo_id' => $repo_id);
	$sql = 'SELECT * FROM merge_requests'
		. ' WHERE repo_id = @@repo_id@@'
		. $add
		. ' ORDER BY itime';
	if ($limit > 0)
		$sql .= ' LIMIT ' . $limit;
	$res = rg_sql_query_params($db, $sql, $params);
	if ($res === FALSE) {
		rg_mr_set_error("Cannot load merge requests (" . rg_sql_error() . ")");
		return FALSE;
	}

	$ret = array();
	while (($row = rg_sql_fetch_array($res))) {
		rg_mr_cosmetic($db, $row);
		$ret[] = $row;
	}
	rg_sql_free_result($res);

	return $ret;
}

/*
 * Loads a merge request
 */
function rg_mr_load_one($db, $repo_id, $id)
{
	rg_prof_start('mr_load_one');
	rg_log('mr_load_one: repo_id=' . $repo_id . ' id=' . $id);

	$ret = FALSE;
	while (1) {
		$params = array('repo_id' => $repo_id, 'id' => $id);
		$sql = 'SELECT * FROM merge_requests'
			. ' WHERE repo_id = @@repo_id@@'
			. ' AND id = @@id@@';
		$res = rg_sql_query_params($db, $sql, $params);
		if ($res === FALSE) {
			rg_mr_set_error('cannot load the merge request');
			break;
		}

		$rows = rg_sql_num_rows($res);
		if ($rows)
			$ret = rg_sql_fetch_array($res);
		rg_sql_free_result($res);

		if ($rows == 0) {
			rg_mr_set_error('mr not found');
			break;
		}

		rg_mr_cosmetic($db, $ret);
		break;
	}

	rg_prof_end('mr_load_one');
	return $ret;
}

/*
 * Sets the status ('done' filed of a merge request
 * @status - 0 - not merged, > 10 = timestamp when the merge took place
 */
function rg_mr_merge_set_status($db, $repo_id, $id, $status)
{
	$ret = FALSE;
	while (1) {
		$params = array('repo_id' => $repo_id,
			'id' => $id,
			'status' => $status
		);
		$sql = 'UPDATE merge_requests'
			. ' SET done = @@status@@'
			. ' WHERE repo_id = @@repo_id@@'
			. ' AND id = @@id@@';
		$res = rg_sql_query_params($db, $sql, $params);
		if ($res === FALSE) {
			rg_mr_set_error('cannot update status (' . rg_sql_error());
			break;
		}
		rg_sql_free_result($res);

		$ret = TRUE;
		break;
	}

	return $ret;
}

/*
 * High level merge request function
 */
function rg_mr_high_level($db, &$rg, $paras)
{
	rg_prof_start('mr_high_level');
	rg_log_enter('mr_high_level');

	$ret = '';
	while (1) {
		if ($rg['ri']['git_dir_done'] == 0) {
			$ret .= rg_template('repo/no_git_dir.html',
				$rg, TRUE /*xss*/);
			break;
		}

		// TODO: mrs.html is empty!
		$ret .= rg_template('repo/mrs.html', $rg, TRUE /*xss*/);

		$op = array_shift($paras);
		if (empty($op)) {
			$op = 'pending';
		} else {
			$mr = sprintf('%u', $op);
			if ($mr > 0)
				$op = '';
		}

		rg_log('DEBUG: op=' . $op);
		$rg['menu']['mr'][$op] = 1;
		$rg['HTML:menu_repo_level2'] =
			rg_template('repo/mr/menu.html', $rg, TRUE /*xss*/);

		if ((strcmp($op, 'pending') == 0) || (strcmp($op, 'closed') == 0)) {
			$rg['mr']['op'] = $op;
			$r = rg_mr_load($db, $rg['ri']['repo_id'], $op,
				0 /*no limit*/);
			if ($r === FALSE) {
				$ret .= 'error getting merge request list ('
					. rg_mr_error() . ')';
			} else {
				$ret .= rg_template_table('repo/mr/list', $r, $rg);
			}
			break;
		} else if (strcmp($op, 'create') == 0) {
			$ret .= rg_warning('not yet implemented');
			break;
		}

		$mri = rg_mr_load_one($db, $rg['ri']['repo_id'], $mr);
		if ($mri === FALSE) {
			$ret .= 'error loading merge request'
				. ' (' . rg_mr_error() . ')';
			break;
		}

		$mri['merge_in_progress'] = 0;
		$mri['already_merged'] = 0;
		$against = rg_git_short($mri['refname']);

		$mr_op = array_shift($paras);
		rg_log('DEBUG: mr_op=' . $mr_op);
		if (strcmp($mr_op, 'merge') == 0) {
			if ($rg['can_admin'] !== 1) {
				$ret .= rg_warning('Not allowed!');
				break;
			}

			if (!rg_valid_referer()) {
				$ret .= rg_warning('Invalid referer; try again.');
				break;
			}

			if (!rg_token_valid($db, $rg, 'mr_merge', FALSE)) {
				$ret .= rg_warning('Invalid token; try again.');
				break;
			}

			$event = array(
				'category' => 'mr_merge',
				'prio' => 30,
				'ri' => $rg['ri'],
				'ui' => $rg['login_ui'],
				'repo_path' => $rg['repo_path'],
				'mri' => $mri,
				'merge_against' => $against,
				'merge_ff' => rg_var_uint('merge_ff'),
				'merge_msg' => rg_var_str('merge_msg')
			);
			$r = rg_event_add($db, $event);
			if ($r !== TRUE) {
				$ret .= rg_warning('Cannot add event; try again later.');
				break;
			}
			rg_event_signal_daemon('', 0);

			$mri['merge_in_progress'] = 1;
			$mri['HTML:body'] = rg_template(
				'repo/mr/merge_in_progress.html',
				$rg, TRUE /*xss*/);
		} else {
			$mri['HTML:body'] = '';

			if ($mri['done'] > 10) { // already merged
				$mri['merge_in_progress'] = 1;
				$mri['already_merged'] = 1;
				$mri['done_nice'] =
					gmdate('Y-m-d H:i', $mri['done']) . ' UTC';
				$mri['can_merge_without_conflicts'] = 0;
			} else {
				$r = rg_git_merge_without_conflict($rg['repo_path'],
					$against, $mri['new_rev']);
				if ($r === FALSE) {
					$ret .= rg_warning('Error testing if merge will work'
						. ' (' . rg_git_error() . ').');
					break;
				}
				rg_log('DEBUG: cmwc=' . $r);
				$mri['can_merge_without_conflicts'] = $r;

				if ($mri['can_merge_without_conflicts'] == 0) {
					$base = rg_git_merge_base($rg['repo_path'],
						$against, $mri['new_rev']);
					if ($base === FALSE) {
						$ret .= rg_warning('Error: finding base: '
							. rg_git_error() . '.');
						break;
					}

					$mri['HTML:status'] = rg_git_merge_tree_html(
						$rg['repo_path'], $base, $against,
						$mri['new_rev']);
					rg_log_ml('DEBUG: status: ' . print_r($mri['HTML:status'], TRUE));
					$mri['HTML:body'] .= rg_template(
						'repo/mr/conflicts.html', $mri, TRUE /*xss*/);
				}
			}

			$_log = rg_git_log($rg['repo_path'], 0, $mri['old_rev'],
				$mri['new_rev'], TRUE);
			if ($_log === FALSE) {
				$ret .= rg_warning('Error generating patch.');
				break;
			}

			$rg['HTML:commit_labels'] = '';
			$mri['HTML:body'] .=
				rg_git_log2listing($_log, $rg, TRUE);

			if ($mri['can_merge_without_conflicts'] == 1)
				$rg['rg_form_token'] = rg_token_get($db, $rg, 'mr_merge');
		}

		//rg_log_ml('DEBUG: mri: ' . print_r($mri, TRUE));
		$rg['mr'] = $mri;

		$hints = array();
		$hints[]['HTML:hint'] = rg_template('hints/repo/merge.html',
			$rg, TRUE /*xss*/);
		$rg['mr']['HTML:hints'] = rg_template_table('hints/list',
			$hints, $rg);

		$ret .= rg_template('repo/mr/page.html', $rg,
			TRUE/*xss*/);
		break;
	}

	rg_log_exit();
	rg_prof_end('mr_high_level');
	return $ret;
}

?>