<?php
// Storage API
// PHP Backend
// CBlue SPRL, Jean-Karim Bockstael, <jeankarim@cblue.be>

require_once('../inc/global.inc.php');

// variable cleaning...
foreach (array("svkey", "svvalue") as $key) {
    $_REQUEST[$key] = Database::escape_string($_REQUEST[$key]);
}

foreach (array("svuser", "svcourse", "svsco", "svlength", "svasc") as $key) {
    $_REQUEST[$key] = intval($_REQUEST[$key]);
}

switch ($_REQUEST['action']) {
    case "get":
        print storage_get($_REQUEST['svuser'], $_REQUEST['svcourse'], $_REQUEST['svsco'], $_REQUEST['svkey']);
        break;
    case "set":
        if (storage_can_set($_REQUEST['svuser'])) {
            print storage_set($_REQUEST['svuser'], $_REQUEST['svcourse'], $_REQUEST['svsco'], $_REQUEST['svkey'], $_REQUEST['svvalue']);
        }
        break;
    case "getall":
        print storage_getall($_REQUEST['svuser'], $_REQUEST['svcourse'], $_REQUEST['svsco']);
        break;
    case "stackpush":
        if (storage_can_set($_REQUEST['svuser'])) {
            print storage_stack_push($_REQUEST['svuser'], $_REQUEST['svcourse'], $_REQUEST['svsco'], $_REQUEST['svkey'], $_REQUEST['svvalue']);
        }
        break;
    case "stackpop":
        if (storage_can_set($_REQUEST['svuser'])) {
            print storage_stack_pop($_REQUEST['svuser'], $_REQUEST['svcourse'], $_REQUEST['svsco'], $_REQUEST['svkey']);
        }
        break;
    case "stacklength":
        print storage_stack_length($_REQUEST['svuser'], $_REQUEST['svcourse'], $_REQUEST['svsco'], $_REQUEST['svkey']);
        break;
    case "stackclear":
        if (storage_can_set($_REQUEST['svuser'])) {
            print storage_stack_clear($_REQUEST['svuser'], $_REQUEST['svcourse'], $_REQUEST['svsco'], $_REQUEST['svkey']);
        }
        break;
    case "stackgetall":
        if (storage_can_set($_REQUEST['svuser']))
            print storage_stack_getall($_REQUEST['svuser'], $_REQUEST['svcourse'], $_REQUEST['svsco'], $_REQUEST['svkey']);
        break;
    case "getposition":
        print storage_get_position($_REQUEST['svuser'], $_REQUEST['svcourse'], $_REQUEST['svsco'], $_REQUEST['svkey'], $_REQUEST['svasc']);
        break;
    case "getleaders":
        print storage_get_leaders($_REQUEST['svuser'], $_REQUEST['svcourse'], $_REQUEST['svsco'], $_REQUEST['svkey'], $_REQUEST['svasc'], $_REQUEST['svlength']);
        break;
    case "usersgetall":
// security issue
        print "NOT allowed, security issue, see sources";
//		print storage_get_all_users();
        break;
    default:
        // Do nothing
}

function storage_can_set($sv_user) {
    // platform admin can change any user's stored values, other users can only change their own values
    $allowed = ((api_is_platform_admin()) || ($sv_user == api_get_user_id()));
    if (!$allowed) {
        print "ERROR : Not allowed";
    }
    return $allowed;
}

function storage_get($sv_user, $sv_course, $sv_sco, $sv_key) {
    $sql = "select sv_value
        from ".Database::get_main_table(TABLE_TRACK_STORED_VALUES)."
        where user_id= '$sv_user'
        and sco_id = '$sv_sco'
        and course_id = '$sv_course'
        and sv_key = '$sv_key'";
    $res = Database::query($sql);
    if (Database::num_rows($res) > 0) {
        $row = Database::fetch_assoc($res);
        if (get_magic_quotes_gpc()) {
            return stripslashes($row['sv_value']);
        } else {
            return $row['sv_value'];
        }
    }
    else {
        return null;
    }
}

function storage_get_leaders($sv_user, $sv_course, $sv_sco, $sv_key, $sv_asc, $sv_length) {

    // get leaders
    $sql_leaders = "select u.user_id, firstname, lastname, email, username, sv_value as value
        from ".Database::get_main_table(TABLE_TRACK_STORED_VALUES)." sv,
            ".Database::get_main_table(TABLE_MAIN_USER)." u
        where u.user_id=sv.user_id
        and sco_id = '$sv_sco'
        and course_id = '$sv_course'
        and sv_key = '$sv_key'
        order by sv_value ".($sv_asc ? "ASC": "DESC")." limit $sv_length";
//	$sql_data = "select sv.user_id as user_id, sv_key as variable, sv_value as value
//		from ".Database::get_main_table(TABLE_TRACK_STORED_VALUES)." sv
//		where sv.user_id in (select u2.user_id from ($sql_leaders) u2)
//		and sco_id = '$sv_sco'
//		and course_id = '$sv_course'";
//	$resData = Database::query($sql_data);
//	$data = Array();
//	while($row = Database::fetch_assoc($resData))
//		$data[] = $row; // fetching all data
//
    $resLeaders = Database::query($sql_leaders);
    $result = array();
    while ($row = Database::fetch_assoc($resLeaders)) {
        $row["values"] = array();
//		foreach($data as $dataRow) {
//			if ($dataRow["user_id"] = $row["user_id"])
//				$row["values"][$dataRow["variable"]] = $dataRow["value"];
//		}
        $result[] = $row;
    }
    return json_encode($result);
}

function storage_get_position($sv_user, $sv_course, $sv_sco, $sv_key, $sv_asc, $sv_length) {
    $sql = "select count(list.user_id) as position
        from ".Database::get_main_table(TABLE_TRACK_STORED_VALUES)." search,
            ".Database::get_main_table(TABLE_TRACK_STORED_VALUES)." list
        where search.user_id= '$sv_user'
        and search.sco_id = '$sv_sco'
        and search.course_id = '$sv_course'
        and search.sv_key = '$sv_key'
        and list.sv_value ".($sv_asc ? "<=": ">=")." search.sv_value
        and list.sco_id = search.sco_id
        and list.course_id = search.course_id
        and list.sv_key = search.sv_key
        order by list.sv_value" ;
    $res = Database::query($sql);
    if (Database::num_rows($res) > 0) {
        $row = Database::fetch_assoc($res);
        return $row['position'];
    }
    else {
        return null;
    }
}

function storage_set($sv_user, $sv_course, $sv_sco, $sv_key, $sv_value) {
    $sv_value = Database::escape_string($sv_value);
    $sql = "replace into ".Database::get_main_table(TABLE_TRACK_STORED_VALUES)."
        (user_id, sco_id, course_id, sv_key, sv_value)
        values
        ('$sv_user','$sv_sco','$sv_course','$sv_key','$sv_value')";
    $res = Database::query($sql);
    return Database::affected_rows($res);
}

function storage_getall($sv_user, $sv_course, $sv_sco) {
    $sql = "select sv_key, sv_value
        from ".Database::get_main_table(TABLE_TRACK_STORED_VALUES)."
        where user_id= '$sv_user'
        and sco_id = '$sv_sco'
        and course_id = '$sv_course'";
    $res = Database::query($sql);
    $data = array();
    while ($row = Database::fetch_assoc($res)) {
        if (get_magic_quotes_gpc()) {
            $row['sv_value'] = stripslashes($row['sv_value']);
        }
        $data[] = $row;
    }
    return json_encode($data);
}

function storage_stack_push($sv_user, $sv_course, $sv_sco, $sv_key, $sv_value) {
    $sv_value = Database::escape_string($sv_value);
    Database::query("start transaction");
    $sqlorder = "select ifnull((select max(stack_order)
        from ".Database::get_main_table(TABLE_TRACK_STORED_VALUES_STACK)."
        where user_id= '$sv_user'
        and sco_id='$sv_sco'
        and course_id='$sv_course'
        and sv_key='$sv_key'
        ), 0) as stack_order";
    $resorder = Database::query($sqlorder);
    $row = Database::fetch_assoc($resorder);
    $stack_order = (1 + $row['stack_order']);
    $sqlinsert = "insert into ".Database::get_main_table(TABLE_TRACK_STORED_VALUES_STACK)."
        (user_id, sco_id, course_id, sv_key, stack_order, sv_value)
        values
        ('$sv_user', '$sv_sco', '$sv_course', '$sv_key', '$stack_order', '$sv_value')";
    $resinsert = Database::query($sqlinsert);
    if ($resorder && $resinsert) {
        Database::query("commit");
        return 1;
    }
    else {
        Database::query("rollback");
        return 0;
    }
}

function storage_stack_pop($sv_user, $sv_course, $sv_sco, $sv_key) {
    Database::query("start transaction");
    $sqlselect = "select sv_value, stack_order
        from ".Database::get_main_table(TABLE_TRACK_STORED_VALUES_STACK)."
        where user_id= '$sv_user'
        and sco_id='$sv_sco'
        and course_id='$sv_course'
        and sv_key='$sv_key'
        order by stack_order desc
        limit 1";
    $resselect = Database::query($sqlselect);
    $rowselect = Database::fetch_assoc($resselect);
    $stack_order = $rowselect['stack_order'];
    $sqldelete = "delete
        from ".Database::get_main_table(TABLE_TRACK_STORED_VALUES_STACK)."
        where user_id= '$sv_user'
        and sco_id='$sv_sco'
        and course_id='$sv_course'
        and sv_key='$sv_key'
        and stack_order='$stack_order'";
    $resdelete = Database::query($sqldelete);
    if ($resselect && $resdelete) {
        Database::query("commit");
        if (get_magic_quotes_gpc()) {
            return stripslashes($rowselect['sv_value']);
        } else {
            return $rowselect['sv_value'];
        }
    } else {
        Database::query("rollback");
        return null;
    }
}

function storage_stack_length($sv_user, $sv_course, $sv_sco, $sv_key) {
    $sql = "select count(*) as length
        from ".Database::get_main_table(TABLE_TRACK_STORED_VALUES_STACK)."
        where user_id= '$sv_user'
        and sco_id='$sv_sco'
        and course_id='$sv_course'
        and sv_key='$sv_key'";
    $res = Database::query($sql);
    $row = Database::fetch_assoc($res);
    return $row['length'];
}

function storage_stack_clear($sv_user, $sv_course, $sv_sco, $sv_key) {
    $sql = "delete
        from ".Database::get_main_table(TABLE_TRACK_STORED_VALUES_STACK)."
        where user_id= '$sv_user'
        and sco_id='$sv_sco'
        and course_id='$sv_course'
        and sv_key='$sv_key'";
    $res = Database::query($sql);
    return Database::num_rows($res);
}

function storage_stack_getall($sv_user, $sv_course, $sv_sco, $sv_key) {
    $sql = "select stack_order as stack_order, sv_value as value
        from ".Database::get_main_table(TABLE_TRACK_STORED_VALUES_STACK)."
        where user_id= '$sv_user'
        and sco_id='$sv_sco'
        and course_id='$sv_course'
        and sv_key='$sv_key'";
    $res = Database::query($sql);
    $results = array();
    while ($row = Database::fetch_assoc($res)) {
        if (get_magic_quotes_gpc()) {
            $row['value'] = stripslashes($row['value']);
        }
        $results[] = $row;
    }
    return json_encode($results);
}

function storage_get_all_users() {
    $sql = "select user_id, username, firstname, lastname
        from ".Database::get_main_table(TABLE_MAIN_USER)."
        order by user_id asc";
    $res = Database::query($sql);
    $results = array();
    while ($row = Database::fetch_assoc($res)) {
        $results[] = $row;
    }
    return json_encode($results);
}