<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.

/**
 * A page displaying the user's contacts and messages
 *
 * @package    core_message
 * @copyright  2010 Andrew Davis
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

require_once('../config.php');
require_once('lib.php');
require_once('send_form.php');

require_login(0, false);

if (isguestuser()) {
    redirect($CFG->wwwroot);
}

if (empty($CFG->messaging)) {
    print_error('disabled', 'message');
}

//'viewing' is the preferred URL parameter but we'll still accept usergroup in case its referenced externally
$usergroup = optional_param('usergroup', MESSAGE_VIEW_UNREAD_MESSAGES, PARAM_ALPHANUMEXT);
$viewing = optional_param('viewing', $usergroup, PARAM_ALPHANUMEXT);

$history   = optional_param('history', MESSAGE_HISTORY_SHORT, PARAM_INT);
$search    = optional_param('search', '', PARAM_CLEAN); //TODO: use PARAM_RAW, but make sure we use s() and p() properly

//the same param as 1.9 and the param we have been logging. Use this parameter.
$user1id   = optional_param('user1', $USER->id, PARAM_INT);
//2.0 shipped using this param. Retaining it only for compatibility. It should be removed.
$user1id   = optional_param('user', $user1id, PARAM_INT);

//the same param as 1.9 and the param we have been logging. Use this parameter.
$user2id   = optional_param('user2', 0, PARAM_INT);
//The class send_form supplies the receiving user id as 'id'
$user2id   = optional_param('id', $user2id, PARAM_INT);

$addcontact     = optional_param('addcontact',     0, PARAM_INT); // adding a contact
$removecontact  = optional_param('removecontact',  0, PARAM_INT); // removing a contact
$blockcontact   = optional_param('blockcontact',   0, PARAM_INT); // blocking a contact
$unblockcontact = optional_param('unblockcontact', 0, PARAM_INT); // unblocking a contact
$deletemessageid = optional_param('deletemessageid', 0, PARAM_INT);
$deletemessageconfirm = optional_param('deletemessageconfirm', 0, PARAM_BOOL);
if ($deletemessageid) {
    $deletemessagetype = required_param('deletemessagetype', PARAM_ALPHAEXT);
}

//for search
$advancedsearch = optional_param('advanced', 0, PARAM_INT);

//if they have numerous contacts or are viewing course participants we might need to page through them
$page = optional_param('page', 0, PARAM_INT);

$url = new moodle_url('/message/index.php', array('user1' => $user1id));

if ($user2id !== 0) {
    $url->param('user2', $user2id);

    //Switch view back to contacts if:
    //1) theyve searched and selected a user
    //2) they've viewed recent messages or notifications and clicked through to a user
    if ($viewing == MESSAGE_VIEW_SEARCH || $viewing == MESSAGE_VIEW_RECENT_NOTIFICATIONS) {
        $viewing = MESSAGE_VIEW_CONTACTS;
    }
}

if ($viewing != MESSAGE_VIEW_UNREAD_MESSAGES) {
    $url->param('viewing', $viewing);
}

$PAGE->set_url($url);

// Disable message notification popups while the user is viewing their messages
$PAGE->set_popup_notification_allowed(false);

$user1 = null;
$currentuser = true;
$showactionlinks = true;
if ($user1id != $USER->id) {
    $user1 = $DB->get_record('user', array('id' => $user1id));
    if (!$user1) {
        print_error('invaliduserid');
    }
    $currentuser = false;//if we're looking at someone else's messages we need to lock/remove some UI elements
    $showactionlinks = false;
} else {
    $user1 = $USER;
}
unset($user1id);

$user2 = null;
if (!empty($user2id)) {
    $user2 = core_user::get_user($user2id);
    if (!$user2) {
        print_error('invaliduserid');
    }
}
unset($user2id);

$user2realuser = !empty($user2) && core_user::is_real_user($user2->id);
$showactionlinks = $showactionlinks && $user2realuser;
$systemcontext = context_system::instance();

if ($currentuser === false && !has_capability('moodle/site:readallmessages', $systemcontext)) {
    print_error('accessdenied','admin');
}

if (substr($viewing, 0, 7) == MESSAGE_VIEW_COURSE) {
    $courseid = intval(substr($viewing, 7));
    require_login($courseid);
    require_capability('moodle/course:viewparticipants', context_course::instance($courseid));
    $PAGE->set_pagelayout('incourse');
} else {
    $PAGE->set_pagelayout('standard');
}
// Page context should always be set to user.
$PAGE->set_context(context_user::instance($user1->id));
if (!empty($user1->id) && $user1->id != $USER->id) {
    $PAGE->navigation->extend_for_user($user1);
}
if (!empty($user2->id) && $user2realuser && ($user2->id != $USER->id)) {
    $PAGE->navigation->extend_for_user($user2);
}

$strmessages = get_string('messages', 'message');
if ($user2realuser) {
    $user2fullname = fullname($user2);

    $PAGE->set_title("$strmessages: $user2fullname");
    $PAGE->set_heading("$strmessages: $user2fullname");
} else {
    $PAGE->set_title("{$SITE->shortname}: $strmessages");
    $PAGE->set_heading("{$SITE->shortname}: $strmessages");
}

/// Process any contact maintenance requests there may be
if ($addcontact and confirm_sesskey()) {
    message_add_contact($addcontact);
    redirect($CFG->wwwroot . '/message/index.php?viewing=contacts&id='.$addcontact);
}
if ($removecontact and confirm_sesskey()) {
    message_remove_contact($removecontact);
}
if ($blockcontact and confirm_sesskey()) {
    message_block_contact($blockcontact);
}
if ($unblockcontact and confirm_sesskey()) {
    message_unblock_contact($unblockcontact);
}
if ($deletemessageid and confirm_sesskey()) {
    // Check that the message actually exists.
    if ($message = $DB->get_record($deletemessagetype, array('id' => $deletemessageid))) {
        // Check that we are allowed to delete this message.
        if (message_can_delete_message($message, $user1->id)) {
            if (!$deletemessageconfirm) {
                $confirmurl = new moodle_url('/message/index.php', array('user1' => $user1->id, 'user2' => $user2->id,
                    'viewing' => $viewing, 'deletemessageid' => $message->id, 'deletemessagetype' => $deletemessagetype,
                    'deletemessageconfirm' => 1, 'sesskey' => sesskey()));
                $confirmbutton = new single_button($confirmurl, get_string('delete'), 'post');
                $strdeletemessage = get_string('deletemessage', 'message');
                $PAGE->set_title($strdeletemessage);
                echo $OUTPUT->header();
                echo $OUTPUT->heading($strdeletemessage);
                echo $OUTPUT->confirm(get_string('deletemessageconfirmation', 'message'), $confirmbutton, $url);
                echo $OUTPUT->footer();
                exit();
            }
            message_delete_message($message, $user1->id);
        }
    }
    redirect($url);
}

//was a message sent? Do NOT allow someone looking at someone else's messages to send them.
$messageerror = null;
if ($currentuser && !empty($user2) && has_capability('moodle/site:sendmessage', $systemcontext)) {
    // Check that the user is not blocking us!!
    if (message_is_user_blocked($user2, $user1)) {
        $messageerror = get_string('userisblockingyou', 'message');
    }
    // Check that we're not non-contact block by the user.
    if (message_is_user_non_contact_blocked($user2, $user1)) {
        $messageerror = get_string('userisblockingyounoncontact', 'message', fullname($user2));
    }

    if (empty($messageerror)) {
        $mform = new send_form();
        $defaultmessage = new stdClass;
        $defaultmessage->id = $user2->id;
        $defaultmessage->viewing = $viewing;
        $defaultmessage->message = '';

        //Check if the current user has sent a message
        $data = $mform->get_data();
        if (!empty($data) && !empty($data->message)) {
            if (!confirm_sesskey()) {
                print_error('invalidsesskey');
            }
            $messageid = message_post_message($user1, $user2, $data->message, FORMAT_MOODLE);
            if (!empty($messageid)) {
                //including the id of the user sending the message in the logged URL so the URL works for admins
                //note message ID may be misleading as the message may potentially get a different ID when moved from message to message_read
                redirect($CFG->wwwroot . '/message/index.php?viewing='.$viewing.'&id='.$user2->id);
            }
        }
    }
}

$strmessages = get_string('messages', 'message');
if ($user2realuser) {
    $user2fullname = fullname($user2);

    $PAGE->set_title("$strmessages: $user2fullname");
} else {
    $PAGE->set_title("{$SITE->shortname}: $strmessages");
}
$PAGE->set_heading(fullname($user1));

// Remove the user node from the main navigation for this page.
$usernode = $PAGE->navigation->find('users', null);
$usernode->remove();

$settings = $PAGE->settingsnav->find('messages', null);
$settings->make_active();

// Get the renderer and the information we are going to be use.
$renderer = $PAGE->get_renderer('core_message');
$requestedconversation = false;
if (!$user2realuser) {
    $conversations = \core_message\api::get_conversations($user1->id, 0, 0, 20);
    $contacts = $conversations->contacts;

    if (!empty($contacts)) {
        // If there are conversations then render the most recent one by default.
        $contact = reset($contacts);
        $otheruserid = $contact->userid;
        $conversations->otheruserid = $otheruserid;

        // Mark the conversation as read.
        if ($currentuser) {
            $contact->isread = 1;
            message_mark_all_read_for_user($user1->id, $otheruserid);
        }

        $messages = \core_message\api::get_messages($user1->id, $otheruserid, 0, 20, 'timecreated DESC');
    } else {
        $messages = null;
    }
} else {
    // Mark the conversation as read.
    if ($currentuser) {
        message_mark_all_read_for_user($user1->id, $user2->id);
    }

    $conversations = \core_message\api::get_conversations($user1->id, $user2->id, 0, 20);
    $messages = \core_message\api::get_messages($user1->id, $user2->id);
    // The user has specifically requested to see this conversation. Add the flag
    // to the context so that we can render the messaging app appropriately.
    $requestedconversation = true;
}
$messagearea = new \core_message\output\messagearea\message_area($user1->id, $conversations, $messages, $requestedconversation);

// Now the page contents.
echo $OUTPUT->header();
// Display a message that the user is viewing someone else's messages.
if (!$currentuser) {
    $notify = new \core\output\notification(get_string('viewinganotherusersmessagearea', 'message'),
        \core\output\notification::NOTIFY_WARNING);
    echo $OUTPUT->render($notify);
}
echo $renderer->render($messagearea);
echo $OUTPUT->footer();