<?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/>.

/**
 * Lets users configure which filters are active in a sub-context.
 *
 * @license    http://www.gnu.org/copyleft/gpl.html GNU Public License
 * @package    core
 * @subpackage filter
 */

require_once(dirname(__FILE__) . '/../config.php');
require_once($CFG->libdir . '/adminlib.php');

$contextid = required_param('contextid',PARAM_INT);
$forfilter = optional_param('filter', '', PARAM_SAFEPATH);

list($context, $course, $cm) = get_context_info_array($contextid);

/// Check login and permissions.
require_login($course, false, $cm);
require_capability('moodle/filter:manage', $context);
$PAGE->set_context($context);

$args = array('contextid'=>$contextid);
$baseurl = new moodle_url('/filter/manage.php', $args);
if (!empty($forfilter)) {
    $args['filter'] = $forfilter;
}
$PAGE->set_url($baseurl, $args);

// This is a policy decision, rather than something that would be impossible to implement.
if (!in_array($context->contextlevel, array(CONTEXT_COURSECAT, CONTEXT_COURSE, CONTEXT_MODULE))) {
    print_error('cannotcustomisefiltersblockuser', 'error');
}

$isfrontpage = ($context->contextlevel == CONTEXT_COURSE && $context->instanceid == SITEID);

$contextname = print_context_name($context);

if ($context->contextlevel == CONTEXT_COURSECAT) {
    $heading = "$SITE->fullname: ".get_string("categories");
} else if ($context->contextlevel == CONTEXT_COURSE) {
    $heading = $course->fullname;
} else if ($context->contextlevel == CONTEXT_MODULE) {
    // Must be module context.
    $heading = $PAGE->activityrecord->name;
} else {
    $heading = '';
}

/// Check login and permissions.
require_login($course, false, $cm);
require_capability('moodle/filter:manage', $context);

$PAGE->set_context($context);
$PAGE->set_heading($heading);

/// Get the list of available filters.
$availablefilters = filter_get_available_in_context($context);
if (!$isfrontpage && empty($availablefilters)) {
    print_error('nofiltersenabled', 'error');
}

// If we are handling local settings for a particular filter, start processing.
if ($forfilter) {
    if (!filter_has_local_settings($forfilter)) {
        print_error('filterdoesnothavelocalconfig', 'error', $forfilter);
    }
    require_once($CFG->dirroot . '/filter/local_settings_form.php');
    require_once($CFG->dirroot . '/' . $forfilter . '/filterlocalsettings.php');
    $formname = basename($forfilter) . '_filter_local_settings_form';
    $settingsform = new $formname($CFG->wwwroot . '/filter/manage.php', $forfilter, $context);
    if ($settingsform->is_cancelled()) {
        redirect($baseurl);
    } else if ($data = $settingsform->get_data()) {
        $settingsform->save_changes($data);
        redirect($baseurl);
    }
}

/// Process any form submission.
if ($forfilter == '' && optional_param('savechanges', false, PARAM_BOOL) && confirm_sesskey()) {
    foreach ($availablefilters as $filter => $filterinfo) {
        $newstate = optional_param(str_replace('/', '_', $filter), false, PARAM_INT);
        if ($newstate !== false && $newstate != $filterinfo->localstate) {
            filter_set_local_state($filter, $context->id, $newstate);
        }
    }
    redirect($CFG->wwwroot . '/filter/manage.php?contextid=' . $context->id, get_string('changessaved'), 1);
}

/// Work out an appropriate page title.
if ($forfilter) {
    $a = new stdClass;
    $a->filter = filter_get_name($forfilter);
    $a->context = $contextname;
    $title = get_string('filtersettingsforin', 'filters', $a);
} else {
    $title = get_string('filtersettingsin', 'filters', $contextname);
}
$straction = get_string('filters', 'admin'); // Used by tabs.php

/// Print the header and tabs
if ($isfrontpage) {
    admin_externalpage_setup('frontpagefilters');
    echo $OUTPUT->header();
} else {
    $PAGE->set_cacheable(false);
    $PAGE->set_title($title);
    $PAGE->set_pagelayout('admin');
    echo $OUTPUT->header();
}

/// Print heading.
echo $OUTPUT->heading_with_help($title, 'filtersettings', 'filters');

if (empty($availablefilters)) {
    echo '<p class="centerpara">' . get_string('nofiltersenabled', 'filters') . "</p>\n";
} else if ($forfilter) {
    $current = filter_get_local_config($forfilter, $contextid);
    $settingsform->set_data((object) $current);
    $settingsform->display();
} else {
    $settingscol = false;
    foreach ($availablefilters as $filter => $notused) {
        $hassettings = filter_has_local_settings($filter);
        $availablefilters[$filter]->hassettings = $hassettings;
        $settingscol = $settingscol || $hassettings;
    }

    $strsettings = get_string('settings');
    $stroff = get_string('off', 'filters');
    $stron = get_string('on', 'filters');
    $strdefaultoff = get_string('defaultx', 'filters', $stroff);
    $strdefaulton = get_string('defaultx', 'filters', $stron);
    $activechoices = array(
        TEXTFILTER_INHERIT => '',
        TEXTFILTER_OFF => $stroff,
        TEXTFILTER_ON => $stron,
    );

    echo html_writer::start_tag('form', array('action'=>$baseurl->out(), 'method'=>'post'));
    echo html_writer::start_tag('div');
    echo html_writer::empty_tag('input', array('type'=>'hidden', 'name'=>'sesskey', 'value'=>sesskey()));

    $table = new html_table();
    $table->head  = array(get_string('filter'), get_string('isactive', 'filters'));
    $table->align = array('left', 'left');
    if ($settingscol) {
        $table->head[] = $strsettings;
        $table->align[] = 'left';
    }
    $table->width = ' ';
    $table->data = array();

    // iterate through filters adding to display table
    foreach ($availablefilters as $filter => $filterinfo) {
        $row = array();

        // Filter name.
        $row[] = filter_get_name($filter);

        // Default/on/off choice.
        if ($filterinfo->inheritedstate == TEXTFILTER_ON) {
            $activechoices[TEXTFILTER_INHERIT] = $strdefaulton;
        } else {
            $activechoices[TEXTFILTER_INHERIT] = $strdefaultoff;
        }
        $row[] = html_writer::select($activechoices, str_replace('/', '_', $filter), $filterinfo->localstate, false);

        // Settings link, if required
        if ($settingscol) {
            $settings = '';
            if ($filterinfo->hassettings) {
                $settings = '<a href="' . $baseurl->out(true, array('filter'=>$filter)). '">' . $strsettings . '</a>';
            }
            $row[] = $settings;
        }

        $table->data[] = $row;
    }

    echo html_writer::table($table);
    echo html_writer::start_tag('div', array('class'=>'buttons'));
    echo html_writer::empty_tag('input', array('type'=>'submit', 'name'=>'savechanges', 'value'=>get_string('savechanges')));
    echo html_writer::end_tag('div');
    echo html_writer::end_tag('div');
    echo html_writer::end_tag('form');
}

/// Appropriate back link.
if (!$isfrontpage) {
    echo html_writer::start_tag('div', array('class'=>'backlink'));
    echo html_writer::tag('a', get_string('backto', '', $contextname), array('href'=>get_context_url($context)));
    echo html_writer::end_tag('div');
}

echo $OUTPUT->footer();

