/**
 * Automatically clean-up all plugin data and remove the plugin DB tables
 *
 * NOTE: do not call directly, use new /admin/plugins.php?uninstall=component instead!
 *
 * @param string $type The plugin type, eg. 'mod', 'qtype', 'workshopgrading' etc.
 * @param string $name The plugin name, eg. 'forum', 'multichoice', 'accumulative' etc.
 * @uses global $OUTPUT to produce notices and other messages
 * @return void
 */
function uninstall_plugin($type, $name)
{
    global $CFG, $DB, $OUTPUT;
    // This may take a long time.
    core_php_time_limit::raise();
    // Recursively uninstall all subplugins first.
    $subplugintypes = core_component::get_plugin_types_with_subplugins();
    if (isset($subplugintypes[$type])) {
        $base = core_component::get_plugin_directory($type, $name);
        if (file_exists("{$base}/db/subplugins.php")) {
            $subplugins = array();
            include "{$base}/db/subplugins.php";
            foreach ($subplugins as $subplugintype => $dir) {
                $instances = core_component::get_plugin_list($subplugintype);
                foreach ($instances as $subpluginname => $notusedpluginpath) {
                    uninstall_plugin($subplugintype, $subpluginname);
                }
            }
        }
    }
    $component = $type . '_' . $name;
    // eg. 'qtype_multichoice' or 'workshopgrading_accumulative' or 'mod_forum'
    if ($type === 'mod') {
        $pluginname = $name;
        // eg. 'forum'
        if (get_string_manager()->string_exists('modulename', $component)) {
            $strpluginname = get_string('modulename', $component);
        } else {
            $strpluginname = $component;
        }
    } else {
        $pluginname = $component;
        if (get_string_manager()->string_exists('pluginname', $component)) {
            $strpluginname = get_string('pluginname', $component);
        } else {
            $strpluginname = $component;
        }
    }
    echo $OUTPUT->heading($pluginname);
    // Delete all tag instances associated with this plugin.
    require_once $CFG->dirroot . '/tag/lib.php';
    tag_delete_instances($component);
    // Custom plugin uninstall.
    $plugindirectory = core_component::get_plugin_directory($type, $name);
    $uninstalllib = $plugindirectory . '/db/uninstall.php';
    if (file_exists($uninstalllib)) {
        require_once $uninstalllib;
        $uninstallfunction = 'xmldb_' . $pluginname . '_uninstall';
        // eg. 'xmldb_workshop_uninstall()'
        if (function_exists($uninstallfunction)) {
            // Do not verify result, let plugin complain if necessary.
            $uninstallfunction();
        }
    }
    // Specific plugin type cleanup.
    $plugininfo = core_plugin_manager::instance()->get_plugin_info($component);
    if ($plugininfo) {
        $plugininfo->uninstall_cleanup();
        core_plugin_manager::reset_caches();
    }
    $plugininfo = null;
    // perform clean-up task common for all the plugin/subplugin types
    //delete the web service functions and pre-built services
    require_once $CFG->dirroot . '/lib/externallib.php';
    external_delete_descriptions($component);
    // delete calendar events
    $DB->delete_records('event', array('modulename' => $pluginname));
    // Delete scheduled tasks.
    $DB->delete_records('task_scheduled', array('component' => $pluginname));
    // Delete Inbound Message datakeys.
    $DB->delete_records_select('messageinbound_datakeys', 'handler IN (SELECT id FROM {messageinbound_handlers} WHERE component = ?)', array($pluginname));
    // Delete Inbound Message handlers.
    $DB->delete_records('messageinbound_handlers', array('component' => $pluginname));
    // delete all the logs
    $DB->delete_records('log', array('module' => $pluginname));
    // delete log_display information
    $DB->delete_records('log_display', array('component' => $component));
    // delete the module configuration records
    unset_all_config_for_plugin($component);
    if ($type === 'mod') {
        unset_all_config_for_plugin($pluginname);
    }
    // delete message provider
    message_provider_uninstall($component);
    // delete the plugin tables
    $xmldbfilepath = $plugindirectory . '/db/install.xml';
    drop_plugin_tables($component, $xmldbfilepath, false);
    if ($type === 'mod' or $type === 'block') {
        // non-frankenstyle table prefixes
        drop_plugin_tables($name, $xmldbfilepath, false);
//.........这里部分代码省略.........

//.........这里部分代码省略.........
        }
        // clear course.modinfo for courses that used this module
        $sql = "UPDATE {course}\n                   SET modinfo=''\n                 WHERE id IN (SELECT DISTINCT course\n                                FROM {course_modules}\n                               WHERE module=?)";
        $DB->execute($sql, array($module->id));
        // delete all the course module records
        $DB->delete_records('course_modules', array('module' => $module->id));
        // delete module contexts
        if ($coursemods) {
            foreach ($coursemods as $coursemod) {
                if (!delete_context(CONTEXT_MODULE, $coursemod->id)) {
                    echo $OUTPUT->notification("Could not delete the context for {$strpluginname} with id = {$coursemod->id}");
                }
            }
        }
        // delete the module entry itself
        $DB->delete_records('modules', array('name' => $module->name));
        // cleanup the gradebook
        require_once $CFG->libdir . '/gradelib.php';
        grade_uninstalled_module($module->name);
        // Perform any custom uninstall tasks
        if (file_exists($CFG->dirroot . '/mod/' . $module->name . '/lib.php')) {
            require_once $CFG->dirroot . '/mod/' . $module->name . '/lib.php';
            $uninstallfunction = $module->name . '_uninstall';
            if (function_exists($uninstallfunction)) {
                debugging("{$uninstallfunction}() has been deprecated. Use the plugin's db/uninstall.php instead", DEBUG_DEVELOPER);
                if (!$uninstallfunction()) {
                    echo $OUTPUT->notification('Encountered a problem running uninstall function for ' . $module->name . '!');
                }
            }
        }
    } else {
        if ($type === 'enrol') {
            // NOTE: this is a bit brute force way - it will not trigger events and hooks properly
            // nuke all role assignments
            role_unassign_all(array('component' => $component));
            // purge participants
            $DB->delete_records_select('user_enrolments', "enrolid IN (SELECT id FROM {enrol} WHERE enrol = ?)", array($name));
            // purge enrol instances
            $DB->delete_records('enrol', array('enrol' => $name));
            // tweak enrol settings
            if (!empty($CFG->enrol_plugins_enabled)) {
                $enabledenrols = explode(',', $CFG->enrol_plugins_enabled);
                $enabledenrols = array_unique($enabledenrols);
                $enabledenrols = array_flip($enabledenrols);
                unset($enabledenrols[$name]);
                $enabledenrols = array_flip($enabledenrols);
                if (is_array($enabledenrols)) {
                    set_config('enrol_plugins_enabled', implode(',', $enabledenrols));
                }
            }
        } else {
            if ($type === 'block') {
                if ($block = $DB->get_record('block', array('name' => $name))) {
                    // Inform block it's about to be deleted
                    if (file_exists("{$CFG->dirroot}/blocks/{$block->name}/block_{$block->name}.php")) {
                        $blockobject = block_instance($block->name);
                        if ($blockobject) {
                            $blockobject->before_delete();
                            //only if we can create instance, block might have been already removed
                        }
                    }
                    // First delete instances and related contexts
                    $instances = $DB->get_records('block_instances', array('blockname' => $block->name));
                    foreach ($instances as $instance) {
                        blocks_delete_instance($instance);
                    }
                    // Delete block
                    $DB->delete_records('block', array('id' => $block->id));
                }
            }
        }
    }
    // perform clean-up task common for all the plugin/subplugin types
    // delete calendar events
    $DB->delete_records('event', array('modulename' => $pluginname));
    // delete all the logs
    $DB->delete_records('log', array('module' => $pluginname));
    // delete log_display information
    $DB->delete_records('log_display', array('component' => $component));
    // delete the module configuration records
    unset_all_config_for_plugin($pluginname);
    // delete message provider
    message_provider_uninstall($component);
    // delete message processor
    if ($type === 'message') {
        message_processor_uninstall($name);
    }
    // delete the plugin tables
    $xmldbfilepath = $plugindirectory . '/db/install.xml';
    drop_plugin_tables($component, $xmldbfilepath, false);
    if ($type === 'mod' or $type === 'block') {
        // non-frankenstyle table prefixes
        drop_plugin_tables($name, $xmldbfilepath, false);
    }
    // delete the capabilities that were defined by this module
    capabilities_cleanup($component);
    // remove event handlers and dequeue pending events
    events_uninstall($component);
    echo $OUTPUT->notification(get_string('success'), 'notifysuccess');
}

/**
 * Automatically clean-up all plugin data and remove the plugin DB tables
 *
 * @param string $type The subplugin type, eg. 'vmoodleadminset' etc.
 * @param string $name The subplugin name, eg. 'example', 'generic', etc.
 * @uses global $OUTPUT to produce notices and other messages
 * @return void
 */
function vmoodle_uninstall_plugin($type, $name, $plugindirectory)
{
    global $CFG, $DB, $OUTPUT;
    // This may take a long time.
    @set_time_limit(0);
    $component = $type . '_' . $name;
    // eg. 'qtype_multichoice' or 'workshopgrading_accumulative' or 'mod_forum'
    $pluginname = $component;
    if (get_string_manager()->string_exists('pluginname', $component)) {
        $strpluginname = get_string('pluginname', $component);
    } else {
        $strpluginname = $component;
    }
    echo $OUTPUT->heading($pluginname);
    $uninstalllib = $plugindirectory . '/db/uninstall.php';
    if (file_exists($uninstalllib)) {
        require_once $uninstalllib;
        $uninstallfunction = 'xmldb_' . $pluginname . '_uninstall';
        // eg. 'xmldb_workshop_uninstall()'
        if (function_exists($uninstallfunction)) {
            if (!$uninstallfunction()) {
                echo $OUTPUT->notification('Encountered a problem running uninstall function for ' . $pluginname);
            }
        }
    }
    // Perform clean-up task common for all the plugin/subplugin types.
    // Delete the web service functions and pre-built services.
    require_once $CFG->dirroot . '/lib/externallib.php';
    external_delete_descriptions($component);
    // Delete calendar events.
    $DB->delete_records('event', array('modulename' => $pluginname));
    // Delete all the logs.
    $DB->delete_records('log', array('module' => $pluginname));
    // Delete log_display information.
    $DB->delete_records('log_display', array('component' => $component));
    // Delete the module configuration records.
    unset_all_config_for_plugin($pluginname);
    // delete message provider
    message_provider_uninstall($component);
    // Delete message processor.
    if ($type === 'message') {
        message_processor_uninstall($name);
    }
    // Delete the plugin tables.
    $xmldbfilepath = $plugindirectory . '/db/install.xml';
    drop_plugin_tables($component, $xmldbfilepath, false);
    // Delete the capabilities that were defined by this module.
    capabilities_cleanup($component);
    // Remove event handlers and dequeue pending events.
    events_uninstall($component);
    echo $OUTPUT->notification(get_string('success'), 'notifysuccess');
}