<?php

namespace Vector;

use HTMLForm;
use MediaWiki\MediaWikiServices;
use OutputPage;
use SkinTemplate;
use SkinVector;
use User;

/**
 * Presentation hook handlers for Vector skin.
 *
 * Hook handler method names should be in the form of:
 *	on<HookName>()
 */
class Hooks {
	/**
	 * BeforePageDisplayMobile hook handler
	 *
	 * Make Vector responsive when operating in mobile mode (useformat=mobile)
	 *
	 * @see https://www.mediawiki.org/wiki/Extension:MobileFrontend/BeforePageDisplayMobile
	 * @param OutputPage $out
	 * @param SkinTemplate $sk
	 */
	public static function onBeforePageDisplayMobile( OutputPage $out, $sk ) {
		// This makes Vector behave in responsive mode when MobileFrontend is installed
		if ( $sk instanceof SkinVector ) {
			$sk->enableResponsiveMode();
		}
	}

	/**
	 * Add Vector preferences to the user's Special:Preferences page directly underneath skins.
	 *
	 * @param User $user User whose preferences are being modified.
	 * @param array[] &$prefs Preferences description array, to be fed to a HTMLForm object.
	 */
	public static function onGetPreferences( User $user, array &$prefs ) {
		if ( !self::getConfig( Constants::CONFIG_KEY_SHOW_SKIN_PREFERENCES ) ) {
			// Do not add Vector skin specific preferences.
			return;
		}

		// Preferences to add.
		$vectorPrefs = [
			Constants::PREF_KEY_SKIN_VERSION => [
				'type' => 'toggle',
				// The checkbox title.
				'label-message' => 'prefs-vector-enable-vector-1-label',
				// Show a little informational snippet underneath the checkbox.
				'help-message' => 'prefs-vector-enable-vector-1-help',
				// The tab location and title of the section to insert the checkbox. The bit after the slash
				// indicates that a prefs-skin-prefs string will be provided.
				'section' => 'rendering/skin/skin-prefs',
				// Convert the preference string to a boolean presentation.
				'default' =>
					$user->getOption( Constants::PREF_KEY_SKIN_VERSION ) === Constants::SKIN_VERSION_LATEST ?
						'0' :
						'1',
				// Only show this section when the Vector skin is checked. The JavaScript client also uses
				// this state to determine whether to show or hide the whole section.
				'hide-if' => [ '!==', 'wpskin', Constants::SKIN_NAME ]
			],
		];

		// Seek the skin preference section to add Vector preferences just below it.
		$skinSectionIndex = array_search( 'skin', array_keys( $prefs ) );
		if ( $skinSectionIndex !== false ) {
			// Skin preference section found. Inject Vector skin-specific preferences just below it.
			// This pattern can be found in Popups too. See T246162.
			$vectorSectionIndex = $skinSectionIndex + 1;
			$prefs = array_slice( $prefs, 0, $vectorSectionIndex, true )
				+ $vectorPrefs
				+ array_slice( $prefs, $vectorSectionIndex, null, true );
		} else {
			// Skin preference section not found. Just append Vector skin-specific preferences.
			$prefs += $vectorPrefs;
		}
	}

	/**
	 * Hook executed on user's Special:Preferences form save. This is used to convert the boolean
	 * presentation of skin version to a version string. That is, a single preference change by the
	 * user may trigger two writes: a boolean followed by a string.
	 *
	 * @param array $formData Form data submitted by user
	 * @param HTMLForm $form A preferences form
	 * @param User $user Logged-in user
	 * @param bool &$result Variable defining is form save successful
	 * @param array $oldPreferences
	 */
	public static function onPreferencesFormPreSave(
		array $formData,
		HTMLForm $form,
		User $user,
		&$result,
		$oldPreferences
	) {
		$preference = null;
		$isVectorEnabled = ( $formData[ 'skin' ] ?? '' ) === Constants::SKIN_NAME;
		if ( $isVectorEnabled && array_key_exists( Constants::PREF_KEY_SKIN_VERSION, $formData ) ) {
			// A preference was set. However, Special:Preferences converts the result to a boolean when a
			// version name string is wanted instead. Convert the boolean to a version string in case the
			// preference display is changed to a list later (e.g., a "_new_ new Vector" / '3' or
			// 'alpha').
			$preference = $formData[ Constants::PREF_KEY_SKIN_VERSION ] ?
				Constants::SKIN_VERSION_LEGACY :
				Constants::SKIN_VERSION_LATEST;
		} elseif ( array_key_exists( Constants::PREF_KEY_SKIN_VERSION, $oldPreferences ) ) {
			// The setting was cleared. However, this is likely because a different skin was chosen and
			// the skin version preference was hidden.
			$preference = $oldPreferences[ Constants::PREF_KEY_SKIN_VERSION ];
		}
		if ( $preference !== null ) {
			$user->setOption( Constants::PREF_KEY_SKIN_VERSION, $preference );
		}
	}

	/**
	 * Called on each pageview to populate preference defaults for existing users.
	 *
	 * @param array &$defaultPrefs
	 */
	public static function onUserGetDefaultOptions( array &$defaultPrefs ) {
		$default = self::getConfig( Constants::CONFIG_KEY_DEFAULT_SKIN_VERSION_FOR_EXISTING_ACCOUNTS );
		$defaultPrefs[ Constants::PREF_KEY_SKIN_VERSION ] = $default;
	}

	/**
	 * Called one time when initializing a users preferences for a newly created account.
	 *
	 * @param User $user Newly created user object.
	 * @param bool $isAutoCreated
	 */
	public static function onLocalUserCreated( User $user, $isAutoCreated ) {
		$default = self::getConfig( Constants::CONFIG_KEY_DEFAULT_SKIN_VERSION_FOR_NEW_ACCOUNTS );
		// Permanently set the default preference. The user can later change this preference, however,
		// self::onLocalUserCreated() will not be executed for that account again.
		$user->setOption( Constants::PREF_KEY_SKIN_VERSION, $default );
	}

	/**
	 * Get a configuration variable such as `Constants::CONFIG_KEY_SHOW_SKIN_PREFERENCES`.
	 *
	 * @param string $name Name of configuration option.
	 * @return mixed Value configured.
	 * @throws \ConfigException
	 */
	private static function getConfig( $name ) {
		/* @var Config */ $service =
			MediaWikiServices::getInstance()->getService( Constants::SERVICE_CONFIG );
		return $service->get( $name );
	}
}