<?php
/**
 * Where dark mode applies: which place a screen belongs to, and whether the site and the user have it on there.
 *
 * Places are WordPress's own areas (groups of core screens) and other plugins, one plugin at a time. A plugin's screens
 * are found through the admin menu: the function that draws each page tells which plugin folder it comes from.
 * Other plugins stay off until an administrator turns them on, with the standard dark styles or with inverted colours.
 *
 * @package Adminight
 */

defined( 'ABSPATH' ) || exit;

define( 'ADMINIGHT_AREAS_OPTION', 'adminight_areas' );
define( 'ADMINIGHT_PLUGINS_OPTION', 'adminight_plugins' );
define( 'ADMINIGHT_USER_OFF_META', 'adminight_off' );

/**
 * WordPress's own areas, with their labels and a screen to open them on.
 *
 * @return array<string,array{label:string,description:string,url:string}>
 */
function adminight_areas() {
	$areas = array(
		'core'       => array(
			'label'       => __( 'Dashboard and content', 'adminight' ),
			'description' => __( 'Dashboard, posts, pages, media, comments, users, tools, settings, plugins and updates.', 'adminight' ),
			'url'         => admin_url( 'index.php' ),
		),
		'editor'     => array(
			'label'       => __( 'Editors', 'adminight' ),
			'description' => __( 'The block editor around the writing area, the classic editor and the code editors.', 'adminight' ),
			'url'         => admin_url( 'post-new.php' ),
		),
		'appearance' => array(
			'label'       => __( 'Appearance', 'adminight' ),
			'description' => __( 'Themes, the Customizer, the Site Editor, widgets and menus.', 'adminight' ),
			'url'         => admin_url( 'themes.php' ),
		),
		'login'      => array(
			'label'       => __( 'Login screen', 'adminight' ),
			'description' => __( 'Follows the default mode, since nobody is signed in there yet.', 'adminight' ),
			'url'         => wp_login_url(),
		),
	);
	if ( class_exists( 'WooCommerce' ) ) {
		$areas['woocommerce'] = array(
			'label'       => __( 'WooCommerce', 'adminight' ),
			'description' => __( 'Products, orders, coupons and the WooCommerce settings.', 'adminight' ),
			'url'         => admin_url( 'edit.php?post_type=product' ),
		);
	}
	return $areas;
}

/**
 * Plugin modes: off, the standard dark styles, or inverted colours.
 *
 * @return array<string,string>
 */
function adminight_plugin_modes() {
	return array(
		'off'    => __( 'Off', 'adminight' ),
		'dark'   => __( 'Dark', 'adminight' ),
		'invert' => __( 'Inverted colours (experimental)', 'adminight' ),
	);
}

/**
 * Areas the administrator has turned on. Every area is on until it is turned off.
 *
 * @return array<string,bool>
 */
function adminight_site_areas() {
	$saved = get_option( ADMINIGHT_AREAS_OPTION, array() );
	$saved = is_array( $saved ) ? $saved : array();
	$out   = array();
	foreach ( array_keys( adminight_areas() ) as $key ) {
		$out[ $key ] = isset( $saved[ $key ] ) ? (bool) $saved[ $key ] : true;
	}
	return $out;
}

/**
 * The administrator's choice for each plugin, keyed by plugin folder. Plugins not listed are off.
 *
 * @return array<string,string>
 */
function adminight_site_plugins() {
	$saved = get_option( ADMINIGHT_PLUGINS_OPTION, array() );
	return is_array( $saved ) ? $saved : array();
}

/**
 * The places a user has turned off for themselves ("core", "editor", … or "p-<plugin folder>").
 *
 * @param int $user_id User ID; the current user when 0.
 * @return string[]
 */
function adminight_user_off( $user_id = 0 ) {
	$user_id = $user_id ? $user_id : get_current_user_id();
	$off     = $user_id ? get_user_meta( $user_id, ADMINIGHT_USER_OFF_META, true ) : array();
	return is_array( $off ) ? $off : array();
}

/**
 * Whether a post type or taxonomy belongs to WooCommerce.
 *
 * @param string $post_type Post type of the screen.
 * @param string $taxonomy  Taxonomy of the screen.
 * @return bool
 */
function adminight_is_woo_type( $post_type, $taxonomy ) {
	if ( in_array( $post_type, array( 'product', 'product_variation', 'shop_order', 'shop_order_refund', 'shop_coupon', 'shop_order_placehold' ), true ) ) {
		return true;
	}
	return in_array( $taxonomy, array( 'product_cat', 'product_tag', 'product_shipping_class', 'product_brand' ), true ) || 0 === strpos( (string) $taxonomy, 'pa_' );
}

/**
 * Whether a plugin folder is WooCommerce (or one of its own bundled parts), which has its own area.
 *
 * @param string $folder Plugin folder.
 * @return bool
 */
function adminight_is_woo_folder( $folder ) {
	return class_exists( 'WooCommerce' ) && 0 === strpos( $folder, 'woocommerce' );
}

/**
 * The plugin folder a PHP file belongs to, or "" when it is not inside a plugin.
 *
 * @param string $file Absolute file path.
 * @return string
 */
function adminight_file_plugin( $file ) {
	if ( '' === (string) $file ) {
		return '';
	}
	$base = plugin_basename( $file );
	if ( $base === wp_normalize_path( $file ) || 0 === strpos( $base, '/' ) || preg_match( '#^[a-z]:#i', $base ) ) {
		return '';
	}
	$folder = false !== strpos( $base, '/' ) ? strtok( $base, '/' ) : preg_replace( '/\.php$/', '', $base );
	return sanitize_key( (string) $folder );
}

/**
 * The file a callback is defined in.
 *
 * @param mixed $callback A hook callback.
 * @return string
 */
function adminight_callback_file( $callback ) {
	try {
		if ( is_string( $callback ) && false !== strpos( $callback, '::' ) ) {
			$callback = explode( '::', $callback, 2 );
		}
		if ( is_array( $callback ) && 2 === count( $callback ) ) {
			$ref = new ReflectionMethod( $callback[0], $callback[1] );
		} elseif ( $callback instanceof Closure || ( is_string( $callback ) && function_exists( $callback ) ) ) {
			$ref = new ReflectionFunction( $callback );
		} elseif ( is_object( $callback ) && method_exists( $callback, '__invoke' ) ) {
			$ref = new ReflectionMethod( $callback, '__invoke' );
		} else {
			return '';
		}
		return (string) $ref->getFileName();
	} catch ( ReflectionException $e ) {
		return '';
	}
}

/**
 * The plugin folder that draws an admin page (page=$page under $parent), or "" when that is not known.
 *
 * @param string $page   Page slug.
 * @param string $parent Parent menu slug ("" for a top-level page).
 * @return string
 */
function adminight_page_owner( $page, $parent ) {
	global $wp_filter;
	$hook = get_plugin_page_hookname( $page, $parent );
	if ( empty( $wp_filter[ $hook ] ) ) {
		return '';
	}
	foreach ( $wp_filter[ $hook ]->callbacks as $callbacks ) {
		foreach ( $callbacks as $callback ) {
			$folder = adminight_file_plugin( adminight_callback_file( $callback['function'] ) );
			if ( '' !== $folder ) {
				return $folder;
			}
		}
	}
	return '';
}

/**
 * The place the current admin screen belongs to: an area key, or "p-<plugin folder>" for another plugin's screen.
 *
 * @return string
 */
function adminight_current_scope() {
	global $pagenow, $plugin_page, $typenow, $taxnow;

	$post_type = isset( $typenow ) ? (string) $typenow : '';
	$taxonomy  = isset( $taxnow ) ? (string) $taxnow : '';

	if ( isset( $pagenow ) && 'customize.php' === $pagenow ) {
		return 'appearance';
	}

	if ( ! empty( $plugin_page ) ) {
		if ( in_array( $plugin_page, array( 'custom-header', 'custom-background' ), true ) ) {
			return 'appearance';
		}
		$owner = adminight_page_owner( $plugin_page, (string) get_admin_page_parent() );
		if ( 'adminight' === $owner || 'adminight' === $plugin_page ) {
			return 'core';
		}
		if ( adminight_is_woo_folder( $owner ) ) {
			return 'woocommerce';
		}
		return '' !== $owner ? 'p-' . $owner : 'p-' . sanitize_key( $plugin_page );
	}

	if ( class_exists( 'WooCommerce' ) && adminight_is_woo_type( $post_type, $taxonomy ) ) {
		return 'woocommerce';
	}

	// Page builders open their own editor through post.php?action=<builder>; that editor belongs to the builder.
	// phpcs:ignore WordPress.Security.NonceVerification.Recommended -- only reads which screen this is.
	$action = isset( $_GET['action'] ) ? sanitize_key( wp_unslash( $_GET['action'] ) ) : '';
	if ( isset( $pagenow ) && 'post.php' === $pagenow && '' !== $action && 'edit' !== $action ) {
		return 'p-' . $action;
	}

	switch ( isset( $pagenow ) ? $pagenow : '' ) {
		case 'post.php':
		case 'post-new.php':
		case 'theme-editor.php':
		case 'plugin-editor.php':
			return 'editor';
		case 'themes.php':
		case 'theme-install.php':
		case 'site-editor.php':
		case 'widgets.php':
		case 'nav-menus.php':
			return 'appearance';
	}
	return 'core';
}

/**
 * How dark mode applies to a place for a user: "dark", "invert" or "" (not here).
 *
 * @param string $scope   An area key or "p-<plugin folder>".
 * @param int    $user_id User ID; the current user when 0.
 * @return string
 */
function adminight_scope_style( $scope, $user_id = 0 ) {
	if ( in_array( $scope, adminight_user_off( $user_id ), true ) ) {
		return '';
	}
	if ( 0 === strpos( $scope, 'p-' ) ) {
		$plugins = adminight_site_plugins();
		$folder  = substr( $scope, 2 );
		$mode    = isset( $plugins[ $folder ] ) ? $plugins[ $folder ] : 'off';
		return in_array( $mode, array( 'dark', 'invert' ), true ) ? $mode : '';
	}
	$areas = adminight_site_areas();
	return ! empty( $areas[ $scope ] ) ? 'dark' : '';
}

/**
 * Whether "?adminight=off" asks for this one page without dark mode (a way back when a screen looks wrong).
 *
 * @return bool
 */
function adminight_paused() {
	// phpcs:ignore WordPress.Security.NonceVerification.Recommended -- read-only display switch for the current page; nothing is saved.
	return isset( $_GET['adminight'] ) && 'off' === sanitize_key( wp_unslash( $_GET['adminight'] ) );
}

/**
 * How dark mode applies to the current screen for the current user.
 *
 * @return string "dark", "invert" or "".
 */
function adminight_current_style() {
	if ( adminight_paused() ) {
		return '';
	}
	return adminight_scope_style( adminight_current_scope() );
}

/**
 * Other plugins that add pages to the admin menu, as plugin folder => [label, url]. WooCommerce has its own area.
 *
 * @return array<string,array{label:string,url:string}>
 */
function adminight_detected_plugins() {
	global $menu, $submenu;
	if ( ! function_exists( 'get_plugins' ) ) {
		require_once ABSPATH . 'wp-admin/includes/plugin.php';
	}
	$names = array();
	foreach ( get_plugins() as $file => $data ) {
		$folder = sanitize_key( false !== strpos( $file, '/' ) ? strtok( $file, '/' ) : preg_replace( '/\.php$/', '', $file ) );
		if ( empty( $names[ $folder ] ) ) {
			$names[ $folder ] = $data['Name'];
		}
	}

	$pages = array();
	foreach ( (array) $menu as $item ) {
		if ( ! empty( $item[2] ) && false === strpos( $item[2], '.php' ) ) {
			$pages[] = array( (string) $item[2], '', admin_url( 'admin.php?page=' . rawurlencode( $item[2] ) ) );
		}
	}
	foreach ( (array) $submenu as $parent => $items ) {
		foreach ( (array) $items as $item ) {
			if ( empty( $item[2] ) || false !== strpos( $item[2], '.php' ) ) {
				continue;
			}
			$url     = false !== strpos( $parent, '.php' ) ? add_query_arg( 'page', rawurlencode( $item[2] ), admin_url( $parent ) ) : admin_url( 'admin.php?page=' . rawurlencode( $item[2] ) );
			$pages[] = array( (string) $item[2], (string) $parent, $url );
		}
	}

	$found = array();
	foreach ( $pages as $page ) {
		$folder = adminight_page_owner( $page[0], $page[1] );
		if ( '' === $folder || 'adminight' === $folder || adminight_is_woo_folder( $folder ) || isset( $found[ $folder ] ) ) {
			continue;
		}
		$found[ $folder ] = array(
			'label' => isset( $names[ $folder ] ) ? $names[ $folder ] : $folder,
			'url'   => $page[2],
		);
	}

	uasort(
		$found,
		function ( $a, $b ) {
			return strnatcasecmp( $a['label'], $b['label'] );
		}
	);
	return $found;
}