<?php
/**
 * Look of the content elements on the page: one of three styles and an accent color (tab "Design").
 *
 * Font and text color always come from the theme; the style only decides lines, surfaces and corners. The accent
 * is either the theme's own color or one of the eight colors of the table styles, so the plugin has one palette.
 * Only names are stored, never a color value from a form.
 *
 * @package ThreeCE
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Element style and accent color.
 */
class ThreeCE_Design {

	const OPTION = 'threece_design';
	const GROUP  = 'threece_design';
	const STYLES = array( 'schlicht', 'weich', 'kontur' );

	/**
	 * Accent colors, the same as .threece-table--accent-* in elements.css. Each carries white text at 4.5:1 or more.
	 */
	const ACCENTS = array(
		'blue'   => '#1d4ed8',
		'green'  => '#15803d',
		'red'    => '#b91c1c',
		'purple' => '#6d28d9',
		'orange' => '#c2410c',
		'teal'   => '#0f766e',
		'gray'   => '#4b5563',
		'black'  => '#111827',
	);

	/**
	 * Hooks.
	 */
	public static function init(): void {
		add_action( 'init', array( __CLASS__, 'register_setting' ) );
		add_action( 'init', array( __CLASS__, 'accent_style' ), 20 );
		add_filter( 'body_class', array( __CLASS__, 'body_class' ) );
		add_filter( 'tiny_mce_before_init', array( __CLASS__, 'tinymce' ) );
	}

	/**
	 * Same style class and accent in the classic editor, which already loads the element stylesheet, so elements
	 * look while writing as they will on the page.
	 *
	 * @param mixed $init TinyMCE settings.
	 * @return mixed
	 */
	public static function tinymce( $init ) {
		if ( ! is_array( $init ) ) {
			return $init;
		}
		$settings           = self::settings();
		$class              = 'threece-style-' . $settings['style'];
		$init['body_class'] = trim( ( is_string( $init['body_class'] ?? null ) ? $init['body_class'] : '' ) . ' ' . $class );
		if ( 'theme' !== $settings['accent'] ) {
			$style                 = 'body{--threece-element-accent:' . self::ACCENTS[ $settings['accent'] ] . '}';
			$init['content_style'] = trim( ( is_string( $init['content_style'] ?? null ) ? $init['content_style'] : '' ) . ' ' . $style );
		}
		return $init;
	}

	/**
	 * Style class on the page body, so the element stylesheet can switch between the three styles.
	 *
	 * @param mixed $classes Body classes (other plugins may hand on anything).
	 * @return string[]
	 */
	public static function body_class( $classes ): array {
		$classes   = is_array( $classes ) ? $classes : array();
		$classes[] = 'threece-style-' . self::settings()['style'];
		return $classes;
	}

	/**
	 * A chosen accent travels with the element stylesheet: printed only on pages that use an element, and only as
	 * one fixed value from the palette. "From the theme" prints nothing.
	 */
	public static function accent_style(): void {
		$accent = self::settings()['accent'];
		if ( 'theme' === $accent ) {
			return;
		}
		wp_add_inline_style( 'threece-elements', 'body{--threece-element-accent:' . self::ACCENTS[ $accent ] . '}' );
	}

	/**
	 * Registers the setting so every save goes through sanitize().
	 */
	public static function register_setting(): void {
		register_setting(
			self::GROUP,
			self::OPTION,
			array(
				'type'              => 'array',
				'sanitize_callback' => array( __CLASS__, 'sanitize' ),
				'show_in_rest'      => false,
			)
		);
	}

	/**
	 * Accent colors by name.
	 *
	 * @return array<string, string>
	 */
	public static function accents(): array {
		return self::ACCENTS;
	}

	/**
	 * Names of the accent colors, in the order of ACCENTS.
	 *
	 * @return array<string, string>
	 */
	public static function accent_labels(): array {
		return array(
			'blue'   => __( 'Blue', '3task-toolbar-for-classic-editor' ),
			'green'  => __( 'Green', '3task-toolbar-for-classic-editor' ),
			'red'    => __( 'Red', '3task-toolbar-for-classic-editor' ),
			'purple' => __( 'Purple', '3task-toolbar-for-classic-editor' ),
			'orange' => __( 'Orange', '3task-toolbar-for-classic-editor' ),
			'teal'   => __( 'Teal', '3task-toolbar-for-classic-editor' ),
			'gray'   => __( 'Gray', '3task-toolbar-for-classic-editor' ),
			'black'  => __( 'Black', '3task-toolbar-for-classic-editor' ),
		);
	}

	/**
	 * Names of the element styles, in the order of STYLES.
	 *
	 * @return array<string, string>
	 */
	public static function style_labels(): array {
		return array(
			'schlicht' => __( 'Plain', '3task-toolbar-for-classic-editor' ),
			'weich'    => __( 'Soft', '3task-toolbar-for-classic-editor' ),
			'kontur'   => __( 'Outline', '3task-toolbar-for-classic-editor' ),
		);
	}

	/**
	 * Keeps a known style and a known accent name; each field falls back on its own. Anything that is not an
	 * array is not a form and gives the factory defaults.
	 *
	 * @param mixed $input Raw value.
	 * @return array{style: string, accent: string}
	 */
	public static function sanitize( $input ): array {
		$settings = array(
			'style'  => 'schlicht',
			'accent' => 'theme',
		);
		if ( ! is_array( $input ) ) {
			return $settings;
		}
		$style  = $input['style'] ?? '';
		$accent = $input['accent'] ?? '';
		if ( is_string( $style ) && in_array( $style, self::STYLES, true ) ) {
			$settings['style'] = $style;
		}
		if ( is_string( $accent ) && isset( self::ACCENTS[ $accent ] ) ) {
			$settings['accent'] = $accent;
		}
		return $settings;
	}

	/**
	 * Saved settings, cleaned again so an old or broken option never reaches the page.
	 *
	 * @return array{style: string, accent: string}
	 */
	public static function settings(): array {
		return self::sanitize( get_option( self::OPTION, array() ) );
	}
}