prautoblogger/includes/frontend/class-article-typography.php

<?php
declare(strict_types=1);

/**
 * Injects frontend typography and table styles for PRAutoBlogger-generated posts.
 *
 * What: Outputs inline CSS on single post pages that have the
 *       _prautoblogger_generated meta flag, applying user-configured
 *       font family, font size, and table border styles.
 * Who calls it: PRAutoBlogger::register_frontend_hooks() hooks this
 *               into wp_head.
 * Dependencies: Reads wp_options for typography settings.
 *
 * @see class-prautoblogger.php       — Registers the wp_head hook.
 * @see class-settings-fields.php     — Defines the Display settings section.
 * @see admin/class-admin-page.php    — Renders the settings form.
 */
class PRAutoBlogger_Article_Typography {

	/** Option key for article font family. */
	private const OPT_FONT_FAMILY = 'prautoblogger_article_font_family';

	/** Option key for article body font size in pixels. */
	private const OPT_FONT_SIZE = 'prautoblogger_article_font_size';

	/** Option key for table border toggle. */
	private const OPT_TABLE_BORDERS = 'prautoblogger_table_borders';

	/**
	 * Output inline CSS in <head> for PRAutoBlogger posts.
	 *
	 * Only outputs on singular post pages generated by PRAutoBlogger.
	 * The CSS targets .post-content (PR Theme's article body class)
	 * and overrides the theme's CSS custom properties so the cascade
	 * works naturally with headings and sub-elements.
	 *
	 * Side effects: echoes a <style> block.
	 *
	 * @return void
	 */
	public function on_wp_head(): void {
		if ( ! is_singular( 'post' ) ) {
			return;
		}

		$post_id = get_queried_object_id();
		if ( '1' !== get_post_meta( $post_id, '_prautoblogger_generated', true ) ) {
			return;
		}

		$css = $this->build_css();
		if ( '' === $css ) {
			return;
		}

		printf(
			"\n<style id=\"prautoblogger-typography\">\n%s\n</style>\n",
			$css // Already escaped — contains only sanitized option values.
		);
	}

	/**
	 * Build the CSS string from current settings.
	 *
	 * Reads each setting at call time (never cached) so changes
	 * take effect immediately without cache invalidation.
	 *
	 * @return string CSS rules, or empty string if all defaults.
	 */
	private function build_css(): string {
		$rules = [];

		$font_family = $this->get_font_family_stack();
		if ( '' !== $font_family ) {
			$rules[] = sprintf(
				".post-content,\n.post-content p,\n.post-content li {\n\tfont-family: %s;\n}",
				$font_family
			);
		}

		$font_size = absint( get_option( self::OPT_FONT_SIZE, 0 ) );
		if ( $font_size > 0 ) {
			$rules[] = sprintf(
				".post-content,\n.post-content p,\n.post-content li {\n\tfont-size: %dpx;\n\tline-height: 1.7;\n}",
				$font_size
			);
		}

		$table_borders = get_option( self::OPT_TABLE_BORDERS, '1' );
		if ( '1' === $table_borders ) {
			$rules[] = implode( "\n", [
				'.post-content table {',
				"\tborder-collapse: collapse;",
				"\twidth: 100%;",
				"\tmargin: 1.5em 0;",
				'}',
				'.post-content th,',
				'.post-content td {',
				"\tborder: 1px solid #d1d5db;",
				"\tpadding: 0.6em 1em;",
				"\ttext-align: left;",
				'}',
				'.post-content thead th {',
				"\tbackground: #f3f4f6;",
				"\tfont-weight: 600;",
				'}',
				'.post-content tbody tr:nth-child(even) {',
				"\tbackground: #f9fafb;",
				'}',
			] );
		}

		return implode( "\n\n", $rules );
	}

	/**
	 * Map the stored font-family key to a full CSS font stack.
	 *
	 * Returns empty string for 'default' (let the theme decide).
	 *
	 * @return string CSS font-family value, or empty for theme default.
	 */
	private function get_font_family_stack(): string {
		$key = sanitize_text_field( get_option( self::OPT_FONT_FAMILY, 'default' ) );

		$stacks = [
			'default'    => '',
			'inter'      => '"Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif',
			'georgia'    => '"Georgia", "Times New Roman", Times, serif',
			'merriweather' => '"Merriweather", Georgia, "Times New Roman", serif',
			'lora'       => '"Lora", Georgia, "Times New Roman", serif',
			'open_sans'  => '"Open Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif',
			'roboto'     => '"Roboto", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif',
			'system'     => '-apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue", sans-serif',
		];

		return $stacks[ $key ] ?? '';
	}

	/**
	 * Get available font choices for the settings UI.
	 *
	 * @return array<string, string> Map of key => display label.
	 */
	public static function get_font_choices(): array {
		return [
			'default'      => __( 'Theme Default (Inter)', 'prautoblogger' ),
			'inter'        => __( 'Inter (Sans-serif)', 'prautoblogger' ),
			'georgia'      => __( 'Georgia (Serif)', 'prautoblogger' ),
			'merriweather' => __( 'Merriweather (Serif)', 'prautoblogger' ),
			'lora'         => __( 'Lora (Serif)', 'prautoblogger' ),
			'open_sans'    => __( 'Open Sans (Sans-serif)', 'prautoblogger' ),
			'roboto'       => __( 'Roboto (Sans-serif)', 'prautoblogger' ),
			'system'       => __( 'System Default', 'prautoblogger' ),
		];
	}

	/**
	 * Enqueue Google Fonts stylesheet when a web font is selected.
	 *
	 * Only loads on singular PRAutoBlogger posts that use a Google-hosted font.
	 *
	 * Side effects: enqueues a remote stylesheet.
	 *
	 * @return void
	 */
	public function on_enqueue_fonts(): void {
		if ( ! is_singular( 'post' ) ) {
			return;
		}

		$post_id = get_queried_object_id();
		if ( '1' !== get_post_meta( $post_id, '_prautoblogger_generated', true ) ) {
			return;
		}

		$font = sanitize_text_field( get_option( self::OPT_FONT_FAMILY, 'default' ) );

		// Map font keys to Google Fonts URLs. Inter is already loaded by the theme.
		$google_fonts = [
			'merriweather' => 'https://fonts.googleapis.com/css2?family=Merriweather:wght@400;700&display=swap',
			'lora'         => 'https://fonts.googleapis.com/css2?family=Lora:wght@400;700&display=swap',
			'open_sans'    => 'https://fonts.googleapis.com/css2?family=Open+Sans:wght@400;600;700&display=swap',
			'roboto'       => 'https://fonts.googleapis.com/css2?family=Roboto:wght@400;500;700&display=swap',
		];

		if ( isset( $google_fonts[ $font ] ) ) {
			wp_enqueue_style(
				'prautoblogger-google-font',
				$google_fonts[ $font ],
				[],
				null // No version for external CDN URLs.
			);
		}
	}
}