<?php
/**
 * Frontend Asset Loader.
 *
 * @package Accessibility_Audio_TTS
 */

namespace Accessibility_Audio_TTS\Admin;

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

/**
 * Frontend Asset Loader - Handles frontend script and style enqueuing.
 * Single Responsibility: Loading frontend assets for posts with audio.
 */
class Frontend_Asset_Loader {

	/**
	 * Enqueues frontend assets for posts with generated audio.
	 */
	public function enqueue_frontend_assets() {
		if ( ! $this->should_enqueue_assets() ) {
			return;
		}

		$this->enqueue_frontend_styles();
		$this->enqueue_frontend_scripts();
		$this->configure_frontend_scripts();
		$this->add_frontend_localization();
	}

	/**
	 * Determines if frontend assets should be enqueued.
	 *
	 * @return bool
	 */
	private function should_enqueue_assets() {
		if ( ! is_singular() ) {
			return false;
		}

		$post_id = get_the_ID();
		if ( ! $post_id ) {
			return false;
		}

		// Check if post has generated audio (either by URL or generated flag).
		$audio_url       = get_post_meta( $post_id, 'accessibility_audio_tts_url', true );
		$audio_generated = get_post_meta( $post_id, 'accessibility_audio_tts_generated', true );

		return ! empty( $audio_url ) || ! empty( $audio_generated );
	}

	/**
	 * Enqueues frontend CSS styles.
	 */
	private function enqueue_frontend_styles() {
		wp_enqueue_style(
			'accessibility-audio-tts-audio-player',
			ACCESSIBILITY_AUDIO_TTS_ASSETS_URL . 'public/player.min.css',
			array(),
			accessibility_audio_tts_get_asset_version( 'assets/public/player.min.css' )
		);
	}

	/**
	 * Enqueues frontend JavaScript modules.
	 */
	private function enqueue_frontend_scripts() {
		// Enqueue Service Worker manager first.
		wp_enqueue_script(
			'accessibility-audio-tts-service-worker-manager',
			ACCESSIBILITY_AUDIO_TTS_ASSETS_URL . 'public/core/service-worker-manager.min.js',
			array(),
			accessibility_audio_tts_get_asset_version( 'assets/public/core/service-worker-manager.min.js' ),
			true
		);

		wp_enqueue_script(
			'accessibility-audio-tts-audio-player',
			ACCESSIBILITY_AUDIO_TTS_ASSETS_URL . 'public/player/player-core.min.js',
			array( 'jquery', 'accessibility-audio-tts-service-worker-manager' ),
			accessibility_audio_tts_get_asset_version( 'assets/public/player/player-core.min.js' ),
			true
		);

		// Anonymous measurement is server-side only: no browser telemetry or consent bridge.
		if ( $this->can_track_public_post() ) {
			wp_enqueue_script(
				'accessibility-audio-tts-listening-tracker',
				ACCESSIBILITY_AUDIO_TTS_ASSETS_URL . 'public/core/listening-tracker.min.js',
				array(),
				accessibility_audio_tts_get_asset_version( 'assets/public/core/listening-tracker.min.js' ),
				true
			);
		}
	}


	/** Only public, unprotected articles are eligible for browser measurement or Google events. */
	private function can_track_public_post() {
		if ( 'consented' !== \Accessibility_Audio_TTS\Core\Privacy_Settings::get( 'analytics_mode' ) || is_admin() || is_preview() ) { return false; }
		$post = get_post( get_the_ID() );
		return $post && 'publish' === $post->post_status && '' === (string) $post->post_password && is_post_type_viewable( $post->post_type );
	}

	/**
	 * Configures frontend script attributes.
	 */
	private function configure_frontend_scripts() {
		add_filter(
			'script_loader_tag',
			function ( $tag, $handle ) {
				if ( in_array( $handle, array( 'accessibility-audio-tts-audio-player', 'accessibility-audio-tts-service-worker-manager' ), true ) ) {
					return str_replace( ' src', ' type="module" src', $tag );
				}
				return $tag;
			},
			10,
			2
		);
	}

	/**
	 * Adds localization data for frontend player.
	 */
	private function add_frontend_localization() {
		wp_localize_script(
			'accessibility-audio-tts-audio-player',
			'accessibilityAudioTtsPlayerL10n',
			array(
				'play'                => __( 'Play', 'accessibility-audio-tts-text-to-speech-for-articles' ),
				'pause'               => __( 'Pause', 'accessibility-audio-tts-text-to-speech-for-articles' ),
				'mute'                => __( 'Mute', 'accessibility-audio-tts-text-to-speech-for-articles' ),
				'unmute'              => __( 'Unmute', 'accessibility-audio-tts-text-to-speech-for-articles' ),
				'loading'             => __( 'Loading...', 'accessibility-audio-tts-text-to-speech-for-articles' ),
				'cached'              => __( 'Available offline', 'accessibility-audio-tts-text-to-speech-for-articles' ),
				'offline'             => __( 'Offline mode', 'accessibility-audio-tts-text-to-speech-for-articles' ),
				'offline_unavailable' => __( 'Audio unavailable offline', 'accessibility-audio-tts-text-to-speech-for-articles' ),
			)
		);

		// Localize script with AJAX data.
		wp_localize_script(
			'accessibility-audio-tts-audio-player',
			'accessibility_audio_tts_frontend',
			array(
				'ajax_url' => admin_url( 'admin-ajax.php' ),
				'nonce'    => wp_create_nonce( 'accessibility_audio_tts_frontend_nonce' ),
			)
		);

		wp_localize_script( 'accessibility-audio-tts-audio-player', 'accessibilityAudioTtsPlayback', array( 'i18n' => $this->get_frontend_translations() ) );

		if ( $this->can_track_public_post() ) {
			wp_localize_script(
				'accessibility-audio-tts-listening-tracker',
				'accessibilityAudioTtsPublicAjax',
				array(
					'ajaxurl' => admin_url( 'admin-ajax.php' ),
					'listening_nonce' => wp_create_nonce( 'accessibility_audio_tts_listening_nonce' ),
					'tracking_enabled' => true,
					'analytics_mode' => 'consented',
					'public_post_ids' => array( get_the_ID() ),
					'ga4_enabled' => (bool) \Accessibility_Audio_TTS\Core\Privacy_Settings::get( 'ga4_enabled' ),
					'ga4_transport' => \Accessibility_Audio_TTS\Core\Privacy_Settings::get( 'ga4_transport' ),
					'ga4_measurement_id' => \Accessibility_Audio_TTS\Core\Privacy_Settings::get( 'ga4_measurement_id' ),
					// Override automatic page metadata: article URLs may contain personal query values.
					'ga4_page_location' => home_url( '/' ),
					'post_id' => get_the_ID(),
					'i18n' => $this->get_frontend_translations(),
				)
			);
		}

		// Add Service Worker configuration.
		wp_localize_script(
			'accessibility-audio-tts-service-worker-manager',
			'accessibilityAudioTtsServiceWorker',
			array(
				'swPath'    => ACCESSIBILITY_AUDIO_TTS_ASSETS_URL . 'public/core/aat-service-worker.js',
				'pluginUrl' => ACCESSIBILITY_AUDIO_TTS_PLUGIN_URL,
				'enabled'   => true,
			)
		);
	}

	/**
	 * Gets frontend translations for JavaScript.
	 *
	 * @return array
	 */
	private function get_frontend_translations() {
		return array(
			// Audio player error messages.
			'audio_loading_failed'        => __( 'Audio loading failed', 'accessibility-audio-tts-text-to-speech-for-articles' ),
			'audio_format_not_supported'  => __( 'Audio format not supported', 'accessibility-audio-tts-text-to-speech-for-articles' ),
			'audio_loading_aborted'       => __( 'Audio loading was aborted', 'accessibility-audio-tts-text-to-speech-for-articles' ),
			'network_error_loading_audio' => __( 'Network error while loading audio', 'accessibility-audio-tts-text-to-speech-for-articles' ),
			'audio_decoding_failed'       => __( 'Audio decoding failed', 'accessibility-audio-tts-text-to-speech-for-articles' ),
			'loading_stalled'             => __( 'Loading stalled', 'accessibility-audio-tts-text-to-speech-for-articles' ),
			'loading_timeout'             => __( 'Loading timeout', 'accessibility-audio-tts-text-to-speech-for-articles' ),
			'manual_retry'                => __( 'Manual retry', 'accessibility-audio-tts-text-to-speech-for-articles' ),
			'playback_failed'             => __( 'Playback failed', 'accessibility-audio-tts-text-to-speech-for-articles' ),
			'playback_aborted'            => __( 'Playback aborted', 'accessibility-audio-tts-text-to-speech-for-articles' ),
			'playback_blocked_by_browser' => __( 'Playback blocked by browser (user needs to interact first)', 'accessibility-audio-tts-text-to-speech-for-articles' ),
			'audio_source_not_found'      => __( 'Audio source not found', 'accessibility-audio-tts-text-to-speech-for-articles' ),

			// Listening tracker messages.
			'failed_to_get_post_stats'    => __( 'Failed to get post stats', 'accessibility-audio-tts-text-to-speech-for-articles' ),
		);
	}
}