<?php

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

final class AI_Narration_Plugin {
	private static ?self $instance = null;

	private AI_Narration_Placement $placement;
	private AI_Narration_Content $content;
	private AI_Narration_Background $background;
	private AI_Narration_Cache $cache;
	private AI_Narration_Admin $admin;
	private AI_Narration_Audio $audio;

	public static function instance(): self {
		if ( null === self::$instance ) {
			self::$instance = new self();
		}
		return self::$instance;
	}

	private function __construct() {
		$this->placement = new AI_Narration_Placement();
		$this->content = new AI_Narration_Content( $this->placement );
		$this->background = new AI_Narration_Background();
		$this->cache   = new AI_Narration_Cache( $this->content );
		$this->admin   = new AI_Narration_Admin( $this->content, $this->cache );
		$this->audio   = new AI_Narration_Audio( $this->content, $this->cache );

		add_action( 'init', array( $this->placement, 'register_shortcodes' ) );
		add_action( 'wp_enqueue_scripts', array( $this, 'enqueue_assets' ) );
		add_filter( 'the_content', array( $this, 'filter_content' ), 99 );
	}

	public function enqueue_assets(): void {
		if ( is_admin() || ! is_singular() ) {
			return;
		}

		$post_id = get_queried_object_id();
		$has_article_player = $post_id
			&& $this->content->is_eligible( $post_id )
			&& $this->content->has_narration_marker( $post_id )
			&& null !== $this->cache->get_available_manifest( $post_id );
		if ( ! $has_article_player ) {
			return;
		}

		wp_enqueue_style(
			'ai-narration-player',
			AI_NARRATION_URL . 'assets/player-v4.0.0.css',
			array(),
			AI_NARRATION_VERSION
		);

		wp_enqueue_script(
			'ai-narration-player',
			AI_NARRATION_URL . 'assets/player-v4.0.0.js',
			array(),
			AI_NARRATION_VERSION,
			true
		);
		wp_script_add_data( 'ai-narration-player', 'strategy', 'defer' );

		wp_localize_script(
			'ai-narration-player',
			'AINarrationConfig',
			array(
				'ajaxUrl' => admin_url( 'admin-ajax.php' ),
				'strings' => array(
					'play'                => __( 'Play', 'ai-narration' ),
					'pause'               => __( 'Pause', 'ai-narration' ),
					'loading'             => __( 'Loading…', 'ai-narration' ),
					'buffering'           => __( 'Buffering…', 'ai-narration' ),
					'ready'               => __( 'Narration ready.', 'ai-narration' ),
					'ended'               => __( 'Narration finished.', 'ai-narration' ),
					'error'               => __( 'Playback failed', 'ai-narration' ),
					'rateLimited'         => __( 'Try again later', 'ai-narration' ),
					'retry'               => __( 'Retry', 'ai-narration' ),
					'unsupported'         => __( 'Audio unavailable', 'ai-narration' ),
				),
			)
		);
	}

	public function filter_content( string $content ): string {
		if ( is_admin() || is_feed() || AI_Narration_Content::is_extracting() || ! is_singular() ) {
			return $content;
		}

		$post_id = get_queried_object_id();
		if ( ! $post_id || ( get_the_ID() && get_the_ID() !== $post_id ) ) {
			return $content;
		}

		$enabled = $this->content->is_eligible( $post_id )
			&& null !== $this->cache->get_available_manifest( $post_id );
		$player  = $enabled ? $this->player_markup( $post_id ) : '';
		return $this->placement->render_article( $content, $player, $enabled );
	}

	private function player_markup( int $post_id ): string {
		$bootstrap         = $this->audio->create_bootstrap_token( $post_id );
		$estimated_minutes = $this->content->estimate_listening_minutes( $post_id );
		$duration_label    = null === $estimated_minutes
			? '—:——'
			/* translators: %d: estimated listening duration in whole minutes. */
			: sprintf( __( '~%d:00', 'ai-narration' ), $estimated_minutes );
		$show_idle_duration = AI_Narration_Admin::show_idle_duration() && null !== $estimated_minutes;
		$estimated_time_accessible = null === $estimated_minutes
			? ''
			/* translators: %d: estimated listening duration in whole minutes. */
			: sprintf( _n( 'Estimated listening time: approximately %d minute.', 'Estimated listening time: approximately %d minutes.', $estimated_minutes, 'ai-narration' ), $estimated_minutes );

		ob_start();
		?>
		<section class="ai-narration<?php echo $show_idle_duration ? ' has-idle-duration' : ''; ?>" style="<?php echo esc_attr( AI_Narration_Admin::player_style_attribute() ); ?>" data-ai-narration-player data-ai-narration-mode="article" data-post-id="<?php echo esc_attr( (string) $post_id ); ?>" data-bootstrap="<?php echo esc_attr( $bootstrap ); ?>" aria-label="<?php esc_attr_e( 'AI Narration — AI-generated voice', 'ai-narration' ); ?>">
			<div class="ai-narration__controls">
				<button class="ai-narration__play" type="button" aria-label="<?php esc_attr_e( 'Play', 'ai-narration' ); ?>">
					<svg class="ai-narration__icon ai-narration__icon--play" viewBox="0 0 24 24" aria-hidden="true"><path d="M5.5 3.5v17L20 12z"/></svg>
					<svg class="ai-narration__icon ai-narration__icon--pause" viewBox="0 0 24 24" aria-hidden="true"><path d="M5.5 3.5h5v17h-5zm8 0h5v17h-5z"/></svg>
					<svg class="ai-narration__spinner" viewBox="0 0 24 24" aria-hidden="true" focusable="false">
						<path d="M12 3a9 9 0 1 1-6.36 2.64">
							<animateTransform attributeName="transform" type="rotate" from="0 12 12" to="360 12 12" dur="0.8s" repeatCount="indefinite"/>
						</path>
					</svg>
					<span class="ai-narration__play-text screen-reader-text"><?php esc_html_e( 'Play', 'ai-narration' ); ?></span>
				</button>

				<div class="ai-narration__timeline is-idle">
					<span class="ai-narration__title"><?php echo esc_html( AI_Narration_Admin::player_heading() ); ?></span>
					<?php if ( $show_idle_duration ) : ?><span class="ai-narration__idle-meta"><span class="ai-narration__idle-divider" aria-hidden="true"></span><span class="ai-narration__idle-duration" aria-hidden="true"><?php echo esc_html( $duration_label ); ?></span><span class="screen-reader-text"><?php echo esc_html( $estimated_time_accessible ); ?></span></span><?php endif; ?>
					<div class="ai-narration__status" role="status" aria-live="polite"></div>
					<div class="ai-narration__transport">
						<div class="ai-narration__time" aria-hidden="true"><span class="ai-narration__duration"><?php echo esc_html( $duration_label ); ?></span></div>
						<span class="ai-narration__transport-divider" aria-hidden="true"></span>
						<div class="ai-narration__skip-group">
						<button class="ai-narration__skip ai-narration__skip--back" type="button" aria-label="<?php esc_attr_e( 'Rewind 15 seconds', 'ai-narration' ); ?>" disabled>
							<svg class="ai-narration__skip-icon" viewBox="0 0 20 20" aria-hidden="true"><path d="M9 4v12L1.5 10 9 4Zm9 0v12l-7.5-6L18 4Z"/></svg>
						</button>
						<span class="ai-narration__skip-divider" aria-hidden="true"></span>
						<button class="ai-narration__skip ai-narration__skip--forward" type="button" aria-label="<?php esc_attr_e( 'Forward 15 seconds', 'ai-narration' ); ?>" disabled>
							<svg class="ai-narration__skip-icon" viewBox="0 0 20 20" aria-hidden="true"><path d="M9 4v12L1.5 10 9 4Zm9 0v12l-7.5-6L18 4Z"/></svg>
						</button>
						</div>
					</div>
				</div>
				<span class="ai-narration__disclosure"><?php echo esc_html( AI_Narration_Admin::player_disclosure() ); ?></span>
			</div>
		</section>
		<?php
		return (string) ob_get_clean();
	}

}