<?php
/**
 * Outputs other software can consume:
 *
 * - External player files: `/?streamsera_playlist={station}&format=m3u|pls` (VLC, Winamp, car apps).
 * - Plain-text now playing: `GET streamsera/v1/now-playing/{station}/text` (OBS text source, signage).
 * - Overlay page: `/?streamsera_overlay={station}` — transparent "now playing" card for OBS browser sources.
 *
 * @package StreamSera
 */

namespace StreamSera\Modules;

use StreamSera\Metadata\Resolver;
use StreamSera\PostTypes\Station;
use WP_REST_Request;
use WP_REST_Response;

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

/**
 * Feeds & external outputs.
 */
class Feeds {

	const NS             = 'streamsera/v1';
	const QUERY_PLAYLIST = 'streamsera_playlist';
	const QUERY_OVERLAY  = 'streamsera_overlay';

	/**
	 * Hook in.
	 */
	public function register() {
		add_filter( 'query_vars', array( $this, 'query_vars' ) );
		add_action( 'template_redirect', array( $this, 'render' ) );
		add_action( 'rest_api_init', array( $this, 'routes' ) );
		add_filter( 'streamsera_public_station', array( $this, 'station_links' ), 10, 2 );
		add_filter( 'streamsera_admin_data', array( $this, 'admin_data' ) );
	}

	/**
	 * Register query vars.
	 *
	 * @param array $vars Vars.
	 * @return array
	 */
	public function query_vars( $vars ) {
		$vars[] = self::QUERY_PLAYLIST;
		$vars[] = self::QUERY_OVERLAY;
		return $vars;
	}

	/**
	 * One option from the query string of a playlist / overlay request (read-only display
	 * options, so no nonce): unslashed, sanitized as a key, '' when absent. Callers check it
	 * against their allowed values.
	 *
	 * @param string $name Query argument.
	 * @return string
	 */
	private static function query_arg( $name ) {
		// phpcs:ignore WordPress.Security.NonceVerification.Recommended -- read-only display option.
		return isset( $_GET[ $name ] ) && is_string( $_GET[ $name ] ) ? sanitize_key( wp_unslash( $_GET[ $name ] ) ) : '';
	}

	/* ------------------------------------------------------------------ URLs */

	/**
	 * URL of the .m3u / .pls file for a station.
	 *
	 * @param int    $station_id Station.
	 * @param string $format     m3u|pls.
	 * @return string
	 */
	public static function playlist_url( $station_id, $format = 'm3u' ) {
		return add_query_arg(
			array(
				self::QUERY_PLAYLIST => (int) $station_id,
				'format'             => 'pls' === $format ? 'pls' : 'm3u',
			),
			home_url( '/' )
		);
	}

	/**
	 * URL of the OBS overlay page for a station.
	 *
	 * @param int $station_id Station.
	 * @return string
	 */
	public static function overlay_url( $station_id ) {
		return add_query_arg( self::QUERY_OVERLAY, (int) $station_id, home_url( '/' ) );
	}

	/**
	 * Add the external-player links to the public station payload.
	 *
	 * @param array $data       Payload.
	 * @param int   $station_id Station.
	 * @return array
	 */
	public function station_links( $data, $station_id ) {
		if ( ! empty( $data['streams'] ) ) {
			$data['m3u'] = self::playlist_url( $station_id, 'm3u' );
			$data['pls'] = self::playlist_url( $station_id, 'pls' );
		}
		return $data;
	}

	/**
	 * Expose the URL patterns to the admin app (Settings → Feeds & overlays).
	 *
	 * @param array $data Admin bootstrap.
	 * @return array
	 */
	public function admin_data( $data ) {
		$data['feeds'] = array(
			'm3u'     => self::playlist_url( 0, 'm3u' ),
			'pls'     => self::playlist_url( 0, 'pls' ),
			'overlay' => self::overlay_url( 0 ),
			'text'    => rest_url( self::NS . '/now-playing/0/text' ),
			'json'    => rest_url( self::NS . '/now-playing/0' ),
		);
		return $data;
	}

	/* -------------------------------------------------------- front-end pages */

	/**
	 * Serve the playlist file or the overlay page.
	 */
	public function render() {
		$station_id = (int) get_query_var( self::QUERY_PLAYLIST );
		if ( $station_id ) {
			$this->render_playlist( $station_id );
		}
		$station_id = (int) get_query_var( self::QUERY_OVERLAY );
		if ( $station_id ) {
			$this->render_overlay( $station_id );
		}
	}

	/**
	 * .m3u / .pls download.
	 *
	 * @param int $station_id Station.
	 */
	private function render_playlist( $station_id ) {
		$station = Station::to_public( $station_id );
		if ( ! $station || empty( $station['streams'] ) ) {
			status_header( 404 );
			exit;
		}
		$format = 'pls' === self::query_arg( 'format' ) ? 'pls' : 'm3u';
		$slug   = sanitize_title( $station['name'] );
		$slug   = $slug ? $slug : 'station';
		nocache_headers();
		header( 'X-Content-Type-Options: nosniff' );
		header( 'Content-Disposition: attachment; filename="' . $slug . '.' . $format . '"' );

		// Only the station's own stream URLs (sanitized as URLs) and its name/labels (sanitized as text)
		// go into the file, and every line is escaped again when it is printed.
		$name    = sanitize_text_field( (string) $station['name'] );
		$entries = array();
		foreach ( $station['streams'] as $stream ) {
			$url = empty( $stream['url'] ) ? '' : esc_url_raw( (string) $stream['url'], array( 'http', 'https' ) );
			if ( '' === $url ) {
				continue;
			}
			$label     = empty( $stream['label'] ) ? '' : sanitize_text_field( (string) $stream['label'] );
			$entries[] = array(
				'url'   => $url,
				'title' => $name . ( '' !== $label ? ' (' . $label . ')' : '' ),
			);
		}

		if ( 'pls' === $format ) {
			header( 'Content-Type: audio/x-scpls; charset=utf-8' );
			echo "[playlist]\r\n";
			foreach ( $entries as $i => $entry ) {
				$n = $i + 1;
				echo 'File' . absint( $n ) . '=' . esc_url_raw( $entry['url'] ) . "\r\n";
				echo 'Title' . absint( $n ) . '=' . esc_html( $entry['title'] ) . "\r\n";
				echo 'Length' . absint( $n ) . "=-1\r\n";
			}
			echo 'NumberOfEntries=' . absint( count( $entries ) ) . "\r\n";
			echo "Version=2\r\n";
		} else {
			header( 'Content-Type: audio/x-mpegurl; charset=utf-8' );
			echo "#EXTM3U\r\n";
			foreach ( $entries as $entry ) {
				echo '#EXTINF:-1,' . esc_html( $entry['title'] ) . "\r\n";
				echo esc_url_raw( $entry['url'] ) . "\r\n";
			}
		}
		exit;
	}

	/**
	 * Transparent now-playing card for OBS / vMix browser sources.
	 *
	 * Query options: `theme=light|dark` (default dark text on transparent), `art=0` hides artwork,
	 * `size=sm|md|lg`, `align=left|center`.
	 *
	 * @param int $station_id Station.
	 */
	private function render_overlay( $station_id ) {
		$station = Station::to_public( $station_id );
		if ( ! $station ) {
			status_header( 404 );
			exit;
		}
		$np       = Resolver::now_playing( $station_id );
		$theme    = 'light' === self::query_arg( 'theme' ) ? 'light' : 'dark';
		$show_art = '0' !== self::query_arg( 'art' );
		$size     = self::query_arg( 'size' );
		$size     = in_array( $size, array( 'sm', 'lg' ), true ) ? $size : 'md';
		$align    = 'center' === self::query_arg( 'align' ) ? 'center' : 'left';
		$interval = max( 5, (int) streamsera_get_setting( 'cache_ttl', 15 ) );
		$endpoint = rest_url( self::NS . '/now-playing/' . $station_id );
		$classes  = array( 'ss-ov-theme-' . $theme, 'ss-ov-size-' . $size, 'ss-ov-align-' . $align );
		nocache_headers();
		header( 'Content-Type: text/html; charset=utf-8' );
		?>
<!DOCTYPE html>
<html <?php language_attributes(); ?>>
<head>
	<meta charset="utf-8">
	<meta name="viewport" content="width=device-width, initial-scale=1">
	<meta name="robots" content="noindex">
	<title><?php echo esc_html( $station['name'] ); ?> · <?php esc_html_e( 'Now playing overlay', 'streamsera' ); ?></title>
	<?php \StreamSera\Frontend\Assets::print_standalone_styles( 'overlay', array() ); ?>
</head>
<body class="<?php echo esc_attr( implode( ' ', $classes ) ); ?>">
	<div class="ss-ov" id="ov" data-endpoint="<?php echo esc_url( $endpoint ); ?>" data-logo="<?php echo esc_url( (string) $station['logo'] ); ?>" data-every="<?php echo esc_attr( (string) ( $interval * 1000 ) ); ?>">
		<?php $art_src = ! empty( $np['artwork'] ) ? (string) $np['artwork'] : (string) $station['logo']; ?>
		<img class="ss-ov__art" id="art" alt=""<?php if ( $art_src ) : ?> src="<?php echo esc_url( $art_src ); ?>"<?php endif; ?><?php if ( ! $show_art || ! $art_src ) : ?> hidden<?php endif; ?> data-ss-show-art="<?php echo esc_attr( $show_art ? '1' : '0' ); ?>">
		<div class="ss-ov__text">
			<div class="ss-ov__k"><?php echo esc_html( $station['name'] ); ?></div>
			<div class="ss-ov__t" id="t"><?php echo esc_html( ! empty( $np['title'] ) ? $np['title'] : ( ! empty( $np['raw'] ) ? $np['raw'] : $station['slogan'] ) ); ?></div>
			<div class="ss-ov__a" id="a"><?php echo esc_html( ! empty( $np['artist'] ) ? $np['artist'] : '' ); ?></div>
		</div>
	</div>
	<?php \StreamSera\Frontend\Assets::print_standalone_scripts( 'overlay', array() ); ?>
</body>
</html>
		<?php
		exit;
	}

	/* ------------------------------------------------------------------ REST */

	/**
	 * Routes.
	 */
	public function routes() {
		register_rest_route(
			self::NS,
			'/now-playing/(?P<station>\d+)/text',
			array(
				'methods'             => 'GET',
				'permission_callback' => '__return_true',
				'args'                => array(
					'station' => array(
						'sanitize_callback' => 'absint',
						'validate_callback' => static function ( $value ) {
							return is_numeric( $value ) && (int) $value > 0;
						},
					),
					'format'  => array(
						'type'              => 'string',
						'default'           => '{artist} - {title}',
						'maxLength'         => 200,
						'sanitize_callback' => 'sanitize_text_field',
						'validate_callback' => 'rest_validate_request_arg',
					),
				),
				'callback'            => array( $this, 'text' ),
			)
		);
	}

	/**
	 * Plain-text now playing. `format` accepts {artist}, {title}, {raw}, {station}, {listeners}.
	 *
	 * @param WP_REST_Request $request Request.
	 * @return WP_REST_Response
	 */
	public function text( WP_REST_Request $request ) {
		$station_id = (int) streamsera_url_param( $request, 'station' );
		$station    = Station::to_public( $station_id );
		if ( ! $station ) {
			return new WP_REST_Response( '', 404 );
		}
		$np     = Resolver::now_playing( $station_id );
		$format = sanitize_text_field( (string) $request['format'] );
		$text   = strtr(
			$format,
			array(
				'{artist}'    => isset( $np['artist'] ) ? sanitize_text_field( (string) $np['artist'] ) : '',
				'{title}'     => isset( $np['title'] ) ? sanitize_text_field( (string) $np['title'] ) : '',
				'{raw}'       => isset( $np['raw'] ) ? sanitize_text_field( (string) $np['raw'] ) : '',
				'{station}'   => sanitize_text_field( (string) $station['name'] ),
				'{listeners}' => isset( $np['listeners'] ) && null !== $np['listeners'] ? (string) $np['listeners'] : '',
			)
		);
		// "{artist} - {title}" with no artist collapses to just the title.
		$text = trim( preg_replace( '/^\s*-\s*|\s*-\s*$/', '', $text ) );
		if ( '' === $text && ! empty( $np['raw'] ) ) {
			$text = sanitize_text_field( (string) $np['raw'] );
		}
		$response = new WP_REST_Response( $text );
		$response->header( 'Content-Type', 'text/plain; charset=utf-8' );
		$response->header( 'Cache-Control', 'public, max-age=' . max( 3, (int) ( isset( $np['ttl'] ) ? $np['ttl'] : 10 ) ) );
		add_filter( 'rest_pre_serve_request', array( $this, 'serve_text' ), 10, 2 );
		return $response;
	}

	/**
	 * Serve a text/plain response body without JSON encoding.
	 *
	 * @param bool             $served Whether served.
	 * @param WP_REST_Response $result Result.
	 * @return bool
	 */
	public function serve_text( $served, $result ) {
		if ( $served || ! $result instanceof WP_REST_Response ) {
			return $served;
		}
		$type = $result->get_headers();
		if ( empty( $type['Content-Type'] ) || 0 !== strpos( $type['Content-Type'], 'text/plain' ) ) {
			return $served;
		}
		echo esc_html( sanitize_text_field( (string) $result->get_data() ) );
		return true;
	}
}