<?php
/**
 * Streaming Access Control for WooCommerce.
 *
 * @package WP_FediStream
 */

namespace WP_FediStream\WooCommerce;

// Prevent direct file access.
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Controls streaming access based on purchases.
 */
class StreamingAccess {

	/**
	 * Constructor.
	 */
	public function __construct() {
		// Filter audio URL access.
		add_filter( 'fedistream_can_stream_track', array( $this, 'can_stream_track' ), 10, 3 );

		// Add streaming access check to AJAX handler.
		add_filter( 'fedistream_track_data', array( $this, 'filter_track_data' ), 10, 2 );

		// Handle preview access.
		add_action( 'init', array( $this, 'handle_preview_request' ) );

		// Add purchase buttons to track display.
		add_action( 'fedistream_after_track_player', array( $this, 'add_purchase_button' ) );
	}

	/**
	 * Check if user can stream a track.
	 *
	 * @param bool $can_stream Default access (true).
	 * @param int  $track_id   Track ID.
	 * @param int  $user_id    User ID (0 for guests).
	 * @return bool
	 */
	public function can_stream_track( bool $can_stream, int $track_id, int $user_id ): bool {
		// Check if WooCommerce integration is enabled.
		if ( ! get_option( 'wp_fedistream_enable_woocommerce', 0 ) ) {
			return $can_stream;
		}

		// Check if track requires purchase.
		$requires_purchase = $this->track_requires_purchase( $track_id );

		if ( ! $requires_purchase ) {
			return true;
		}

		// Guest users can't stream paid content.
		if ( ! $user_id ) {
			return false;
		}

		// Check if user has purchased this track.
		if ( Integration::user_has_purchased( $user_id, 'track', $track_id ) ) {
			return true;
		}

		// Check if user has purchased the album containing this track.
		$album_id = get_post_meta( $track_id, '_fedistream_album_id', true );
		if ( $album_id && Integration::user_has_purchased( $user_id, 'album', $album_id ) ) {
			return true;
		}

		return false;
	}

	/**
	 * Check if a track requires purchase to stream.
	 *
	 * @param int $track_id Track ID.
	 * @return bool
	 */
	private function track_requires_purchase( int $track_id ): bool {
		// Find WooCommerce products linked to this track.
		$products = $this->get_products_for_track( $track_id );

		if ( empty( $products ) ) {
			// Also check album products.
			$album_id = get_post_meta( $track_id, '_fedistream_album_id', true );
			if ( $album_id ) {
				$products = $this->get_products_for_album( $album_id );
			}
		}

		if ( empty( $products ) ) {
			return false;
		}

		// Check if any product includes streaming.
		foreach ( $products as $product ) {
			$include_streaming = get_post_meta( $product->ID, '_fedistream_include_streaming', true );
			if ( 'yes' === $include_streaming ) {
				return true;
			}
		}

		return false;
	}

	/**
	 * Get WooCommerce products linked to a track.
	 *
	 * @param int $track_id Track ID.
	 * @return array
	 */
	private function get_products_for_track( int $track_id ): array {
		return get_posts(
			array(
				'post_type'      => 'product',
				'post_status'    => 'publish',
				'posts_per_page' => -1,
				'meta_query'     => array( // phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_query
					array(
						'key'   => '_fedistream_linked_track',
						'value' => $track_id,
					),
				),
			)
		);
	}

	/**
	 * Get WooCommerce products linked to an album.
	 *
	 * @param int $album_id Album ID.
	 * @return array
	 */
	private function get_products_for_album( int $album_id ): array {
		return get_posts(
			array(
				'post_type'      => 'product',
				'post_status'    => 'publish',
				'posts_per_page' => -1,
				'meta_query'     => array( // phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_query
					array(
						'key'   => '_fedistream_linked_album',
						'value' => $album_id,
					),
				),
			)
		);
	}

	/**
	 * Filter track data for AJAX responses.
	 *
	 * @param array $data    Track data.
	 * @param int   $track_id Track ID.
	 * @return array Modified track data.
	 */
	public function filter_track_data( array $data, int $track_id ): array {
		$user_id    = get_current_user_id();
		$can_stream = apply_filters( 'fedistream_can_stream_track', true, $track_id, $user_id );

		if ( ! $can_stream ) {
			// Return preview URL instead of full audio.
			$data['audio_url']   = $this->get_preview_url( $track_id );
			$data['preview_only'] = true;
			$data['purchase_url'] = $this->get_purchase_url( $track_id );
		} else {
			$data['preview_only'] = false;
		}

		// Add purchase status.
		$data['user_has_purchased'] = $user_id && (
			Integration::user_has_purchased( $user_id, 'track', $track_id ) ||
			Integration::user_has_purchased( $user_id, 'album', get_post_meta( $track_id, '_fedistream_album_id', true ) )
		);

		return $data;
	}

	/**
	 * Get preview URL for a track.
	 *
	 * @param int $track_id Track ID.
	 * @return string
	 */
	private function get_preview_url( int $track_id ): string {
		return add_query_arg(
			array(
				'fedistream_preview' => $track_id,
				'_'                  => time(), // Cache buster.
			),
			home_url( '/' )
		);
	}

	/**
	 * Get purchase URL for a track.
	 *
	 * @param int $track_id Track ID.
	 * @return string
	 */
	private function get_purchase_url( int $track_id ): string {
		// Find product for this track.
		$products = $this->get_products_for_track( $track_id );

		if ( ! empty( $products ) ) {
			return get_permalink( $products[0]->ID );
		}

		// Check for album product.
		$album_id = get_post_meta( $track_id, '_fedistream_album_id', true );
		if ( $album_id ) {
			$album_products = $this->get_products_for_album( $album_id );
			if ( ! empty( $album_products ) ) {
				return get_permalink( $album_products[0]->ID );
			}
		}

		return '';
	}

	/**
	 * Handle preview request.
	 *
	 * @return void
	 */
	public function handle_preview_request(): void {
		// phpcs:ignore WordPress.Security.NonceVerification.Recommended
		if ( ! isset( $_GET['fedistream_preview'] ) ) {
			return;
		}

		$track_id = absint( $_GET['fedistream_preview'] ); // phpcs:ignore WordPress.Security.NonceVerification.Recommended

		if ( ! $track_id ) {
			wp_die( esc_html__( 'Invalid track.', 'wp-fedistream' ) );
		}

		$track = get_post( $track_id );
		if ( ! $track || 'fedistream_track' !== $track->post_type ) {
			wp_die( esc_html__( 'Track not found.', 'wp-fedistream' ) );
		}

		// Get audio file.
		$audio_id = get_post_meta( $track_id, '_fedistream_audio_file', true );
		if ( ! $audio_id ) {
			wp_die( esc_html__( 'No audio file available.', 'wp-fedistream' ) );
		}

		$file_path = get_attached_file( $audio_id );
		if ( ! $file_path || ! file_exists( $file_path ) ) {
			wp_die( esc_html__( 'File not found.', 'wp-fedistream' ) );
		}

		// Get preview settings.
		$preview_start    = (int) get_post_meta( $track_id, '_fedistream_preview_start', true );
		$preview_duration = (int) get_post_meta( $track_id, '_fedistream_preview_duration', true );

		// Default 30 seconds preview.
		if ( ! $preview_duration ) {
			$preview_duration = 30;
		}

		// For now, serve the full file with range headers.
		// In production, you'd use FFmpeg to extract a preview clip.
		$this->serve_audio_preview( $file_path, $preview_start, $preview_duration );
	}

	/**
	 * Serve audio preview with limited duration.
	 *
	 * @param string $file_path       File path.
	 * @param int    $start_seconds   Start time in seconds.
	 * @param int    $duration_seconds Duration in seconds.
	 * @return void
	 */
	private function serve_audio_preview( string $file_path, int $start_seconds, int $duration_seconds ): void {
		$file_size = filesize( $file_path );
		$mime_type = wp_check_filetype( $file_path )['type'] ?: 'audio/mpeg';

		// Calculate byte range for preview (rough approximation).
		// This is a simplified approach; proper implementation would use FFmpeg.
		$duration_total = (int) get_post_meta( $this->get_track_id_from_path( $file_path ), '_fedistream_duration', true );

		if ( $duration_total > 0 ) {
			$bytes_per_second = $file_size / $duration_total;
			$start_byte       = (int) ( $start_seconds * $bytes_per_second );
			$end_byte         = (int) min( ( $start_seconds + $duration_seconds ) * $bytes_per_second, $file_size - 1 );
		} else {
			// Serve first 30% of file as fallback.
			$start_byte = 0;
			$end_byte   = (int) ( $file_size * 0.3 );
		}

		// Clean output buffer.
		while ( ob_get_level() ) {
			ob_end_clean();
		}

		// Set headers for partial content.
		header( 'HTTP/1.1 206 Partial Content' );
		header( 'Content-Type: ' . $mime_type );
		header( 'Accept-Ranges: bytes' );
		header( 'Content-Length: ' . ( $end_byte - $start_byte + 1 ) );
		header( "Content-Range: bytes {$start_byte}-{$end_byte}/{$file_size}" );
		header( 'Content-Disposition: inline' );
		header( 'Cache-Control: no-cache, no-store, must-revalidate' );

		// Serve partial content.
		$fp = fopen( $file_path, 'rb' ); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_fopen
		if ( $fp ) {
			fseek( $fp, $start_byte );
			echo fread( $fp, $end_byte - $start_byte + 1 ); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_fread,WordPress.Security.EscapeOutput.OutputNotEscaped
			fclose( $fp ); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_fclose
		}

		exit;
	}

	/**
	 * Get track ID from file path (for cached lookups).
	 *
	 * @param string $file_path File path.
	 * @return int Track ID or 0.
	 */
	private function get_track_id_from_path( string $file_path ): int {
		global $wpdb;

		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching
		$attachment_id = $wpdb->get_var(
			$wpdb->prepare(
				"SELECT ID FROM {$wpdb->posts} WHERE guid LIKE %s",
				'%' . $wpdb->esc_like( basename( $file_path ) )
			)
		);

		if ( ! $attachment_id ) {
			return 0;
		}

		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching
		$track_id = $wpdb->get_var(
			$wpdb->prepare(
				"SELECT post_id FROM {$wpdb->postmeta} WHERE meta_key = '_fedistream_audio_file' AND meta_value = %d",
				$attachment_id
			)
		);

		return (int) $track_id;
	}

	/**
	 * Add purchase button after track player.
	 *
	 * @param int $track_id Track ID.
	 * @return void
	 */
	public function add_purchase_button( int $track_id ): void {
		if ( ! get_option( 'wp_fedistream_enable_woocommerce', 0 ) ) {
			return;
		}

		$user_id = get_current_user_id();

		// Check if already purchased.
		if ( $user_id ) {
			$album_id = get_post_meta( $track_id, '_fedistream_album_id', true );

			if ( Integration::user_has_purchased( $user_id, 'track', $track_id ) ) {
				echo '<p class="fedistream-purchase-status">' . esc_html__( 'You own this track.', 'wp-fedistream' ) . '</p>';
				return;
			}

			if ( $album_id && Integration::user_has_purchased( $user_id, 'album', $album_id ) ) {
				echo '<p class="fedistream-purchase-status">' . esc_html__( 'You own this album.', 'wp-fedistream' ) . '</p>';
				return;
			}
		}

		// Find product for this track.
		$products = $this->get_products_for_track( $track_id );

		if ( ! empty( $products ) ) {
			$product = wc_get_product( $products[0]->ID );
			if ( $product ) {
				echo '<div class="fedistream-purchase-button">';
				echo '<a href="' . esc_url( get_permalink( $products[0]->ID ) ) . '" class="button">';
				echo esc_html__( 'Buy Track', 'wp-fedistream' ) . ' - ' . wp_kses_post( $product->get_price_html() );
				echo '</a>';
				echo '</div>';
			}
		}

		// Also show album option if available.
		$album_id = get_post_meta( $track_id, '_fedistream_album_id', true );
		if ( $album_id ) {
			$album_products = $this->get_products_for_album( $album_id );
			if ( ! empty( $album_products ) ) {
				$album_product = wc_get_product( $album_products[0]->ID );
				$album         = get_post( $album_id );
				if ( $album_product && $album ) {
					echo '<div class="fedistream-purchase-button fedistream-purchase-album">';
					echo '<a href="' . esc_url( get_permalink( $album_products[0]->ID ) ) . '" class="button button-secondary">';
					/* translators: %s: Album name */
					echo esc_html( sprintf( __( 'Buy Full Album: %s', 'wp-fedistream' ), $album->post_title ) );
					echo ' - ' . wp_kses_post( $album_product->get_price_html() );
					echo '</a>';
					echo '</div>';
				}
			}
		}
	}
}