<?php
/**
 * Audio File Writer.
 *
 * Handles writing audio files to disk in a safe, WP-compliant manner.
 *
 * @package Accessibility_Audio_TTS\API
 */

namespace Accessibility_Audio_TTS\API;

use Accessibility_Audio_TTS\API\Interfaces\File_Writer_Interface;
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Writes audio files to disk.
 *
 * Audio File Writer - Handles writing audio files to disk.
 *
 * Single Responsibility: writing and saving audio content to files.
 */
class Audio_File_Writer extends Abstract_Audio_File_Handler implements File_Writer_Interface {

	/**
	 * Directory manager for upload paths.
	 *
	 * @var Audio_Directory_Manager
	 */
	private $directory_manager;

	/**
	 * Constructor with dependency injection.
	 *
	 * @param Audio_Directory_Manager|null $directory_manager Directory manager.
	 */
	public function __construct( ?Audio_Directory_Manager $directory_manager = null ) {
		$this->directory_manager = $directory_manager ?? new Audio_Directory_Manager();
	}

	/**
	 * Save audio content to a uniquely named file based on post ID.
	 *
	 * @param string $audio_content Binary audio content.
	 * @param int    $post_id       Post ID for filename generation.
	 * @return array Result with success status, URL, path, filename and size.
	 */
	public function save_audio_file( string $audio_content, int $post_id ): array {
		try {
			accessibility_audio_tts_debug_log( '[AudioFileWriter] Starting file save process for post ID: ' . $post_id );

			$filename = $this->generate_final_filename_for_post( $post_id );
			if ( class_exists( '\\Accessibility_Audio_TTS\\Core\\Audio_Access' ) ) {
				$relative_directory = gmdate( 'Y/m' );
				\Accessibility_Audio_TTS\Core\Audio_Access::assert_storage_ready( $relative_directory );
				$stage = \Accessibility_Audio_TTS\Core\Audio_Access::working_directory( get_post( $post_id ) ) . '/' . $filename . '.part';
				try {
					$result = $this->write_file_to_disk( $stage, $audio_content );
					if ( ! $result['success'] ) { return $result; }
					return \Accessibility_Audio_TTS\Core\Audio_Access::publish_file( $post_id, $stage, $relative_directory . '/' . $filename, 99999 === $post_id && ! get_post( $post_id ) );
				} finally { if ( is_file( $stage ) ) { wp_delete_file( $stage ); } }
			}
			$upload_path = $this->directory_manager->get_upload_path();
			if ( ! $this->directory_manager->ensure_directory_exists() ) {
				return array( 'success' => false, 'error' => 'Cannot create directory: ' . $upload_path );
			}
			$filepath = $upload_path . '/' . $filename;

			$write_result = $this->write_file_to_disk( $filepath, $audio_content );

			if ( ! $write_result['success'] ) {
				return $write_result; // Return error details from write_file_to_disk.
			}

			$this->set_file_permissions( $filepath );
			$file_url = $this->directory_manager->get_upload_url() . '/' . $filename;

			accessibility_audio_tts_debug_log( '[AudioFileWriter] File saved successfully: ' . $filepath );
			return array(
				'success'  => true,
				'url'      => $file_url,
				'path'     => $filepath,
				'filename' => $filename, // Added filename to the return array.
				'size'     => $write_result['bytes_written'],
			);

		} catch ( \Exception $e ) {
			accessibility_audio_tts_debug_log( '[AudioFileWriter] Exception in save_audio_file: ' . $e->getMessage() );
			return array(
				'success' => false,
				'error'   => $e->getMessage(),
			);
		}
	}

	/**
	 * Saves raw audio content to a specified full file path.
	 *
	 * @param string $audio_content  Binary audio content.
	 * @param string $full_file_path The absolute path where the file should be saved.
	 * @return bool True on success, false on failure.
	 */
	public function save_raw_audio_content( string $audio_content, string $full_file_path ): bool {
		try {
			accessibility_audio_tts_debug_log( '[AudioFileWriter] Attempting to save raw audio to: ' . $full_file_path );
			$directory_path = dirname( $full_file_path );

			// The supplied destination can be private; public uploads are unrelated.
			if ( ( ! is_dir( $directory_path ) && ! wp_mkdir_p( $directory_path ) ) || ! wp_is_writable( $directory_path ) ) {
				accessibility_audio_tts_debug_log( '[AudioFileWriter] Failed to ensure directory exists: ' . $directory_path );
				return false;
			}

			$write_result = $this->write_file_to_disk( $full_file_path, $audio_content );
			if ( $write_result['success'] ) {
				$this->set_file_permissions( $full_file_path );
				accessibility_audio_tts_debug_log( '[AudioFileWriter] Raw audio content saved successfully to: ' . $full_file_path );
				return true;
			}
			// Error message is already logged by write_file_to_disk.
			return false;
		} catch ( \Exception $e ) {
			accessibility_audio_tts_debug_log( '[AudioFileWriter] Exception in save_raw_audio_content: ' . $e->getMessage() );
			return false;
		}
	}

	/**
	 * Generate unique final filename for an audio file associated with a post.
	 *
	 * @param int    $post_id   Post ID.
	 * @param string $extension File extension (default: 'mp3').
	 * @return string The generated filename (e.g., accessibility_audio_tts_123_abcdef123456.mp3).
	 */
	public function generate_final_filename_for_post( int $post_id, string $extension = 'mp3' ): string {
		// Sanitize extension just in case.
		$extension = preg_replace( '/[^a-zA-Z0-9]/', '', $extension );
		return 'accessibility_audio_tts_' . $post_id . '_' . uniqid( '', true ) . '.' . $extension;
	}

	/**
	 * Write file content to disk.
	 *
	 * @param string $filepath       Absolute file path.
	 * @param string $audio_content  Binary audio content.
	 * @return array { success: bool, bytes_written?: int, error?: string }.
	 */
	private function write_file_to_disk( $filepath, $audio_content ) {
		accessibility_audio_tts_debug_log( '[AudioFileWriter] Writing audio file to: ' . $filepath );

		global $wp_filesystem;
		if ( ! $wp_filesystem ) {
			require_once ABSPATH . 'wp-admin/includes/file.php';
			WP_Filesystem();
		}

		if ( $wp_filesystem ) {
			$bytes_written = $wp_filesystem->put_contents( $filepath, $audio_content );
			if ( ! $bytes_written ) {
				accessibility_audio_tts_debug_log( '[AudioFileWriter] Failed to write file to: ' . $filepath . ' - Check permissions and disk space.' );
				return array(
					'success' => false,
					'error'   => 'Cannot save audio file. Check server permissions and available disk space.',
				);
			}
		} else {
			// Fallback when WP_Filesystem is unavailable (local filesystem only).
			$bytes_written = file_put_contents( $filepath, $audio_content ); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_file_put_contents
			if ( false === $bytes_written ) {
				accessibility_audio_tts_debug_log( '[AudioFileWriter] Failed to write file to: ' . $filepath . ' - Check permissions and disk space.' );
				return array(
					'success' => false,
					'error'   => 'Cannot save audio file. Check server permissions and available disk space.',
				);
			}
		}

		accessibility_audio_tts_debug_log( '[AudioFileWriter] Successfully wrote ' . $bytes_written . ' bytes to file: ' . $filepath );
		return array(
			'success'       => true,
			'bytes_written' => (int) $bytes_written,
		);
	}

	/**
	 * Set appropriate file permissions.
	 *
	 * @param string $filepath Absolute file path.
	 * @return void
	 */
	private function set_file_permissions( $filepath ) {
		File_Validation_Helper::set_file_permissions( $filepath, 0644 );
	}
}