<?php
/**
 * Format Validator Utility Class
 *
 * Handles image format validation and MIME type configuration.
 *
 * @package Gatewell
 * @subpackage Utilities
 * @since 1.0.0
 */

namespace Gatewell;

defined( 'ABSPATH' ) || exit;

/**
 * Class Format_Validator
 *
 * Utility class for managing image formats and MIME types.
 *
 * @since 1.0.0
 */
class Format_Validator {

	/**
	 * Get default format configuration.
	 *
	 * @return array Default format settings.
	 * @since 1.0.0
	 */
	public static function get_default_formats() {
		return array(
			'jpeg' => true,
			'png'  => true,
			'gif'  => true,
			'webp' => true,
			'avif' => false, // Off by default: encoding needs PHP 8.1+ GD or ImageMagick.
			'heic' => true,
			'svg'  => false, // Disabled by default for security.
		);
	}

	/**
	 * Convert format settings to MIME type array.
	 *
	 * Converts format configuration (jpeg, png, etc.) to an array of MIME types.
	 *
	 * @param array $formats Format configuration array (e.g., array('jpeg' => true, 'png' => false)).
	 * @return array Array of allowed MIME types.
	 * @since 1.0.0
	 */
	public static function get_mime_types_from_formats( $formats ) {
		$mime_types = array();

		if ( ! empty( $formats['jpeg'] ) ) {
			$mime_types[] = 'image/jpeg';
		}
		if ( ! empty( $formats['png'] ) ) {
			$mime_types[] = 'image/png';
		}
		if ( ! empty( $formats['gif'] ) ) {
			$mime_types[] = 'image/gif';
		}
		if ( ! empty( $formats['webp'] ) ) {
			$mime_types[] = 'image/webp';
		}
		if ( ! empty( $formats['avif'] ) ) {
			$mime_types[] = 'image/avif';
		}
		if ( ! empty( $formats['heic'] ) ) {
			$mime_types[] = 'image/heic';
			$mime_types[] = 'image/heif';
		}
		if ( ! empty( $formats['svg'] ) ) {
			$mime_types[] = 'image/svg+xml';
		}

		return $mime_types;
	}

	/**
	 * Get all allowed MIME types based on saved settings.
	 *
	 * Returns the enabled image MIME types. Builds that ship the non-image
	 * upload pipeline extend the list with the other file type categories; in
	 * this build that code is not present and non-image uploads are rejected.
	 *
	 * @return array Array of allowed MIME types.
	 * @since 1.0.0
	 */
	public static function get_allowed_mime_types() {
		$default_formats = self::get_default_formats();
		$allowed_formats = get_option( 'gatewell_allowed_formats', $default_formats );

		// Type check and fallback.
		if ( ! is_array( $allowed_formats ) ) {
			$allowed_formats = $default_formats;
		}

		// Ensure all required keys exist.
		$allowed_formats = wp_parse_args( $allowed_formats, $default_formats );

		// Start with image MIME types (always enabled).
		$allowed_mime_types = self::get_mime_types_from_formats( $allowed_formats );


		return array_unique( $allowed_mime_types );
	}

	/**
	 * Check if a MIME type is allowed.
	 *
	 * @param string $mime_type MIME type to check.
	 * @return bool True if allowed, false otherwise.
	 * @since 1.0.0
	 */
	public static function is_mime_type_allowed( $mime_type ) {
		$allowed_mime_types = self::get_allowed_mime_types();
		return in_array( $mime_type, $allowed_mime_types, true );
	}

	/**
	 * Get file extension from MIME type.
	 *
	 * @param string $mime_type MIME type.
	 * @return string File extension (without dot).
	 * @since 1.0.0
	 */
	public static function get_extension_from_mime( $mime_type ) {
		$extensions = array(
			'image/jpeg'    => 'jpg',
			'image/png'     => 'png',
			'image/gif'     => 'gif',
			'image/webp'    => 'webp',
			'image/avif'    => 'avif',
			'image/svg+xml' => 'svg',
		);

		return isset( $extensions[ $mime_type ] ) ? $extensions[ $mime_type ] : 'jpg';
	}

	/**
	 * Check if a MIME type is SVG.
	 *
	 * @param string $mime_type MIME type to check.
	 * @return bool True if SVG, false otherwise.
	 * @since 1.1.0
	 */
	public static function is_svg( $mime_type ) {
		return 'image/svg+xml' === $mime_type;
	}

	/**
	 * Get WordPress default MIME types by category.
	 *
	 * Returns all WordPress-supported file types categorized by type. The
	 * image list drives get_file_type_category(), which routes uploads to the
	 * image processor; the other categories are only reachable in builds that
	 * ship the non-image upload pipeline.
	 *
	 * @return array Categorized MIME types.
	 * @since 1.4.0
	 */
	public static function get_wordpress_mime_types_by_category() {
		return array(
			'image' => array(
				'image/jpeg',
				'image/png',
				'image/gif',
				'image/webp',
				'image/avif',
				'image/svg+xml',
				'image/heic',
				'image/heif',
			),
			'video' => array(
				'video/mp4',
				'video/quicktime',
				'video/x-msvideo',
				'video/x-ms-wmv',
				'video/mpeg',
				'video/ogg',
				'video/3gpp',
			),
			'audio' => array(
				'audio/mpeg',
				'audio/ogg',
				'audio/wav',
				'audio/x-wav',
			),
			'document' => array(
				'application/pdf',
				'application/msword',
				'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
				'application/vnd.ms-powerpoint',
				'application/vnd.openxmlformats-officedocument.presentationml.presentation',
				'application/vnd.ms-excel',
				'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
				'application/vnd.oasis.opendocument.text',
			),
			'archive' => array(
				'application/zip',
				'application/x-tar',
				'application/x-gzip',
			),
		);
	}

	/**
	 * Get file type category from MIME type.
	 *
	 * Determines which category (image, video, audio, document, archive)
	 * a given MIME type belongs to.
	 *
	 * @param string $mime_type MIME type.
	 * @return string Category (image, video, audio, document, archive, unknown).
	 * @since 1.4.0
	 */
	public static function get_file_type_category( $mime_type ) {
		$categories = self::get_wordpress_mime_types_by_category();

		foreach ( $categories as $category => $mime_types ) {
			if ( in_array( $mime_type, $mime_types, true ) ) {
				return $category;
			}
		}

		return 'unknown';
	}

	/**
	 * Get metadata fields applicable to a file type category.
	 *
	 * Returns which metadata fields should be shown/available
	 * for each file type category.
	 *
	 * @param string $category File type category.
	 * @return array Array of field names that should be shown.
	 * @since 1.4.0
	 */
	public static function get_applicable_metadata_fields( $category ) {
		$field_map = array(
			'image'    => array( 'filename', 'alt_text', 'title', 'caption', 'description' ),
			'video'    => array( 'filename', 'title', 'caption', 'description' ),
			'audio'    => array( 'filename', 'title', 'description' ),
			'document' => array( 'filename', 'title', 'description' ),
			'archive'  => array( 'filename', 'description' ),
		);

		return isset( $field_map[ $category ] ) ? $field_map[ $category ] : array( 'filename' );
	}

	/**
	 * Get file extension from MIME type (extended for all file types).
	 *
	 * Maps MIME types to file extensions for all supported file categories.
	 *
	 * @param string $mime_type MIME type.
	 * @return string File extension (without dot).
	 * @since 1.4.0
	 */
	public static function get_extension_from_mime_extended( $mime_type ) {
		$extensions = array(
			// Images.
			'image/jpeg'    => 'jpg',
			'image/png'     => 'png',
			'image/gif'     => 'gif',
			'image/webp'    => 'webp',
			'image/avif'    => 'avif',
			'image/svg+xml' => 'svg',
			'image/heic'    => 'heic',
			'image/heif'    => 'heif',
			// Videos.
			'video/mp4'         => 'mp4',
			'video/quicktime'   => 'mov',
			'video/x-msvideo'   => 'avi',
			'video/x-ms-wmv'    => 'wmv',
			'video/mpeg'        => 'mpg',
			'video/ogg'         => 'ogv',
			'video/3gpp'        => '3gp',
			// Audio.
			'audio/mpeg'  => 'mp3',
			'audio/ogg'   => 'ogg',
			'audio/wav'   => 'wav',
			'audio/x-wav' => 'wav',
			// Documents.
			'application/pdf'  => 'pdf',
			'application/msword' => 'doc',
			'application/vnd.openxmlformats-officedocument.wordprocessingml.document' => 'docx',
			'application/vnd.ms-powerpoint' => 'ppt',
			'application/vnd.openxmlformats-officedocument.presentationml.presentation' => 'pptx',
			'application/vnd.ms-excel' => 'xls',
			'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' => 'xlsx',
			'application/vnd.oasis.opendocument.text' => 'odt',
			// Archives.
			'application/zip'    => 'zip',
			'application/x-tar'  => 'tar',
			'application/x-gzip' => 'gz',
		);

		if ( isset( $extensions[ $mime_type ] ) ) {
			return $extensions[ $mime_type ];
		}

		// Fallback to original method for backward compatibility.
		return self::get_extension_from_mime( $mime_type );
	}

}