<?php
/**
 * TMDO_Type_Caster - 型別轉換器
 *
 * 負責：
 * - PHP → DB 序列化（寫入）
 * - DB → PHP 反序列化（讀取）
 * - wpdb format string 生成
 * - 型別驗證與清理
 *
 * @package WP_Data_Optimizer
 */

declare(strict_types=1);

// phpcs:disable Squiz.Commenting,Generic.Commenting,WordPress.DB.PreparedSQL.NotPrepared,WordPress.DB.PreparedSQL.InterpolatedNotPrepared,WordPress.DB.PreparedSQLPlaceholders.ReplacementsWrongNumber,Generic.CodeAnalysis.UnusedFunctionParameter,Generic.CodeAnalysis.EmptyStatement,Squiz.PHP.DisallowMultipleAssignments,Squiz.PHP.DisallowSizeFunctionsInLoops,WordPress.WP.I18n.MissingTranslatorsComment,WordPress.PHP.NoSilencedErrors,WordPress.WP.AlternativeFunctions.file_get_contents_file_get_contents,Squiz.PHP.CommentedOutCode,Universal.NamingConventions.NoReservedKeywordParameterNames,WordPress.PHP.YodaConditions,Squiz.Commenting.InlineComment.InvalidEndChar -- PR-1 ported from UAE; cleanup PR scheduled.


defined( 'ABSPATH' ) || exit;

final class TMDO_Type_Caster {

	/**
	 * PHP → DB 轉換（寫入）
	 */
	public static function to_db( $value, array $field_def ) {
		$type = $field_def['type'] ?? 'text';

		// null 值處理
		if ( $value === null ) {
			if ( ! empty( $field_def['required'] ) ) {
				return $field_def['default'] ?? '';
			}
			return null;
		}

		switch ( $type ) {
			case 'integer':
				return (int) $value;

			case 'decimal':
				return (float) $value;

			case 'boolean':
				return self::to_bool( $value ) ? 1 : 0;

			case 'date':
				return self::format_date( $value, 'Y-m-d' );

			case 'datetime':
			case 'timestamp':
				return self::format_date( $value, 'Y-m-d H:i:s' );

			case 'json':
				if ( is_string( $value ) ) {
					// 若已是 JSON 字串則直接儲存（驗證後）
					$decoded = json_decode( $value, true );
					if ( json_last_error() === JSON_ERROR_NONE ) {
						return $value;
					}
				}
				return wp_json_encode( $value, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES );

			case 'enum':
				$options = $field_def['options'] ?? array();
				$str     = (string) $value;
				return ( ! empty( $options ) && in_array( $str, $options, true ) ) ? $str : ( $field_def['default'] ?? '' );

			case 'binary':
				return $value;

			case 'text':
				return self::fit_text( is_scalar( $value ) ? (string) $value : maybe_serialize( $value ), $field_def );

			case 'textarea':
				// Arrays / objects are serialized like WP stores them in native meta;
				// (string) would store the literal "Array".
				return is_scalar( $value ) ? (string) $value : maybe_serialize( $value );

			default:
				// 未知型別：嘗試序列化（向後相容 WordPress get_metadata 行為）
				return maybe_serialize( $value );
		}
	}

	/** 'text' columns are VARCHAR(255) (TMDO_Schema_Manager type map). */
	public const TEXT_MAX_CHARS = 255;

	/**
	 * Keep a text value only if it fits its VARCHAR(255) column; otherwise
	 * store NULL (native meta keeps the full value) and log the overflow.
	 *
	 * @param string               $value     Value to store.
	 * @param array<string, mixed> $field_def Field definition.
	 * @return string|null
	 */
	private static function fit_text( string $value, array $field_def ): ?string {
		$length = mb_strlen( $value );
		if ( $length <= self::TEXT_MAX_CHARS ) {
			return $value;
		}
		TMDO_Logger::warning(
			'text_overflow',
			array(
				'group'  => $field_def['group'] ?? '',
				'key'    => $field_def['key'] ?? '',
				'length' => $length,
			)
		);
		return null;
	}

	/**
	 * DB → PHP 轉換（讀取）
	 */
	public static function from_db( $value, array $field_def ) {
		$type = $field_def['type'] ?? 'text';

		if ( $value === null ) {
			return null;
		}

		switch ( $type ) {
			case 'integer':
				return (int) $value;

			case 'decimal':
				return (float) $value;

			case 'boolean':
				return (bool) (int) $value;

			case 'date':
			case 'datetime':
			case 'timestamp':
				return (string) $value;

			case 'json':
				$decoded = json_decode( (string) $value, true );
				return ( json_last_error() === JSON_ERROR_NONE ) ? $decoded : $value;

			case 'enum':
				return (string) $value;

			case 'text':
			case 'textarea':
				// Arrays were stored serialized (to_db); plain strings pass through.
				return TMDO_Safe_Unserialize::run( (string) $value );

			default:
				// v2.13.3: object-injection-safe unserialize (fixes L-DESER-1).
				return TMDO_Safe_Unserialize::run( $value );
		}
	}

	/**
	 * wpdb format 字串（%s / %d / %f）
	 */
	public static function get_wpdb_format( string $type ): string {
		return match ( $type ) {
			'integer', 'boolean' => '%d',
			'decimal'            => '%f',
			default              => '%s',
		};
	}

	// ─────────────────────────────────────────────────────────
	// 工具方法
	// ─────────────────────────────────────────────────────────

	private static function to_bool( $value ): bool {
		if ( is_bool( $value ) ) {
			return $value;
		}
		if ( is_numeric( $value ) ) {
			return (int) $value !== 0;
		}
		$str = strtolower( trim( (string) $value ) );
		return in_array( $str, array( 'true', 'yes', 'y', '1', 'on' ), true );
	}

	private static function format_date( $value, string $format ): ?string {
		if ( $value === '' || $value === null ) {
			return null;
		}

		// 接受 Unix timestamp
		if ( is_numeric( $value ) ) {
			return gmdate( $format, (int) $value );
		}

		$ts = strtotime( (string) $value );
		if ( $ts === false ) {
			return null;
		}

		return gmdate( $format, $ts );
	}
}