<?php
/**
 * Cleaning of the values of schema fields.
 *
 * @package ElevenRank
 * @since   1.0.0
 */

namespace ElevenRank\Modules\Schema;

use DateTimeImmutable;
use ElevenRank\Sanitize;

defined( 'ABSPATH' ) || exit;

/**
 * Turns what was typed into a value that is safe to print, or an empty string.
 *
 * Kinds: `text`, `textarea`, `url`, `date` (YYYY-MM-DD), `datetime` (ISO 8601; a time without a zone is
 * read in the site's zone), `integer`, `decimal`, `currency` (three capital letters), `country` (two
 * capital letters), `gtin` (8, 12, 13 or 14 digits), `select`, `lines` (one value per line) and
 * `image` (an attachment id). Anything that does not fit becomes an empty string, so a wrong entry
 * is left out of the markup instead of being printed.
 *
 * @since 1.0.0
 */
final class Field_Values {

	/**
	 * Most lines kept in a `lines` field.
	 *
	 * @since 1.0.0
	 *
	 * @var int
	 */
	const MAX_LINES = 50;

	/**
	 * Cleans one value for a field definition.
	 *
	 * @since 1.0.0
	 *
	 * @param array<string, mixed> $field Field definition.
	 * @param mixed                $value Raw value.
	 * @return string|int Empty string when there is nothing valid; an integer for `image`.
	 */
	public static function clean( array $field, $value ) {
		if ( is_array( $value ) || is_object( $value ) ) {
			return '';
		}

		$value = is_bool( $value ) ? '' : trim( (string) $value );
		$max   = isset( $field['max'] ) ? (int) $field['max'] : 0;

		switch ( (string) $field['kind'] ) {
			case 'text':
				return Sanitize::text( $value, $max );

			case 'textarea':
				return self::textarea( $value, $max );

			case 'lines':
				return self::lines( $value );

			case 'url':
				return Sanitize::url( $value );

			case 'date':
				return self::date( $value );

			case 'datetime':
				return self::datetime( $value );

			case 'integer':
				return self::integer( $value, $field );

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

			case 'currency':
				return 1 === preg_match( '/^[A-Za-z]{3}$/', $value ) ? strtoupper( $value ) : '';

			case 'country':
				return 1 === preg_match( '/^[A-Za-z]{2}$/', $value ) ? strtoupper( $value ) : '';

			case 'gtin':
				$digits = (string) preg_replace( '/[\s-]+/', '', $value );

				return 1 === preg_match( '/^(\d{8}|\d{12,14})$/', $digits ) ? $digits : '';

			case 'select':
				return isset( $field['options'] ) && is_array( $field['options'] ) && array_key_exists( $value, $field['options'] ) ? $value : '';

			case 'image':
				return is_numeric( $value ) ? max( 0, (int) $value ) : 0;
		}

		return '';
	}

	/**
	 * The lines of a `lines` value, cleaned.
	 *
	 * @since 1.0.0
	 *
	 * @param string $value Stored value.
	 * @return string[]
	 */
	public static function split_lines( string $value ): array {
		$lines = array();

		$parts = preg_split( '/\r\n|\r|\n/', $value );

		foreach ( is_array( $parts ) ? $parts : array() as $line ) {
			$line = Sanitize::text( $line, 500 );

			if ( '' !== $line ) {
				$lines[] = $line;
			}

			if ( count( $lines ) >= self::MAX_LINES ) {
				break;
			}
		}

		return $lines;
	}

	/**
	 * Minutes as an ISO 8601 duration, such as `PT1H30M`.
	 *
	 * @since 1.0.0
	 *
	 * @param int $minutes Minutes.
	 * @return string Empty for zero or less.
	 */
	public static function duration_from_minutes( int $minutes ): string {
		if ( $minutes < 1 ) {
			return '';
		}

		$hours = intdiv( $minutes, 60 );
		$rest  = $minutes % 60;

		return 'PT' . ( $hours > 0 ? $hours . 'H' : '' ) . ( $rest > 0 ? $rest . 'M' : '' );
	}

	/**
	 * Seconds as an ISO 8601 duration, such as `PT1M30S`.
	 *
	 * @since 1.0.0
	 *
	 * @param int $seconds Seconds.
	 * @return string Empty for zero or less.
	 */
	public static function duration_from_seconds( int $seconds ): string {
		if ( $seconds < 1 ) {
			return '';
		}

		$hours   = intdiv( $seconds, 3600 );
		$minutes = intdiv( $seconds % 3600, 60 );
		$rest    = $seconds % 60;

		return 'PT' . ( $hours > 0 ? $hours . 'H' : '' ) . ( $minutes > 0 ? $minutes . 'M' : '' ) . ( $rest > 0 ? $rest . 'S' : '' );
	}

	/**
	 * Plain text with line breaks kept.
	 *
	 * @since 1.0.0
	 *
	 * @param string $value Raw value.
	 * @param int    $max   Longest accepted value; 0 for no limit.
	 * @return string
	 */
	private static function textarea( string $value, int $max ): string {
		$value = sanitize_textarea_field( $value );

		if ( $max > 0 && mb_strlen( $value ) > $max ) {
			$value = mb_substr( $value, 0, $max );
		}

		return $value;
	}

	/**
	 * Lines of text, kept as one string with line breaks.
	 *
	 * @since 1.0.0
	 *
	 * @param string $value Raw value.
	 * @return string
	 */
	private static function lines( string $value ): string {
		return implode( "\n", self::split_lines( $value ) );
	}

	/**
	 * A calendar date.
	 *
	 * @since 1.0.0
	 *
	 * @param string $value Raw value.
	 * @return string `YYYY-MM-DD` or empty.
	 */
	private static function date( string $value ): string {
		$date = DateTimeImmutable::createFromFormat( '!Y-m-d', substr( $value, 0, 10 ) );

		if ( false === $date || $date->format( 'Y-m-d' ) !== substr( $value, 0, 10 ) ) {
			return '';
		}

		return $date->format( 'Y-m-d' );
	}

	/**
	 * A date and time as ISO 8601 with a time zone offset.
	 *
	 * @since 1.0.0
	 *
	 * @param string $value Raw value, such as `2026-11-01T19:00`, `2026-11-01 19:00:00` or `2026-11-01T19:00:00+01:00`.
	 * @return string
	 */
	private static function datetime( string $value ): string {
		if ( 1 !== preg_match( '/^(\d{4}-\d{2}-\d{2})[T ](\d{2}):(\d{2})(?::(\d{2}))?(?:\.\d+)?(Z|[+-]\d{2}:?\d{2})?$/', $value, $parts ) ) {
			return self::date( $value );
		}

		if ( '' === self::date( $parts[1] ) || (int) $parts[2] > 23 || (int) $parts[3] > 59 || ( isset( $parts[4] ) && '' !== $parts[4] && (int) $parts[4] > 59 ) ) {
			return '';
		}

		$time = $parts[2] . ':' . $parts[3] . ':' . ( isset( $parts[4] ) && '' !== $parts[4] ? $parts[4] : '00' );
		$zone = isset( $parts[5] ) ? (string) $parts[5] : '';

		if ( 'Z' === $zone ) {
			$zone = '+00:00';
		} elseif ( '' === $zone ) {
			$zone = wp_timezone()->getOffset( new DateTimeImmutable( $parts[1] . 'T' . $time, wp_timezone() ) );
			$sign = $zone < 0 ? '-' : '+';
			$zone = $sign . gmdate( 'H:i', abs( (int) $zone ) );
		} elseif ( false === strpos( $zone, ':' ) ) {
			$zone = substr( $zone, 0, 3 ) . ':' . substr( $zone, 3 );
		}

		return $parts[1] . 'T' . $time . $zone;
	}

	/**
	 * A whole number within the limits of the field.
	 *
	 * @since 1.0.0
	 *
	 * @param string               $value Raw value.
	 * @param array<string, mixed> $field Field definition (`min`, `max`).
	 * @return string The number as text, or empty.
	 */
	private static function integer( string $value, array $field ): string {
		if ( 1 !== preg_match( '/^\d{1,9}$/', $value ) ) {
			return '';
		}

		$number = (int) $value;

		if ( isset( $field['min'] ) && $number < (int) $field['min'] ) {
			return '';
		}

		if ( isset( $field['max'] ) && $number > (int) $field['max'] ) {
			return '';
		}

		return (string) $number;
	}

	/**
	 * A decimal number with a dot, such as a price.
	 *
	 * @since 1.0.0
	 *
	 * @param string $value Raw value.
	 * @return string
	 */
	private static function decimal( string $value ): string {
		$value = str_replace( ',', '.', $value );

		if ( 1 !== preg_match( '/^\d{1,9}(\.\d{1,4})?$/', $value ) ) {
			return '';
		}

		return $value;
	}
}