<?php

namespace AKSRT\WidgetSystem;

defined('ABSPATH') || exit;

/**
 * Field schema defaults and recursive value normalization.
 */
final class FieldSchema {
	private const DISPLAY_ONLY = ['content', 'subheading', 'submessage'];

	public static function supported_types(): array {
		return [
			'text', 'textarea', 'number', 'spinner', 'slider', 'switcher', 'radio',
			'button_set', 'select', 'checkbox', 'color', 'palette', 'image_select', 'icon', 'upload',
			'link', 'spacing', 'background', 'group', 'fieldset', 'accordion', 'terms',
			'content', 'subheading', 'submessage',
		];
	}

	public static function defaults(array $fields): array {
		$defaults = [];
		foreach ($fields as $field) {
			$id   = (string) ($field['id'] ?? '');
			$type = (string) ($field['type'] ?? 'text');
			if ($id === '' || in_array($type, self::DISPLAY_ONLY, true)) {
				continue;
			}
			$defaults[$id] = self::normalize_value($field, $field['default'] ?? self::empty_value($type));
		}
		return $defaults;
	}

	public static function normalize(array $fields, array $input): array {
		$output = [];
		foreach ($fields as $field) {
			$id   = (string) ($field['id'] ?? '');
			$type = (string) ($field['type'] ?? 'text');
			if ($id === '' || in_array($type, self::DISPLAY_ONLY, true)) {
				continue;
			}
			$value       = array_key_exists($id, $input) ? $input[$id] : ($field['default'] ?? self::empty_value($type));
			$output[$id] = self::normalize_value($field, $value);
		}
		return $output;
	}

	public static function normalize_value(array $field, $value) {
		$type = (string) ($field['type'] ?? 'text');
		switch ($type) {
			case 'switcher':
				return filter_var($value, FILTER_VALIDATE_BOOLEAN);
			case 'number':
			case 'spinner':
			case 'slider':
				return self::number($field, $value);
			case 'radio':
			case 'button_set':
			case 'select':
			case 'palette':
			case 'image_select':
				return self::choice($field, $value);
			case 'checkbox':
				return self::checkbox($field, $value);
			case 'terms':
				return self::terms($value);
			case 'link':
				return self::link($value);
			case 'spacing':
				return self::spacing($value);
			case 'background':
				return self::background($value);
			case 'group':
				return self::group($field, $value);
			case 'fieldset':
			case 'accordion':
				return self::nested($field, $value);
			case 'upload':
				return esc_url_raw((string) $value);
			case 'color':
				return self::color((string) $value);
			case 'icon':
				return sanitize_text_field((string) $value);
			case 'textarea':
				return !empty($field['allow_html']) ? wp_kses_post((string) $value) : sanitize_textarea_field((string) $value);
			case 'text':
			default:
				if (($field['sanitize'] ?? '') === 'url') {
					return esc_url_raw((string) $value);
				}
				if (($field['sanitize'] ?? '') === 'ids') {
					return implode(',', array_values(array_unique(array_filter(array_map('absint', preg_split('/[,，\s]+/', (string) $value))))));
				}
				if (($field['sanitize'] ?? '') === 'reference_ids') {
					$tokens = preg_split('/[,，\s]+/', trim((string) $value), -1, PREG_SPLIT_NO_EMPTY);
					$tokens = array_map(static fn($token): string => preg_match('/^-?\d+$/', (string) $token) ? (string) (int) $token : '', $tokens ?: []);
					return implode(',', array_values(array_unique(array_filter($tokens, static fn($token): bool => $token !== ''))));
				}
				return !empty($field['allow_html']) ? wp_kses_post((string) $value) : sanitize_text_field((string) $value);
		}
	}

	private static function empty_value(string $type) {
		if ($type === 'switcher') {
			return false;
		}
		if (in_array($type, ['group', 'checkbox', 'terms'], true)) {
			return [];
		}
		if (in_array($type, ['link', 'spacing', 'background', 'fieldset', 'accordion'], true)) {
			return [];
		}
		return '';
	}

	private static function number(array $field, $value) {
		$number = is_numeric($value) ? (float) $value : (float) ($field['default'] ?? 0);
		if (isset($field['min'])) {
			$number = max((float) $field['min'], $number);
		}
		if (isset($field['max'])) {
			$number = min((float) $field['max'], $number);
		}
		$step = (float) ($field['step'] ?? 1);
		// Whole values stay int so JSON round trips keep normalize identity
		// even for fractional-step fields (e.g. partners speed 0.1–10s).
		return $step >= 1 || fmod($number, 1.0) === 0.0 ? (int) round($number) : $number;
	}

	private static function choice(array $field, $value) {
		$options = (array) ($field['options'] ?? []);
		if (!empty($field['multiple'])) {
			$values = is_array($value) ? $value : [];
			return array_values(array_filter(array_map('strval', $values), static fn($item) => array_key_exists($item, $options)));
		}
		$key = (string) $value;
		return array_key_exists($key, $options) ? $key : (string) ($field['default'] ?? array_key_first($options) ?? '');
	}

	private static function checkbox(array $field, $value) {
		$options = (array) ($field['options'] ?? []);
		if (!$options) {
			return filter_var($value, FILTER_VALIDATE_BOOLEAN);
		}
		$values = is_array($value) ? $value : [];
		return array_values(array_filter(array_map('strval', $values), static fn($item) => array_key_exists($item, $options)));
	}

	private static function terms($value): array {
		$values = is_array($value) ? $value : (preg_split('/[,，\s]+/', (string) $value) ?: []);
		return array_values(array_unique(array_filter(array_map('absint', $values))));
	}

	private static function link($value): array {
		$value = is_array($value) ? $value : [];
		return [
			'url'    => esc_url_raw((string) ($value['url'] ?? '')),
			'text'   => sanitize_text_field((string) ($value['text'] ?? '')),
			'target' => ($value['target'] ?? '') === '_blank' ? '_blank' : '',
		];
	}

	private static function spacing($value): array {
		$value  = is_array($value) ? $value : [];
		$result = [];
		foreach (['top', 'right', 'bottom', 'left'] as $edge) {
			$result[$edge] = isset($value[$edge]) && is_numeric($value[$edge]) ? (int) $value[$edge] : '';
		}
		return $result;
	}

	private static function background($value): array {
		$value = is_array($value) ? $value : [];
		return [
			'color'      => self::color((string) ($value['color'] ?? '')),
			'image'      => esc_url_raw((string) ($value['image'] ?? '')),
			'position'   => self::allow((string) ($value['position'] ?? 'center center'), ['center center', 'top center', 'bottom center', 'center left', 'center right'], 'center center'),
			'repeat'     => self::allow((string) ($value['repeat'] ?? 'no-repeat'), ['no-repeat', 'repeat', 'repeat-x', 'repeat-y'], 'no-repeat'),
			'attachment' => self::allow((string) ($value['attachment'] ?? 'scroll'), ['scroll', 'fixed'], 'scroll'),
			'size'       => self::allow((string) ($value['size'] ?? 'cover'), ['cover', 'contain', 'auto'], 'cover'),
		];
	}

	private static function group(array $field, $value): array {
		$rows     = is_array($value) ? array_values($value) : [];
		$max      = max(1, (int) ($field['max_items'] ?? 50));
		$children = (array) ($field['fields'] ?? []);
		return array_map(static fn($row) => self::normalize($children, is_array($row) ? $row : []), array_slice($rows, 0, $max));
	}

	private static function nested(array $field, $value): array {
		$children = (array) ($field['fields'] ?? []);
		return self::normalize($children, is_array($value) ? $value : []);
	}

	private static function color(string $value): string {
		$value = trim($value);
		if ($value === '') {
			return '';
		}
		$hex = sanitize_hex_color($value);
		if ($hex) {
			return $hex;
		}
		return preg_match('/^rgba?\(\s*\d{1,3}\s*,\s*\d{1,3}\s*,\s*\d{1,3}(?:\s*,\s*(?:0|1|0?\.\d+))?\s*\)$/', $value) ? $value : '';
	}

	private static function allow(string $value, array $allowed, string $fallback): string {
		return in_array($value, $allowed, true) ? $value : $fallback;
	}
}