<?php

/**
 *+------------------
 * madong
 *+------------------
 * Copyright (c) https://gitee.com/motion-code All rights reserved.
 *+------------------
 * Author: Mr. April (405784684@qq.com)
 *+------------------
 * Official Website: http://www.madong.tech
 */

namespace madong\query;

use madong\query\enum\Operator;
use madong\query\enum\QueryMode;

/**
 * 查询参数解析器
 * 支持大写前缀和标准模式双兼容
 */
class QueryParamParser
{
 /**
 * 解析查询参数
 *
 * @param array $params
 * @return array ['mode', 'conditions', 'sort', 'page', 'pageSize', 'keyword', 'raw']
 */
 public static function parse(array $params): array
 {
 // 检测模式
 $mode = self::detectMode($params);

 // 根据模式解析
 $conditions = match ($mode) {
 QueryMode::STANDARD->value => self::parseStandardMode($params),
 QueryMode::UPPERCASE->value => self::parseUppercaseMode($params),
 default => [],
 };

 // 解析排序
 $sort = self::parseSort($params);

 // 解析分页
 [$page, $pageSize] = self::parsePagination($params);

 // 提取关键词
 $keyword = self::parseKeyword($params);

 return [
 'mode' => $mode,
 'conditions' => $conditions,
 'sort' => $sort,
 'page' => $page,
 'pageSize' => $pageSize,
 'keyword' => $keyword,
 'raw' => $params,
 ];
 }

 /**
 * 检测查询模式
 *
 * @param array $params
 * @return string
 */
 public static function detectMode(array $params): string
 {
 // 优先检测标准模式
 if (isset($params['filters'])) {
 return QueryMode::STANDARD->value;
 }

 // 检测大写前缀模式
 $uppercaseMap = Operator::uppercaseMap();
 foreach (array_keys($params) as $key) {
 if (preg_match('/^(' . implode('|', array_keys($uppercaseMap)) . ')_/', $key)) {
 return QueryMode::UPPERCASE->value;
 }
 }

 // 默认使用大写前缀模式(兼容现有系统)
 return QueryMode::UPPERCASE->value;
 }

 /**
 * 解析标准模式参数
 * filters[field]=operator:value
 *
 * @param array $params
 * @return array
 */
 private static function parseStandardMode(array $params): array
 {
 $conditions = [];
 $filters = $params['filters'] ?? [];

 if (!is_array($filters)) {
 return $conditions;
 }

 foreach ($filters as $field => $value) {
 // 解析 operator:value 格式
 $parts = explode(':', $value, 2);
 $operator = $parts[0] ?? 'eq';
 $filterValue = $parts[1] ?? null;

 // 特殊处理 null 操作符
 if (in_array($operator, ['null', 'not_null'])) {
 $conditions[] = new QueryCondition($field, $operator, null);
 } else {
 $conditions[] = new QueryCondition($field, $operator, $filterValue);
 }
 }

 return $conditions;
 }

 /**
 * 解析大写前缀模式参数
 * LIKE_user_name='yhg', EQ_status=1
 * 或者三元素数组格式: [['real_name', 'LIKE', '%超级%']]
 *
 * @param array $params
 * @return array
 */
 private static function parseUppercaseMode(array $params): array
 {
 $conditions = [];
 $skipKeys = ['page', 'limit', 'pageSize', 'orderBy', 'orderDirection', 'sort', 'keyword', 'fields'];

 foreach ($params as $key => $value) {
 // 跳过非查询字段
 if (in_array($key, $skipKeys)) {
 continue;
 }

 // 处理三元素数组格式: ['field', 'operator', 'value']
 if (is_array($value) && count($value) === 3 && isset($value[0], $value[1], $value[2])) {
 $field = $value[0];
 $operator = strtolower($value[1]);
 $filterValue = $value[2];

 $conditions[] = new QueryCondition($field, $operator, $filterValue);
 continue;
 }

 // 匹配大写前缀格式:操作符_字段
 if (preg_match('/^([A-Z]+)_(.+)$/', $key, $matches)) {
 $operatorUpper = $matches[1];
 $field = $matches[2];

 // 转换操作符
 $uppercaseMap = Operator::uppercaseMap();
 $operator = $uppercaseMap[$operatorUpper] ?? 'eq';

 $conditions[] = new QueryCondition($field, $operator, $value);
 } else {
 // 普通字段默认使用 eq 操作符
 $conditions[] = new QueryCondition($key, 'eq', $value);
 }
 }

 return $conditions;
 }

 /**
 * 解析排序参数
 *
 * @param array $params
 * @return array
 */
 private static function parseSort(array $params): array
 {
 $sort = [];

 // 标准模式:sort=field:direction 或 sort[]=field:direction
 if (isset($params['sort'])) {
 $sortParams = is_array($params['sort']) ? $params['sort'] : [$params['sort']];
 foreach ($sortParams as $sortParam) {
 $parts = explode(':', $sortParam);
 $field = $parts[0] ?? 'id';
 $direction = $parts[1] ?? 'desc';
 $sort[] = ['field' => $field, 'direction' => strtolower($direction)];
 }
 }

 // 大写前缀模式:orderBy & orderDirection
 elseif (isset($params['orderBy'])) {
 $sort[] = [
 'field' => $params['orderBy'],
 'direction' => ($params['orderDirection'] ?? 'desc')
 ];
 }

 // 默认排序
 if (empty($sort)) {
 $sort[] = ['field' => 'id', 'direction' => 'desc'];
 }

 return $sort;
 }

 /**
 * 解析分页参数
 *
 * @param array $params
 * @return array [page, pageSize]
 */
 private static function parsePagination(array $params): array
 {
 $page = (int)($params['page'] ?? 1);
 $pageSize = (int)($params['limit'] ?? $params['pageSize'] ?? 20);

 return [$page, max(1, min($pageSize, 100))];
 }

 /**
 * 解析关键词
 *
 * @param array $params
 * @return string|null
 */
 private static function parseKeyword(array $params): ?string
 {
 return $params['keyword'] ?? null;
 }

 /**
 * 验证操作符是否有效
 *
 * @param string $operator
 * @return bool
 */
 public static function isValidOperator(string $operator): bool
 {
 return Operator::isValid($operator);
 }

 /**
 * 获取所有支持的操作符
 *
 * @return array
 */
 public static function getSupportedOperators(): array
 {
 return Operator::all();
 }
}