/*
 * Copyright (c) 2011-2024, baomidou (jobob@qq.com).
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.baomidou.mybatisplus.core.conditions.query;

import com.baomidou.mybatisplus.core.conditions.AbstractLambdaWrapper;
import com.baomidou.mybatisplus.core.conditions.SharedString;
import com.baomidou.mybatisplus.core.conditions.segments.MergeSegments;
import com.baomidou.mybatisplus.core.metadata.TableFieldInfo;
import com.baomidou.mybatisplus.core.metadata.TableInfoHelper;
import com.baomidou.mybatisplus.core.toolkit.Assert;
import com.baomidou.mybatisplus.core.toolkit.CollectionUtils;
import com.baomidou.mybatisplus.core.toolkit.support.SFunction;

import java.util.List;
import java.util.Map;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.function.Predicate;

/**
 * Lambda 语法使用 Wrapper
 *
 * @author hubin miemie HCL
 * @since 2017-05-26
 */
public class LambdaQueryWrapper<T> extends AbstractLambdaWrapper<T, LambdaQueryWrapper<T>>
    implements Query<LambdaQueryWrapper<T>, T, SFunction<T, ?>> {

    /**
     * 查询字段
     */
    private SharedString sqlSelect = new SharedString();

    public LambdaQueryWrapper() {
        this((T) null);
    }

    public LambdaQueryWrapper(T entity) {
        super.setEntity(entity);
        super.initNeed();
    }

    public LambdaQueryWrapper(Class<T> entityClass) {
        super.setEntityClass(entityClass);
        super.initNeed();
    }

    LambdaQueryWrapper(T entity, Class<T> entityClass, SharedString sqlSelect, AtomicInteger paramNameSeq,
                       Map<String, Object> paramNameValuePairs, MergeSegments mergeSegments, SharedString paramAlias,
                       SharedString lastSql, SharedString sqlComment, SharedString sqlFirst) {
        super.setEntity(entity);
        super.setEntityClass(entityClass);
        this.paramNameSeq = paramNameSeq;
        this.paramNameValuePairs = paramNameValuePairs;
        this.expression = mergeSegments;
        this.sqlSelect = sqlSelect;
        this.paramAlias = paramAlias;
        this.lastSql = lastSql;
        this.sqlComment = sqlComment;
        this.sqlFirst = sqlFirst;
    }

    @Override
    public LambdaQueryWrapper<T> select(boolean condition, List<SFunction<T, ?>> columns) {
        return doSelect(condition, columns);
    }

    /**
     * 过滤查询的字段信息(主键除外!)
     * <p>例1: 只要 java 字段名以 "test" 开头的             -> select(i -&gt; i.getProperty().startsWith("test"))</p>
     * <p>例2: 只要 java 字段属性是 CharSequence 类型的     -> select(TableFieldInfo::isCharSequence)</p>
     * <p>例3: 只要 java 字段没有填充策略的                 -> select(i -&gt; i.getFieldFill() == FieldFill.DEFAULT)</p>
     * <p>例4: 要全部字段                                   -> select(i -&gt; true)</p>
     * <p>例5: 只要主键字段                                 -> select(i -&gt; false)</p>
     *
     * @param predicate 过滤方式
     * @return this
     */
    @Override
    public LambdaQueryWrapper<T> select(Class<T> entityClass, Predicate<TableFieldInfo> predicate) {
        if (entityClass == null) {
            entityClass = getEntityClass();
        } else {
            setEntityClass(entityClass);
        }
        Assert.notNull(entityClass, "entityClass can not be null");
        this.sqlSelect.setStringValue(TableInfoHelper.getTableInfo(entityClass).chooseSelect(predicate));
        return typedThis;
    }

    @Override
    @SafeVarargs
    public final LambdaQueryWrapper<T> select(SFunction<T, ?>... columns) {
        return doSelect(true, CollectionUtils.toList(columns));
    }

    @Override
    @SafeVarargs
    public final LambdaQueryWrapper<T> select(boolean condition, SFunction<T, ?>... columns) {
        return doSelect(condition, CollectionUtils.toList(columns));
    }

    /**
     * @since 3.5.4
     */
    protected LambdaQueryWrapper<T> doSelect(boolean condition, List<SFunction<T, ?>> columns) {
        if (condition && CollectionUtils.isNotEmpty(columns)) {
            this.sqlSelect.setStringValue(columnsToString(false, columns));
        }
        return typedThis;
    }

    @Override
    public String getSqlSelect() {
        return sqlSelect.getStringValue();
    }

    /**
     * 用于生成嵌套 sql
     * <p>故 sqlSelect 不向下传递</p>
     */
    @Override
    protected LambdaQueryWrapper<T> instance() {
        return new LambdaQueryWrapper<>(getEntity(), getEntityClass(), null, paramNameSeq, paramNameValuePairs,
            new MergeSegments(), paramAlias, SharedString.emptyString(), SharedString.emptyString(), SharedString.emptyString());
    }

    @Override
    public void clear() {
        super.clear();
        sqlSelect.toNull();
    }
}
