<?php
// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK ]
// +----------------------------------------------------------------------
// | Copyright (c) 2006~2016 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------

namespace think\model\relation;

use think\Db;
use think\db\Query;
use think\Model;
use think\model\Relation;

class HasMany extends Relation
{
    /**
     * 架构函数
     * @access public
     * @param Model  $parent 上级模型对象
     * @param string $model 模型名
     * @param string $foreignKey 关联外键
     * @param string $localKey 关联主键
     * @param array  $alias 别名定义
     */
    public function __construct(Model $parent, $model, $foreignKey, $localKey, $alias = [])
    {
        $this->parent     = $parent;
        $this->model      = $model;
        $this->foreignKey = $foreignKey;
        $this->localKey   = $localKey;
        $this->alias      = $alias;
        $this->query      = (new $model)->db();
    }

    /**
     * 延迟获取关联数据
     * @access public
     */
    public function getRelation()
    {
        return $this->select();
    }

    /**
     * 预载入关联查询
     * @access public
     * @param array     $resultSet 数据集
     * @param string    $relation 当前关联名
     * @param string    $subRelation 子关联名
     * @param \Closure  $closure 闭包
     * @param string    $class 数据集对象名 为空表示数组
     * @return void
     */
    public function eagerlyResultSet(&$resultSet, $relation, $subRelation, $closure, $class)
    {
        $localKey   = $this->localKey;
        $foreignKey = $this->foreignKey;

        $range = [];
        foreach ($resultSet as $result) {
            // 获取关联外键列表
            if (isset($result->$localKey)) {
                $range[] = $result->$localKey;
            }
        }

        if (!empty($range)) {
            $this->where[$foreignKey] = ['in', $range];
            $data                     = $this->eagerlyOneToMany($this, [
                $foreignKey => [
                    'in',
                    $range,
                ],
            ], $relation, $subRelation, $closure);

            // 关联数据封装
            foreach ($resultSet as $result) {
                if (!isset($data[$result->$localKey])) {
                    $data[$result->$localKey] = [];
                }
                $result->setAttr($relation, $this->resultSetBuild($data[$result->$localKey], $class));
            }
        }
    }

    /**
     * 预载入关联查询
     * @access public
     * @param Model     $result 数据对象
     * @param string    $relation 当前关联名
     * @param string    $subRelation 子关联名
     * @param \Closure  $closure 闭包
     * @param string    $class 数据集对象名 为空表示数组
     * @return void
     */
    public function eagerlyResult(&$result, $relation, $subRelation, $closure, $class)
    {
        $localKey   = $this->localKey;
        $foreignKey = $this->foreignKey;

        if (isset($result->$localKey)) {
            $data = $this->eagerlyOneToMany($this, [$foreignKey => $result->$localKey], $relation, $subRelation, $closure);
            // 关联数据封装
            if (!isset($data[$result->$localKey])) {
                $data[$result->$localKey] = [];
            }
            $result->setAttr($relation, $this->resultSetBuild($data[$result->$localKey], $class));
        }
    }

    /**
     * 一对多 关联模型预查询
     * @access public
     * @param object    $model 关联模型对象
     * @param array     $where 关联预查询条件
     * @param string    $relation 关联名
     * @param string    $subRelation 子关联
     * @param bool      $closure
     * @return array
     */
    protected function eagerlyOneToMany($model, $where, $relation, $subRelation = '', $closure = false)
    {
        $foreignKey = $this->foreignKey;
        // 预载入关联查询 支持嵌套预载入
        if ($closure) {
            call_user_func_array($closure, [ & $model]);
        }
        $list = $model->where($where)->with($subRelation)->select();

        // 组装模型数据
        $data = [];
        foreach ($list as $set) {
            $data[$set->$foreignKey][] = $set;
        }
        return $data;
    }

    /**
     * 保存（新增）当前关联数据对象
     * @access public
     * @param mixed     $data 数据 可以使用数组 关联模型对象 和 关联对象的主键
     * @return integer
     */
    public function save($data)
    {
        if ($data instanceof Model) {
            $data = $data->getData();
        }
        // 保存关联表数据
        $data[$this->foreignKey] = $this->parent->{$this->localKey};
        $model                   = new $this->model;
        return $model->save($data);
    }

    /**
     * 批量保存当前关联数据对象
     * @access public
     * @param array     $dataSet 数据集
     * @return integer
     */
    public function saveAll(array $dataSet)
    {
        $result = false;
        foreach ($dataSet as $key => $data) {
            $result = $this->save($data);
        }
        return $result;
    }

    /**
     * 根据关联条件查询当前模型
     * @access public
     * @param Model     $model 模型对象
     * @param string    $operator 比较操作符
     * @param integer   $count 个数
     * @param string    $id 关联表的统计字段
     * @return Query
     */
    public function has($model, $operator = '>=', $count = 1, $id = '*')
    {
        $table = $this->query->getTable();
        return $model->db()->alias('a')
            ->join($table . ' b', 'a.' . $this->localKey . '=b.' . $this->foreignKey, $this->joinType)
            ->group('b.' . $this->foreignKey)
            ->having('count(' . $id . ')' . $operator . $count);
    }

    /**
     * 根据关联条件查询当前模型
     * @access public
     * @param Model    $model 模型对象
     * @param mixed     $where 查询条件（数组或者闭包）
     * @return Query
     */
    public function hasWhere($model, $where = [])
    {
        $table = $this->query->getTable();
        if (is_array($where)) {
            foreach ($where as $key => $val) {
                if (false === strpos($key, '.')) {
                    $where['b.' . $key] = $val;
                    unset($where[$key]);
                }
            }
        }
        return $model->db()->alias('a')
            ->field('a.*')
            ->join($table . ' b', 'a.' . $this->localKey . '=b.' . $this->foreignKey, $this->joinType)
            ->where($where);
    }

    /**
     * 执行基础查询（进执行一次）
     * @access protected
     * @return void
     */
    protected function baseQuery()
    {
        if (empty($this->baseQuery)) {
            if (isset($this->where)) {
                $this->query->where($this->where);
            } elseif (isset($this->parent->{$this->localKey})) {
                // 关联查询带入关联条件
                $this->query->where($this->foreignKey, $this->parent->{$this->localKey});
            }
            $this->baseQuery = true;
        }
    }

}
