<?php
// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK ]
// +----------------------------------------------------------------------
// | Copyright (c) 2006~2018 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------

namespace think\model\concern;

use think\Collection;
use think\db\Query;
use think\Exception;
use think\Loader;
use think\Model;
use think\model\Relation;
use think\model\relation\BelongsTo;
use think\model\relation\BelongsToMany;
use think\model\relation\HasMany;
use think\model\relation\HasManyThrough;
use think\model\relation\HasOne;
use think\model\relation\MorphMany;
use think\model\relation\MorphOne;
use think\model\relation\MorphTo;

/**
 * 模型关联处理
 */
trait RelationShip
{
    /**
     * 父关联模型对象
     * @var object
     */
    private $parent;

    /**
     * 模型关联数据
     * @var array
     */
    private $relation = [];

    /**
     * 关联写入定义信息
     * @var array
     */
    private $together;

    /**
     * 关联自动写入信息
     * @var array
     */
    protected $relationWrite;

    /**
     * 设置父关联对象
     * @access public
     * @param  Model $model  模型对象
     * @return $this
     */
    public function setParent($model)
    {
        $this->parent = $model;

        return $this;
    }

    /**
     * 获取父关联对象
     * @access public
     * @return Model
     */
    public function getParent()
    {
        return $this->parent;
    }

    /**
     * 获取当前模型的关联模型数据
     * @access public
     * @param  string $name 关联方法名
     * @return mixed
     */
    public function getRelation($name = null)
    {
        if (is_null($name)) {
            return $this->relation;
        } elseif (array_key_exists($name, $this->relation)) {
            return $this->relation[$name];
        }
        return;
    }

    /**
     * 设置关联数据对象值
     * @access public
     * @param  string $name  属性名
     * @param  mixed  $value 属性值
     * @param  array  $data  数据
     * @return $this
     */
    public function setRelation($name, $value, $data = [])
    {
        // 检测修改器
        $method = 'set' . Loader::parseName($name, 1) . 'Attr';

        if (method_exists($this, $method)) {
            $value = $this->$method($value, array_merge($this->data, $data));
        }

        $this->relation[$name] = $value;

        return $this;
    }

    /**
     * 绑定（一对一）关联属性到当前模型
     * @access protected
     * @param  string   $relation    关联名称
     * @param  array    $attrs       绑定属性
     * @return $this
     * @throws Exception
     */
    public function bindAttr($relation, array $attrs = [])
    {
        $relation = $this->getRelation($relation);

        foreach ($attrs as $key => $attr) {
            $key   = is_numeric($key) ? $attr : $key;
            $value = $this->getOrigin($key);

            if (!is_null($value)) {
                throw new Exception('bind attr has exists:' . $key);
            }

            $this->setAttr($key, $relation ? $relation->getAttr($attr) : null);
        }

        return $this;
    }

    /**
     * 关联数据写入
     * @access public
     * @param  array|string $relation 关联
     * @return $this
     */
    public function together($relation)
    {
        if (is_string($relation)) {
            $relation = explode(',', $relation);
        }

        $this->together = $relation;

        $this->checkAutoRelationWrite();

        return $this;
    }

    /**
     * 根据关联条件查询当前模型
     * @access public
     * @param  string  $relation 关联方法名
     * @param  mixed   $operator 比较操作符
     * @param  integer $count    个数
     * @param  string  $id       关联表的统计字段
     * @param  string  $joinType JOIN类型
     * @return Query
     */
    public static function has($relation, $operator = '>=', $count = 1, $id = '*', $joinType = 'INNER')
    {
        $relation = (new static())->$relation();

        if (is_array($operator) || $operator instanceof \Closure) {
            return $relation->hasWhere($operator);
        }

        return $relation->has($operator, $count, $id, $joinType);
    }

    /**
     * 根据关联条件查询当前模型
     * @access public
     * @param  string $relation 关联方法名
     * @param  mixed  $where    查询条件（数组或者闭包）
     * @param  mixed  $fields   字段
     * @return Query
     */
    public static function hasWhere($relation, $where = [], $fields = '*')
    {
        return (new static())->$relation()->hasWhere($where, $fields);
    }

    /**
     * 查询当前模型的关联数据
     * @access public
     * @param  string|array $relations          关联名
     * @param  array        $withRelationAttr   关联获取器
     * @return $this
     */
    public function relationQuery($relations, $withRelationAttr = [])
    {
        if (is_string($relations)) {
            $relations = explode(',', $relations);
        }

        foreach ($relations as $key => $relation) {
            $subRelation = '';
            $closure     = null;

            if ($relation instanceof \Closure) {
                // 支持闭包查询过滤关联条件
                $closure  = $relation;
                $relation = $key;
            }

            if (is_array($relation)) {
                $subRelation = $relation;
                $relation    = $key;
            } elseif (strpos($relation, '.')) {
                list($relation, $subRelation) = explode('.', $relation, 2);
            }

            $method       = Loader::parseName($relation, 1, false);
            $relationName = Loader::parseName($relation);

            $relationResult = $this->$method();

            if (isset($withRelationAttr[$relationName])) {
                $relationResult->getQuery()->withAttr($withRelationAttr[$relationName]);
            }

            $this->relation[$relation] = $relationResult->getRelation($subRelation, $closure);
        }

        return $this;
    }

    /**
     * 预载入关联查询 返回数据集
     * @access public
     * @param  array  $resultSet        数据集
     * @param  string $relation         关联名
     * @param  array  $withRelationAttr 关联获取器
     * @param  bool   $join             是否为JOIN方式
     * @return array
     */
    public function eagerlyResultSet(&$resultSet, $relation, $withRelationAttr = [], $join = false)
    {
        $relations = is_string($relation) ? explode(',', $relation) : $relation;

        foreach ($relations as $key => $relation) {
            $subRelation = '';
            $closure     = null;

            if ($relation instanceof \Closure) {
                $closure  = $relation;
                $relation = $key;
            }

            if (is_array($relation)) {
                $subRelation = $relation;
                $relation    = $key;
            } elseif (strpos($relation, '.')) {
                list($relation, $subRelation) = explode('.', $relation, 2);
            }

            $relation     = Loader::parseName($relation, 1, false);
            $relationName = Loader::parseName($relation);

            $relationResult = $this->$relation();

            if (isset($withRelationAttr[$relationName])) {
                $relationResult->getQuery()->withAttr($withRelationAttr[$relationName]);
            }

            $relationResult->eagerlyResultSet($resultSet, $relation, $subRelation, $closure, $join);
        }
    }

    /**
     * 预载入关联查询 返回模型对象
     * @access public
     * @param  Model  $result           数据对象
     * @param  string $relation         关联名
     * @param  array  $withRelationAttr 关联获取器
     * @param  bool   $join             是否为JOIN方式
     * @return Model
     */
    public function eagerlyResult(&$result, $relation, $withRelationAttr = [], $join = false)
    {
        $relations = is_string($relation) ? explode(',', $relation) : $relation;

        foreach ($relations as $key => $relation) {
            $subRelation = '';
            $closure     = null;

            if ($relation instanceof \Closure) {
                $closure  = $relation;
                $relation = $key;
            }

            if (is_array($relation)) {
                $subRelation = $relation;
                $relation    = $key;
            } elseif (strpos($relation, '.')) {
                list($relation, $subRelation) = explode('.', $relation, 2);
            }

            $relation     = Loader::parseName($relation, 1, false);
            $relationName = Loader::parseName($relation);

            $relationResult = $this->$relation();

            if (isset($withRelationAttr[$relationName])) {
                $relationResult->getQuery()->withAttr($withRelationAttr[$relationName]);
            }

            $relationResult->eagerlyResult($result, $relation, $subRelation, $closure, $join);
        }
    }

    /**
     * 关联统计
     * @access public
     * @param  Model    $result     数据对象
     * @param  array    $relations  关联名
     * @param  string   $aggregate  聚合查询方法
     * @param  string   $field      字段
     * @return void
     */
    public function relationCount(&$result, $relations, $aggregate = 'sum', $field = '*')
    {
        foreach ($relations as $key => $relation) {
            $closure = $name = null;

            if ($relation instanceof \Closure) {
                $closure  = $relation;
                $relation = $key;
            } elseif (is_string($key)) {
                $name     = $relation;
                $relation = $key;
            }

            $relation = Loader::parseName($relation, 1, false);

            $count = $this->$relation()->relationCount($result, $closure, $aggregate, $field, $name);

            if (empty($name)) {
                $name = Loader::parseName($relation) . '_' . $aggregate;
            }

            $result->setAttr($name, $count);
        }
    }

    /**
     * HAS ONE 关联定义
     * @access public
     * @param  string $model      模型名
     * @param  string $foreignKey 关联外键
     * @param  string $localKey   当前主键
     * @return HasOne
     */
    public function hasOne($model, $foreignKey = '', $localKey = '')
    {
        // 记录当前关联信息
        $model      = $this->parseModel($model);
        $localKey   = $localKey ?: $this->getPk();
        $foreignKey = $foreignKey ?: $this->getForeignKey($this->name);

        return new HasOne($this, $model, $foreignKey, $localKey);
    }

    /**
     * BELONGS TO 关联定义
     * @access public
     * @param  string $model      模型名
     * @param  string $foreignKey 关联外键
     * @param  string $localKey   关联主键
     * @return BelongsTo
     */
    public function belongsTo($model, $foreignKey = '', $localKey = '')
    {
        // 记录当前关联信息
        $model      = $this->parseModel($model);
        $foreignKey = $foreignKey ?: $this->getForeignKey((new $model)->getName());
        $localKey   = $localKey ?: (new $model)->getPk();
        $trace      = debug_backtrace(false, 2);
        $relation   = Loader::parseName($trace[1]['function']);

        return new BelongsTo($this, $model, $foreignKey, $localKey, $relation);
    }

    /**
     * HAS MANY 关联定义
     * @access public
     * @param  string $model      模型名
     * @param  string $foreignKey 关联外键
     * @param  string $localKey   当前主键
     * @return HasMany
     */
    public function hasMany($model, $foreignKey = '', $localKey = '')
    {
        // 记录当前关联信息
        $model      = $this->parseModel($model);
        $localKey   = $localKey ?: $this->getPk();
        $foreignKey = $foreignKey ?: $this->getForeignKey($this->name);

        return new HasMany($this, $model, $foreignKey, $localKey);
    }

    /**
     * HAS MANY 远程关联定义
     * @access public
     * @param  string $model      模型名
     * @param  string $through    中间模型名
     * @param  string $foreignKey 关联外键
     * @param  string $throughKey 关联外键
     * @param  string $localKey   当前主键
     * @return HasManyThrough
     */
    public function hasManyThrough($model, $through, $foreignKey = '', $throughKey = '', $localKey = '')
    {
        // 记录当前关联信息
        $model      = $this->parseModel($model);
        $through    = $this->parseModel($through);
        $localKey   = $localKey ?: $this->getPk();
        $foreignKey = $foreignKey ?: $this->getForeignKey($this->name);
        $throughKey = $throughKey ?: $this->getForeignKey((new $through)->getName());

        return new HasManyThrough($this, $model, $through, $foreignKey, $throughKey, $localKey);
    }

    /**
     * BELONGS TO MANY 关联定义
     * @access public
     * @param  string $model      模型名
     * @param  string $table      中间表名
     * @param  string $foreignKey 关联外键
     * @param  string $localKey   当前模型关联键
     * @return BelongsToMany
     */
    public function belongsToMany($model, $table = '', $foreignKey = '', $localKey = '')
    {
        // 记录当前关联信息
        $model      = $this->parseModel($model);
        $name       = Loader::parseName(basename(str_replace('\\', '/', $model)));
        $table      = $table ?: Loader::parseName($this->name) . '_' . $name;
        $foreignKey = $foreignKey ?: $name . '_id';
        $localKey   = $localKey ?: $this->getForeignKey($this->name);

        return new BelongsToMany($this, $model, $table, $foreignKey, $localKey);
    }

    /**
     * MORPH  One 关联定义
     * @access public
     * @param  string       $model 模型名
     * @param  string|array $morph 多态字段信息
     * @param  string       $type  多态类型
     * @return MorphOne
     */
    public function morphOne($model, $morph = null, $type = '')
    {
        // 记录当前关联信息
        $model = $this->parseModel($model);

        if (is_null($morph)) {
            $trace = debug_backtrace(false, 2);
            $morph = Loader::parseName($trace[1]['function']);
        }

        if (is_array($morph)) {
            list($morphType, $foreignKey) = $morph;
        } else {
            $morphType  = $morph . '_type';
            $foreignKey = $morph . '_id';
        }

        $type = $type ?: get_class($this);

        return new MorphOne($this, $model, $foreignKey, $morphType, $type);
    }

    /**
     * MORPH  MANY 关联定义
     * @access public
     * @param  string       $model 模型名
     * @param  string|array $morph 多态字段信息
     * @param  string       $type  多态类型
     * @return MorphMany
     */
    public function morphMany($model, $morph = null, $type = '')
    {
        // 记录当前关联信息
        $model = $this->parseModel($model);

        if (is_null($morph)) {
            $trace = debug_backtrace(false, 2);
            $morph = Loader::parseName($trace[1]['function']);
        }

        $type = $type ?: get_class($this);

        if (is_array($morph)) {
            list($morphType, $foreignKey) = $morph;
        } else {
            $morphType  = $morph . '_type';
            $foreignKey = $morph . '_id';
        }

        return new MorphMany($this, $model, $foreignKey, $morphType, $type);
    }

    /**
     * MORPH TO 关联定义
     * @access public
     * @param  string|array $morph 多态字段信息
     * @param  array        $alias 多态别名定义
     * @return MorphTo
     */
    public function morphTo($morph = null, $alias = [])
    {
        $trace    = debug_backtrace(false, 2);
        $relation = Loader::parseName($trace[1]['function']);

        if (is_null($morph)) {
            $morph = $relation;
        }

        // 记录当前关联信息
        if (is_array($morph)) {
            list($morphType, $foreignKey) = $morph;
        } else {
            $morphType  = $morph . '_type';
            $foreignKey = $morph . '_id';
        }

        return new MorphTo($this, $morphType, $foreignKey, $alias, $relation);
    }

    /**
     * 解析模型的完整命名空间
     * @access protected
     * @param  string $model 模型名（或者完整类名）
     * @return string
     */
    protected function parseModel($model)
    {
        if (false === strpos($model, '\\')) {
            $path = explode('\\', static::class);
            array_pop($path);
            array_push($path, Loader::parseName($model, 1));
            $model = implode('\\', $path);
        }

        return $model;
    }

    /**
     * 获取模型的默认外键名
     * @access protected
     * @param  string $name 模型名
     * @return string
     */
    protected function getForeignKey($name)
    {
        if (strpos($name, '\\')) {
            $name = basename(str_replace('\\', '/', $name));
        }

        return Loader::parseName($name) . '_id';
    }

    /**
     * 检查属性是否为关联属性 如果是则返回关联方法名
     * @access protected
     * @param  string $attr 关联属性名
     * @return string|false
     */
    protected function isRelationAttr($attr)
    {
        $relation = Loader::parseName($attr, 1, false);

        if (method_exists($this, $relation) && !method_exists('think\Model', $relation)) {
            return $relation;
        }

        return false;
    }

    /**
     * 智能获取关联模型数据
     * @access protected
     * @param  Relation  $modelRelation 模型关联对象
     * @return mixed
     */
    protected function getRelationData(Relation $modelRelation)
    {
        if ($this->parent && !$modelRelation->isSelfRelation() && get_class($this->parent) == get_class($modelRelation->getModel())) {
            $value = $this->parent;
        } else {
            // 获取关联数据
            $value = $modelRelation->getRelation();
        }

        return $value;
    }

    /**
     * 关联数据自动写入检查
     * @access protected
     * @return void
     */
    protected function checkAutoRelationWrite()
    {
        foreach ($this->together as $key => $name) {
            if (is_array($name)) {
                if (key($name) === 0) {
                    $this->relationWrite[$key] = [];
                    // 绑定关联属性
                    foreach ((array) $name as $val) {
                        if (isset($this->data[$val])) {
                            $this->relationWrite[$key][$val] = $this->data[$val];
                        }
                    }
                } else {
                    // 直接传入关联数据
                    $this->relationWrite[$key] = $name;
                }
            } elseif (isset($this->relation[$name])) {
                $this->relationWrite[$name] = $this->relation[$name];
            } elseif (isset($this->data[$name])) {
                $this->relationWrite[$name] = $this->data[$name];
                unset($this->data[$name]);
            }
        }
    }

    /**
     * 自动关联数据更新（针对一对一关联）
     * @access protected
     * @return void
     */
    protected function autoRelationUpdate()
    {
        foreach ($this->relationWrite as $name => $val) {
            if ($val instanceof Model) {
                $val->isUpdate()->save();
            } else {
                $model = $this->getRelation($name);
                if ($model instanceof Model) {
                    $model->isUpdate()->save($val);
                }
            }
        }
    }

    /**
     * 自动关联数据写入（针对一对一关联）
     * @access protected
     * @return void
     */
    protected function autoRelationInsert()
    {
        foreach ($this->relationWrite as $name => $val) {
            $method = Loader::parseName($name, 1, false);
            $this->$method()->save($val);
        }
    }

    /**
     * 自动关联数据删除（支持一对一及一对多关联）
     * @access protected
     * @return void
     */
    protected function autoRelationDelete()
    {
        foreach ($this->relationWrite as $key => $name) {
            $name   = is_numeric($key) ? $name : $key;
            $result = $this->getRelation($name);

            if ($result instanceof Model) {
                $result->delete();
            } elseif ($result instanceof Collection) {
                foreach ($result as $model) {
                    $model->delete();
                }
            }
        }
    }
}