<?php
// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK IT ]
// +----------------------------------------------------------------------
// | Copyright (c) 2006-2014 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------
namespace Think\Model;
use Think\Model;
/**
 * ThinkPHP视图模型扩展 
 */
class ViewModel extends Model {

 protected $viewFields = array();

 /**
 * 自动检测数据表信息
 * @access protected
 * @return void
 */
 protected function _checkTableInfo() {}

 /**
 * 得到完整的数据表名
 * @access public
 * @return string
 */
 public function getTableName() {
 if(empty($this->trueTableName)) {
 $tableName = '';
 foreach ($this->viewFields as $key=>$view){
 // 获取数据表名称
 if(isset($view['_table'])) { // 2011年10月17日 添加实际表名定义支持 可以实现同一个表的视图
 $tableName .= $view['_table'];
 $prefix = $this->tablePrefix;
 $tableName = preg_replace_callback("/__([A-Z_-]+)__/sU", function($match) use($prefix){ return $prefix.strtolower($match[1]);}, $tableName);
 }else{
 $class = $key.'Model';
 $Model = class_exists($class)?new $class():M($key);
 $tableName .= $Model->getTableName();
 }
 // 表别名定义
 $tableName .= !empty($view['_as'])?' '.$view['_as']:' '.$key;
 // 支持ON 条件定义
 $tableName .= !empty($view['_on'])?' ON '.$view['_on']:'';
 // 指定JOIN类型 例如 RIGHT INNER LEFT 下一个表有效
 $type = !empty($view['_type'])?$view['_type']:'';
 $tableName .= ' '.strtoupper($type).' JOIN ';
 $len = strlen($type.'_JOIN ');
 }
 $tableName = substr($tableName,0,-$len);
 $this->trueTableName = $tableName;
 }
 return $this->trueTableName;
 }

 /**
 * 表达式过滤方法
 * @access protected
 * @param string $options 表达式
 * @return void
 */
 protected function _options_filter(&$options) {
 if(isset($options['field']))
 $options['field'] = $this->checkFields($options['field']);
 else
 $options['field'] = $this->checkFields();
 if(isset($options['group']))
 $options['group'] = $this->checkGroup($options['group']);
 if(isset($options['where']))
 $options['where'] = $this->checkCondition($options['where']);
 if(isset($options['order']))
 $options['order'] = $this->checkOrder($options['order']);
 }

 /**
 * 检查是否定义了所有字段
 * @access protected
 * @param string $name 模型名称
 * @param array $fields 字段数组
 * @return array
 */
 private function _checkFields($name,$fields) {
 if(false !== $pos = array_search('*',$fields)) {// 定义所有字段
 $fields = array_merge($fields,M($name)->getDbFields());
 unset($fields[$pos]);
 }
 return $fields;
 }

 /**
 * 检查条件中的视图字段
 * @access protected
 * @param mixed $data 条件表达式
 * @return array
 */
 protected function checkCondition($where) {
 if(is_array($where)) {
 $view = array();
 // 检查视图字段
 foreach ($this->viewFields as $key=>$val){
 $k = isset($val['_as'])?$val['_as']:$key;
 $val = $this->_checkFields($key,$val);
 foreach ($where as $name=>$value){
 if(false !== $field = array_search($name,$val,true)) {
 // 存在视图字段
 $_key = is_numeric($field)? $k.'.'.$name : $k.'.'.$field;
 $view[$_key] = $value;
 unset($where[$name]);
 }
 }
 }
 $where = array_merge($where,$view);
 }
 return $where;
 }

 /**
 * 检查Order表达式中的视图字段
 * @access protected
 * @param string $order 字段
 * @return string
 */
 protected function checkOrder($order='') {
 if(is_string($order) && !empty($order)) {
 $orders = explode(',',$order);
 $_order = array();
 foreach ($orders as $order){
 $array = explode(' ',trim($order));
 $field = $array[0];
 $sort = isset($array[1])?$array[1]:'ASC';
 // 解析成视图字段
 foreach ($this->viewFields as $name=>$val){
 $k = isset($val['_as'])?$val['_as']:$name;
 $val = $this->_checkFields($name,$val);
 if(false !== $_field = array_search($field,$val,true)) {
 // 存在视图字段
 $field = is_numeric($_field)?$k.'.'.$field:$k.'.'.$_field;
 break;
 }
 }
 $_order[] = $field.' '.$sort;
 }
 $order = implode(',',$_order);
 }
 return $order;
 }

 /**
 * 检查Group表达式中的视图字段
 * @access protected
 * @param string $group 字段
 * @return string
 */
 protected function checkGroup($group='') {
 if(!empty($group)) {
 $groups = explode(',',$group);
 $_group = array();
 foreach ($groups as $field){
 // 解析成视图字段
 foreach ($this->viewFields as $name=>$val){
 $k = isset($val['_as'])?$val['_as']:$name;
 $val = $this->_checkFields($name,$val);
 if(false !== $_field = array_search($field,$val,true)) {
 // 存在视图字段
 $field = is_numeric($_field)?$k.'.'.$field:$k.'.'.$_field;
 break;
 }
 }
 $_group[] = $field;
 }
 $group = implode(',',$_group);
 }
 return $group;
 }

 /**
 * 检查fields表达式中的视图字段
 * @access protected
 * @param string $fields 字段
 * @return string
 */
 protected function checkFields($fields='') {
 if(empty($fields) || '*'==$fields ) {
 // 获取全部视图字段
 $fields = array();
 foreach ($this->viewFields as $name=>$val){
 $k = isset($val['_as'])?$val['_as']:$name;
 $val = $this->_checkFields($name,$val);
 foreach ($val as $key=>$field){
 if(is_numeric($key)) {
 $fields[] = $k.'.'.$field.' AS '.$field;
 }elseif('_' != substr($key,0,1)) {
 // 以_开头的为特殊定义
 if( false !== strpos($key,'*') || false !== strpos($key,'(') || false !== strpos($key,'.')) {
 //如果包含* 或者 使用了sql方法 则不再添加前面的表名
 $fields[] = $key.' AS '.$field;
 }else{
 $fields[] = $k.'.'.$key.' AS '.$field;
 }
 }
 }
 }
 $fields = implode(',',$fields);
 }else{
 if(!is_array($fields))
 $fields = explode(',',$fields);
 // 解析成视图字段
 $array = array();
 foreach ($fields as $key=>$field){
 if(strpos($field,'(') || strpos(strtolower($field),' as ')){
 // 使用了函数或者别名
 $array[] = $field;
 unset($fields[$key]);
 }
 }
 foreach ($this->viewFields as $name=>$val){
 $k = isset($val['_as'])?$val['_as']:$name;
 $val = $this->_checkFields($name,$val);
 foreach ($fields as $key=>$field){
 if(false !== $_field = array_search($field,$val,true)) {
 // 存在视图字段
 if(is_numeric($_field)) {
 $array[] = $k.'.'.$field.' AS '.$field;
 }elseif('_' != substr($_field,0,1)){
 if( false !== strpos($_field,'*') || false !== strpos($_field,'(') || false !== strpos($_field,'.'))
 //如果包含* 或者 使用了sql方法 则不再添加前面的表名
 $array[] = $_field.' AS '.$field;
 else
 $array[] = $k.'.'.$_field.' AS '.$field;
 }
 }
 }
 }
 $fields = implode(',',$array);
 }
 return $fields;
 }
}