<?php
// +----------------------------------------------------------------------
// | TOPThink [ WE CAN DO IT JUST THINK ]
// +----------------------------------------------------------------------
// | Copyright (c) 2011 http://topthink.com All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------

namespace Think;

class View {
    protected $engine   =   null;       // 模板引擎实例
    protected $theme    =   '';         // 模板主题名称
    protected $data     =   [];    // 模板变量
    protected $config   =   [       // 视图参数
        'http_output_content'   =>  true,
        'http_content_type'     =>  'text/html',
        'http_charset'          =>  'utf-8',
        'http_cache_control'    =>  'private',
        'http_render_content'   =>  false,
        'theme_on'              =>  false,
        'auto_detect_theme'     =>  false,
        'var_theme'             =>  't',
        'default_theme'         =>  'default',
        'http_cache_id'         =>  null,
        'view_path'             =>  '',
        'view_suffix'           =>  '.html',

    ];
    
    /**
     * 模板变量赋值
     * @access public
     * @param mixed $name
     * @param mixed $value
     */
    public function assign($name,$value=''){
        if(is_array($name)) {
            $this->data   =  array_merge($this->data,$name);
            return $this;
        }else {
            $this->data[$name] = $value;
        }
    }

    /**
     * 视图参数设置
     * @access public
     * @param mixed $name
     * @param mixed $value
     */
    public function __set($name,$value=''){
        $this->config[$name] = $value;
    }

    public function __construct(array $config=[]){
        $this->config   =   array_merge($this->config,$config);
    }
    
    /**
     * 设置当前模板解析的引擎
     * @access public
     * @param string $engine 引擎名称
     * @param array $config 引擎参数
     * @return View
     */
    public function engine($engine,$config=[]){
        $class  =   '\\Think\\View\\Driver\\'.ucwords($engine);
        $this->engine =   new $class($config);
        return $this;
    }
    
    /**
     * 设置当前输出的模板主题
     * @access public
     * @param mixed $theme 主题名称
     * @return View
     */
    public function theme($theme){
        if(true === $theme) { // 自动侦测
            $this->config['theme_on']   =   true;
            $this->config['auto_detect_theme']  =   true;
        }elseif(false === $theme){ // 关闭主题
            $this->config['theme_on']   =   false;
        }else{ // 指定模板主题
            $this->config['theme_on']   =   true;
            $this->theme    =   $theme;
        }
        return $this;
    }

    /**
     * 加载模板和页面输出 可以返回输出内容
     * @access public
     * @param string $template 模板文件名
     * @param array $vars 模板输出变量
     * @param string $cacheId 模板缓存标识
     * @return mixed
     */
    public function display($template='',$vars=[],$cacheId='') {
        Tag::listen('view_begin',$template);
        // 解析并获取模板内容
        $content = $this->fetch($template,$vars,$cacheId);
        // 输出内容过滤
        Tag::listen('view_filter',$content);
        // 输出模板内容
        if($this->config['http_output_content']) {
            $this->render($content);
        }else{ // 返回解析后的内容
            return $content;
        }
    }

    /**
     * 解析和获取模板内容 用于输出
     * @access protected
     * @param string $template 模板文件名或者内容
     * @param array $vars 模板输出变量
     * @param string $cacheId 模板缓存标识
     * @return string
     */
    protected function fetch($template,$vars=[],$cacheId='') {
        if(!$this->config['http_render_content']) {
            $template   =   $this->parseTemplate($template);
            // 模板不存在 抛出异常
            if(!is_file($template)) 
                E('template file not exists:'.$template);
        }
        $vars   =   $vars?$vars:$this->data;
        // 页面缓存
        ob_start();
        ob_implicit_flush(0);
        if($this->engine) { // 指定模板引擎
            $this->engine->fetch($template,$vars,$cacheId);
        }else{  // 原生PHP解析
            extract($vars, EXTR_OVERWRITE);
            is_file($template)?include $template:eval('?>'.$template);
        }
        // 获取并清空缓存
        return ob_get_clean();
    }

    /**
     * 自动定位模板文件
     * @access private
     * @param string $template 模板文件规则
     * @return string
     */
    private function parseTemplate($template) {
        if(is_file($template)) {
            return $template;
        }
        $template   =   str_replace(':','/',$template);
        // 获取当前主题名称
        $theme  =   $this->getTemplateTheme();
        // 分析模板文件规则
        if(''==$template) {
            // 如果模板文件名为空 按照默认规则定位
            $template = CONTROLLER_NAME.'/'.ACTION_NAME;
        }elseif(false === strpos($template,'/')){
            $template = CONTROLLER_NAME.'/'.$template;
        }
        return ($this->config['view_path']?$this->config['view_path']:MODULE_PATH.'View/').$theme.$template.$this->config['view_suffix'];
    }

    /**
     * 获取当前的模板主题
     * @access private
     * @return string
     */
    private function getTemplateTheme() {
        if($this->config['theme_on']) {
            if($this->theme) { // 指定模板主题
                $theme  =   $this->theme;
            }elseif($this->config['auto_detect_theme']){
                // 自动侦测模板主题
                $t = $this->config['var_theme'];
                if (isset($_GET[$t])){
                    $theme = $_GET[$t];
                }elseif(Cookie::get('think_theme')){
                    $theme = Cookie::get('think_theme');
                }
                if(!is_dir(MODULE_PATH.'View/'.$theme)) {
                    $theme  =   $this->config['default_theme'];
                }
                Cookie::set('think_theme',$theme,864000);
            }else{
                $theme  =   $this->config['default_theme'];
            }
            return $theme.'/';
        }
        return '';
    }

    /**
     * 视图输出参数设置
     * @access public
     * @param mixed $config
     * @param mixed $value
     */
    public function http($config=[],$value=''){
        if(is_array($config)) {
            $this->config   =   array_merge($this->config,$config);
        }else{
            $this->config[$config]  =   $value;
        }
        return $this;
    }

    /**
     * 输出内容文本可以包括Html
     * @access private
     * @param string $content 输出内容
     * @param string $charset 模板输出字符集
     * @param string $contentType 输出类型
     * @return mixed
     */
    private function render($content){
        // 网页字符编码
        header('Content-Type:'.$this->config['http_content_type'].'; charset='.$this->config['http_charset']);
        header('Cache-control: '.$this->config['http_cache_control']);  // 页面缓存控制
        header('X-Powered-By:ThinkPHP');
        // 输出模板文件
        echo $content;
    }
}