const express = require('express');
const lodash = require('lodash');
const path = require('path');
var bodyParser = require('body-parser');


const app =  express();
var router = express.Router();

app.set('view engine', 'jade');
app.set('views', path.join(__dirname, 'views'));
app.use(bodyParser.json({ extended: true }));


app.get('/',function (req, res) {
    res.send('Hello World');
})

app.post('/post',function (req, res) {
    function merge(target, source) {
        for (let key in source) {
            if (key in source && key in target) {
                merge(target[key], source[key])
            } else {
                target[key] = source[key]
            }
        }
    }
    var malicious_payload = JSON.stringify(req.body);
    var body = JSON.parse(JSON.stringify(req.body));
    var a = {};
    merge(a, JSON.parse(malicious_payload));
    console.log(a.name);
    res.render('index.jade', {
        title: 'HTML',
        name: a.name || ''
    });
})
app.listen(1113, () => console.log('Example app listening on port http://127.0.0.1:1113 !'))

res.render('index.jade', {
        title: 'HTML',
        name: a.name || ''
    });

exports.compile = function(str, options){
  var options = options || {}
    , filename = options.filename
      ? utils.stringify(options.filename)
      : 'undefined'
    , fn;

  str = String(str);

  var parsed = parse(str, options);
  if (options.compileDebug !== false) {
    fn = [
        'var jade_debug = [ new jade.DebugItem( 1, ' + filename + ' ) ];'
      , 'try {'
      , parsed.body
      , '} catch (err) {'
      , '  jade.rethrow(err, jade_debug[0].filename, jade_debug[0].lineno' + (options.compileDebug === true ? ',' + utils.stringify(str) : '') + ');'
      , '}'
    ].join('\n');
  } else {
    fn = parsed.body;
  }
  fn = new Function('locals, jade', fn)
  var res = function(locals){ return fn(locals, Object.create(runtime)) };
  if (options.client) {
    res.toString = function () {
      var err = new Error('The `client` option is deprecated, use the `jade.compileClient` method instead');
      err.name = 'Warning';
      console.error(err.stack || /* istanbul ignore next */ err.message);
      return exports.compileClient(str, options);
    };
  }
  res.dependencies = parsed.dependencies;
  return res;
};

function parse(str, options){

  if (options.lexer) {
    console.warn('Using `lexer` as a local in render() is deprecated and '
               + 'will be interpreted as an option in Jade 2.0.0');
  }//如果options.lexer存在，就会产生警告

  // Parse
  var parser = new (options.parser || Parser)(str, options.filename, options);//创建一个parser
  var tokens;
  try {
    // Parse
    tokens = parser.parse();
  } catch (err) {
    parser = parser.context();
    runtime.rethrow(err, parser.filename, parser.lexer.lineno, parser.input);
  }//尝试通过parse获取到tokens

  // Compile
  var compiler = new (options.compiler || Compiler)(tokens, options);
  var js;
  try {
    js = compiler.compile();//创建一个编译器并且通过compile变成js
  } catch (err) {
    if (err.line && (err.filename || !options.filename)) {
      runtime.rethrow(err, err.filename, err.line, parser.input);
    } else {
      if (err instanceof Error) {
        err.message += '\n\nPlease report this entire error and stack trace to https://github.com/jadejs/jade/issues';
      }
      throw err;
    }
  }

  // Debug compiler
  if (options.debug) {
    console.error('\nCompiled Function:\n\n\u001b[90m%s\u001b[0m', js.replace(/^/gm, '  '));
  }//检查是否是debug模式，如果是就打印异常

  var globals = [];//定义globals数组

  if (options.globals) {//如果options.globals存在，就slice
    globals = options.globals.slice();
  }

  globals.push('jade');
  globals.push('jade_mixins');
  globals.push('jade_interp');
  globals.push('jade_debug');
  globals.push('buf');//将这些属性赋值给globals

  var body = ''
    + 'var buf = [];\n'
    + 'var jade_mixins = {};\n'
    + 'var jade_interp;\n'
    + (options.self
      ? 'var self = locals || {};\n' + js
      : addWith('locals || {}', '\n' + js, globals)) + ';'//这里比较关键，如果options.self设置为了true，拼接var self = locals || {};\n' + js，否则拼接addWith('locals || {}', '\n' + js, globals)
    + 'return buf.join("");';
  return {body: body, dependencies: parser.dependencies};//最后返回一个对象，由body和dependencies组成，只要控制body变量就能执行代码
}

this.buf = [];
    if (this.pp) this.buf.push("var jade_indent = [];");
    this.lastBufferedIdx = -1;

visitCode: function(code){
    // Wrap code blocks with {}.
    // we only wrap unbuffered code blocks ATM
    // since they are usually flow control

    // Buffer code
    if (code.buffer) {
      var val = code.val.trim();
      val = 'null == (jade_interp = '+val+') ? "" : jade_interp';
      if (code.escape) val = 'jade.escape(' + val + ')';
      this.bufferExpression(val);
    } else {
      this.buf.push(code.val);
    }

    // Block support
    if (code.block) {
      if (!code.buffer) this.buf.push('{');
      this.visit(code.block);
      if (!code.buffer) this.buf.push('}');
    }
  },