var cache = {};
// 通过解析Function.prototype.toString()取得参数名
function getParamNames(func) {
  // 正则表达式出自http://krasimirtsonev.com/blog/article/Dependency-injection-in-JavaScript
  var paramNames = func.toString().match(/^function\s*[^\(]*\(\s*([^\)]*)\)/m)[1];
  paramNames = paramNames.replace(/ /g, '');
  paramNames = paramNames.split(',');
  return paramNames;
}
var injector = {
  // 将func作用域中的this关键字绑定到bind对象上，bind对象可以为空
  resolve: function (func, bind) {
    // 取得参数名
    var paramNames = getParamNames(func);
    var params = [];
    for (var i = 0; i < paramNames.length; i++) {
      // 通过参数名在cache中取出相应的依赖
      params.push(cache[paramNames[i]]);
    }
    // 注入依赖并执行函数
    func.apply(bind, params);
  }
};
 
function Notebook() {}
Notebook.prototype.printName = function () {
  console.log('this is a notebook');
};
 
function Pencil() {}
Pencil.prototype.printName = function () {
  console.log('this is a pencil');
};
 
function Student() {}
Student.prototype.write = function (notebook, pencil) {
  if (!notebook || !pencil) {
    throw new Error('Dependencies not provided!');
  }
  console.log('writing...');
};
// 提供notebook依赖
cache['notebook'] = new Notebook();
// 提供pencil依赖
cache['pencil'] = new Pencil();
var student = new Student();
injector.resolve(student.write, student); // writing...

function Injector() {
  this._cache = {};
}
 
Injector.prototype.put = function (name, obj) {
  this._cache[name] = obj;
};
 
Injector.prototype.getParamNames = function (func) {
  // 正则表达式出自http://krasimirtsonev.com/blog/article/Dependency-injection-in-JavaScript
  var paramNames = func.toString().match(/^function\s*[^\(]*\(\s*([^\)]*)\)/m)[1];
  paramNames = paramNames.replace(/ /g, '');
  paramNames = paramNames.split(',');
  return paramNames;
};
 
Injector.prototype.resolve = function (func, bind) {
  var self = this;
  var paramNames = self.getParamNames(func);
  var params = paramNames.map(function (name) {
    return self._cache[name];
  });
  func.apply(bind, params);
};
 
var injector = new Injector();
 
var student = new Student();
injector.put('notebook', new Notebook());
injector.put('pencil', new Pencil())
injector.resolve(student.write, student); // writing...

function Eraser() {}
Eraser.prototype.printName = function () {
  console.log('this is an eraser');
};
 
// 为Student增加draw方法
Student.prototype.draw = function (notebook, pencil, eraser) {
  if (!notebook || !pencil || !eraser) {
    throw new Error('Dependencies not provided!');
  }
  console.log('drawing...');
};
 
injector.put('eraser', new Eraser());
injector.resolve(student.draw, student);

Student.prototype.write.depends = ['notebook', 'pencil'];
Student.prototype.draw.depends = ['notebook', 'pencil', 'eraser'];
Injector.prototype.resolve = function (func, bind) {
  var self = this;
  // 首先检查func上是否有depends属性，如果没有，再用正则表达式解析
  func.depends = func.depends || self.getParamNames(func);
  var params = func.depends.map(function (name) {
    return self._cache[name];
  });
  func.apply(bind, params);
};
var student = new Student();
injector.resolve(student.write, student); // writing...
injector.resolve(student.draw, student); // draw...

class Pencil {
  public printName() {
    console.log('this is a pencil');
  }
}
 
class Eraser {
  public printName() {
    console.log('this is an eraser');
  }
}
 
class Notebook {
  public printName() {
    console.log('this is a notebook');
  }
}
 
class Student {
  pencil: Pencil;
  eraser: Eraser;
  notebook: Notebook;
  public constructor(notebook: Notebook, pencil: Pencil, eraser: Eraser) {
    this.notebook = notebook;
    this.pencil = pencil;
    this.eraser = eraser;
  }
  public write() {
    if (!this.notebook || !this.pencil) {
      throw new Error('Dependencies not provided!');
    }
    console.log('writing...');
  }
  public draw() {
    if (!this.notebook || !this.pencil || !this.eraser) {
      throw new Error('Dependencies not provided!');
    }
    console.log('drawing...');
  }
}

var dependenciesMap = {};
var injector = {
  resolve: function (constructor) {
    var dependencies = dependenciesMap[constructor.name];
    dependencies = dependencies.map(function (dependency) {
      return new dependency();
    });
    // 如果可以使用ES6的语法，下面的代码可以合并为一行：
    // return new constructor(...dependencies);
    var mockConstructor: any = function () {
      constructor.apply(this, dependencies);
    };
    mockConstructor.prototype = constructor.prototype;
    return new mockConstructor();
  }
};
function Inject(...dependencies) {
  return function (constructor) {
    dependenciesMap[constructor.name] = dependencies;
    return constructor;
  };
}

// 装饰器的使用非常简单，只需要在类定义的上方添加一行代码
// Inject是装饰器的名字，后面是function Inject的参数
@Inject(Notebook, Pencil, Eraser)
class Student {
  pencil: Pencil;
  eraser: Eraser;
  notebook: Notebook;
  public constructor(notebook: Notebook, pencil: Pencil, eraser: Eraser) {
    this.notebook = notebook;
    this.pencil = pencil;
    this.eraser = eraser;
  }
  public write() {
    if (!this.notebook || !this.pencil) {
      throw new Error('Dependencies not provided!');
    }
    console.log('writing...');
  }
  public draw() {
    if (!this.notebook || !this.pencil || !this.eraser) {
      throw new Error('Dependencies not provided!');
    }
    console.log('drawing...');
  }
}
var student = injector.resolve(Student);
console.log(student instanceof Student); // true
student.notebook.printName(); // this is a notebook
student.pencil.printName(); // this is a pencil
student.eraser.printName(); // this is an eraser
student.draw(); // drawing
student.write(); // writing

function RadicalInject(...dependencies){
  var wrappedFunc:any = function (target: any) {
    dependencies = dependencies.map(function (dependency) {
      return new dependency();
    });
    // 使用mockConstructor的原因和上例相同
    function mockConstructor() {
      target.apply(this, dependencies);
    }
    mockConstructor.prototype = target.prototype;
 
    // 为什么需要使用reservedConstructor呢？因为使用RadicalInject对Student方法装饰之后，
    // Student指向的构造函数已经不是一开始我们声明的class Student了，而是这里的返回值，
    // 即reservedConstructor。Student的指向变了并不是一件不能接受的事，但是如果要
    // 保证student instanceof Student如我们所期望的那样工作，这里就应该将
    // reservedConstructor的prototype属性指向原Student的prototype
    function reservedConstructor() {
      return new mockConstructor();
    }
    reservedConstructor.prototype = target.prototype;
    return reservedConstructor;
  }
  return wrappedFunc;
}

@RadicalInject(Notebook, Pencil, Eraser)
class Student {
  pencil: Pencil;
  eraser: Eraser;
  notebook: Notebook;
  public constructor() {}
  public constructor(notebook: Notebook, pencil: Pencil, eraser: Eraser) {
    this.notebook = notebook;
    this.pencil = pencil;
    this.eraser = eraser;
  }
  public write() {
    if (!this.notebook || !this.pencil) {
      throw new Error('Dependencies not provided!');
    }
    console.log('writing...');
  }
  public draw() {
    if (!this.notebook || !this.pencil || !this.eraser) {
      throw new Error('Dependencies not provided!');
    }
    console.log('drawing...');
  }
}
// 不再出现injector，直接调用构造函数
var student = new Student(); 
console.log(student instanceof Student); // true
student.notebook.printName(); // this is a notebook
student.pencil.printName(); // this is a pencil
student.eraser.printName(); // this is an eraser
student.draw(); // drawing
student.write(); // writing

interface NotebookInterface {
  printName(): void;
}
interface PencilInterface {
  printName(): void;
}
interface EraserInterface {
  printName(): void;
}
interface StudentInterface {
  notebook: NotebookInterface;
  pencil: PencilInterface;
  eraser: EraserInterface;
  write(): void;
  draw(): void;
}
class Notebook implements NotebookInterface {
  public printName() {
    console.log('this is a notebook');
  }
}
class Pencil implements PencilInterface {
  public printName() {
    console.log('this is a pencil');
  }
}
class Eraser implements EraserInterface {
  public printName() {
    console.log('this is an eraser');
  }
}
 
class Student implements StudentInterface {
  notebook: NotebookInterface;
  pencil: PencilInterface;
  eraser: EraserInterface;
  constructor(notebook: NotebookInterface, pencil: PencilInterface, eraser: EraserInterface) {
    this.notebook = notebook;
    this.pencil = pencil;
    this.eraser = eraser;
  }
  write() {
    console.log('writing...');
  }
  draw() {
    console.log('drawing...');
  }
}

import { Inject } from "inversify";
 
@Inject("NotebookInterface", "PencilInterface", "EraserInterface")
class Student implements StudentInterface {
  notebook: NotebookInterface;
  pencil: PencilInterface;
  eraser: EraserInterface;
  constructor(notebook: NotebookInterface, pencil: PencilInterface, eraser: EraserInterface) {
    this.notebook = notebook;
    this.pencil = pencil;
    this.eraser = eraser;
  }
  write() {
    console.log('writing...');
  }
  draw() {
    console.log('drawing...');
  }
}

import { TypeBinding, Kernel } from "inversify";
 
var kernel = new Kernel();
kernel.bind(new TypeBinding("NotebookInterface", Notebook));
kernel.bind(new TypeBinding("PencilInterface", Pencil));
kernel.bind(new TypeBinding("EraserInterface", Eraser));
kernel.bind(new TypeBinding("StudentInterface", Student));

var student: StudentInterface = kernel.resolve("StudentInterface");
console.log(student instanceof Student); // true
student.notebook.printName(); // this is a notebook
student.pencil.printName(); // this is a pencil
student.eraser.printName(); // this is an eraser
student.draw(); // drawing
student.write(); // writing