pocka/rusted

import panic from './panic';

import {check_type} from './util';

let factory=function(variants){
    let EnumValue=function(name,data){
        Object.defineProperties(this,{
            '__rusted':{
                value:true,
                writable:false,
                enumerable:false,
                configurable:false
            },
            '__name':{
                value:name,
                writable:false,
                enumerable:true,
                configurable:false
            },
            '__data':{
                value:data,
                writable:false,
                enumerable:true,
                configurable:false
            }
        });
    };

    Object.keys(variants).forEach((variant)=>{
        let data=variants[variant];

        if(data===null){
            Object.defineProperty(EnumValue,variant,{
                get(){
                    return new EnumValue(variant);
                },
                enumerable:true,
                configurable:false
            });
        }else{
            Object.defineProperty(EnumValue,variant,{
                value(value){
                    let {match,expected,actual}=check_type(data,value);
                    match
                        || panic(`enum arm "${variant}" expects ${expected}, but ${actual} was passed.`) ;
                    return new EnumValue(variant,value);
                },
                writable:false,
                enumerable:true,
                configurable:false
            });
        }
    });

    return EnumValue;
};

export default factory;