// @flow

const commandsSym = Symbol("__commands");

function init(obj: Object) {
    obj.demon[commandsSym] = {};
    obj.demon.patcher.after(
        "sendMessage",
        obj.demon.webpack.findByProps("sendMessage"),
        (args, otherRes) => {
            let res;
            for (const key of Reflect.ownKeys(obj.demon[commandsSym])) {
                let command = obj.demon[commandsSym][key];
                if (args[1].content.split(" ")[0] === ">" + command.name) {
                    res = command.callback(args);
                    break;
                }
            }
            if (res !== undefined) args[1].content = res;
            return args;
        }
    );
}

// command = {
// 	name: "name",
// 	callback: (args)=>"Hello, world!"
// }
function add(command: {
    name: string,
    callback: (args: Array<any>) => string
}): () => void {
    let sym = Symbol(command.name);
    window.demon[commandsSym][sym] = command;
    return () => {
        delete window.demon[commandsSym][sym];
    };
}

export default {
    add: add,
    init: init
};