class MessageCenter { 
    constructor() { 
        this.iframeMap = new Map();
        this.messageCallbackMap = new Map();
        // this.listen()
    }

    findIframeById(id) { 
        let target = this.iframeMap.get(id);
        if (!target) { 
            target = document.getElementById(id)
            this.iframeMap.set('id', target)
        }
        return target
    }

    send(id, actionType, data) {
        const target = this.findIframeById(id);
        target && target.contentWindow.postMessage({
            actionType,
            data
        }, '*')
    }

    // don't use
    add(actionType, callback) {
        let activeQuene = this.messageCallbackMap.get(actionType);
        if (activeQuene?.length > 0) {
            activeQuene.push(callback)
        } else { 
            this.messageCallbackMap.set(actionType, [callback])
        }
    }
    // don't use
    listen() { 
        window.addEventListener('message', (e) => { 
            const { actionType, data } = e.data;
            console.log('get message in content ...', actionType, data)
            const quene = this.messageCallbackMap.get(actionType) ||  [];
            while (quene.length > 0) { 
                let callback = quene.pop();
                callback(data)
            }
        })
    }
}

const messageCenter = new MessageCenter();

export default messageCenter;