export default class Stream {
    constructor (id) {
        this.id = id;
        this.partialContent = "";
        this.eof = false;

        this.listeners = {
            data: [],
            end: [],
        };

        let onResponse = (msg) => {
            if (this.eof) return;

            if (msg.eof) {
                this.eof = true;
                this.handle('end');
            } else {
                this.partialContent += msg.data;
                this.handle('data', msg.data);
            }
        };

        this.contentPromise = new Promise((resolve, reject) => {
            this.handle("end", () => {
                resolve(this.partialContent);
            });
        });
    }

    feed (chunk) {
        if (this.eof) return;
        this.partialContent += chunk;
        this.handle('data', chunk);
    }

    close () {
        this.eof = true;
        this.handle('end', this.partialContent);
    }

    getContent () {
        return this.contentPromise;
    }

    handle (event, ...args) {
        for (let fn of this.listeners[event]) {
            fn(...args)
        }
    }

    on (event, callback) {
        this.listeners[event].push(callback);

        if (event == "data" && this.partialContent) {
            callback(this.partialContent);
        }
        if (event == "end" && this.eof) {
            callback();
        }
    }
}