"use strict";

var utils = require("../utils");
var GenericWorker = require("../stream/GenericWorker");

/**
 * A worker that use a nodejs stream as source.
 * @constructor
 * @param {String} filename the name of the file entry for this stream.
 * @param {Readable} stream the nodejs stream.
 */
function NodejsStreamInputAdapter(filename, stream) {
    GenericWorker.call(this, "Nodejs stream input adapter for " + filename);
    this._upstreamEnded = false;
    this._bindStream(stream);
}

utils.inherits(NodejsStreamInputAdapter, GenericWorker);

/**
 * Prepare the stream and bind the callbacks on it.
 * Do this ASAP on node 0.10 ! A lazy binding doesn't always work.
 * @param {Stream} stream the nodejs stream to use.
 */
NodejsStreamInputAdapter.prototype._bindStream = function (stream) {
    var self = this;
    this._stream = stream;
    stream.pause();
    stream
        .on("data", function (chunk) {
            self.push({
                data: chunk,
                meta : {
                    percent : 0
                }
            });
        })
        .on("error", function (e) {
            if(self.isPaused) {
                this.generatedError = e;
            } else {
                self.error(e);
            }
        })
        .on("end", function () {
            if(self.isPaused) {
                self._upstreamEnded = true;
            } else {
                self.end();
            }
        });
};
NodejsStreamInputAdapter.prototype.pause = function () {
    if(!GenericWorker.prototype.pause.call(this)) {
        return false;
    }
    this._stream.pause();
    return true;
};
NodejsStreamInputAdapter.prototype.resume = function () {
    if(!GenericWorker.prototype.resume.call(this)) {
        return false;
    }

    if(this._upstreamEnded) {
        this.end();
    } else {
        this._stream.resume();
    }

    return true;
};

module.exports = NodejsStreamInputAdapter;