var sys     = require('sys'),
    http    = require('http'),
    fs      = require('fs'),
    auth    = "************************", // "ユーザ名:パスワード" を Base64 したもの
    queue   = new process.EventEmitter(), // イベント通知用
    backlog = [],
    maxlogs = 100,
    port    = 5000;


var main = function() {
    http.createServer(handle_request).listen(port);

    var client  = http.createClient(80, "chirpstream.twitter.com");
    var request = client.request(
        'GET', '/2b/user.json',
        { 'Host': 'chirpstream.twitter.com',
          'Authorization': auth }      // とりあえず Basic 認証
    );
    request.addListener('response', function (response) {
        sys.puts('STATUS: ' + response.statusCode);
        sys.puts('HEADERS: ' + JSON.stringify(response.headers));
        response.setEncoding('utf8');
        response.addListener('data', read_chunked(queue_writer));
    });
    request.end();
};

var queue_writer = function(input) {
    if (queue.listeners("message").length) { // listener がいたらイベント通知
        queue.emit("message", input);
    }
    else { // いなければ backlog に積んでおく
        while ( backlog.length > maxlogs ) {
            backlog.shift();
        }
        backlog.push(input);
    }
};

// バッファリングして改行ごとに writer に渡す
var read_chunked = function( writer ) {
    var buf = "";
    return function(chunk) {
        if (chunk.match(/\n/)) {
            var chunks = chunk.split(/\r?\n/);
            writer( buf + chunks.shift() );
            if (chunks.length) {
                buf = chunks.pop();
            }
            var c = ""
            while ( c = chunks.shift() ) {
                writer(c);
            }
            return;
        }
        buf += chunk;
    }
};

// HTTP server のリクエストハンドラ
var handle_request = function (request, response) {
    if (request.url == "/") {
        // ファイルを読み込んで返す
        response.writeHead(200, {'Content-Type': 'text/html; charset=utf-8'});
        var file = fs.createReadStream("./client.html");
        file.addListener('data', function(data) { response.write(data) });
        file.addListener('end', function(chunk) { response.end() });
    }
    else if (request.url == "/stream") {
        var send_response = function(msg) {
            response.writeHead(200, {'Content-Type': 'application/json'});
            response.end(msg);
        };
        if (backlog.length) { // backlogがたまってたらそれを返す
            send_response(backlog.shift());
        }
        else {
            // イベント通知を待つ listener を作って callback で返す
            var listener = function(msg) {
                send_response(msg);
                queue.removeListener("message", listener);
            };
            queue.addListener("message", listener);
        }
    }
    else {
        response.writeHead(404, {'Content-Type': 'text/plain'});
        response.end("Not Found\n");
    }
};

main();