'use strict';

// configuration values (these are the only things that should need to be changed)
var config = {
    'MCE_PORT':       5150,           // port MCE Controller is listening on
    'WEB_PORT':       6224,           // port for webserver and websocket
    'STATIC_DIR':     'MouseHelper',  // subdirectory name for static web files
    'RETRY_INTERVAL': 2,              // interval (in s) to retry connecting to MCE Controller

    'DEBUG':          false,          // turn on debugging output
};

var VERSION = "2023-05-15"

console.log('Starting MouseHelper interface (version: ' + VERSION + ')...');

// pull in required modules
var express = require('express');
var net = require('net');
var webSocket = require('ws');

// webserver variables
var app;
var webserver;

// websocket server
var wss;

// MCE Controller client connection
var mceClient;
var mceClientConnecting;

// for drag and drop button state, cleaner to maintain here than on webpage
var dragging = false;

// set up webserver and websocket server
var app = express();
app.use(express.static(config.STATIC_DIR));  // serve static pages from this directory
var webserver = app.listen(config.WEB_PORT);
var wss = new webSocket.Server({ server: webserver });

// create socket for connecting to MCE Controller
var mceClient = new net.Socket();

// handlers for connecting to MCE Controller
function mceClientConnected() {
    // check to prevent multiple connection messages on retries
    if (mceClientConnecting) {
        console.log('Socket connection established with MCE Controller...');
        mceClientConnecting = false;
    }
}
function mceClientTryConnect() {
    // attempting to connect...
    mceClientConnecting = true;

    // only provide the connection listener on the first try, not retries
    mceClient.connect(config.MCE_PORT, '127.0.0.1', mceClientConnected);
}

// handle retrying to connect to MCE Controller (in case it isn't up yet or we get dropped)
mceClient.on('error', function(e) {
    console.log('Unable to connect to MCE Controller, will try again in ' + config.RETRY_INTERVAL + ' seconds...');

    setTimeout(mceClientTryConnect, config.RETRY_INTERVAL * 1000);
});

// connect to MCE Controller
mceClientTryConnect();

// handle websocket connection inputs
wss.on('connection', function(ws) {

    console.log('WebSocket connection established with web interface...');

    ws.on('message', function(cmdstr) {
        var cmdArray; // parsed array of commands/data
        var cmd;      // extracted command name
        var cmdData;  // extracted command data (optional)

        if (config.DEBUG) {
            console.log('received: %s', cmdstr);
        }

        // parse command string
        cmdArray = cmdstr.toString().split(':');
        cmd = cmdArray[0]
        if (cmdArray.length > 1) {
            cmdData = cmdArray[1];
        }

        switch (cmd) {
            // handle mouse button clicks; if we're already dragging,
            //  turn off drag rather than register button click
            case 'lefttap':
                if (dragging) {
                    mceClient.write('mouse:lbu\r\n');
                    dragging = false;
                } else {
                    mceClient.write('mouse:lbc\r\n');
                }
                break;

            case 'leftdoubletap':
                if (dragging) {
                    mceClient.write('mouse:lbu\r\n');
                    dragging = false;
                } else {
                    mceClient.write('mouse:lbdc\r\n');
                }
                break;

            case 'righttap':
                if (dragging) {
                    mceClient.write('mouse:lbu\r\n');
                    dragging = false;
                } else {
                    mceClient.write('mouse:rbc\r\n');
                }
                break;

            case 'rightdoubletap':
                if (dragging) {
                    mceClient.write('mouse:lbu\r\n');
                    dragging = false;
                } else {
                    mceClient.write('mouse:rbdc\r\n');
                }
                break;

                // handle button presses (for easier drag and drop)
            case 'press':
                if (dragging) {
                    // already dragging, so turn it off
                    mceClient.write('mouse:lbu\r\n');
                    dragging = false;
                } else {
                    dragging = true;
                    mceClient.write('mouse:lbd\r\n');
                }
                break;

                // handle mouse movement
            case 'mousemove':
                mceClient.write('mouse:mm,' + cmdData + '\r\n');
                break;

                // handle scrolling
            case 'scroll':
                mceClient.write('mouse:vs,' + cmdData + '\r\n');
                break;

            default:
                console.log('ERROR: unrecognized command: "' + cmd + '", ignoring...')
        } // done with that command
    }); // done with that message
});