var http = require('http');
var url  = require('url');
var m = require('mraa'); //Import MRAA for I2C functions

var toByte = function(value) {
    return (value & 255) || 0;
}

var devices = {
    servo: {
        addr: [0x74],
        fields: ['actuator', 'speed', 'direction'],
        fn: function(device, data) {
            //the actuator only accepts 1-11
            if(!/^[1-9]|1[01]$/.test(data.actuator)) {
                return false;
            }

            device.writeReg((data.actuator*2)-1, toByte(data.speed));
            device.writeReg(data.actuator*2, toByte(data.direction));

            return true;
        }
    },
    led: {
        addr: [0x69],
        fields: ['intentity','actuator'],
        fn: function(device, data) {
            if(!/^RED|GREEN|BLUE|WHITE$/i.test(data.actuator)) {
                return false;
            }
            device.writeReg(data.actuator.toUpperCase(), toByte(data.intentity) );

            return true;
        }
    }
};

var executeDevice = function(query) {
    if(!('type' in query)) {
        return false;
    }

    if(!devices.hasOwnProperty(query.type)) {
        return false;
    }

    if(!('id' in query) || isNaN(query.id)) {
        return false;
    }

    var deviceData = devices[query.type];

    if(!deviceData.addr[query.id]) {
        return false;
    }

    //we need to check if all required fields exist
    var length = deviceData.fields.length;
    for(var i = 0; i < length; i++) {
        if(!(deviceData.fields[i] in query)) {
            return false;
        }
    }

    var device = new m.I2c(0);
    device.address(deviceData.addr[query.id]);

    return deviceData.fn(device, query);
};

var handleGetRequest = function(res, url_parsed) {
    console.log('query: ' + JSON.stringify(url_parsed.query));
    console.log('path: ' + url_parsed.path);
    console.log('pathname: ' + url_parsed.pathname);

    switch(url_parsed.pathname) {
        case '/I2C/write':
            console.log("I2C");
            console.log(typeof(url_parsed.query))
            //runNextMethod(url_parsed.query);
            //executeArray(queryToArray(url_parsed.query));
            executeDevice(url_parsed.query);
            res.end();
            break;
        default:
            console.log(url_parsed.pathname, "404")
            res.writeHead(404);
    }
};

var handleApiRequest = function(res, url_parsed, method) {
    if (url_parsed.pathname !== '/api') {
        res.statusCode = 404;
    }
    res.end(method);
};

var server = http.createServer(function(req, res) {
    var url_parsed = url.parse(req.url, true);
    switch(req.method) {
        case 'GET':
            handleGetRequest(res, url_parsed);
            break;
        case 'PUT':
        case 'POST':
        case 'DELETE':
            handleApiRequest(res, url_parsed, req.method);
            break;
        default:
            res.end('Method not supported');
    }
});
server.listen(8003);