var GUI_control = function() {
    this.auto_connect = false;
    this.connecting_to = false;
    this.connected_to = false;
    this.active_tab;
    this.operating_system;
    this.interval_array = [];
    this.timeout_array = [];
    
    // check which operating system is user running
    if (navigator.appVersion.indexOf("Win") != -1)          this.operating_system = "Windows";
    else if (navigator.appVersion.indexOf("Mac") != -1)     this.operating_system = "MacOS";
    else if (navigator.appVersion.indexOf("CrOS") != -1)    this.operating_system = "ChromeOS";
    else if (navigator.appVersion.indexOf("Linux") != -1)   this.operating_system = "Linux";
    else if (navigator.appVersion.indexOf("X11") != -1)     this.operating_system = "UNIX";
};

// Timer managing methods

// name = string
// code = function reference (code to be executed)
// interval = time interval in miliseconds
// first = true/false if code should be ran initially before next timer interval hits
GUI_control.prototype.interval_add = function(name, code, interval, first) {
    var data = {'name': name, 'timer': undefined, 'code': code, 'interval': interval, 'fired': 0, 'paused': false};
    
    if (first == true) {
        code(); // execute code
        
        data.fired++; // increment counter
    }
    
    data.timer = setInterval(function() {
        code(); // execute code
        
        data.fired++; // increment counter
    }, interval);
    
    this.interval_array.push(data); // push to primary interval array
};

// name = string
GUI_control.prototype.interval_remove = function(name) {
    for (var i = 0; i < this.interval_array.length; i++) {
        if (this.interval_array[i].name == name) {
            clearInterval(this.interval_array[i].timer); // stop timer
            
            this.interval_array.splice(i, 1); // remove element/object from array
        
            return true;
        }
    }
    
    return false;
};

// name = string
GUI_control.prototype.interval_pause = function(name) {
    for (var i = 0; i < this.interval_array.length; i++) {
        if (this.interval_array[i].name == name) {
            clearInterval(this.interval_array[i].timer);
            this.interval_array[i].paused = true;
        
            return true;
        }
    }
    
    return false;
};

// name = string
GUI_control.prototype.interval_resume = function(name) {
    for (var i = 0; i < this.interval_array.length; i++) {
        if (this.interval_array[i].name == name && this.interval_array[i].paused) {
            var obj = this.interval_array[i];
            
            obj.timer = setInterval(function() {
                obj.code(); // execute code
                
                obj.fired++; // increment counter
            }, obj.interval);
            
            obj.paused = false;
        
            return true;
        }
    }
    
    return false;
};

// input = array of timers thats meant to be kept, or nothing
// return = returns timers killed in last call
GUI_control.prototype.interval_kill_all = function(keep_array) {
    var self = this;
    var timers_killed = 0;
    
    for (var i = (this.interval_array.length - 1); i >= 0; i--) { // reverse iteration
        var keep = false;
        if (keep_array) { // only run through the array if it exists
            keep_array.forEach(function(name) {
                if (self.interval_array[i].name == name) {
                    keep = true;
                }
            });
        }
        
        if (!keep) {
            clearInterval(this.interval_array[i].timer); // stop timer
            this.interval_array[i].timer = undefined; // set timer property to undefined (mostly for debug purposes, but it doesn't hurt to have it here)
            
            this.interval_array.splice(i, 1); // remove element/object from array
            
            timers_killed++;
        }
    }
    
    return timers_killed;
};

// name = string
// code = function reference (code to be executed)
// timeout = timeout in miliseconds
GUI_control.prototype.timeout_add = function(name, code, timeout) {
    var self = this;
    // start timer with "cleaning" callback
    var timer = setTimeout(function() {
        code(); // execute code
        
        self.timeout_remove(name); // cleanup
    }, timeout);
    
    this.timeout_array.push({'name': name, 'timer': timer, 'timeout': timeout}); // push to primary timeout array
};

// name = string
GUI_control.prototype.timeout_remove = function(name) {
    for (var i = 0; i < this.timeout_array.length; i++) {
        if (this.timeout_array[i].name == name) {
            clearTimeout(this.timeout_array[i].timer); // stop timer
            
            this.timeout_array.splice(i, 1); // remove element/object from array
            
            return true;
        }
    }
    
    return false;
};

// no input paremeters
// return = returns timers killed in last call
GUI_control.prototype.timeout_kill_all = function() {
    var timers_killed = 0;
    
    for (var i = 0; i < this.timeout_array.length; i++) {
        clearTimeout(this.timeout_array[i].timer); // stop timer
        
        timers_killed++;
    }
    
    this.timeout_array = []; // drop objects
    
    return timers_killed;
};

// message = string
GUI_control.prototype.log = function(message) {
    var command_log = $('div#log');
    var d = new Date();
    var time = ((d.getHours() < 10) ? '0' + d.getHours(): d.getHours()) 
        + ':' + ((d.getMinutes() < 10) ? '0' + d.getMinutes(): d.getMinutes()) 
        + ':' + ((d.getSeconds() < 10) ? '0' + d.getSeconds(): d.getSeconds());
    
    $('div.wrapper', command_log).append('<p>' + time + ' -- ' + message + '</p>');
    command_log.scrollTop($('div.wrapper', command_log).height());   
};

// Method is called every time a valid tab change event is received
// callback = code to run when cleanup is finished
// default switch doesn't require callback to be set
GUI_control.prototype.tab_switch_cleanup = function(callback) {
    MSP.callbacks_cleanup(); // we don't care about any old data that might or might not arrive
    
    switch (this.active_tab) {
        case 'initial_setup':
            GUI.interval_remove('initial_setup_data_pull');
            
            if (callback) callback();
            break;
        case 'pid_tuning':
            GUI.interval_remove('pid_data_poll');
        
            if (callback) callback();
            break;
        case 'receiver':
            GUI.interval_remove('receiver_poll');
            
            if (callback) callback();
            break;
        case 'auxiliary_configuration':
            GUI.interval_remove('aux_data_poll');
            
            if (callback) callback();
            break;
        case 'servos':
            GUI.interval_remove('servos_data_poll');
            
            if (callback) callback();
            break;
        case 'gps':
            GUI.interval_remove('gps_pull');
            
            if (callback) callback();
            break;
        case 'motor_outputs':
            GUI.interval_remove('motor_poll');
            
            // only enforce mincommand if necessary
            if (MOTOR_DATA != undefined) {
                var update = false;
                
                for (var i = 0; i < MOTOR_DATA.length; i++) {
                    if (MOTOR_DATA[i] > MISC.mincommand) {
                        update = true;
                        break;
                    }
                }
                
                if (update) {
                    // send data to mcu
                    var buffer_out = [];
                    
                    for (var i = 0; i < 8; i++) {
                        buffer_out.push(lowByte(MISC.mincommand));
                        buffer_out.push(highByte(MISC.mincommand));
                    }

                    send_message(MSP_codes.MSP_SET_MOTOR, buffer_out, false, function() {
                        if (callback) callback();
                    });
                } else {
                    if (callback) callback();
                }
            } else {
                if (callback) callback();
            }
            break;
        case 'sensors':
            GUI.interval_kill_all(['port_usage']);
            serial.empty_output_buffer();
            
            // sensor data tab uses scrollbars, emptying the content before loading another tab
            // prevents scrollbar exposure to any of the tabs while new content is loaded in
            $('#content').empty();
            
            if (callback) callback();
            break;
        case 'cli':
            var bufferOut = new ArrayBuffer(5);
            var bufView = new Uint8Array(bufferOut);
            
            bufView[0] = 0x65; // e
            bufView[1] = 0x78; // x
            bufView[2] = 0x69; // i
            bufView[3] = 0x74; // t
            bufView[4] = 0x0D; // enter

            serial.send(bufferOut, function(writeInfo) {
                // we could handle this "nicely", but this will do for now
                // (another approach is however much more complicated):
                // we can setup an interval asking for data lets say every 200ms, when data arrives, callback will be triggered and tab switched
                // we could probably implement this someday
                GUI.timeout_add('waiting_for_bootup', function() {
                    CLI_active = false;
                    CLI_valid = false;
                    
                    if (callback) callback();
                }, 5000); // if we dont allow enough time to reboot, CRC of "first" command sent will fail, keep an eye for this one
            });
            break;
        
        case 'firmware_flasher':
            PortHandler.flush_callbacks();
            
            if (callback) callback();
            break;
            
        default:
            if (callback) callback();
    }
};

// initialize object into GUI variable
var GUI = new GUI_control();