/* CodeQ: an online programming tutor.
   Copyright (C) 2015 UL FRI

This program is free software: you can redistribute it and/or modify it under
the terms of the GNU Affero General Public License as published by the Free
Software Foundation, either version 3 of the License, or (at your option) any
later version.

This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
details.

You should have received a copy of the GNU Affero General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */

/**
 * The robot state of the state machine. When it is entered it'll prepare the code editor and load a sub-state machine which represents the 3 different parts of the screen.
 */

(function() {
    "use strict";
    var subScreens, //this will be the actual (sub)state machine
        stateNameTag = 'stateName', //a tag for data which is added to some html elements
        jqScreen = $('#screen_robot'), // the screen container element
        //quadrants
        jqDescription = jqScreen.find('.block1'),
        jqCode = jqScreen.find('.block2'),
        jqConsole = jqScreen.find('.block3'),
        jqInfo = jqScreen.find('.block4'),
        jqAllQuadrants = jqDescription.add(jqCode).add(jqConsole).add(jqInfo), // all the quadrants
        // buttons
        jqBtnPlan = jqScreen.find('.btn-plan'),
        jqBtnHint = jqScreen.find('.btn-hint').ladda(),
        jqBtnRun = jqScreen.find('.btn-run'),
        jqBtnStop = jqScreen.find('.btn-stop'),
        jqInfoButtons = jqBtnPlan.add(jqBtnHint), // all info-focusing buttons
        jqAllButtons = jqInfoButtons.add(jqBtnRun).add(jqBtnStop), // all buttons
        // misc
        currentSubState = null,
        transitionEventName = 'mousedown',//event name of the event which will trigger the transition between these substates - the most common transition at least (there are some corner cases on the hint and test buttons -> see the code below)
        substates = {
            'description': {
                'enter': function () {
                    currentSubState = 'block1';
                    jqScreen.addClass(currentSubState);
                },
                'exit': function () {
                    jqScreen.removeClass(currentSubState);
                    currentSubState = null;
                }
            },
            'code': {
                'enter': function () {
                    currentSubState = 'block2';
                    jqScreen.addClass(currentSubState);
                },
                'exit': function () {
                    jqScreen.removeClass(currentSubState);
                    currentSubState = null;
                }
            },
            'info': {
                'enter': function () {
                    currentSubState = 'block4';
                    jqScreen.addClass(currentSubState);
                },
                'exit': function () {
                    jqScreen.removeClass(currentSubState);
                    currentSubState = null;
                }
            },
            'console': {
                'enter': function () {
                    currentSubState = 'block3';
                    jqScreen.addClass(currentSubState);
                },
                'exit': function () {
                    jqScreen.removeClass(currentSubState);
                    currentSubState = null;
                }
            }
        };

    var enterFun = function(problemDef, commonDef, currentSolution){
        $('#navigation-problem_list').css('display', '');
        var navigationRobot = $("#navigation-robot");
        navigationRobot.addClass("active");
        navigationRobot.css('display', '');

        jqScreen.css('display', '');//we have to show the screen now so the code editor shows its initial values correctly
        robotHandler = createRobotHandler(problemDef, commonDef, currentSolution);
        subScreens = codeq.makeStateMachine(substates);
        subScreens.transition(jqDescription.data(stateNameTag));

        jqInfoButtons.on(transitionEventName, function (event) {
            subScreens.transition('info'); // set focus on the hints quadrant
            event.stopPropagation(); // don't allow the event to go on and trigger further transition
        });
        jqBtnRun.on(transitionEventName, function (event) {
            subScreens.transition('console'); // set focus on the hints quadrant
            event.stopPropagation(); // don't allow the event to go on and trigger further transition
        });

        jqAllQuadrants.on(transitionEventName, function () {
            subScreens.transition($(this).data(stateNameTag));
        });
    };

    var robotHandler; //created when we enter the robot state and destroyed once we leave it
    codeq.globalStateMachine.register('robot', {
        'jqScreen': jqScreen,

        'enter': function (ref, data) {
            codeq.loadProblemData(ref,data).then(function(problem){
                    //codeq.log.debug("then:"+JSON.stringify(problem));
                    enterFun(problem.generalProblemData,data.commonDef,problem.solution);
                })
                .fail(function (reason) {
                    codeq.log.error('Failed to obtain the problem definition: ' + reason, reason);
                    alert('Failed to obtain the problem definition: ' + reason);

                    history.back();//TODO test
                })
                .done();
        },
        'exit': function () {
            jqAllButtons.off(); // unregister all event handlers
            jqAllQuadrants.off();
            jqScreen.css('display', 'none');
            robotHandler.destroy();
            robotHandler = null;
            subScreens.destroy();
            subScreens = null;
            jqScreen.addClass('block1');

            $('#navigation-problem_list').css('display', 'none');
            var navigationRobot = $("#navigation-robot");
            navigationRobot.removeClass("active");
            navigationRobot.css('display', 'none');
        }
    });

    jqDescription.data(stateNameTag, 'description');
    jqCode.data(stateNameTag, 'code');
    jqConsole.data(stateNameTag, 'console');
    jqInfo.data(stateNameTag, 'info');

    // a constant
    var firstCharacterPos = {'line': 0, 'ch': 0};

    var makeRobotTerminalHandler = function (jqConsole, editor, problem_id, activityHandler) {
        var terminal = codeq.makeConsole(jqConsole, {
                'greeting': 'Robot messages\n--------------\n\n',
            });
        terminal.inputDisable();
        return terminal;
    };

    codeq.on('init', function (args) {
        codeq.tr.registerDictionary('robot', codeq.tr.emptyDictionary); // to make the translator happy, when this screen is not active
    });

    var createRobotHandler = function (problemDef, commonDef, currentSolution) {
        var jqDescriptionContent = jqDescription.find('.description'),
            jqEditor = jqCode.find('.code_editor'),
            jqTerminal = jqConsole.find('.console'),
            jqHints = jqInfo.find('.hints'),
            jqStatus = jqConsole.find('.status'),
            editor = codeq.makeEditor(jqEditor[0],
                {
                    mode: 'python',
                    indentUnit: 4,
                    value: currentSolution || ''
                },
                function () {
                    jqBtnRun.focus();
                }),
            activityHandler = codeq.makeActivityHandler(editor, problemDef.id),
            terminal = makeRobotTerminalHandler(jqTerminal, editor, problemDef.id, activityHandler),
            hinter = codeq.makeHinter(jqHints, jqEditor, editor, 'robot_hints', problemDef, commonDef),
            commError = function (error) {
                alert(error);
            },
            reconnectTimer = null,
            url = 'ws://' + codeq.settings['robot_address'] + ':8000/',
            socket = eio(url);

        // set up the websocket events
        socket.on('close', function (data) {
            console.log('websocket closed, trying to reopen in 1 s');
            jqStatus.html('Not connected.');
            reconnectTimer = setTimeout(function () {
                reconnectTimer = null;
                socket.open();
            }, 1000);
        });
        socket.on('message', function(data) {
            //console.log('Received: ' + data);
            var json_obj = JSON.parse(data),
                sensors, sensor, text = '';
            if (json_obj.event == 'update') {
                sensors = json_obj.sensors;
                for (sensor in sensors) {
                    if (!sensors.hasOwnProperty(sensor)) continue;
                    text += sensor + ': ' + sensors[sensor] + '<br />\n'
                }
                jqStatus.html(text);
            }
            else if (json_obj.event == 'output') {
                text = json_obj.text;
                terminal.append(text, 'output');
            }
        });

        codeq.template.processDictionary(problemDef.translations.description,
                [problemDef.language, problemDef.group, problemDef.problem]);
        codeq.tr.registerDictionary('robot', problemDef.translations);
        codeq.tr.translateDom(jqScreen);
        jqBtnPlan.prop('disabled', !hinter.hasNextPlan());

        editor.on('change', function (instance, changeObj) {
            var doc = editor.getDoc(),
                pos = codeq.codePointCount(doc.getRange(firstCharacterPos, changeObj.from)),
                text;

            text = changeObj.removed.join('\n');
            if (text) {
                activityHandler.queueTrace({'typ': 'rm', 'off': pos, 'txt': text});
            }

            text = changeObj.text.join('\n');
            if (text) {
                activityHandler.queueTrace({'typ': 'ins', 'off': pos, 'txt': text});
            }
        });

        jqBtnPlan.on('click', function () {
            activityHandler.queueTrace({'typ': 'plan'});
            if (!hinter.planNext()) {
                jqBtnPlan.prop('disabled', true).blur();
            }
        });
        jqBtnHint.on('click', function () {
            editor.setOption('readOnly', true);
            jqBtnHint.ladda('start');
            codeq.comms.sendHint({
                'language': 'robot',
                'program': editor.getDoc().getValue(),
                'problem_id': problemDef.id
            })
            .then(function (data) {
                if (data.code === 0) {
                    activityHandler.queueTrace({'typ': 'hint', 'feedback': data.hints});
                    hinter.handle(data.hints);
                }
                else {
                    commError('error: ' + data.message);
                }
            })
            .fail(commError)
            .fin(function () {
                editor.setOption('readOnly', false);
                jqBtnHint.ladda('stop');
            })
            .done();
        });
        jqBtnRun.on('click', function () {
            var program = editor.getDoc().getValue();
            activityHandler.queueTrace({'typ': 'robot_run', 'program': program});
            socket.send(JSON.stringify({action: 'run', program: program}));
            terminal.append('<run>\n', 'output');
        });
        jqBtnStop.on('click', function () {
            activityHandler.queueTrace({'typ': 'robot_stop'});
            socket.send(JSON.stringify({action: 'stop'}));
            terminal.append('<stop>\n', 'output');
        });

        codeq.comms.loadProblem(problemDef.id).done();
        activityHandler.queueTrace({
            'typ': 'open',
            'time': Date.now(),
            'content': editor.getDoc().getValue()
        });

        return {
            destroy: function () {
                codeq.comms.endProblem().done();

                if (socket) {
                    socket.off('close');
                    socket.off('message');
                    socket.close();
                    socket = null;
                }
                if (reconnectTimer !== null) {
                    clearTimeout(reconnectTimer);
                    reconnectTimer = null;
                }

                $('#screen_robot .title').text('');//empty the title text
                jqAllButtons.off();
                editor.off('change');
                activityHandler.queueTrace({'typ': 'close'});
                activityHandler.flush();
                hinter.destroy();
                jqDescriptionContent.empty();
                jqEditor.empty(); // TODO: perhaps you do not want to "free" the editor, just empty it
                jqDescriptionContent = null;
                jqEditor = null;
                jqHints = null;
                codeq.tr.registerDictionary('robot', codeq.tr.emptyDictionary);
            }
        };
    };
})();