/**
 * Created by robert on 9/15/15.
 */

codeq.makeStateMachine = function(def){
    var currState = null;
    return {
        'transition': function(name){
            if(currState !== null) currState.exit();
            currState = def[name];
            currState.enter();
        },
        'destroy': function(){
            if(currState !== null) currState.exit();
            currState = null;
        }
    }
}




var loginFun = function(){
    var identifier = $('#problem_group').val().split('/'),
        problem = $('#problems').val();
    if (identifier.length < 2) alert('Choose a problem group');
    else if (!problem) alert('Choose a problem');
    else {
        $('#disabled').css('display', '');
        codeq.comms.login($('#username').val(), $('#password').val())
            .then(function (data) {
                $('#disabled').css('display', 'none');
                if (data.code !== 0) throw new Error('Login failed, code: ' + data.code + ', message: ' + data.message);
            })
            .then(function () {
                return codeq.comms.getProblem(identifier[0], identifier[1], problem);
            })
            .then(function (data) {
                if (data.code !== 0) throw new Error('Failed to obtain problem data, code: ' + data.code + ', message: ' + data.message);
                $('#disabled').css('display', 'none');
                switch (identifier[0]) {
                    case 'prolog':
                        // TODO: assignment to window for debug only
                        //$('#screen_login').css('display', 'none');
                        //$('#screen_prolog').css('display', '');
                        codeq.globalStateMachine.transition('prolog');
                        window.phandler = codeq.createPrologHandler(data.data);
                        break;
                    case 'python':
                        // TODO: assignment to window for debug only
                        //$('#screen_login').css('display', 'none');
                        //$('#screen_prolog').css('display', '');
                        codeq.globalStateMachine.transition('prolog');
                        window.phandler = codeq.createPythonHandler(data.data);
                        break;
                    default:
                        alert('Unknown language: ' + identifier[0]);
                        break;
                }
            })
            .fail(function (reason) {
                $('#disabled').css('display', 'none');
                alert('Login request failed: ' + reason);
            })
            .done();
    }
};

codeq.globalStateMachine = codeq.makeStateMachine({
    'login':{
        'enter': function(){
            codeq.comms.connect().then(function () {
                return codeq.comms.send({'action': 'list_problems'});//currently problem list and the actual login are still in the same state
            }).then(
                function success(data) {
                    var i, groups, group, problems, problem, first_group,
                        jqGroup = $('#problem_group'),
                        jqProblems = $('#problems'),
                        html = [],
                        mapping = {},
                        onGroupChange = function () {
                            var problems = mapping[jqGroup.val()],
                                html = [],
                                i, p;
                            if (problems) {
                                for (i = 0; i < problems.length; i++) {
                                    p = problems[i];
                                    html.push('<option value="', p.identifier, '">', p.name, '</option>\n')
                                }
                            }
                            jqProblems.html(html.join(''));
                        };

                    if (data && (data.code === 0)) {
                        $('#disabled').css('display', 'none');
                        groups = data.problems;
                        for (i = 0; i < groups.length; i++) {
                            group = groups[i];
                            var identifier = group.identifier.language + '/' + group.identifier.group;
                            var name = group.name.language + ': ' + group.name.group;
                            html.push('<option value="', identifier, '">', name, '</option>\n');
                            mapping[identifier] = group.problems;
                        }
                        jqGroup.html(html.join(''));
                        first_group = html[1];
                        html = null;

                        jqGroup.on('click', onGroupChange);
                        jqGroup.val(first_group);
                        onGroupChange();

                        $("#submit").on('click', loginFun);
                    }
                    else {
                        $('#disabled').css('cursor', '');
                        alert('Obtaining list of problems failed: code=' + data.code + ', reason=' + data.message);
                    }
                },

                function failure(reason) {
                    $('#disabled').css('cursor', '');
                    alert('Request to obtain list of problems failed: ' + reason);
                }
            ).done();
        },
        'exit' : function(){
            $("#submit").off('click', loginFun);
            $("#screen_login").css('display', 'none');
        }
    },

    'prolog':{
        'enter': function(){
            $('#screen_prolog').css('display', '');
            removeFocusFromElements();
            problems = codeq.makeStateMachine(substates);
            //problems.transition('instructions');
            problems.transition('instructions');
        },
        'exit': function(){
            $('#screen_prolog').css('display', 'none');
            problems.destroy();
        }
    }
});

/*
the following variables are used in the sub-state machine representing the 4 different panels in the codeq app
 */
var problems,//this will the actual state machine
    description = $('div.col-lg-3.col-md-6.col-sm-12:has(#description)'),//lets actually find the needed divs for later use
    code = $('div.col-lg-3.col-md-6.col-sm-12:has(#code_editor)'),
    consoleDiv = $('div.col-lg-3.col-md-6.col-sm-12:has(#console)'),//named 'consoleDiv', because 'console' is already in use
    info = $('div.col-lg-3.col-md-6.col-sm-12:has(#info)'),

    //some functions used inside the enter and exit functions of the state machine
    eventName = 'mousedown',//event name of the event which will trigger the transition between these substates
    mouseDownEventFunctionDescription = function(){
        problems.transition('instructions');
    },
    mouseDownEventFunctionCode = function(){
        problems.transition('code');
    },
    mouseDownEventFunctionConsole = function(){
        problems.transition('console');
    },
    mouseDownEventFunctionInfo = function(){
        problems.transition('info');
    },
    removeListenersFromDivs = function(){
        description.off(eventName,mouseDownEventFunctionDescription);
        code.off(eventName,mouseDownEventFunctionCode);
        consoleDiv.off(eventName,mouseDownEventFunctionConsole);
        info.off(eventName,mouseDownEventFunctionInfo);
    },
    removeBlockClassesFromDivs = function(){
        description.removeClass('block');
        code.removeClass('block');
        consoleDiv.removeClass('block');
        info.removeClass('block');
    },
    removeChangedClassesFromDivs = function(){
        description.removeClass('block-focus block-less-width block-less-height block-less-everything').addClass('block');//these class names were chosen for the view where the screen is partitioned in 4 quarters (2 by 2)
        code.removeClass('block-focus block-less-width block-less-height block-less-everything').addClass('block');
        consoleDiv.removeClass('block-focus block-less-width block-less-height block-less-everything').addClass('block');
        info.removeClass('block-focus block-less-width block-less-height block-less-everything').addClass('block');
    },
    setTransitionsBetweenDivs = function(current){
        if(current !== description)description.on(eventName,mouseDownEventFunctionDescription);
        if(current !== code)code.on( eventName,mouseDownEventFunctionCode);
        if(current !== info)info.on( eventName,mouseDownEventFunctionInfo);
        if(current !== consoleDiv)consoleDiv.on( eventName,mouseDownEventFunctionConsole);
    },
    removeFocusFromElements = function(){

    },

    //the states of the sub-state machine
    substates = {
        'instructions':{
            'enter': function(){
                removeBlockClassesFromDivs();

                description.addClass('block-focus');
                code.addClass('block-less-width');
                consoleDiv.addClass('block-less-height');
                info.addClass('block-less-everything');

                setTransitionsBetweenDivs(description);
            },
            'exit': function(){
                removeFocusFromElements();
                removeChangedClassesFromDivs();
                removeListenersFromDivs();
            }
        },
            'code':{
            'enter': function(){
                removeBlockClassesFromDivs();

                description.addClass('block-less-width');
                code.addClass('block-focus');
                consoleDiv.addClass('block-less-everything');
                info.addClass('block-less-height');

                setTransitionsBetweenDivs(code);
            },
            'exit': function(){
                removeFocusFromElements();
                removeChangedClassesFromDivs();
                removeListenersFromDivs();
            }
        },
            'info':{
            'enter': function(){
                removeBlockClassesFromDivs();

                description.addClass('block-less-everything');
                code.addClass('block-less-height');
                consoleDiv.addClass('block-less-width');
                info.addClass('block-focus');

                setTransitionsBetweenDivs(info);
            },
            'exit': function(){
                removeFocusFromElements();
                removeChangedClassesFromDivs();
                removeListenersFromDivs();
            }
        },
            'console':{
            'enter': function(){
                removeBlockClassesFromDivs();

                description.addClass('block-less-height');
                code.addClass('block-less-everything');
                consoleDiv.addClass('block-focus');
                info.addClass('block-less-width');

                setTransitionsBetweenDivs(consoleDiv);
            },
            'exit': function(){
                removeFocusFromElements();
                removeChangedClassesFromDivs();
                removeListenersFromDivs();
            }
        }
    };