// initialize moment.js
moment().format();

$(document).ready(function() {
    for (m = 0; m <= 11; m++) {
        $('#month').append('<option value="' + m + '">' + moment().month(m).format('MMMM') + '</option>' );
    }
    $('.results-wrapper').hide();
});

// call validation when the submit button is clicked
$('#preg-submit').on('click keyup', function(e) {
    return validateInput(e);
});

// also call validation when the enter key is clicked on any form element
$('#month, #date, #year, #cycle-days').on('keyup', function(e) {

    // set a variable that handles the key event for all browsers
    var keycode = (event.keyCode ? event.keyCode : event.which);

    // if the return key (ASCII number 13) is pressed, run the function.
    if (keycode == '13') {
        return validateInput(e);
    }
});
// check the validity of the #cycle-days value before
// we allow the data to be parsed and displayed
function validateInput(e) {
    // Get input values
    var month = parseInt($('#month').val());
    var date = parseInt($('#date').val());
    var year = parseInt($('#year').val());
    var cycle = parseInt($('#cycle-days').val());

    return checkMonthInput();

    // check that a month has been selected
    function checkMonthInput() {
        if (!isNaN(month)) {
            // make sure the error message container is hidden
            $('.month-selector small').addClass('hidden');

            // check the year
            return checkYearInput();
        } else {
            // put the brakes on form submission
            e.stopPropagation();

            // rehide the content if it's been unhidden
            $('.results-wrapper').hide();

            // alert the user to the problem
            $('.month-selector small').addClass('has-error').removeClass('hidden').html('Please select a month.');

            // put focus back on the field that is missing information
            $('#month').focus();
        }
    }

    function checkYearInput() {
        var yearLength = $('#year').val().length;
        if (!isNaN(year) && yearLength === 4) {
            // make sure the error message container is hidden
            $('.year-input small').addClass('hidden');

            // check the date
            return checkDateInput();
        } else {
            // put the brakes on form submission
            e.stopPropagation();

            // rehide the content if it's been unhidden
            $('.results-wrapper').hide();

            // alert the user to the problem
            $('.year-input small').addClass('has-error').removeClass('hidden').text('Please enter the year in YYYY format. For example, this year is ' + moment().year());

            // put focus back on the field that is missing information
            $('#year').focus();
        }
    }

    // check that the date is valid given the month and year
    function checkDateInput() {
        var dateLength = $('#date').val().length;

        if (!isNaN(date) && (dateLength == 1 || dateLength == 2)) {
            console.log(moment(month).format('MMMM'));
            if (month === 1) {
                if (moment(year).isLeapYear() === false) {
                    if (date > 28) {
                        // put the brakes on form submission
                        e.stopPropagation();

                        // rehide the content if it's been unhidden
                        $('.results-wrapper').hide();

                        // alert the user to the problem
                        $('.date-input small').addClass('has-error').removeClass('hidden').text('There are 28 days in ' + $('#month > option:selected').text() + ' in ' + moment().year() + '. Please correct your input.');

                        // put focus back on the field that is missing information
                        $('#date').focus();
                    } else {
                        // make sure the error message container is hidden
                        $('.date-input small').addClass('hidden').removeClass('has-error');

                        // check the cycle length
                        return checkCycleLength();
                    }
                } else if (moment(year).isLeapYear() === true) {
                    if (date > 29) {
                        // put the brakes on form submission
                        e.stopPropagation();

                        // rehide the content if it's been unhidden
                        $('.results-wrapper').hide();

                        // alert the user to the problem
                        $('.date-input small').addClass('has-error').removeClass('hidden').text('There are 29 days in February in ' + $('#month > option:selected').text() + ' in ' + moment().year() + '. Please correct your input.');

                        // put focus back on the field that is missing information
                        $('#date').focus();
                    } else {
                        console.log(moment(month).format('MMMM'));
                        // make sure the error message container is hidden
                        $('.date-input small').addClass('hidden').removeClass('has-error');

                        // check the cycle length
                        return checkCycleLength();
                    }
                }
            } else if (month === 3 || month === 5 || month === 8 || month === 10) {
                if (date > 30) {
                    // put the brakes on form submission
                    e.stopPropagation();

                    // rehide the content if it's been unhidden
                    $('.results-wrapper').hide();

                    // alert the user to the problem
                    $('.date-input small').addClass('has-error').removeClass('hidden').text('There are 30 days in ' + $('#month > option:selected').text() + '. Please correct your input.');

                    // put focus back on the field that is missing information
                    $('#date').focus();
                } else {
                    // make sure the error message container is hidden
                    $('.date-input small').addClass('hidden').removeClass('has-error');

                    // check the cycle length
                    return checkCycleLength();
                }
            } else {
                if (date > 31) {
                    // put the brakes on form submission
                    e.stopPropagation();

                    // rehide the content if it's been unhidden
                    $('.results-wrapper').hide();

                    // alert the user to the problem
                    $('.date-input small').addClass('has-error').removeClass('hidden').text('There are 31 days in ' + $('#month > option:selected').text() + '. Please correct your input.');

                    // put focus back on the field that is missing information
                    $('#date').focus();
                } else {
                    // make sure the error message container is hidden
                    $('.date-input small').addClass('hidden').removeClass('has-error');

                    // check the cycle length
                    return checkCycleLength();
                }
            }
        } else {
            // put the brakes on form submission
            e.stopPropagation();

            // rehide the content if it's been unhidden
            $('.results-wrapper').hide();

            // alert the user to the problem
            $('.date-input small').addClass('has-error').removeClass('hidden').text('Please correct your date entry. For example, today\'s date is: ' + moment().date());

            // put focus back on the field that is missing information
            $('#date').focus();
        }
    }

    // check to see if the cycle length has been entered
    function checkCycleLength() {
        if (cycle > 23 && cycle < 44) {
            // make sure the error message container is hidden
            $('.cycle-input small').removeClass('has-error has-warning').addClass('hidden');

            // check the cycle length
            return outputData();
        } else if (cycle <= 22 || cycle >= 45) {
            // if the cycle interval is too short
            if (cycle <= 22) {
                // alert the user and allow the calculation to continue
                $('.cycle-input small').addClass('has-warning').removeClass('hidden has-error').html('The cycle length you entered is too short to make an accurate prediction, but we\'ll do our best.');

                // process the provided data
                return outputData();
            } else if (cycle >= 45) {
                // alert the user and allow the calculation to continue
                $('.cycle-input small').addClass('has-warning').removeClass('hidden has-error').html('The cycle length you entered is too long to make an accurate prediction, but we\'ll do our best.');

                // process the provided data
                return outputData();
            }
        } else {
            // put the brakes on form submission
            e.stopPropagation();

            // rehide the content if it's been unhidden
            $('.results-wrapper').hide();

            // alert the user to the problem
            $('.cycle-input small').addClass('has-error').removeClass('hidden has-warning').html('We can\'t make a prediction until you\'ve completed all the fields. Please enter your cycle length.');

            // put focus back on the field that is missing information
            $('#cycle-days').focus();
        }
    }

    // give the user some data
    function outputData() {
        // set the date of the end of the user's last menstrual cycle
        var menstrualDate = moment().set({
            'date': date,
            'month': month,
            'year': year
        });

        // TODO: Confirm that we only want to show the beginning of the conception period
        // set the ovulation date, conceptionStart date, and conceptionEnd date
        // so we can work with them and output data later.
        var ovulation = moment(menstrualDate + 86400000 * cycle - 1123200000);
        var conceptionStart = moment(ovulation - 432000000);
        //var conceptionEnd = moment(ovulation + 432000000);

        // Set the likely beginning date of the range
        // in which conception could occur
        $('.conception-begin').text(moment(conceptionStart).format('dddd, MMMM Do, YYYY'));

        // Set the likely ending date of the range
        // in which conception could occur
        //$('.conception-end').text(moment(conceptionEnd).format('dddd, MMMM Do, YYYY'));

        // Set the date of the end as the first trimester.
        // Per my source, the first trimester ends at
        // 83 days after the identified date of conception
        $('.first-trimester').text(moment(conceptionStart).add(83, 'days').format('dddd, MMMM Do, YYYY'));

        // Set the date of the end as the first trimester.
        // Per my source, the first trimester ends at
        // 83 days after the identified date of conception
        $('.second-trimester').text(moment(conceptionStart).add(195, 'days').format('dddd, MMMM Do, YYYY'));

        // Set the likely date of birth.
        // Per the internet (and if it's on the internet,
        // it must be true), the human gestational period
        // averages 280 days.
        $('.due-date').text(moment(conceptionStart).add(280, 'days').format('dddd, MMMM Do, YYYY'));

        //unhide the container
        $('.results-wrapper').fadeIn(600);
    }
}