const calendarTextarea = document.getElementById('calendar-textarea');
const untisTextarea = document.getElementById('untis-textarea');

const calendarcalendarCopyButton = document.getElementById('calendar-copy-button');
const untisCopyButton = document.getElementById('untis-copy-button');

const weekList = document.getElementById('week-list');
const exportButton = document.getElementById('export-button');

function loadWeeks() {
    fetch('/newweekavailable?week=' + weekList.options[0].innerHTML)
        .then(response => {
            if (response.ok) {
                return response.json();
            } else {
                throw new Error('Error während des Abrufs');
            }
        }).then(json => {
            if (json[0] == true) {
                weekList.innerHTML = '';
                for (let i = 0; i < json[1].length; i++) {
                    const option = document.createElement('option');
                    option.value = i;
                    option.innerText = json[1][i];
                    weekList.appendChild(option);
                }
            }
        }).catch(error => {
            console.error(error);
        });
}

loadWeeks();
setInterval(loadWeeks, 60000);

let loadingInterval;

function copyToClipboard(button, textarea) {
    navigator.clipboard.writeText(textarea.value).then(() => {
        button.innerText = 'Kopiert!';
            setTimeout(() => {
                button.innerText = 'Kopieren';
            }, 2000);
        }).catch(() => {
            button.innerText = 'Error!';
            setTimeout(() => {
                button.innerText = 'Kopieren';
            }, 2000);
        });
}

function loading() {
    exportButton.disabled = true;
    calendarTextarea.value = 'Wird geladen';
    untisTextarea.value = '';
    loadingInterval = setInterval(() => {
        if (calendarTextarea.value != 'Wird geladen...') {
            calendarTextarea.value += '.';
        } else {
            calendarTextarea.value = 'Wird geladen';
        }
    }, 500);
}

function loaded() {
    exportButton.disabled = false;
    clearInterval(loadingInterval);
    calendarTextarea.value = '';
}

function exportReport() {
    const week = weekList.value;
    
    loading();

    fetch('/getreport?week=' + week)
        .then(response => {
            if (response.ok) {
                return response.text();
            } else {
                calendarTextarea.value = 'Error während des Abrufs';
                throw new Error('Error während des Abrufs');
            }
        }).then(text => {
            loaded();
            
            // parse json
            const json = JSON.parse(text);
            
            calendarTextarea.value = json.calendar;
            calendarTextarea.style.height = "auto";
            calendarTextarea.style.height = calendarTextarea.scrollHeight + "px";
            
            untisTextarea.value = json.untis;
            untisTextarea.style.height = "auto";
            untisTextarea.style.height = untisTextarea.scrollHeight + "px";
        }).catch(error => {
            loaded();
            calendarTextarea.value = 'Error während des Abrufs';
            console.error(error);
        });
}

function autoResize(textarea) {
    textarea.style.height = "auto";
    textarea.style.height = textarea.scrollHeight + "px";
}

calendarTextarea.addEventListener('input', () => {
    autoResize(calendarTextarea);
});
untisTextarea.addEventListener('input', () => {
    autoResize(untisTextarea);
});