main.js

//calendar api : https://classes.engineering.wustl.edu/cse330/content/calendar.js
(function(){Date.prototype.deltaDays=function(c){return new Date(this.getFullYear(),this.getMonth(),this.getDate()+c)};Date.prototype.getSunday=function(){return this.deltaDays(-1*this.getDay())}})();
function Week(c){this.sunday=c.getSunday();this.nextWeek=function(){return new Week(this.sunday.deltaDays(7))};this.prevWeek=function(){return new Week(this.sunday.deltaDays(-7))};this.contains=function(b){return this.sunday.valueOf()===b.getSunday().valueOf()};this.getDates=function(){for(var b=[],a=0;7>a;a++)b.push(this.sunday.deltaDays(a));return b}}
function Month(c,b){this.year=c;this.month=b;this.nextMonth=function(){return new Month(c+Math.floor((b+1)/12),(b+1)%12)};this.prevMonth=function(){return new Month(c+Math.floor((b-1)/12),(b+11)%12)};this.getDateObject=function(a){return new Date(this.year,this.month,a)};this.getWeeks=function(){var a=this.getDateObject(1),b=this.nextMonth().getDateObject(0),c=[],a=new Week(a);for(c.push(a);!a.contains(b);)a=a.nextWeek(),c.push(a);return c}};

//getting the today's date
let today = new Date();
let todayMonth = today.getMonth();
let todayYear = today.getFullYear();

//Starts with the real time current month
var currentMonth = new Month(todayYear, todayMonth); 
//tells whether user is logged
var userLoggedIn = false;
var userId = '';
//check if user is logged in
checkLogin();
//generates calendar table for the currentMonth
generateMonth();
//adds events to the calendar if a user is logged in and has events
updateCalendar();

//when next month button is pressed
document.getElementById("nextBtn").addEventListener("click", function(event){
    currentMonth = currentMonth.nextMonth(); 
    //document.getElementById('calendarTable').innerHTML="<thead><tr><th>Sunday</th><th>Monday</th><th>Tuesday</th><th>Wednseday</th><th>Thursday</th><th>Friday</th><th>Saturday</th></tr></thead>";
    generateMonth();
	updateCalendar(); 
}, false);
//when previous month button is pressed
document.getElementById("prevBtn").addEventListener("click", function(event){
    currentMonth = currentMonth.prevMonth(); // Previous month would be currentMonth.prevMonth()
    //document.getElementById('calendarTable').innerHTML="<thead><tr><th>Sunday</th><th>Monday</th><th>Tuesday</th><th>Wednseday</th><th>Thursday</th><th>Friday</th><th>Saturday</th></tr></thead>";
    generateMonth();
	updateCalendar(); // Whenever the month is updated, we'll need to re-render the calendar in HTML
}, false);

//generates calendar table for the currentMonth
function generateMonth(){
    let monthsArr = ['January','Febuary','March','April','May','June','July','August','September','October','November','December'];
    var weeks = currentMonth.getWeeks();
    document.getElementById('monthAndYear').innerHTML = monthsArr[currentMonth.month]+' '+currentMonth.year;
    document.getElementById('calendarTable').innerHTML="<thead><tr><th>Sunday</th><th>Monday</th><th>Tuesday</th><th>Wednseday</th><th>Thursday</th><th>Friday</th><th>Saturday</th></tr></thead>";
        let i = 1;
        for(var w in weeks){
            var days = weeks[w].getDates();
            let tableRow = document.createElement("tr");
            tableRow.setAttribute('id','row'+i);
            i+=1;
            let week = document.getElementById('calendarTable').appendChild(tableRow);
            let nextMonthDays = document.createElement("th");
            for(var d in days){
                if(currentMonth.month == days[d].getMonth()){
                    dayId = days[d].getDate()+'';
                    day = week.innerHTML+='<th class="day" id="'+dayId+'">'+ days[d].getDate()+'</th>';
                } 
                else{
                    day = week.innerHTML+='<th class="otherDay">'+ monthsArr[days[d].getMonth()]+' '+days[d].getDate()+'</th>';
                }
            }
        }
}
//addeds events if user is logged in
function updateCalendar(){

    if(userLoggedIn){

        getEventsAjax(userId);
    }

}

////////////////////////////////////////////////////////////
//This section handles logging in, logging out, and signing up
////////////////////////////////////////////////////////////

//logging in
document.getElementById("login_btn").addEventListener("click", loginAjax, false);
//logout button
document.getElementById('logout_btn').addEventListener("click",logoutAjax,false);
//signing up button
document.getElementById('signup_btn').addEventListener("click",signupAjax,false);

//check if user is logged that way they're not logged out on page reload
function checkLogin(){
    fetch("includes/checkLoginHandler.php", {
        method: 'POST',
        headers: {'content-type' : 'application/json'}
    })
    .then(response => response.json())
    .then(data => data.success ?  loginDisplay(data.username,data.user_id):logoutDisplay())
    .catch(err => console.error(err));
}
//send data to server to login in
function loginAjax(event) {
    const username = document.getElementById("username").value; // Get the username from the form
    const password = document.getElementById("pwd").value; // Get the password from the form
    
    // Make a URL-encoded string for passing POST data:
    const data = { 'username': username, 'password': password };

    fetch("includes/loginHandler.php", {
            method: 'POST',
            body: JSON.stringify(data),
            headers: { 'content-type': 'application/json' }
        })
        .then(response => response.json())
        .then(data => data.success ? loginDisplay(data.username,data.user_id) : alert(`You were not logged in ${data.message}`))
        .catch(err => console.error(err));
}
//Display when user is logged in so logout button is shown while sign up and log in buttons are not
function loginDisplay(username, user_id){
    //hide signup and login forms and show logout button
    document.getElementById('loginSignup').style.display = 'none';
    document.getElementById('logout').hidden = false;
    //clear the login and sign up inputs
    document.getElementById('username').value ="";
    document.getElementById('pwd').value="";
    document.getElementById('usernameCreate').value ="";
    document.getElementById('pwdCreate').value="";
    document.getElementById('pwd-repeat').value="";
    //show create event button when logged in
    document.getElementById('createEventBtn').hidden = false;
    userLoggedIn = true;
    userId = user_id;
    updateCalendar();
}

function logoutAjax(event){
    fetch("includes/logoutHandler.php", {
        method: 'POST',
        headers: {'content-type' : 'application/json'}
    })
    .then(response => response.json())
    .then(data => data.success ? logoutDisplay() :alert(`You were not logged out ${data.message}`))
    .catch(err => console.error(err));
}

function logoutDisplay(){
    console.log("You've been logged out!");
    document.getElementById('loginSignup').style.display = 'block';
    document.getElementById('logout').hidden = true;
    document.getElementById('createEventBtn').hidden = true;
    userLoggedIn = false;
    userId = '';
    document.getElementById('calendarTable').innerHTML='';
    generateMonth();
}
//user is automatically logged in on sign up so it goes to login in display after they make an account
function signupAjax(event) {
    const username = document.getElementById("usernameCreate").value; // Get the username from the form
    const password = document.getElementById("pwdCreate").value; // Get the password from the form
    const passwordRepeat= document.getElementById("pwd-repeat").value;
    // Make a URL-encoded string for passing POST data:
    
    const data = { 'username': username, 'password': password, 'passwordRepeat':passwordRepeat };

    fetch("includes/signupHandler.php", {
            method: 'POST',
            body: JSON.stringify(data),
            headers: { 'content-type': 'application/json' }
        })
        .then(response => response.json())
        .then(data => data.success ? loginDisplay(data.username,data.user_id) : alert(`Could not create account: ${data.message}`))
        .catch(err => console.error(err));

    }

///////////////////////////////////////////////////////////////////////////////
//This section handles calendar events (ex: creating, fetching, editing, deleting)
///////////////////////////////////////////////////////////////////////////////


//when create event button is pressed the create event input box will pop up on the screen
document.getElementById('createEventBtn').addEventListener("click",function(event){
    document.getElementById('createEvent').hidden = false;
});
//when close button is clicked the create box will disappear
document.getElementById('closeCreateBtn').addEventListener("click",function(event){
    document.getElementById('createEvent').hidden = true;
});
//check when create event form is submitted and run ajax function
document.getElementById('createBtn').addEventListener("click", createEventAjax,false);

//when delete event button is pressed
document.getElementById('deleteEvent').addEventListener('click',deleteEventAjax,false);
document.getElementById('editEventBtn').addEventListener('click',editEventPopUp,false);
//edit fields when edit button is clicked
document.getElementById('changeEvent').addEventListener('click',editEventAjax,false);

function createEventAjax(event){
    const title = document.getElementById("eventTitle").value; // Get the username from the form
    const date = document.getElementById("eventDate").value; // Get the password from the form
    const time= document.getElementById("eventTime").value;
    // Make a URL-encoded string for passing POST data:
    
    const data = { 'title': title, 'date': date, 'time':time };

    fetch("includes/createEventHandler.php", {
            method: 'POST',
            body: JSON.stringify(data),
            headers: { 'content-type': 'application/json' }
        })
        .then(response => response.json())
        .then(data => data.success ? createEventDisplay() : alert(`Could not create event: ${data.message}`))
        .catch(err => console.error(err));
}
//hides create event box and empties inputs. Then updates caledndar with new event
 function createEventDisplay(){
    document.getElementById("eventTitle").value='';
    document.getElementById("eventDate").value='';
    document.getElementById("eventTime").value='';
    document.getElementById('createEvent').hidden = true;
    userLoggedIn = true;
    generateMonth();
    updateCalendar();
 }
 
//gets events that have that user_id
 function getEventsAjax(user_id){
    const data = {'user_id':user_id};

    fetch("includes/getEventHandler.php", {
        method: "POST",
        body: JSON.stringify(data),
        headers: {'content-type': 'application/json'}
    })
    .then(response => response.json())
    .then(data => data.success ? getEventDetails(data.events):console.log('no events available'))
    .catch(err => console.error(err));
 }
//gets the event details 
 function getEventDetails(events){
    events.forEach(event => {
        addEvent(event.title, event.date, event.time,event.id)
    });
 }

//same as generate month except we add events to the month
function addEvent(title, date, time,id){
    //split the event date by components and convert to int so we can make the nessecary comparisons further down
    let eventYear = Number(date.slice(0,4));
    let eventMonth = Number(date.slice(5,7));
    let eventDay = Number(date.slice(8,10));
    let eventHour = Number(time.slice(0,2));
    //convert the mysql time to 12-hour clock convention
    let oldTime = time;
    eventHour;
    let suffix = 'am ';
    if(eventHour>=12){
        eventHour = eventHour-12;
        suffix = 'pm '
    }
    if(eventHour==0){
        eventHour=12;
    }
    time = eventHour+time.slice(2,5)+suffix;
    let monthsArr = ['January','Febuary','March','April','May','June','July','August','September','October','November','December'];
    var weeks = currentMonth.getWeeks();
    document.getElementById('monthAndYear').innerHTML = monthsArr[currentMonth.month]+' '+currentMonth.year;
    for(var w in weeks){
        var days = weeks[w].getDates()
        //only shows events for the current month
        for(var d in days){
            if(currentMonth.month == days[d].getMonth()){
                dayId = days[d].getDate()+'';
                //check if event year, month and day matches
                if(eventYear==days[d].getFullYear() && eventMonth==days[d].getMonth()+1 && eventDay==days[d].getDate()){
                    //html event_id is based on mysql id
                    eventId = 'event'+id;
                    day = document.getElementById(dayId);
                    //create div for event
                    let eventDiv = document.createElement("div");
                    eventDiv.setAttribute('id',eventId);
                    eventDiv.setAttribute('class','events');
                    //display title for event
                    let eventTitle = document.createElement('p');
                    eventTitle.appendChild(document.createTextNode(title));
                    eventTitle.setAttribute('class','eventTitle');
                    //display the time for event
                    let eventTime = document.createElement('small');
                    eventTime.appendChild(document.createTextNode(time));
                    eventTime.setAttribute('class','eventTime');
                    //save all of the event attributes in the div so we can access them when its clicked
                    eventDiv.time = time;
                    eventDiv.oldTime = oldTime;
                    eventDiv.title = title;
                    eventDiv.eventId = id;
                    eventDiv.date = date;
                    eventDiv.appendChild(eventTime);
                    eventDiv.appendChild(eventTitle);
                    day.appendChild(eventDiv);
                    //when div is click the event will pop up
                    document.getElementById(eventId).addEventListener("click",eventPopUp);
                }
            } 
        }

    }
}
//close event popup
document.getElementById('closeEventBtn').addEventListener('click',closeEvent);

//Pops up when event div that is displayed in calendar view is clicked
function eventPopUp(event){
    let popUp = document.getElementById('eventPopUp');
    //attach all of the event details to the different buttons
    document.getElementById('deleteEvent').eventId = event.currentTarget.eventId;
    document.getElementById('changeEvent').eventId = event.currentTarget.eventId;
    document.getElementById('editEventBtn').eventId = event.currentTarget.eventId;
    document.getElementById('editEventBtn').title = event.currentTarget.title;
    document.getElementById('editEventBtn').date = event.currentTarget.date;
    document.getElementById('editEventBtn').time = event.currentTarget.oldTime;

    //empty the previous selected event details
    if(!popUp.hidden){
        document.getElementById('eventTextArea').innerHTML="";
        popUp.hidden=true;
    }
    //heading is the title of the event
    let heading = document.createElement('h3');
    heading.appendChild(document.createTextNode(event.currentTarget.title));
    heading.setAttribute('id','popHeading');
    //details contains the date and time of event
    let details = document.createElement('p');
    details.setAttribute('id','popDetails');
    details.appendChild(document.createTextNode(event.currentTarget.date));
    details.appendChild(document.createTextNode(' '+event.currentTarget.time));
    document.getElementById('eventTextArea').appendChild(heading);
    document.getElementById('eventTextArea').appendChild(details);
    //show the popup
    popUp.hidden = false;
}
//close the event popup and go back to page was before event was clicked
function closeEvent(){
    document.getElementById('eventTextArea').style.display = 'block';
    document.getElementById('editEvent').hidden = true;
    document.getElementById('editEventBtn').style.display = 'inline-block';
    document.getElementById('deleteEvent').style.display = 'inline-block';
    document.getElementById('eventPopUp').hidden = true;
    document.getElementById('eventTextArea').innerHTML='';
}
//deletes the clicked event from mysql
function deleteEventAjax(event){
    const data = {'event_id':event.currentTarget.eventId};

    fetch("includes/deleteEventHandler.php", {
        method: "POST",
        body: JSON.stringify(data),
        headers: {'content-type': 'application/json'}
    })
    .then(response => response.json())
    .then(data => data.success ? deleteEventDisplay(): alert(`Could not delete event: ${data.message}`))
    .catch(err => console.error(err));
}
//reloads calendar after deletion
function deleteEventDisplay(){
    closeEvent();
    generateMonth();
    updateCalendar();
}
//pops up when edit button is clicked
function editEventPopUp(event){
    document.getElementById("editTitle").value= event.currentTarget.title; // Get the username from the form
    document.getElementById("editDate").value = event.currentTarget.date; // Get the password from the form
    document.getElementById("editTime").value = event.currentTarget.time;
    document.getElementById('eventTextArea').style.display = 'none';
    document.getElementById('editEvent').hidden = false;
    document.getElementById('editEventBtn').style.display = 'none';
    document.getElementById('deleteEvent').style.display = 'none';
}

//called when makes changes button is clicked
function editEventAjax(event){
    const title = document.getElementById("editTitle").value; // Get the username from the form
    const date = document.getElementById("editDate").value; // Get the password from the form
    const time= document.getElementById("editTime").value;
    // Make a URL-encoded string for passing POST data:
    const data = { 'title': title, 'date': date, 'time':time, 'event_id':event.currentTarget.eventId };

    fetch("includes/editEventHandler.php", {
            method: 'POST',
            body: JSON.stringify(data),
            headers: { 'content-type': 'application/json' }
        })
        .then(response => response.json())
        .then(data => data.success ? editEventDisplay(data.message) : alert(`Could not edit event: ${data.message}`))
        .catch(err => console.error(err));
}
//reloads calendar after event is edited and clears neccessary fields
function editEventDisplay(message){
    document.getElementById("editTitle").value='';
    document.getElementById("editDate").value='';
    document.getElementById("editTime").value='';
    document.getElementById('eventPopUp').hidden = true;
    document.getElementById('editEvent').hidden = true;
    document.getElementById('eventTextArea').style.display = 'block';
    document.getElementById('eventTextArea').innerHTML="";
    document.getElementById('editEventBtn').style.display = 'inline-block';
    document.getElementById('deleteEvent').style.display = 'inline-block';
    generateMonth();
    updateCalendar();
}