//Gets the DOM of the from
const form  = document.getElementById('newVendorForm');

//Gets the DOM of the description text area seperately because it is not part of the form
const serviceBox = document.getElementById('desc');

//Initializes an event listener on the submit button of the form
form.addEventListener('submit', (e) => {
    e.preventDefault(); //Prevents the page from refreshing

    //Retrieves the values of all input fields in the form and saves it into a data object
    const formData = new FormData(form);
    const data = Object.fromEntries(formData);

    //Retieves the values of the description box
    const service = serviceBox.value;
    
    //Checks if the information is missing or invalid
    if (data.companyName == "") {
        alert("Please fill out your companies name")
    } else if (data.location == ""){
        alert("Please fill out your location")
    } else if (service == "") {
        alert("Please fill out your companies services provided")
    } else if (ValidateInformation(data.phoneNumber, data.email)){ //Validate the email and phone number
        
        //This is where the code to send the email will go in the next unit, utilizing a library
        
        alert("Success");
    }

});

//Checks if the string is only numbers
function isOnlyNumbers(phoneNo) {
    //Loops through each character in the string and checks if it is a number
    for (var i = 0; i < phoneNo.length; i++) {
        //Gets the character code of the current character
        charCode = phoneNo[i].charCodeAt();

        //Char code 48 is 0 and 57 is 9 with inbetween being the numbers 1-9. If the char code is not in this range then it is not a number and the function should return false
        if (charCode < 48 || charCode > 57) {
            return false;
        }
    }

    //If the loop completes then the string is only numbers
    return true;
}

//Valdates phone number by checking if it is only numbers and if it is 10 digits
function ValidateNo(phoneNo) {
    //Checks if the phone number is empty
    if (phoneNo == "" || phoneNo == null) {
        alert("Please enter your Mobile No.");
        return false;
    }
    //Checks if the phone number is the correct length
    else if (phoneNo.length < 10 || phoneNo.length > 10) {
        alert("Mobile No. is not valid, Please Enter 10 Digit Mobile No.");
        return false;
    }
    //Calls the function to check if the phone number is only numbers
    else if (!isOnlyNumbers(phoneNo)){
        alert("Please enter only Numbers for your Phone Number");
    }

    //If all the checks pass then the phone number is valid
    return true;
}


//Validated email by checking if it is in the correct format
function ValidateEmail(email) {
    //Defines the regular expression for an email
    var mailFormat = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;

    //Checks if the email is empty
    if (email == "") {
        alert( "  Please enter your Email Id  ");
    }
    //Checks if the email is in the correct format
    else if (!mailFormat.test(email)) {
        alert( "  Email Address is not valid, Please provide a valid Email ");
        return false;
    }
    //Returns true if the the other checks pass
    else {
        return true;
    }

}

//Ensure both email and phone number are valid
function ValidateInformation(phoneNo, email){
    if (ValidateNo(phoneNo) && ValidateEmail(email)){
        return true;
    } else {
        return false;
    }
}