Using PHP$,$ HTML$,$ Javascript, CSS$,$ and SQL$.$ Please write out all the code.

Your web application will implement a k$-$means based clustering machine learning algorithm, letting the users train and test a personal model with their input data.

You will have to:

Build a web page that:

$$Ensures a secure Session mechanism.

$$Allows the user to sign up and log in$.$

$$For training:

$-$Allows the logged in users to submit a text file $($extension $.$txt ONLY$),$ containing "scores" to train the model.

$$The scores can come from other ML algorithms, but this doesn't concern your application.

$$You can test your program with made up scores.

$-$Allows the user to submit such scores in an input text box too.

$-$Allows the user to give a name to the uploaded model.

$$For testing:

$-$Allows the logged in users to submit a text file $($extension $.$txt ONLY$),$ containing "scores" to test the model, if$,$ and only if$,$ an already existent model is stored in the database for that specific user.

$$If more than one model is stored, the user should be able to select the one that wants to use selecting the name of such model.

Build a web application that:

$$Applies the training and testing mechanism for k$-$means clustering.

Build a MySQL database that:

$$Stores the input models and their names, for any user.

$$Stores the information related to the user account's username, password and email in the most secure way of your knowledge.

$-$All these fields must be validated:

$$The username can contain English letters $($capitalized or not$),$ digits, and the characters $\text{'}\_\text{'}($underscore$)$ and $\text{'}-\text{'}($dash$).$ Nothing else.

$$The email must be well formatted.

$$The password can have limitations of your choice, if you think it's worth it$.$