from wtforms import SubmitField, StringField, HiddenField, validators, TextAreaField
from flask_wtf import FlaskForm
from flask import request, render_template, redirect
from flask_login import login_required, current_user
from wtforms import DateField
from main import db, app, ma
from datetime import date
from sqlalchemy import Sequence
from sqlalchemy.exc import SQLAlchemyError
from status import st, Status

################################################################################
# Class describing Loan in the database, and via sqlalchemy, connected to the DB as well
################################################################################
class Loan(db.Model):
    id = db.Column(db.Integer, db.Sequence('loan_id_seq'), primary_key=True )
    surname = db.Column(db.String(30), unique=False, nullable=False)
    firstnames = db.Column(db.String(50), unique=False, nullable=False)
    contact_details = db.Column(db.String(256), unique=False, nullable=False)
    date_lent = db.Column(db.Date, nullable=False )

    def __repr__(self):
        return "<id: {}, firstnames: {}, surname: {}>".format(self.id,self.firstnames, self.surname)

################################################################################
# Helper class that inherits a .dump() method to turn class Loan into json / useful in jinja2
################################################################################
class LoanSchema(ma.SQLAlchemyAutoSchema):
    class Meta:
        model = Loan
        ordered = True

################################################################################
# Helper class that defines a form for loan, used to make html <form>, with field validation (via wtforms)
################################################################################
class LoanForm(FlaskForm):
    id = HiddenField()
    firstnames = StringField('FirstName(s):', [validators.DataRequired()])
    surname = StringField('Surname:', [validators.DataRequired()])
    contact_details = TextAreaField('Contact Details:', [validators.DataRequired()])
    surname = StringField('Surname:', [validators.DataRequired()])
    date_lent = DateField('Date Lent:', format='%Y-%m-%d', default=date.today(), validators=[validators.DataRequired()] )
    submit = SubmitField('Save' )
    delete = SubmitField('Delete' )

################################################################################
# Routes for loan data
#
# /loans -> GET only -> prints out list of all loans
################################################################################
@app.route("/loans", methods=["GET"])
@login_required
def loans():
    loans = Loan.query.all()
    return render_template("loans.html", loans=loans, alert=st.GetAlert(), message=st.GetMessage())

################################################################################
# /loan -> GET/POST -> creates a new loan type and when created, takes you back to /loans
################################################################################
@app.route("/loan", methods=["GET", "POST"])
@login_required
def new_loan():
    form = LoanForm(request.form)
    page_title='Create new Loan'
    if 'firstnames' not in request.form:
        return render_template("loan.html", form=form, page_title=page_title )
    else:
        loan = Loan( firstnames=request.form["firstnames"], surname=request.form["surname"], date_lent=request.form["date_lent"], contact_details=request.form["contact_details"] )
        try:
            db.session.add(loan)
            db.session.commit()
            st.SetMessage( "Created new Loan (id={})".format(loan.id) )
            return redirect( '/loans' )
        except SQLAlchemyError as e:
            st.SetAlert( "danger" )
            st.SetMessage( "<b>Failed to add Loan:</b>&nbsp;{}".format( e.orig) )
            return render_template("edit_id_name.html", form=form, page_title=page_title, alert=st.GetAlert(), message=st.GetMessage() )


################################################################################
# /loan/<id> -> GET/POST(save or delete) -> shows/edits/delets a single loan
################################################################################
@app.route("/loan/<id>", methods=["GET", "POST"])
@login_required
def loan(id):
    ### DDP: should this be request.form or request.values?
    form = LoanForm(request.form)
    page_title='Edit Loan'
    if request.method == 'POST' and form.validate():
        loan = Loan.query.get(id)
        try:
            if 'delete' in request.form:
                st.SetMessage("Successfully deleted (id={}, who={} {})".format( loan.id, loan.firstnames, loan.surname ) )
                # fall back to direct sql because loan.py is imported before Book_Loan_Link exists
                db.engine.execute("delete from book_loan_link where loan_id = {}".format( loan.id ))
                loan = Loan.query.filter(Loan.id==id).delete()
            if 'submit' in request.form:
                st.SetMessage("Successfully Updated Loan (id={})".format(id) )
                loan.firstnames = request.form['firstnames']
                loan.surname = request.form['surname']
                loan.surname = request.form['surname']
                loan.contact_details = request.form['contact_details']
                loan.date_lent = request.form['date_lent']
            db.session.commit()
            return redirect( '/loans' )
        except SQLAlchemyError as e:
            st.SetAlert( "danger" )
            st.SetMessage( "<b>Failed to modify Loan:</b>&nbsp;{}".format(e.orig) )
            return render_template("edit_id_name.html", form=form, page_title=page_title, alert=st.GetAlert(), message=st.GetMessage() )
    else:
        loan = Loan.query.get(id)
        form = LoanForm(request.values, obj=loan)
    return render_template("loan.html", loan=loan, form=form, page_title=page_title)