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

################################################################################
# Class describing Author in the database, and via sqlalchemy, connected to the DB as well
################################################################################
class Author(db.Model):
    id = db.Column(db.Integer, db.Sequence('author_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)

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

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

################################################################################
# Helper class that defines a form for author, used to make html <form>, with field validation (via wtforms)
################################################################################
class AuthorForm(FlaskForm):
    id = HiddenField()
    firstnames = StringField('FirstName(s):', [validators.DataRequired()])
    surname = StringField('Surname:', [validators.DataRequired()])
    submit = SubmitField('Save' )
    delete = SubmitField('Delete' )

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

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

################################################################################
# /author/<id> -> GET/POST(save or delete) -> shows/edits/delets a single author
################################################################################
@app.route("/author/<id>", methods=["GET", "POST"])
@login_required
def author(id):
    ### DDP: should this be request.form or request.values?
    form = AuthorForm(request.form)
    page_title='Edit Author'
    if request.method == 'POST' and form.validate():
        try:
            author = Author.query.get(id)
            if 'delete' in request.form:
                st.SetMessage( f"Successfully deleted Author: ({author.surname}, {author.firstnames})" )
                author = Author.query.filter(Author.id==id).delete()
            if 'submit' in request.form:
                st.SetMessage( f"Successfully Updated Author: (From: {author.surname}, {author.firstnames}" )
                author.surname = request.form['surname']
                author.firstnames = request.form['firstnames']
                st.AppendMessage( f" To: {author.surname}, {author.firstnames})" )
            db.session.commit()
            return redirect( '/authors' )
        except SQLAlchemyError as e:
            st.SetAlert( "danger" )
            st.SetMessage( f"<b>Failed to modify Author:</b>&nbsp;{e.orig}" )
            return render_template("edit_id_name.html", form=form, page_title=page_title, alert=st.GetAlert(), message=st.GetMessage() )
    else:
        print(id)
        author = Author.query.get(id)
        form = AuthorForm(request.values, obj=author)
    return render_template("edit_id_name.html", object=author, form=form, page_title = page_title, alert=st.GetAlert(), message=st.GetMessage() )

@app.route("/author/<author_id>/books", methods=["GET"])
@login_required
def authors_books(author_id):
    """ show all the books written by the specified author """
    from main import Book, Book_Author_Link
    books=Book.query.join(Book_Author_Link).join(Author).filter(Author.id==author_id).order_by(Book.title).all()

    # now need to re-order books to cater for sub-book ordering
    ordered_books=[]
    processed=[]
    for b in books:
        if b.id not in processed:
            if b.IsParent():
                ordered_books.append(b)
                processed.append( b.id )
                for bb in b.child_ref:
                    tmp=Book.query.get(bb.sub_book_id)
                    ordered_books.append( tmp )
                    processed.append( bb.sub_book_id )
            elif b.IsChild():
                ordered_books.append(b.parent)
                processed.append( b.parent.id )
                cnt=1
                for bb in b.parent.child_ref:
                    tmp=Book.query.get(bb.sub_book_id)
                    # need to set parent_id and sub_book_num for indenting to work in html
                    tmp.parent_id=b.parent.id
                    tmp.sub_book_num=cnt
                    ordered_books.append( tmp )
                    processed.append( bb.sub_book_id )
                    cnt+=1
            else:
                ordered_books.append(b)
                processed.append( b.id )
    a=Author.query.get(author_id)
    return render_template("books.html", books=ordered_books, page_title=f"All {a.surname}, {a.firstnames} books:", no_navbar=True )
    

################################################################################
# helper fund to GetAuthors -> author_list -> jinja2 for author drop-down in book.html
################################################################################
def GetAuthors():
    return Author.query.order_by('surname','firstnames').all()