from flask import (Flask, session, request, redirect, url_for, render_template, 
        flash)
from flaskext.mail import Mail, Message

# local modules
from models import db, Project, Person, Bill
from forms import ProjectForm, AuthenticationForm, BillForm, MemberForm, InviteForm
from utils import get_billform_for, requires_auth

# create the application, initialize stuff
app = Flask(__name__)
mail = Mail()

@app.route("/")
def home():
    project_form = ProjectForm()
    auth_form = AuthenticationForm()
    return render_template("home.html", project_form=project_form, auth_form=auth_form)

@app.route("/authenticate", methods=["GET", "POST"])
def authenticate(redirect_url=None):
    form = AuthenticationForm()
    
    project_id = form.id.data

    redirect_url = redirect_url or url_for("list_bills", project_id=project_id)
    project = Project.query.get(project_id)
    if not project:
        flash("This project doesn't exist (yet). You can create it by filling this form")
        return redirect(url_for("create_project", project_id=project_id))

    # if credentials are already in session, redirect
    if project_id in session and project.password == session[project_id]:
        return redirect(redirect_url)

    # else process the form
    if request.method == "POST":
        if form.validate():
            if not form.password.data == project.password:
                form.errors['password'] = ["The password is not the right one"]
            else:
                # maintain a list of visited projects
                session["projects"].append(project_id)
                session[project_id] = form.password.data
                session.update()
                return redirect(redirect_url)

    return render_template("authenticate.html", form=form)

@app.route("/create", methods=["GET", "POST"])
def create_project():
    form = ProjectForm()
    if request.method == "GET" and 'project_id' in request.values:
        form.name.data = request.values['project_id']

    if request.method == "POST":
        if form.validate():
            # save the object in the db
            project = form.save()
            db.session.add(project)
            db.session.commit()

            # create the session object (authenticate)
            session[project.id] = project.password
            session.update()

            # redirect the user to the next step (invite)
            return redirect(url_for("invite", project_id=project.id))

    return render_template("create_project.html", form=form)

@app.route("/quit")
def quit():
    # delete the session
    session.clear()
    return redirect(url_for("home"))

@app.route("/<string:project_id>/invite", methods=["GET", "POST"])
@requires_auth
def invite(project):

    form = InviteForm()

    if request.method == "POST": 
        if form.validate():
            # send the email

            message_body = render_template("invitation_mail", 
                    email=project.contact_email, project=project)

            message_title = "You have been invited to share your expenses for %s" % project.name
            msg = Message(message_title, 
                body=message_body, 
                recipients=[email.strip() for email in form.emails.data.split(",")])
            mail.send(msg)
            return redirect(url_for("list_bills", project_id=project.id))

    return render_template("send_invites.html", form=form, project=project)

@app.route("/<string:project_id>/")
@requires_auth
def list_bills(project):
    # FIXME filter to only get the bills for this particular project
    bills = Bill.query.order_by(Bill.id.asc())
    return render_template("list_bills.html", 
            bills=bills, project=project, member_form=MemberForm(project))

@app.route("/<string:project_id>/members/add", methods=["GET", "POST"])
@requires_auth
def add_member(project):
    # FIXME manage form errors on the list_bills page
    form = MemberForm(project)
    if request.method == "POST":
        if form.validate():
            db.session.add(Person(name=form.name.data, project=project))
            db.session.commit()
            return redirect(url_for("list_bills", project_id=project.id))
    return render_template("add_member.html", form=form, project=project)

@app.route("/<string:project_id>/add", methods=["GET", "POST"])
@requires_auth
def add_bill(project):
    form = get_billform_for(project.id)
    if request.method == 'POST':
        if form.validate():
            db.session.add(form.save())
            db.session.commit()

            flash("The bill have been added")
            return redirect(url_for('list_bills', project_id=project.id))

    return render_template("add_bill.html", form=form, project=project)


@app.route("/<string:project_id>/compute")
@requires_auth
def compute_bills(project):
    """Compute the sum each one have to pay to each other and display it"""
    # FIXME make it work

    balances, should_pay, should_receive = {}, {}, {}
    # for each person, get the list of should_pay other have for him
    for name, void in PAYER_CHOICES:
        bills = Bill.query.join(BillOwer).filter(Bill.processed==False)\
                .filter(BillOwer.name==name)
        for bill in bills.all():
            if name != bill.payer:
                should_pay.setdefault(name, 0)
                should_pay[name] += bill.pay_each()
                should_receive.setdefault(bill.payer, 0)
                should_receive[bill.payer] += bill.pay_each()

    for name, void in PAYER_CHOICES:
        balances[name] = should_receive.get(name, 0) - should_pay.get(name, 0)

    return render_template("compute_bills.html", balances=balances, project=project)


@app.route("/<string:project_id>/reset")
@requires_auth
def reset_bills(project):
    """Reset the list of bills"""
    # FIXME replace with the archive feature
    # get all the bills which are not processed
    bills = Bill.query.filter(Bill.processed == False)
    for bill in bills:
        bill.processed = True
        db.session.commit()

    return redirect(url_for('list_bills'))


@app.route("/<string:project_id>/delete/<int:bill_id>")
@requires_auth
def delete_bill(project, bill_id):
    Bill.query.filter(Bill.id == bill_id).delete()
    BillOwer.query.filter(BillOwer.bill_id == bill_id).delete()
    db.session.commit()
    flash("the bill was deleted")

    return redirect(url_for('list_bills'))

@app.route("/debug/")
def debug():
    from ipdb import set_trace; set_trace()
    return render_template("debug.html")


def main():
    app.config.from_object("default_settings")
    # db
    db.init_app(app)
    db.app = app
    db.create_all()

    # mail
    mail.init_app(app)

    app.run(host="0.0.0.0", debug=True)

if __name__ == '__main__':
    main()