from flask import render_template, request, redirect, url_for, flash
from flask_login import login_required, current_user
from flask_wtf import FlaskForm
from itsdangerous import Signer, BadSignature
from wtforms import validators
from wtforms.fields.html5 import EmailField

from app.config import FLASK_SECRET
from app.config import URL
from app.dashboard.base import dashboard_bp
from app.email_utils import can_be_used_as_personal_email, email_already_used
from app.email_utils import (
    send_email,
    render,
)
from app.extensions import db
from app.log import LOG
from app.models import (
    GenEmail,
    DeletedAlias,
)
from app.models import Mailbox


class ChangeEmailForm(FlaskForm):
    email = EmailField(
        "email", validators=[validators.DataRequired(), validators.Email()]
    )


@dashboard_bp.route("/mailbox/<int:mailbox_id>/", methods=["GET", "POST"])
@login_required
def mailbox_detail_route(mailbox_id):
    mailbox = Mailbox.get(mailbox_id)
    if not mailbox or mailbox.user_id != current_user.id:
        flash("You cannot see this page", "warning")
        return redirect(url_for("dashboard.index"))

    change_email_form = ChangeEmailForm()

    if mailbox.new_email:
        pending_email = mailbox.new_email
    else:
        pending_email = None

    if change_email_form.validate_on_submit():
        new_email = change_email_form.email.data
        if new_email != mailbox.email and not pending_email:
            # check if this email is not already used
            if (
                email_already_used(new_email)
                or GenEmail.get_by(email=new_email)
                or DeletedAlias.get_by(email=new_email)
            ):
                flash(f"Email {new_email} already used", "error")
            elif not can_be_used_as_personal_email(new_email):
                flash(
                    "You cannot use this email address as your mailbox", "error",
                )
            else:
                mailbox.new_email = new_email
                db.session.commit()

                s = Signer(FLASK_SECRET)
                mailbox_id_signed = s.sign(str(mailbox.id)).decode()
                verification_url = (
                    URL
                    + "/dashboard/mailbox/confirm_change"
                    + f"?mailbox_id={mailbox_id_signed}"
                )

                send_email(
                    new_email,
                    f"Confirm mailbox change on SimpleLogin",
                    render(
                        "transactional/verify-mailbox-change.txt",
                        user=current_user,
                        link=verification_url,
                        mailbox_email=mailbox.email,
                        mailbox_new_email=new_email,
                    ),
                    render(
                        "transactional/verify-mailbox-change.html",
                        user=current_user,
                        link=verification_url,
                        mailbox_email=mailbox.email,
                        mailbox_new_email=new_email,
                    ),
                )

                flash(
                    f"You are going to receive an email to confirm {new_email}.",
                    "success",
                )
                return redirect(
                    url_for("dashboard.mailbox_detail_route", mailbox_id=mailbox_id)
                )

    return render_template("dashboard/mailbox_detail.html", **locals(),)


@dashboard_bp.route(
    "/mailbox/<int:mailbox_id>/cancel_email_change", methods=["GET", "POST"]
)
@login_required
def cancel_mailbox_change_route(mailbox_id):
    mailbox = Mailbox.get(mailbox_id)
    if not mailbox or mailbox.user_id != current_user.id:
        flash("You cannot see this page", "warning")
        return redirect(url_for("dashboard.index"))

    if mailbox.new_email:
        mailbox.new_email = None
        db.session.commit()
        flash("Your mailbox change is cancelled", "success")
        return redirect(
            url_for("dashboard.mailbox_detail_route", mailbox_id=mailbox_id)
        )
    else:
        flash("You have no pending mailbox change", "warning")
        return redirect(
            url_for("dashboard.mailbox_detail_route", mailbox_id=mailbox_id)
        )


@dashboard_bp.route("/mailbox/confirm_change")
def mailbox_confirm_change_route():
    s = Signer(FLASK_SECRET)
    mailbox_id = request.args.get("mailbox_id")

    try:
        r_id = int(s.unsign(mailbox_id))
    except BadSignature:
        flash("Invalid link", "error")
    else:
        mailbox = Mailbox.get(r_id)
        mailbox.email = mailbox.new_email
        mailbox.new_email = None

        # mark mailbox as verified if the change request is sent from an unverified mailbox
        mailbox.verified = True
        db.session.commit()

        LOG.d("Mailbox change %s is verified", mailbox)
        flash(
            f"The {mailbox.email} is updated", "success",
        )
        return redirect(
            url_for("dashboard.mailbox_detail_route", mailbox_id=mailbox.id)
        )