from datetime import datetime
from typing import Optional, List

from flask import render_template, url_for, flash, redirect, Response, Blueprint
from flask.typing import ResponseReturnValue
from flask_wtf import FlaskForm
from sqlalchemy import exc
from wtforms import SelectField, StringField, IntegerField, SubmitField
from wtforms.validators import DataRequired, NumberRange

from app.extensions import db
from app.models.base import Group
from app.models.bridges import BridgeConf
from app.portal.util import response_404, view_lifecycle

bp = Blueprint("bridgeconf", __name__)


_SECTION_TEMPLATE_VARS = {
    "section": "bridgeconf",
    "help_url": "https://bypass.censorship.guide/user/bridges.html"
}


class NewBridgeConfForm(FlaskForm):  # type: ignore
    provider = SelectField('Provider', validators=[DataRequired()])
    method = SelectField('Distribution Method', validators=[DataRequired()])
    description = StringField('Description')
    group = SelectField('Group', validators=[DataRequired()])
    number = IntegerField('Number', validators=[NumberRange(1, message="One or more bridges must be created")])
    submit = SubmitField('Save Changes')


class EditBridgeConfForm(FlaskForm):  # type: ignore
    description = StringField('Description')
    number = IntegerField('Number', validators=[NumberRange(1, message="One or more bridges must be created")])
    submit = SubmitField('Save Changes')


@bp.route("/list")
def bridgeconf_list() -> ResponseReturnValue:
    bridgeconfs: List[BridgeConf] = BridgeConf.query.filter(BridgeConf.destroyed.is_(None)).all()
    return render_template("list.html.j2",
                           title="Tor Bridge Configurations",
                           item="bridge configuration",
                           items=bridgeconfs,
                           new_link=url_for("portal.bridgeconf.bridgeconf_new"),
                           **_SECTION_TEMPLATE_VARS)


@bp.route("/new", methods=['GET', 'POST'])
@bp.route("/new/<group_id>", methods=['GET', 'POST'])
def bridgeconf_new(group_id: Optional[int] = None) -> ResponseReturnValue:
    form = NewBridgeConfForm()
    form.group.choices = [(x.id, x.group_name) for x in Group.query.all()]
    form.provider.choices = [
        ("aws", "AWS Lightsail"),
        ("hcloud", "Hetzner Cloud"),
        ("ovh", "OVH Public Cloud"),
        ("gandi", "GandiCloud VPS")
    ]
    form.method.choices = [
        ("any", "Any (BridgeDB)"),
        ("email", "E-Mail (BridgeDB)"),
        ("moat", "Moat (BridgeDB)"),
        ("https", "HTTPS (BridgeDB)"),
        ("none", "None (Private)")
    ]
    if form.validate_on_submit():
        bridge_conf = BridgeConf()
        bridge_conf.group_id = form.group.data
        bridge_conf.provider = form.provider.data
        bridge_conf.method = form.method.data
        bridge_conf.description = form.description.data
        bridge_conf.number = form.number.data
        bridge_conf.created = datetime.utcnow()
        bridge_conf.updated = datetime.utcnow()
        try:
            db.session.add(bridge_conf)
            db.session.commit()
            flash(f"Created new bridge configuration {bridge_conf.id}.", "success")
            return redirect(url_for("portal.bridgeconf.bridgeconf_list"))
        except exc.SQLAlchemyError:
            flash("Failed to create new bridge configuration.", "danger")
            return redirect(url_for("portal.bridgeconf.bridgeconf_list"))
    if group_id:
        form.group.data = group_id
    return render_template("new.html.j2",
                           form=form,
                           **_SECTION_TEMPLATE_VARS)


@bp.route('/edit/<bridgeconf_id>', methods=['GET', 'POST'])
def bridgeconf_edit(bridgeconf_id: int) -> ResponseReturnValue:
    bridgeconf = BridgeConf.query.filter(BridgeConf.id == bridgeconf_id).first()
    if bridgeconf is None:
        return Response(render_template("error.html.j2",
                                        header="404 Bridge Configuration Not Found",
                                        message="The requested bridge configuration could not be found.",
                                        **_SECTION_TEMPLATE_VARS),
                        status=404)
    form = EditBridgeConfForm(description=bridgeconf.description,
                              number=bridgeconf.number)
    if form.validate_on_submit():
        bridgeconf.description = form.description.data
        bridgeconf.number = form.number.data
        bridgeconf.updated = datetime.utcnow()
        try:
            db.session.commit()
            flash("Saved changes to bridge configuration.", "success")
        except exc.SQLAlchemyError:
            flash("An error occurred saving the changes to the bridge configuration.", "danger")
    return render_template("bridgeconf.html.j2",
                           bridgeconf=bridgeconf,
                           form=form,
                           **_SECTION_TEMPLATE_VARS)


@bp.route("/destroy/<bridgeconf_id>", methods=['GET', 'POST'])
def bridgeconf_destroy(bridgeconf_id: int) -> ResponseReturnValue:
    bridgeconf = BridgeConf.query.filter(BridgeConf.id == bridgeconf_id, BridgeConf.destroyed.is_(None)).first()
    if bridgeconf is None:
        return response_404("The requested bridge configuration could not be found.")
    return view_lifecycle(
        header="Destroy bridge configuration?",
        message=bridgeconf.description,
        success_view="portal.bridgeconf.bridgeconf_list",
        success_message="All bridges from the destroyed configuration will shortly be destroyed at their providers.",
        resource=bridgeconf,
        action="destroy",
        **_SECTION_TEMPLATE_VARS
    )