import base64
import email.message
import hashlib
import logging
import smtplib
import urllib.request

from flask import (
    Blueprint,
    request,
    flash,
    url_for,
    current_app,
    abort,
    render_template,
    redirect,
)
from flask_babel import gettext as _

from .forms import (
    LoginForm,
    AddProfileForm,
    EditProfileForm,
    PasswordResetForm,
    ForgottenPasswordForm,
)
from .flaskutils import current_user, user_needed, moderator_needed
from .models import User


bp = Blueprint(__name__, "home")


@bp.route("/")
def index():
    if not current_user():
        return redirect(url_for("canaille.account.login"))
    return redirect(
        url_for("canaille.account.profile_edition", username=current_user().uid[0])
    )


@bp.route("/login", methods=("GET", "POST"))
def login():
    form = LoginForm(request.form or None)

    if request.form:
        if not form.validate() or not User.authenticate(
            form.login.data, form.password.data, True
        ):
            flash(_("Login failed, please check your information"), "error")
            return render_template("login.html", form=form)

        user = User.get(form.login.data)
        flash(_("Connection successful. Welcome %(user)s", user=user.name), "success")
        return redirect(url_for("canaille.account.index"))

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


@bp.route("/logout")
def logout():
    user = current_user()
    if user:
        flash(
            _("You have been disconnected. See you next time %(user)s", user=user.name),
            "success",
        )
        user.logout()
    return redirect("/")


@bp.route("/users")
@moderator_needed()
def users(user):
    users = User.filter(objectClass=current_app.config["LDAP"]["USER_CLASS"])
    return render_template("users.html", users=users, menuitem="users")


@bp.route("/profile", methods=("GET", "POST"))
@moderator_needed()
def profile_creation(user):
    claims = current_app.config["JWT"]["MAPPING"]
    form = AddProfileForm(request.form or None)
    try:
        del form.sub.render_kw["readonly"]
    except KeyError:
        pass

    if request.form:
        if not form.validate():
            flash(_("User creation failed."), "error")

        else:
            user = User(objectClass=current_app.config["LDAP"]["USER_CLASS"])
            for attribute in form:
                model_attribute_name = claims.get(attribute.name.upper())
                if (
                    not model_attribute_name
                    or model_attribute_name not in user.must + user.may
                ):
                    continue

                user[model_attribute_name] = [attribute.data]

            user.cn = [f"{user.givenName[0]} {user.sn[0]}"]
            user.save()

            flash(_("User creation succeed."), "success")

            return redirect(
                url_for("canaille.account.profile_edition", username=user.uid[0])
            )

    return render_template(
        "profile.html", form=form, menuitem="users", edited_user=None
    )


@bp.route("/profile/<username>", methods=("GET", "POST"))
@user_needed()
def profile_edition(user, username):
    user.moderator or username == user.uid[0] or abort(403)

    if request.method == "GET" or request.form.get("action") == "edit":
        return profile_edit(user, username)

    if request.form.get("action") == "delete":
        return profile_delete(user, username)

    abort(400)


def profile_edit(user, username):
    menuitem = "profile" if username == user.uid[0] else "users"
    claims = current_app.config["JWT"]["MAPPING"]
    if username != user.uid[0]:
        user = User.get(username) or abort(404)

    data = {
        k.lower(): getattr(user, v)[0]
        if getattr(user, v) and isinstance(getattr(user, v), list)
        else getattr(user, v) or ""
        for k, v in claims.items()
    }
    form = EditProfileForm(request.form or None, data=data)
    form.sub.render_kw["readonly"] = "true"

    if request.form:
        if not form.validate():
            flash(_("Profile edition failed."), "error")

        else:
            for attribute in form:
                model_attribute_name = claims.get(attribute.name.upper())
                if (
                    not model_attribute_name
                    or model_attribute_name not in user.must + user.may
                ):
                    continue

                user[model_attribute_name] = [attribute.data]

            if not form.password1.data or user.set_password(form.password1.data):
                flash(_("Profile updated successfuly."), "success")

            user.save()

    return render_template(
        "profile.html", form=form, menuitem=menuitem, edited_user=user
    )


def profile_delete(user, username):
    self_deletion = username == user.uid[0]
    if self_deletion:
        user.logout()
    else:
        user = User.get(username) or abort(404)

    flash(_("The user %(user)s has been sucessfuly deleted", user=user.name), "success")
    user.delete()

    if self_deletion:
        return redirect(url_for("canaille.account.index"))
    return redirect(url_for("canaille.account.users"))


def profile_hash(user, password):
    return hashlib.sha256(
        current_app.config["SECRET_KEY"].encode("utf-8")
        + user.encode("utf-8")
        + password.encode("utf-8")
    ).hexdigest()


@bp.route("/reset", methods=["GET", "POST"])
def forgotten():
    form = ForgottenPasswordForm(request.form)
    if not request.form:
        return render_template("forgotten-password.html", form=form)

    if not form.validate():
        flash(_("Could not send the password reset link."), "error")
        return render_template("forgotten-password.html", form=form)

    user = User.get(form.login.data)

    if not user:
        flash(
            _("A password reset link has been sent at your email address."), "success"
        )
        return render_template("forgotten-password.html", form=form)

    recipient = user.mail
    base_url = url_for("canaille.account.index", _external=True)
    reset_url = url_for(
        "canaille.account.reset",
        uid=user.uid[0],
        hash=profile_hash(user.uid[0], user.userPassword[0]),
        _external=True,
    )
    logo = None
    logo_extension = None
    if current_app.config.get("LOGO"):
        logo_extension = current_app.config["LOGO"].split(".")[-1]
        try:
            with urllib.request.urlopen(current_app.config.get("LOGO")) as f:
                logo = base64.b64encode(f.read()).decode("utf-8")
        except (urllib.error.HTTPError, urllib.error.URLError):
            pass

    subject = _("Password reset on {website_name}").format(
        website_name=current_app.config.get("NAME", reset_url)
    )

    text_body = render_template(
        "mail/reset.txt",
        site_name=current_app.config.get("NAME", reset_url),
        site_url=base_url,
        reset_url=reset_url,
    )
    html_body = render_template(
        "mail/reset.html",
        site_name=current_app.config.get("NAME", reset_url),
        site_url=base_url,
        reset_url=reset_url,
        logo=logo,
        logo_extension=logo_extension,
    )

    msg = email.message.EmailMessage()
    msg.set_content(text_body)
    msg.add_alternative(html_body, subtype="html")
    msg["Subject"] = subject
    msg["From"] = current_app.config["SMTP"]["FROM_ADDR"]
    msg["To"] = recipient

    success = True
    try:
        with smtplib.SMTP(
            host=current_app.config["SMTP"]["HOST"],
            port=current_app.config["SMTP"]["PORT"],
        ) as smtp:
            if current_app.config["SMTP"].get("TLS"):
                smtp.starttls()
            if current_app.config["SMTP"].get("LOGIN"):
                smtp.login(
                    user=current_app.config["SMTP"]["LOGIN"],
                    password=current_app.config["SMTP"].get("PASSWORD"),
                )
            smtp.send_message(msg)

    except smtplib.SMTPRecipientsRefused:
        pass

    except OSError:
        flash(_("Could not reset your password"), "error")
        logging.exception("Could not send password reset email")
        success = False

    if success:
        flash(
            _("A password reset link has been sent at your email address."), "success"
        )

    return render_template("forgotten-password.html", form=form)


@bp.route("/reset/<uid>/<hash>", methods=["GET", "POST"])
def reset(uid, hash):
    form = PasswordResetForm(request.form)
    user = User.get(uid)

    if not user or hash != profile_hash(user.uid[0], user.userPassword[0]):
        flash(
            _("The password reset link that brought you here was invalid."),
            "error",
        )
        return redirect(url_for("canaille.account.index"))

    if request.form and form.validate():
        user.set_password(form.password.data)
        user.login()

        flash(_("Your password has been updated successfuly"), "success")
        return redirect(url_for("canaille.account.profile_edition", username=uid))

    return render_template("reset-password.html", form=form, uid=uid, hash=hash)