from __future__ import annotations

from hashlib import sha256
from random import choices
from typing import Any, Optional

from rio import Component, Column, Row, Text, Spacer, page, Color, Rectangle, TextInput, GuardEvent, ProgressCircle

from elm.types import UserSession, User
from elm.services import UserService, ConfigurationService, MailingService
from elm.components import ElmButton

def forgot_password_page_guard(event: GuardEvent) -> Optional[str]:
    try:
        _ = event.session[UserSession].user_name
        return "/"
    except KeyError:
        return None

@page(name="Forgot password", url_segment="lost-pw", guard=forgot_password_page_guard)
class ForgotPasswordPage(Component):
    mail: str = ""
    success: bool = False
    is_loading: bool = False

    async def on_confirm(self, _: Any = None) -> None:
        self.is_loading = True

        lan_info = self.session[ConfigurationService].get_lan_info()
        user_service = self.session[UserService]
        mailing_service = self.session[MailingService]
        user = await user_service.get_user_by_mail(self.mail.strip())
        if user is not None:
            new_password = "".join(choices(user_service.ALLOWED_USER_NAME_SYMBOLS, k=16))
            user.user_fallback_password = sha256(new_password.encode(encoding="utf-8")).hexdigest()
            await User.save(user)
            await mailing_service.send_email(
                subject=f"Dein neues Passwort für {lan_info.name}",
                body=f"Du hast für den EZGG LAN Manager der {lan_info.name} ein neues Passwort angefragt. "
                     f"Und hier ist es schon:\n\n{new_password}\n\nSolltest du kein neues Passwort angefordert haben, "
                     f"ignoriere diese E-Mail.\n\nLiebe Grüße\nDein {lan_info.name} - Team",
                receiver=self.mail.strip()
            )

        self.success = True
        self.is_loading = False

    def build(self) -> Component:
        return Row(
            Rectangle(
                content=Column(
                    Rectangle(
                        content=Rectangle(
                            content=Row(
                                Text("Passwort vergessen", margin=0.5, selectable=False, overflow="wrap", grow_x=True),
                                ProgressCircle(min_size=1, margin=0.5, color="primary", progress=None if self.is_loading else 0)
                            ),
                            fill=self.session.theme.header_box_background_color,
                            margin=0.4
                        ),
                        stroke_width=0.1,
                        stroke_color=self.session.theme.box_border_color,
                    ),
                    Column(
                        TextInput(
                            text=self.bind().mail,
                            label="Mail Adresse",
                            on_confirm=self.on_confirm
                        ),
                        Text("Prüfe deine Mails!", fill=self.session.theme.success_color, overflow="wrap", justify="center") if self.success else Spacer(grow_x=False, grow_y=False),
                        ElmButton(text="Neues Passwort anfordern", style="small" if self.session.is_mobile() else "normal", on_press=self.on_confirm, wrap=self.session.is_mobile()),
                        margin=1,
                        spacing=1
                    ),
                    Spacer()
                ),
                fill=self.session.theme.box_color,
                stroke_width=0.1,
                stroke_color=self.session.theme.box_border_color,
                min_height=15
            ),
            align_x=0.5,
            align_y=0.5
        )