from __future__ import annotations

from copy import copy
from typing import Any, Optional
from uuid import uuid4

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

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

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

@page(name="Login", url_segment="login", guard=login_page_guard)
class LoginPage(Component):
    user_name: str = ""
    password: str = ""
    error_on_last_attempt: bool = False
    login_in_progress: bool = False

    async def on_login_confirmed(self, _: Any) -> None:
        """ Handler for pressing ENTER inside the text inputs """
        await self.on_login_pressed()

    async def on_login_pressed(self) -> None:
        self.login_in_progress = True
        user_name = copy(self.user_name)  # Prevents race condition name swap
        is_valid = await self.session[UserService].is_login_valid(user_name, self.password)
        if not is_valid:  # Migrated users
            user_name = user_name.lower().capitalize()
            is_valid = await self.session[UserService].is_login_valid(user_name, self.password)
        if is_valid:
            user: User = await self.session[UserService].get_user(user_name)
            self.error_on_last_attempt = False
            user_session = UserSession(id=uuid4(), user_name=user.user_name, is_team_member=user.is_team_member)
            self.session.attach(user_session)
            token = self.session[LocalDataService].set_session(user_session)
            self.session[LocalData].stored_session_token = token
            self.session[UserSession].profile_picture = await self.load_user_picture()
            self.session.attach(self.session[LocalData])
            self.login_in_progress = False
            self.session.navigate_to("./")
        else:
            self.login_in_progress = False
            self.error_on_last_attempt = True

    async def load_user_picture(self) -> bytes:
        try:
            user_picture = await self.session[UserService].get_user_picture(self.session[UserSession].user_name)
            if user_picture is not None and len(user_picture) > 0:
                return user_picture
        except KeyError:
            return self.session[ConfigurationService].DEFAULT_PROFILE_PICTURE
        return self.session[ConfigurationService].DEFAULT_PROFILE_PICTURE

    def on_register_pressed(self) -> None:
        self.session.navigate_to("./register")

    def on_lost_password_pressed(self) -> None:
        self.session.navigate_to("./lost-pw")

    def build(self) -> Component:
        return Row(
            Rectangle(
                content=Column(
                    Rectangle(
                        content=Rectangle(
                            content=Text("Login", margin=0.5, selectable=False, overflow="wrap"),
                            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().user_name,
                            label="Nutzername",
                            on_confirm=self.on_login_confirmed
                        ),
                        TextInput(
                            text=self.bind().password,
                            label="Passwort",
                            is_secret=True,
                            on_confirm=self.on_login_confirmed
                        ),
                        Text("Falscher Nutzername oder Passwort", fill=self.session.theme.danger_color, overflow="wrap", justify="center") if self.error_on_last_attempt else Spacer(grow_x=False, grow_y=False),
                        ElmButton(text="Login", style="small" if self.session.is_mobile() else "normal", on_press=self.on_login_pressed, is_loading=self.login_in_progress),
                        ElmButton(text="Passwort\nvergessen" if self.session.is_mobile() else "Passwort vergessen", style="small" if self.session.is_mobile() else "normal", on_press=self.on_lost_password_pressed),
                        ElmButton(text="Account anlegen", style="small" if self.session.is_mobile() else "normal", on_press=self.on_register_pressed),
                        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
        )