SaraView/Client/App.py

"""What the window's parts share: the config, the current Source (local or
server), toasts, dialogs and the login flow. Changing the source (Settings,
logging in or out) tells every listener to reload."""

from typing import Callable, Optional

import flet as ft

from Core import AppConfig, ChipButton, LoadSessionToken, NotificationStyle, Palette, SaveSessionToken
from Sources import MakeSource, ServerSource, Source, SourceError


class App:
    def __init__(self, Page: ft.Page, Config: AppConfig):
        self.Page = Page
        self.Config = Config
        self.Picker = ft.FilePicker()  # registers itself with the page
        self.Source: Source = MakeSource(Config)
        self.ConnectError = ""  # why the server couldn't be reached, shown instead of the file list
        self.DialogOpen = False  # keyboard shortcuts pause while a dialog is up
        self.Listeners: list[Callable[[], None]] = []  # run after the source changes

    # --- Source -----------------------------------------------------------

    def Connect(self) -> None:
        """(Re)builds the source from Config and, for a server, checks it's
        there and whether the saved login still works. Listeners reload."""
        if isinstance(self.Source, ServerSource):
            self.Source.Close()
        Token = LoadSessionToken(self.Config.ServerUrl) if self.Config.Mode == "Server" and self.Config.RememberLogin else ""
        self.Source = MakeSource(self.Config, Token)
        self.ConnectError = ""
        if isinstance(self.Source, ServerSource):
            try:
                self.Source.Connect()
            except SourceError as Error:
                self.ConnectError = str(Error)
            if Token and self.Source.User is None and not self.ConnectError:
                SaveSessionToken(self.Config.ServerUrl, "")
                self.Notify("Your saved login ended (the server restarted?). Browsing as Guest.", "warning")
        self.Changed()

    def Changed(self) -> None:
        for Listener in self.Listeners:
            Listener()

    @property
    def Server(self) -> Optional[ServerSource]:
        return self.Source if isinstance(self.Source, ServerSource) else None

    def HandleError(self, Error: SourceError, Doing: str = "") -> None:
        """A toast, plus the login dialog when the server wants a login."""
        Text = f"{Doing}: {Error}" if Doing else str(Error)
        if Error.Status == 401 and self.Server is not None:
            if self.Server.User is not None:  # the session ended under us
                self.Server.Logout()
                SaveSessionToken(self.Config.ServerUrl, "")
                self.Changed()
            self.ShowLoginDialog(Reason=Text)
            return
        self.Notify(Text, "error")

    # --- Login ------------------------------------------------------------

    def ShowLoginDialog(self, Reason: str = "") -> None:
        Server = self.Server
        if Server is None:
            return
        UsernameField = ft.TextField(label="Username", value=self.Config.Username, autofocus=not self.Config.Username)
        PasswordField = ft.TextField(label="Password", password=True, can_reveal_password=True,
                                     autofocus=bool(self.Config.Username))
        RememberSwitch = ft.Switch(label="Stay logged in", value=self.Config.RememberLogin)
        ErrorText = ft.Text("", color=Palette.Red, size=12, visible=False)

        def DoLogin(e=None) -> None:
            Username = (UsernameField.value or "").strip()
            if not Username or not PasswordField.value:
                return
            try:
                Server.Login(Username, PasswordField.value)
            except SourceError as Error:
                ErrorText.value = str(Error)
                ErrorText.visible = True
                ErrorText.update()
                return
            self.Config.Username = Username
            self.Config.RememberLogin = RememberSwitch.value
            self.Config.Save()
            SaveSessionToken(self.Config.ServerUrl, Server.Token if RememberSwitch.value else "")
            self.Close()
            self.Notify(f"Logged in as {Username}.", "success")
            self.Changed()

        UsernameField.on_submit = lambda e: PasswordField.focus()
        PasswordField.on_submit = DoLogin
        Content = [ft.Text(Server.Url, color=Palette.Overlay0, size=12)]
        if Reason:
            Content.append(ft.Text(Reason, color=Palette.Yellow, size=13))
        Content += [UsernameField, PasswordField, RememberSwitch, ErrorText]
        self.ShowDialog("Log in", ft.Column(Content, tight=True, spacing=12), [
            ChipButton("Cancel", lambda e: self.Close()),
            ChipButton("Log in", DoLogin),
        ], Width=380)

    def Logout(self) -> None:
        if self.Server is None:
            return
        self.Server.Logout()
        SaveSessionToken(self.Config.ServerUrl, "")
        self.Notify("Logged out. Browsing as Guest.", "info")
        self.Changed()

    # --- UI helpers -------------------------------------------------------

    def Notify(self, Text: str, Kind: str = "info") -> None:
        Background, Accent = NotificationStyle(Kind)
        self.Page.show_dialog(ft.SnackBar(
            content=ft.Text(Text, color=Accent),
            bgcolor=Background,
            shape=ft.RoundedRectangleBorder(radius=4, side=ft.BorderSide(1, Accent)),
            open=True,
        ))

    def ShowDialog(self, Title: str, Content: ft.Control, Actions: list[ft.Control], Width: int = 440) -> None:
        self.DialogOpen = True
        self.Page.show_dialog(ft.AlertDialog(
            title=Title,
            content=ft.Container(Content, width=Width),
            actions=Actions,
            on_dismiss=lambda e: setattr(self, "DialogOpen", False),
        ))

    def Close(self) -> None:
        self.DialogOpen = False
        self.Page.pop_dialog()

    def Confirm(self, Title: str, Text: str, OnYes: Callable[[], None], YesText: str = "Delete") -> None:
        def Yes(e) -> None:
            self.Close()
            OnYes()

        self.ShowDialog(Title, ft.Text(Text), [
            ChipButton("Cancel", lambda e: self.Close()),
            ChipButton(YesText, Yes, Accent=Palette.Red),
        ])

    def AskName(self, Title: str, Value: str, SelectEnd: int, OnDone: Callable[[str], None],
                ActionText: str = "Create", Note: str = "", RequireChange: bool = True) -> None:
        """A one-field dialog with the name's stem preselected, like SaraFem's.
        RequireChange: an unchanged name does nothing (Rename)."""
        NameField = ft.TextField(value=Value, autofocus=True,
                                 selection=ft.TextSelection(base_offset=0, extent_offset=SelectEnd))

        def Done(e=None) -> None:
            NewName = (NameField.value or "").strip()
            self.Close()
            if NewName and (NewName != Value or not RequireChange):
                OnDone(NewName)

        NameField.on_submit = Done
        Content: ft.Control = NameField
        if Note:
            Content = ft.Column([NameField, ft.Text(Note, color=Palette.Overlay0, size=12)], tight=True, spacing=8)
        self.ShowDialog(Title, Content, [
            ChipButton("Cancel", lambda e: self.Close()),
            ChipButton(ActionText, Done),
        ], Width=380)