"""This module contains user interface related code, such as the main screen
and diagram windows."""

# ruff: noqa: E402

from __future__ import annotations

import sys

import gi

gi.require_version("Gtk", "4.0")
gi.require_version("Gdk", "4.0")
gi.require_version("GtkSource", "5")
gi.require_version("Adw", "1")

from gi.repository import Adw, Gio, GtkSource

import gaphor.asyncio
import gaphor.ui.diagramview  # noqa: F401
import gaphor.ui.textfield  # noqa: F401
from gaphor.application import Application, Session
from gaphor.core import event_handler
from gaphor.event import ActiveSessionChanged, ApplicationShutdown, SessionCreated
from gaphor.settings import APPLICATION_ID, StyleVariant, settings
from gaphor.storage.recovery import all_sessions
from gaphor.ui.actiongroup import apply_application_actions

Adw.init()
GtkSource.init()


def run(argv: list[str], *, launch_service="greeter", recover=False) -> int:
    application: Application | None = None

    def app_startup(gtk_app):
        nonlocal application

        @event_handler(SessionCreated)
        def on_session_created(event: SessionCreated):
            event_manager = event.session.get_service("event_manager")
            event_manager.subscribe(on_session_changed)
            main_window = event.session.get_service("main_window")
            main_window.open(gtk_app)

        @event_handler(ActiveSessionChanged)
        def on_session_changed(event: ActiveSessionChanged):
            if isinstance(event.service, Session):
                main_window = event.service.get_service("main_window")
                if main_window.window:
                    main_window.window.present()

        @event_handler(ApplicationShutdown)
        def on_quit(_event: ApplicationShutdown):
            gtk_app.quit()

        try:
            application = Application(gtk_app=gtk_app)
            apply_application_actions(application, gtk_app)
            event_manager = application.get_service("event_manager")
            event_manager.subscribe(on_session_created)
            event_manager.subscribe(on_quit)
            application.get_service(launch_service).init(gtk_app)
            if recover:
                recover_sessions(application)
        except Exception:
            gtk_app.exit_code = 1
            gtk_app.quit()
            raise

    def app_activate(gtk_app):
        assert application
        if not application.sessions:
            application.get_service(launch_service).open()

    def app_open(gtk_app, files, n_files, hint):
        # appfilemanager should take care of this:
        assert application
        if hint == "__new__":
            application.new_session()
        else:
            for file in files:
                application.new_session(filename=file.get_path())

    def update_color_scheme(style_variant: StyleVariant):
        gtk_app.get_style_manager().set_color_scheme(
            {
                StyleVariant.DARK: Adw.ColorScheme.FORCE_DARK,
                StyleVariant.LIGHT: Adw.ColorScheme.FORCE_LIGHT,
            }.get(style_variant, Adw.ColorScheme.DEFAULT)
        )

    # Register session on Darwin, so the NSApplicationDelegate is registered for opening files
    gtk_app = Adw.Application(
        application_id=APPLICATION_ID,
        flags=Gio.ApplicationFlags.HANDLES_OPEN,
        register_session=(sys.platform == "darwin"),
    )

    settings.style_variant_changed(update_color_scheme)
    gtk_app.exit_code = 0
    gtk_app.connect("startup", app_startup)
    gtk_app.connect("activate", app_activate)
    gtk_app.connect("open", app_open)

    with gaphor.asyncio.glib_event_loop_policy():
        gtk_app.run(argv)

    return gtk_app.exit_code


def recover_sessions(application):
    for session_id, filename, template in all_sessions():
        if not any(
            session.session_id == session_id for session in application.sessions
        ):
            application.recover_session(
                session_id=session_id, filename=filename, template=template
            )


if __name__ == "__main__":
    run(sys.argv)
