import os
import sys

from PySide6.QtCore import Qt
from PySide6.QtGui import QColor, QFont, QFontInfo, QIcon, QPalette
from PySide6.QtWidgets import (
    QApplication,
    QGridLayout,
    QHBoxLayout,
    QLabel,
    QMainWindow,
    QPushButton,
    QWidget,
)

from .autoslicer import Autoslicer, AutoslicerParams
from .controller import ScanSlicerControllerMixin
from .ui_builders import ScanSlicerUiBuilderMixin


# _unwrap_qvariant: function definition for ScanSlicer behavior.
def _unwrap_qvariant(value):
    unwrapped = value
    for _ in range(4):
        if hasattr(unwrapped, "variant"):
            try:
                candidate = unwrapped.variant()
            except Exception:
                candidate = unwrapped
            if candidate is not unwrapped:
                unwrapped = candidate
                continue

        if hasattr(unwrapped, "value"):
            try:
                candidate = unwrapped.value()
            except TypeError:
                candidate = unwrapped.value
            except Exception:
                candidate = unwrapped
            if candidate is not unwrapped:
                unwrapped = candidate
                continue
        break
    return unwrapped


# _read_portal_dark_preference: function definition for ScanSlicer behavior.
def _read_portal_dark_preference():
    try:
        from PySide6.QtDBus import QDBusConnection, QDBusInterface, QDBusMessage
    except Exception:
        return None

    bus = QDBusConnection.sessionBus()
    if not bus.isConnected():
        return None

    iface = QDBusInterface(
        "org.freedesktop.portal.Desktop",
        "/org/freedesktop/portal/desktop",
        "org.freedesktop.portal.Settings",
        bus,
    )
    if not iface.isValid():
        return None

    for method in ("ReadOne", "Read"):
        reply = iface.call(method, "org.freedesktop.appearance", "color-scheme")
        if reply.type() == QDBusMessage.MessageType.ErrorMessage:
            continue

        args = reply.arguments()
        if not args:
            continue

        raw_value = _unwrap_qvariant(args[0])
        if isinstance(raw_value, dict) and "color-scheme" in raw_value:
            raw_value = _unwrap_qvariant(raw_value["color-scheme"])
        if isinstance(raw_value, (list, tuple)) and raw_value:
            raw_value = _unwrap_qvariant(raw_value[0])

        try:
            color_scheme = int(raw_value)
        except Exception:
            continue

        # XDG portal color-scheme values:
        # 0 = no preference, 1 = prefer dark, 2 = prefer light
        if color_scheme == 1:
            return True
        if color_scheme == 2:
            return False
    return None