from typing import Literal

from qtpy import QtCore, QtWidgets

from prettyqt import widgets
from prettyqt.utils import bidict, InvalidParamError


area = QtWidgets.QAbstractScrollArea

SIZE_POLICY = bidict(
    content=area.AdjustToContents,
    first_show=area.AdjustToContentsOnFirstShow,
    ignored=area.AdjustIgnored,
)

SizePolicyStr = Literal["content", "first_show", "ignored"]

SCROLLBAR_POLICY = bidict(
    always_on=QtCore.Qt.ScrollBarAlwaysOn,
    always_off=QtCore.Qt.ScrollBarAlwaysOff,
    as_needed=QtCore.Qt.ScrollBarAsNeeded,
)

ScrollBarPolicyStr = Literal["always_on", "always_off", "as_needed"]


QtWidgets.QAbstractScrollArea.__bases__ = (widgets.Frame,)


class AbstractScrollArea(QtWidgets.QAbstractScrollArea):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.h_scrollbar = widgets.ScrollBar()
        self.v_scrollbar = widgets.ScrollBar()
        self.setHorizontalScrollBar(self.h_scrollbar)
        self.setVerticalScrollBar(self.v_scrollbar)

    # @property
    # def h_scrollbar(self):
    #     return self.horizontalScrollbar()

    # @h_scrollbar.setter
    # def h_scrollbar(self, scrollbar):
    #     self.setHorizontalScrollBar(scrollbar)

    # @property
    # def v_scrollbar(self):
    #     return self.verticalScrollBar()

    # @v_scrollbar.setter
    # def v_scrollbar(self, scrollbar):
    #     self.setVerticalScrollBar(scrollbar)

    def set_size_adjust_policy(self, policy: SizePolicyStr):
        """Set size adjust policy.

        Args:
            policy: size adjust policy to use

        Raises:
            InvalidParamError: invalid size adjust policy
        """
        if policy not in SIZE_POLICY:
            raise InvalidParamError(policy, SIZE_POLICY)
        self.setSizeAdjustPolicy(SIZE_POLICY[policy])

    def get_size_adjust_policy(self) -> SizePolicyStr:
        """Return size adjust policy.

        Returns:
            size adjust policy
        """
        return SIZE_POLICY.inverse[self.sizeAdjustPolicy()]

    def set_scrollbar_policy(self, mode: ScrollBarPolicyStr):
        """Set the policy for both scrollbars.

        Args:
            mode: visibilty to set

        Raises:
            InvalidParamError: invalid scrollbar policy
        """
        if mode not in SCROLLBAR_POLICY:
            raise InvalidParamError(mode, SCROLLBAR_POLICY)
        self.setHorizontalScrollBarPolicy(SCROLLBAR_POLICY[mode])
        self.setVerticalScrollBarPolicy(SCROLLBAR_POLICY[mode])

    def set_horizontal_scrollbar_policy(self, mode: ScrollBarPolicyStr):
        """Set the horizontal scrollbar visibility.

        Args:
            mode: visibilty to set

        Raises:
            InvalidParamError: invalid scrollbar policy
        """
        if mode not in SCROLLBAR_POLICY:
            raise InvalidParamError(mode, SCROLLBAR_POLICY)
        self.setHorizontalScrollBarPolicy(SCROLLBAR_POLICY[mode])

    def set_vertical_scrollbar_policy(self, mode: ScrollBarPolicyStr):
        """Set the vertical scrollbar visibility.

        Args:
            mode: visibilty to set

        Raises:
            InvalidParamError: invalid scrollbar policy
        """
        if mode not in SCROLLBAR_POLICY:
            raise InvalidParamError(mode, SCROLLBAR_POLICY)
        self.setVerticalScrollBarPolicy(SCROLLBAR_POLICY[mode])

    def set_scrollbar_width(self, width: int):
        """Set the width for both scrollbars.

        Args:
            width: width in pixels
        """
        self.set_horizontal_scrollbar_width(width)
        self.set_vertical_scrollbar_width(width)

    def set_horizontal_scrollbar_width(self, width: int):
        """Set the horizontal scrollbar width.

        Args:
            width: width in pixels
        """
        with self.h_scrollbar.edit_stylesheet() as ss:
            ss.QScrollBar.horizontal.height.setValue(f"{width}px")

    def set_vertical_scrollbar_width(self, width: int):
        """Set the vertical scrollbar width.

        Args:
            width: width in pixels
        """
        with self.v_scrollbar.edit_stylesheet() as ss:
            ss.QScrollBar.horizontal.height.setValue(f"{width}px")

    def scroll_to_top(self):
        """Scroll to the top of the scroll area."""
        self.verticalScrollBar().scroll_to_min()

    def scroll_to_bottom(self):
        """Scroll to the bottom of the scroll area."""
        self.verticalScrollBar().scroll_to_max()


if __name__ == "__main__":
    app = widgets.app()
    widget = AbstractScrollArea()
    widget.show()
    app.main_loop()
