from maya import cmds


from .main import DwPicker, WINDOW_CONTROL_NAME
from .optionvar import ensure_optionvars_exists
from .namespace import detect_picker_namespace
from .qtutils import remove_workspace_control
from .updatechecker import warn_if_update_available


_dwpicker = None


def show(
        editable=True,
        pickers=None,
        ignore_scene_pickers=False,
        replace_namespace_function=None,
        list_namespaces_function=None):
    """
    This is the dwpicker default startup function.
    kwargs:
        editable: bool
            This allow users to do local edit on their picker. This is NOT
            affecting the original file.

        pickers: list[str]
            Path to pickers to open. If scene contains already pickers,
            they are going to be ignored.

        ignore_scene_pickers: bool
            This is loading the picker empty, ignoring the scene content.

        replace_namespace_function: callable
            Function used when on each target when a namespace switch is
            triggered. Function must follow this templace:
                def function(target: str, namespace: str)
                    -> new_target_name: str

        list_namespaces_function: callable
            Function used when the picker is listing the scene existing
            namespace. The default behavior list all the scene namespaces, but
            in some studios, lot of namespace are not relevant to list, this
            by this way you can customize how it does works.
                def function():
                    -> List[str]

    return:
        DwPicker: window
    """
    ensure_optionvars_exists()
    global _dwpicker
    if not _dwpicker:
        warn_if_update_available()
        _dwpicker = DwPicker(
            replace_namespace_function=replace_namespace_function,
            list_namespaces_function=list_namespaces_function)
    try:
        _dwpicker.show(dockable=True)
    except RuntimeError:
        # Workspace control already exists, UI restore as probably failed.
        remove_workspace_control(WINDOW_CONTROL_NAME)
        _dwpicker.show()

    _dwpicker.set_editable(editable)
    if not ignore_scene_pickers and not pickers:
        _dwpicker.load_saved_pickers()

    if not pickers:
        return _dwpicker

    _dwpicker.clear()
    for filename in pickers:
        try:
            print(filename)
            _dwpicker.add_picker_from_file(filename)
        except BaseException:
            import traceback
            print("Not able to load: {}".format(filename))
            print(traceback.format_exc())
    _dwpicker.store_local_pickers_data()
    return _dwpicker


def toggle():
    """
    Switch the DwPicker visibility.
    """
    if not _dwpicker:
        return show()
    _dwpicker.setVisible(not _dwpicker.isVisible())


def close():
    """
    Close properly the DwPicker.
    It unregister all DwPicker remaining callbacks.
    """
    global _dwpicker
    if not _dwpicker:
        return

    _dwpicker.unregister_callbacks()
    for i in range(_dwpicker.tab.count()):
        picker = _dwpicker.tab.widget(i)
        picker.unregister_callbacks()

    _dwpicker.close()
    _dwpicker = None


class disable():
    """
    This context manager temporarily disable the picker callbacks.
    This is usefull to decorate code which change the maya selection multiple
    times. This can lead constant refresh of the picker and lead performance
    issue. This should fix it.
    """
    def __enter__(self):
        if _dwpicker is None:
            return
        _dwpicker.unregister_callbacks()
        for i in range(_dwpicker.tab.count()):
            picker = _dwpicker.tab.widget(i)
            picker.unregister_callbacks()

    def __exit__(self, *_):
        if _dwpicker is None:
            return
        _dwpicker.register_callbacks()
        for i in range(_dwpicker.tab.count()):
            picker = _dwpicker.tab.widget(i)
            picker.register_callbacks()


def current():
    """
    Get the current picker widget visible in the main tab widget.
    """
    if not _dwpicker:
        return
    return _dwpicker.tab.currentWidget()


def refresh():
    """
    Trigger this function to refresh ui if the picker datas has been changed
    manually inside the scene.
    """
    if not _dwpicker:
        return


def open_picker_file(filepath):
    """
    Add programmatically a picker to the main UI.
    """
    if not _dwpicker:
        return cmds.warning('Please open picker first.')
    _dwpicker.add_picker_from_file(filepath)
    _dwpicker.store_local_pickers_data()


def current_namespace():
    """
    Returns the namespace of the current displayed picker.
    """
    picker = current()
    if not picker:
        return ':'
    return detect_picker_namespace(picker.document.shapes)


def set_layer_visible(layername, visible=True):
    if not _dwpicker:
        return cmds.warning('Please open picker first.')
    picker = current()
    if not picker:
        return
    if visible:
        if layername in picker.layers_menu.hidden_layers:
            picker.layers_menu.hidden_layers.remove(layername)
            picker.update()
        return
    if layername not in picker.layers_menu.hidden_layers:
        picker.layers_menu.hidden_layers.append(layername)
        picker.update()


def toggle_layer_visibility(layername):
    if not _dwpicker:
        return cmds.warning('Please open picker first.')
    picker = current()
    if not picker:
        return
    if layername in picker.layers_menu.hidden_layers:
        picker.layers_menu.hidden_layers.remove(layername)
    else:
        picker.layers_menu.hidden_layers.append(layername)
    picker.update()


def get_shape(shape_id):
    picker = current()
    if not picker:
        return
    return picker.document.shapes_by_id.get(shape_id)