# Copyright (c) 2021 Ultimaker B.V.
# Uranium is released under the terms of the LGPLv3 or higher.

from enum import IntEnum
from typing import Optional, Union, Dict, List

from PyQt5.QtCore import QTimer, pyqtSignal, QObject

from UM.Logger import Logger
from UM.Signal import Signal, signalemitter


@signalemitter
class Message(QObject):
    """Class for displaying messages to the user."""

    class ActionButtonStyle:
        DEFAULT = 0
        LINK = 1
        SECONDARY = 2

    class ActionButtonAlignment:
        ALIGN_LEFT = 2
        ALIGN_RIGHT = 3

    class MessageType(IntEnum):
        POSITIVE = 0
        NEUTRAL = 1
        WARNING = 2
        ERROR = 3

    def __init__(self, text: str = "", lifetime: int = 30, dismissable: bool = True, progress: float = None,
                 title: Optional[str] = None, parent=None, use_inactivity_timer: bool = True, image_source: str = "",
                 image_caption: str = "", option_text: str = "", option_state: bool = True, message_type: MessageType = MessageType.NEUTRAL) -> None:

        """Class for displaying messages to the user.
        Even though the lifetime can be set, in certain cases it can still have a lifetime if nothing happens with the
        the message.
        We define the following cases:

        - A message is dismissible; No timeout (set by lifetime or inactivity)
        - A message is set to not dismissible, without progress; We force the dismissible property to be true
        - A message is set to not dismissible, with progress; After 30 seconds of no progress updates we hide the message.

        :param text: Text that needs to be displayed in the message
        :param lifetime: How long should the message be displayed (in seconds).
            if lifetime is 0, it will never automatically be destroyed.
        :param dismissable: Can the user dismiss the message?
        :param title: Phrase that will be shown above the message.
        :param image_source: an absolute path where an image can be found to be
        displayed (QUrl.toLocalFile()) can be used for that.
        :param image_caption: Text to be displayed below the image (or anywhere
        really, it's up to the QML to handle that).
        :param progress: Is there any progress to be displayed? if -1, it's seen
        as indeterminate.
        :param message_type: Defines the type of message according to the MessageType enum (POSITIVE, NEUTRAL, WARNING,
        ERROR, default: NEUTRAL). Depending on the type, an icon appears next to the message title. The NEUTRAL messages
        contain no icon.
        """

        super().__init__(parent)
        from UM.Application import Application
        self._application = Application.getInstance()
        self._visible = False
        self._text = text.replace("\n", "<br>")
        self._progress = progress  # If progress is set to -1, the progress is seen as indeterminate
        self._max_progress = 100  # type: float
        self._lifetime = lifetime
        self._lifetime_timer = None  # type: Optional[QTimer]

        self._option_text = option_text
        self._option_state = option_state
        self._image_source = image_source
        self._image_caption = image_caption

        self._use_inactivity_timer = use_inactivity_timer
        self._inactivity_timer = None  # type: Optional[QTimer]

        self._dismissable = dismissable  # Can the message be closed by user?
        if not self._dismissable:
            # If the message has no lifetime and no progress, it should be dismissible.
            # this is to prevent messages being permanently visible.
            if self._lifetime == 0 and self._progress is None:
                self._dismissable = True

        self._actions = []  # type: List[Dict[str, Union[str, int]]]
        self._title = title

        self._message_type = message_type

        self.actionTriggered.connect(self._onActionTriggered)

    # We use these signals as QTimers need to be triggered from a qThread. By using signals to pass it,
    # the events are forced to be on the event loop (which is a qThread)
    inactivityTimerStop = pyqtSignal()
    inactivityTimerStart = pyqtSignal()
    # Our signals work a bit differently, but also don't support lambdas. As such, the pyqt version of the same signal
    # is also added.
    # The actionTriggered signal will trigger the PyQtAction triggered signal
    pyQtActionTriggered = pyqtSignal(QObject, str)
    actionTriggered = Signal()
    optionToggled = Signal()

    titleChanged = Signal()
    textChanged = Signal()
    progressChanged = Signal()

    def _onActionTriggered(self, message, action):
        self.pyQtActionTriggered.emit(message, action)

    def _stopInactivityTimer(self) -> None:
        if self._inactivity_timer:
            self._inactivity_timer.stop()

    def _startInactivityTimer(self) -> None:
        if self._inactivity_timer:
            # There is some progress indication, but no lifetime, so the inactivity timer needs to run.
            if self._progress is not None and self._lifetime == 0:
                self._inactivity_timer.start()

    def _onInactivityTriggered(self) -> None:
        Logger.log("d", "Hiding message because of inactivity")
        self.hide()

    def show(self) -> None:
        """Show the message (if not already visible)"""

        if not self._visible:
            self._visible = True
            self._application.showMessageSignal.emit(self)
            self.inactivityTimerStart.emit()

    @property
    def visible(self) -> bool:
        """Returns a boolean indicating whether the message is currently visible."""

        return self._visible

    def isDismissable(self) -> bool:
        """Can the message be closed by user?"""

        return self._dismissable

    def setLifetimeTimer(self, timer: QTimer) -> None:
        """Set the lifetime timer of the message.

        This is used by the QT application once the message is shown.
        If the lifetime is set to 0, no timer is added.
        This function is required as the QTimer needs to be created on a QThread.
        """

        self._lifetime_timer = timer
        if self._lifetime_timer:
            if self._lifetime:
                self._lifetime_timer.setInterval(self._lifetime * 1000)
                self._lifetime_timer.setSingleShot(True)
                self._lifetime_timer.timeout.connect(self.hide)
                self._lifetime_timer.start()
            self._startInactivityTimer()

    def setInactivityTimer(self, inactivity_timer: QTimer) -> None:
        """Set the inactivity timer of the message.

        This function is required as the QTimer needs to be created on a QThread.
        """

        if not self._use_inactivity_timer:
            return
        self._inactivity_timer = inactivity_timer
        self._inactivity_timer.setInterval(30 * 1000)
        self._inactivity_timer.setSingleShot(True)
        self._inactivity_timer.timeout.connect(self._onInactivityTriggered)
        self.inactivityTimerStart.connect(self._startInactivityTimer)
        self.inactivityTimerStop.connect(self._stopInactivityTimer)

    def addAction(self, action_id: str, name: str, icon: str, description: str, button_style: int = ActionButtonStyle.DEFAULT, button_align: int = ActionButtonAlignment.ALIGN_RIGHT):
        """Add an action to the message

        Actions are useful for making messages that require input from the user.
        :param action_id:
        :param name: The displayed name of the action
        :param icon: Source of the icon to be used
        :param button_style: Description the button style (used for Button and Link)
        :param button_align: Define horizontal position of the action item
        """

        self._actions.append({"action_id": action_id, "name": name, "icon": icon, "description": description, "button_style": button_style, "button_align": button_align})

    def getActions(self) -> List[Dict[str, Union[str, int]]]:
        """Get the list of actions to display buttons for on the message.

        Each action is a dictionary with the elements provided in ``addAction``.

        :return: A list of actions.
        """

        return self._actions

    def getOptionText(self) -> str:
        return self._option_text

    def getOptionState(self) -> bool:
        return self._option_state

    def getImageSource(self) -> str:
        return self._image_source

    def getImageCaption(self) -> str:
        return self._image_caption

    def getMessageType(self) -> MessageType:
        """
        Gets the type of the message.
        The message gets a different icon according to its type.
        :return: The type of the message (POSITIVE, NEUTRAL, WARNING, ERROR)
        """
        return self._message_type

    def setText(self, text: str) -> None:
        """Changes the text on the message.

        :param text: The new text for the message. Please ensure that this text
            is internationalised.
        """

        self._text = text.replace("\n", "<br>")
        self.textChanged.emit(self)

    def getText(self) -> str:
        """Returns the text in the message.

        :return: The text in the message.
        """

        return self._text

    def setMaxProgress(self, max_progress: float) -> None:
        """Sets the maximum numerical value of the progress bar on the message.

        If the reported progress hits this number, the bar will appear filled.
        """

        self._max_progress = max_progress

    def getMaxProgress(self) -> float:
        """Gets the maximum value of the progress bar on the message.

        Note that this is not the _current_ value of the progress bar!

        :return: The maximum value of the progress bar on the message.

        :see getProgress
        """

        return self._max_progress

    def setProgress(self, progress: Optional[float]) -> None:
        """Changes the state of the progress bar.

        :param progress: The new progress to display to the user. This should be
        between 0 and the value of `getMaxProgress()`. None to remove the progressbar
        """

        if self._progress != progress:
            self._progress = progress
            self.progressChanged.emit(self)
        self.inactivityTimerStart.emit()

    """Signal that gets emitted whenever the state of the progress bar on this
    message changes.
    """

    def getProgress(self) -> Optional[float]:
        """Returns the current progress.

        This should be a value between 0 and the value of ``getMaxProgress()``.
        If no progress is set (because the message doesn't have it) None is returned
        """

        return self._progress

    def setTitle(self, title: str) -> None:
        """Changes the message title.

        :param title: The new title for the message. Please ensure that this text
        is internationalised.
        """

        self._title = title
        self.titleChanged.emit(self)

    def getTitle(self) -> Optional[str]:
        """Returns the message title.

        :return: The message title.
        """

        return self._title

    def hide(self, send_signal = True) -> None:
        """Hides this message.

        While the message object continues to exist in memory, it appears to the
        user that it is gone.
        """

        if self._visible:
            self._visible = False
            self.inactivityTimerStop.emit()
            if send_signal:
                self._application.hideMessageSignal.emit(self)
