"""Contains all of the events that can be triggered in a gr.Blocks() app, with the exception
of the on-page-load event, which is defined in gr.Blocks().load()."""

from __future__ import annotations

from functools import wraps
from typing import TYPE_CHECKING, Any, Callable, Literal, Sequence

from gradio_client.documentation import document, set_documentation_group

from gradio.blocks import Block
from gradio.deprecation import warn_deprecation
from gradio.helpers import EventData
from gradio.utils import get_cancel_function

if TYPE_CHECKING:  # Only import for type checking (is False at runtime).
    from gradio.components import Component

set_documentation_group("events")


def set_cancel_events(
    block: Block, event_name: str, cancels: None | dict[str, Any] | list[dict[str, Any]]
):
    if cancels:
        if not isinstance(cancels, list):
            cancels = [cancels]
        cancel_fn, fn_indices_to_cancel = get_cancel_function(cancels)
        block.set_event_trigger(
            event_name,
            cancel_fn,
            inputs=None,
            outputs=None,
            queue=False,
            preprocess=False,
            cancels=fn_indices_to_cancel,
        )


class EventListener(Block):
    def __init__(self: Any):
        for event_listener_class in EventListener.__subclasses__():
            if isinstance(self, event_listener_class):
                event_listener_class.__init__(self)


class Dependency(dict):
    def __init__(self, trigger, key_vals, dep_index, fn):
        super().__init__(key_vals)
        self.fn = fn
        self.trigger = trigger
        self.then = EventListenerMethod(
            self.trigger,
            "then",
            trigger_after=dep_index,
            trigger_only_on_success=False,
        )
        """
        Triggered after directly preceding event is completed, regardless of success or failure.
        """
        self.success = EventListenerMethod(
            self.trigger,
            "success",
            trigger_after=dep_index,
            trigger_only_on_success=True,
        )
        """
        Triggered after directly preceding event is completed, if it was successful.
        """

    def __call__(self, *args, **kwargs):
        return self.fn(*args, **kwargs)


class EventListenerMethod:
    """
    Triggered on an event deployment.
    """

    def __init__(
        self,
        trigger: Block,
        event_name: str,
        show_progress: Literal["full", "minimal", "hidden"] = "full",
        callback: Callable | None = None,
        trigger_after: int | None = None,
        trigger_only_on_success: bool = False,
    ):
        self.trigger = trigger
        self.event_name = event_name
        self.show_progress = show_progress
        self.callback = callback
        self.trigger_after = trigger_after
        self.trigger_only_on_success = trigger_only_on_success

    def __call__(
        self,
        fn: Callable | None | Literal["decorator"] = "decorator",
        inputs: Component | Sequence[Component] | set[Component] | None = None,
        outputs: Component | Sequence[Component] | None = None,
        api_name: str | None | Literal[False] = None,
        status_tracker: None = None,
        scroll_to_output: bool = False,
        show_progress: Literal["full", "minimal", "hidden"] | None = None,
        queue: bool | None = None,
        batch: bool = False,
        max_batch_size: int = 4,
        preprocess: bool = True,
        postprocess: bool = True,
        cancels: dict[str, Any] | list[dict[str, Any]] | None = None,
        every: float | None = None,
        _js: str | None = None,
    ) -> Dependency:
        """
        Parameters:
            fn: the function to call when this event is triggered. Often a machine learning model's prediction function. Each parameter of the function corresponds to one input component, and the function should return a single value or a tuple of values, with each element in the tuple corresponding to one output component.
            inputs: List of gradio.components to use as inputs. If the function takes no inputs, this should be an empty list.
            outputs: List of gradio.components to use as outputs. If the function returns no outputs, this should be an empty list.
            api_name: Defines how the endpoint appears in the API docs. Can be a string, None, or False. If False, the endpoint will not be exposed in the api docs. If set to None, the endpoint will be exposed in the api docs as an unnamed endpoint, although this behavior will be changed in Gradio 4.0. If set to a string, the endpoint will be exposed in the api docs with the given name.
            status_tracker: Deprecated and has no effect.
            scroll_to_output: If True, will scroll to output component on completion
            show_progress: If True, will show progress animation while pending
            queue: If True, will place the request on the queue, if the queue has been enabled. If False, will not put this event on the queue, even if the queue has been enabled. If None, will use the queue setting of the gradio app.
            batch: If True, then the function should process a batch of inputs, meaning that it should accept a list of input values for each parameter. The lists should be of equal length (and be up to length `max_batch_size`). The function is then *required* to return a tuple of lists (even if there is only 1 output component), with each list in the tuple corresponding to one output component.
            max_batch_size: Maximum number of inputs to batch together if this is called from the queue (only relevant if batch=True)
            preprocess: If False, will not run preprocessing of component data before running 'fn' (e.g. leaving it as a base64 string if this method is called with the `Image` component).
            postprocess: If False, will not run postprocessing of component data before returning 'fn' output to the browser.
            cancels: A list of other events to cancel when this listener is triggered. For example, setting cancels=[click_event] will cancel the click_event, where click_event is the return value of another components .click method. Functions that have not yet run (or generators that are iterating) will be cancelled, but functions that are currently running will be allowed to finish.
            every: Run this event 'every' number of seconds while the client connection is open. Interpreted in seconds. Queue must be enabled.
        """
        if fn == "decorator":

            def wrapper(func):
                self.__call__(
                    func,
                    inputs,
                    outputs,
                    api_name,
                    status_tracker,
                    scroll_to_output,
                    show_progress,
                    queue,
                    batch,
                    max_batch_size,
                    preprocess,
                    postprocess,
                    cancels,
                    every,
                    _js,
                )

                @wraps(func)
                def inner(*args, **kwargs):
                    return func(*args, **kwargs)

                return inner

            return Dependency(None, {}, None, wrapper)

        if status_tracker:
            warn_deprecation(
                "The 'status_tracker' parameter has been deprecated and has no effect."
            )
        if self.event_name == "stop":
            warn_deprecation(
                "The `stop` event on Video and Audio has been deprecated and will be remove in a future version. Use `ended` instead."
            )

        if isinstance(self, Streamable):
            self.check_streamable()
        if isinstance(show_progress, bool):
            show_progress = "full" if show_progress else "hidden"

        dep, dep_index = self.trigger.set_event_trigger(
            self.event_name,
            fn,
            inputs,
            outputs,
            preprocess=preprocess,
            postprocess=postprocess,
            scroll_to_output=scroll_to_output,
            show_progress=show_progress
            if show_progress is not None
            else self.show_progress,
            api_name=api_name,
            js=_js,
            queue=queue,
            batch=batch,
            max_batch_size=max_batch_size,
            every=every,
            trigger_after=self.trigger_after,
            trigger_only_on_success=self.trigger_only_on_success,
        )
        set_cancel_events(self.trigger, self.event_name, cancels)
        if self.callback:
            self.callback()
        return Dependency(self.trigger, dep, dep_index, fn)


@document("*change", inherit=True)
class Changeable(EventListener):
    def __init__(self):
        self.change = EventListenerMethod(self, "change")
        """
        This listener is triggered when the component's value changes either because of user input (e.g. a user types in a textbox) OR because of a function update (e.g. an image receives a value from the output of an event trigger).
        See `.input()` for a listener that is only triggered by user input.
        """


@document("*input", inherit=True)
class Inputable(EventListener):
    def __init__(self):
        self.input = EventListenerMethod(self, "input")
        """
        This listener is triggered when the user changes the value of the component.
        """


@document("*click", inherit=True)
class Clickable(EventListener):
    def __init__(self):
        self.click = EventListenerMethod(self, "click")
        """
        This listener is triggered when the component (e.g. a button) is clicked.
        """


@document("*submit", inherit=True)
class Submittable(EventListener):
    def __init__(self):
        self.submit = EventListenerMethod(self, "submit")
        """
        This listener is triggered when the user presses the Enter key while the component (e.g. a textbox) is focused.
        """


@document("*edit", inherit=True)
class Editable(EventListener):
    def __init__(self):
        self.edit = EventListenerMethod(self, "edit")
        """
        This listener is triggered when the user edits the component (e.g. image) using the
        built-in editor.
        """


@document("*clear", inherit=True)
class Clearable(EventListener):
    def __init__(self):
        self.clear = EventListenerMethod(self, "clear")
        """
        This listener is triggered when the user clears the component (e.g. image or audio)
        using the X button for the component.
        """


@document("*play", "*pause", "*stop", "*end", inherit=True)
class Playable(EventListener):
    def __init__(self):
        self.play = EventListenerMethod(self, "play")
        """
        This listener is triggered when the user plays the component (e.g. audio or video).
        """

        self.pause = EventListenerMethod(self, "pause")
        """
        This listener is triggered when the media stops playing for any reason (e.g. audio or video).
        """

        self.stop = EventListenerMethod(self, "stop")
        """
        This listener is triggered when the user reaches the end of the media track (e.g. audio or video).
        """

        self.end = EventListenerMethod(self, "end")
        """
        This listener is triggered when the user reaches the end of the media track (e.g. audio or video).
        """


@document("*stream", inherit=True)
class Streamable(EventListener):
    def __init__(self):
        self.streaming: bool
        self.stream = EventListenerMethod(
            self,
            "stream",
            show_progress="hidden",
            callback=lambda: setattr(self, "streaming", True),
        )
        """
        This listener is triggered when the user streams the component (e.g. a live webcam
        component).
        """

    def check_streamable(self):
        pass


class StreamableOutput(EventListener):
    def __init__(self):
        self.streaming: bool

    def stream_output(self, y, output_id: str, first_chunk: bool) -> tuple[bytes, Any]:
        raise NotImplementedError


@document("*start_recording", "*stop_recording", inherit=True)
class Recordable(EventListener):
    def __init__(self):
        self.start_recording = EventListenerMethod(self, "start_recording")
        """
        This listener is triggered when the user starts recording with the component (e.g. audio or video).
        """

        self.stop_recording = EventListenerMethod(self, "stop_recording")
        """
        This listener is triggered when the user stops recording with the component (e.g. audio or video).
        """


@document("*focus", "*blur", inherit=True)
class Focusable(EventListener):
    def __init__(self):
        self.focus = EventListenerMethod(self, "focus")
        """
        This listener is triggered when the component is focused (e.g. when the user clicks inside a textbox).
        """

        self.blur = EventListenerMethod(self, "blur")
        """
        This listener is triggered when the component's is unfocused/blurred (e.g. when the user clicks outside of a textbox). 
        """


@document("*upload", inherit=True)
class Uploadable(EventListener):
    def __init__(self):
        self.upload = EventListenerMethod(self, "upload")
        """
        This listener is triggered when the user uploads a file into the component (e.g. when the user uploads a video into a video component).
        """


@document("*release", inherit=True)
class Releaseable(EventListener):
    def __init__(self):
        self.release = EventListenerMethod(self, "release")
        """
        This listener is triggered when the user releases the mouse on this component (e.g. when the user releases the slider).
        """


@document("*select", inherit=True)
class Selectable(EventListener):
    def __init__(self):
        self.selectable: bool = False
        self.select = EventListenerMethod(
            self, "select", callback=lambda: setattr(self, "selectable", True)
        )
        """
        This listener is triggered when the user selects from within the Component.
        This event has EventData of type gradio.SelectData that carries information, accessible through SelectData.index and SelectData.value.
        See EventData documentation on how to use this event data.
        """


class SelectData(EventData):
    def __init__(self, target: Block | None, data: Any):
        super().__init__(target, data)
        self.index: int | tuple[int, int] = data["index"]
        """
        The index of the selected item. Is a tuple if the component is two dimensional or selection is a range.
        """
        self.value: Any = data["value"]
        """
        The value of the selected item.
        """
        self.selected: bool = data.get("selected", True)
        """
        True if the item was selected, False if deselected.
        """


@document("*like", inherit=True)
class Likeable(EventListener):
    def __init__(self):
        self.likeable: bool = False
        self.like = EventListenerMethod(
            self, "like", callback=lambda: setattr(self, "likeable", True)
        )
        """
        This listener is triggered when the user likes/dislikes from within the Component.
        This event has EventData of type gradio.LikeData that carries information, accessible through LikeData.index and LikeData.value.
        See EventData documentation on how to use this event data.
        """


class LikeData(EventData):
    def __init__(self, target: Block | None, data: Any):
        super().__init__(target, data)
        self.index: int | tuple[int, int] = data["index"]
        """
        The index of the liked/disliked item. Is a tuple if the component is two dimensional.
        """
        self.value: Any = data["value"]
        """
        The value of the liked/disliked item.
        """
        self.liked: bool = data.get("liked", True)
        """
        True if the item was liked, False if disliked.
        """