from __future__ import annotations

from typing import Any, Callable

from gradio.components.base import FormComponent
from gradio.events import Events


class SimpleTextbox(FormComponent):
    """
    Creates a very simple textbox for user to enter string input or display string output.
    """

    EVENTS = [
        Events.change,
        Events.input,
        Events.submit,
    ]

    def __init__(
        self,
        value: str | Callable | None = None,
        *,
        placeholder: str | None = None,
        label: str | None = None,
        every: float | None = None,
        show_label: bool | None = None,
        scale: int | None = None,
        min_width: int = 160,
        interactive: bool | None = None,
        visible: bool = True,
        rtl: bool = False,
        elem_id: str | None = None,
        elem_classes: list[str] | str | None = None,
        render: bool = True,
    ):
        """
        Parameters:
            value: default text to provide in textbox. If callable, the function will be called whenever the app loads to set the initial value of the component.
            placeholder: placeholder hint to provide behind textbox.
            label: component name in interface.
            every: If `value` is a callable, run the function 'every' number of seconds while the client connection is open. Has no effect otherwise. The event can be accessed (e.g. to cancel it) via this component's .load_event attribute.
            show_label: if True, will display label.
            scale: relative size compared to adjacent Components. For example if Components A and B are in a Row, and A has scale=2, and B has scale=1, A will be twice as wide as B. Should be an integer. scale applies in Rows, and to top-level Components in Blocks where fill_height=True.
            min_width: minimum pixel width, will wrap if not sufficient screen space to satisfy this value. If a certain scale value results in this Component being narrower than min_width, the min_width parameter will be respected first.
            interactive: if True, will be rendered as an editable textbox; if False, editing will be disabled. If not provided, this is inferred based on whether the component is used as an input or output.
            visible: If False, component will be hidden.
            rtl: If True and `type` is "text", sets the direction of the text to right-to-left (cursor appears on the left of the text). Default is False, which renders cursor on the right.
            elem_id: An optional string that is assigned as the id of this component in the HTML DOM. Can be used for targeting CSS styles.
            elem_classes: An optional list of strings that are assigned as the classes of this component in the HTML DOM. Can be used for targeting CSS styles.
            render: If False, component will not render be rendered in the Blocks context. Should be used if the intention is to assign event listeners now but render the component later.
        """
        self.placeholder = placeholder
        self.rtl = rtl
        super().__init__(
            label=label,
            every=every,
            show_label=show_label,
            scale=scale,
            min_width=min_width,
            interactive=interactive,
            visible=visible,
            elem_id=elem_id,
            elem_classes=elem_classes,
            value=value,
            render=render,
        )

    def preprocess(self, payload: str | None) -> str | None:
        """
        Parameters:
            payload: the text entered in the textarea.
        Returns:
            Passes text value as a {str} into the function.
        """
        return None if payload is None else str(payload)

    def postprocess(self, value: str | None) -> str | None:
        """
        Parameters:
            value: Expects a {str} returned from function and sets textarea value to it.
        Returns:
            The value to display in the textarea.
        """
        return None if value is None else str(value)

    def api_info(self) -> dict[str, Any]:
        return {"type": "string"}

    def example_payload(self) -> Any:
        return "Hello!!"

    def example_value(self) -> Any:
        return "Hello!!"
