use std::rc::Rc;

use gpui::prelude::FluentBuilder as _;
use gpui::{
    Anchor, AnyElement, App, Context, Div, ElementId, FocusHandle, InteractiveElement as _,
    IntoElement, MouseButton, ParentElement, RenderOnce, Stateful, StyleRefinement, Styled, Window,
};
use gpui_base::Popover as BasePopover;
pub use gpui_base::PopoverState;

use crate::{Selectable, StyledExt as _, v_flex};

/// A popover element that can be triggered by a button or any other element.
#[derive(IntoElement)]
pub struct Popover {
    id: ElementId,
    style: StyleRefinement,
    anchor: Anchor,
    default_open: bool,
    open: Option<bool>,
    tracked_focus_handle: Option<FocusHandle>,
    #[allow(clippy::type_complexity)]
    trigger: Option<Box<dyn FnOnce(bool, &Window, &App) -> AnyElement + 'static>>,
    #[allow(clippy::type_complexity)]
    content: Option<
        Rc<
            dyn Fn(&mut PopoverState, &mut Window, &mut Context<PopoverState>) -> AnyElement
                + 'static,
        >,
    >,
    children: Vec<AnyElement>,
    /// Style for trigger element.
    /// This is used for hotfix the trigger element style to support w_full.
    trigger_style: Option<StyleRefinement>,
    mouse_button: MouseButton,
    appearance: bool,
    overlay_closable: bool,
    #[allow(clippy::type_complexity)]
    on_open_change: Option<Rc<dyn Fn(&bool, &mut Window, &mut App)>>,
}

impl Popover {
    /// Create a new Popover with `view` mode.
    pub fn new(id: impl Into<ElementId>) -> Self {
        Self {
            id: id.into(),
            style: StyleRefinement::default(),
            anchor: Anchor::TopLeft,
            trigger: None,
            trigger_style: None,
            content: None,
            tracked_focus_handle: None,
            children: vec![],
            mouse_button: MouseButton::Left,
            appearance: true,
            overlay_closable: true,
            default_open: false,
            open: None,
            on_open_change: None,
        }
    }

    /// Set the anchor corner of the popover, default is `Corner::TopLeft`.
    ///
    /// This method is kept for backward compatibility with `Corner` type.
    /// Internally, it converts `Corner` to `Anchor`.
    pub fn anchor(mut self, anchor: impl Into<Anchor>) -> Self {
        self.anchor = anchor.into();
        self
    }

    /// Set the mouse button to trigger the popover, default is `MouseButton::Left`.
    pub fn mouse_button(mut self, mouse_button: MouseButton) -> Self {
        self.mouse_button = mouse_button;
        self
    }

    /// Set the trigger element of the popover.
    pub fn trigger<T>(mut self, trigger: T) -> Self
    where
        T: Selectable + IntoElement + 'static,
    {
        self.trigger = Some(Box::new(|is_open, _, _| {
            let selected = trigger.is_selected();
            trigger.selected(selected || is_open).into_any_element()
        }));
        self
    }

    /// Set the trigger from a builder, for elements that have no selected state.
    ///
    /// [`Self::trigger`] marks the trigger as selected while the popover is
    /// open, so it cannot be used with elements whose selection carries a
    /// different meaning, such as a row that indicates the current room.
    pub fn trigger_with<F>(mut self, trigger: F) -> Self
    where
        F: FnOnce(bool, &Window, &App) -> AnyElement + 'static,
    {
        self.trigger = Some(Box::new(trigger));
        self
    }

    /// Set the default open state of the popover, default is `false`.
    ///
    /// This is only used to initialize the open state of the popover.
    ///
    /// And please note that if you use the `open` method, this value will be ignored.
    pub fn default_open(mut self, open: bool) -> Self {
        self.default_open = open;
        self
    }

    /// Force set the open state of the popover.
    ///
    /// If this is set, the popover will be controlled by this value.
    ///
    /// NOTE: You must be used in conjunction with `on_open_change` to handle state changes.
    pub fn open(mut self, open: bool) -> Self {
        self.open = Some(open);
        self
    }

    /// Add a callback to be called when the open state changes.
    ///
    /// The first `&bool` parameter is the **new open state**.
    ///
    /// This is useful when using the `open` method to control the popover state.
    pub fn on_open_change<F>(mut self, callback: F) -> Self
    where
        F: Fn(&bool, &mut Window, &mut App) + 'static,
    {
        self.on_open_change = Some(Rc::new(callback));
        self
    }

    /// Set the style for the trigger element.
    pub fn trigger_style(mut self, style: StyleRefinement) -> Self {
        self.trigger_style = Some(style);
        self
    }

    /// Set whether clicking outside the popover will dismiss it, default is `true`.
    pub fn overlay_closable(mut self, closable: bool) -> Self {
        self.overlay_closable = closable;
        self
    }

    /// Set the content builder for content of the Popover.
    ///
    /// This callback will called every time on render the popover.
    /// So, you should avoid creating new elements or entities in the content closure.
    pub fn content<F, E>(mut self, content: F) -> Self
    where
        E: IntoElement,
        F: Fn(&mut PopoverState, &mut Window, &mut Context<PopoverState>) -> E + 'static,
    {
        self.content = Some(Rc::new(move |state, window, cx| {
            content(state, window, cx).into_any_element()
        }));
        self
    }

    /// Set whether the popover no style, default is `false`.
    ///
    /// If no style:
    ///
    /// - The popover will not have a bg, border, shadow, or padding.
    /// - The click out of the popover will not dismiss it.
    pub fn appearance(mut self, appearance: bool) -> Self {
        self.appearance = appearance;
        self
    }

    /// Bind the focus handle to receive focus when the popover is opened.
    /// If you not set this, a new focus handle will be created for the popover to
    ///
    /// If popover is opened, the focus will be moved to the focus handle.
    pub fn track_focus(mut self, handle: &FocusHandle) -> Self {
        self.tracked_focus_handle = Some(handle.clone());
        self
    }
}

impl ParentElement for Popover {
    fn extend(&mut self, elements: impl IntoIterator<Item = AnyElement>) {
        self.children.extend(elements);
    }
}

impl Styled for Popover {
    fn style(&mut self) -> &mut StyleRefinement {
        &mut self.style
    }
}

impl Popover {
    pub(crate) fn render_popover_content(
        anchor: Anchor,
        appearance: bool,
        _: &mut Window,
        cx: &mut App,
    ) -> Stateful<Div> {
        v_flex()
            .id("content")
            .occlude()
            .tab_group()
            .when(appearance, |this| this.popover_style(cx).p_3())
            .map(|this| match anchor {
                Anchor::TopLeft | Anchor::TopCenter | Anchor::TopRight => this.top_1(),
                Anchor::BottomLeft | Anchor::BottomCenter | Anchor::BottomRight => this.bottom_1(),
                Anchor::LeftCenter | Anchor::RightCenter => this.top_1(), // Fallback for centered
            })
    }
}

impl RenderOnce for Popover {
    fn render(self, _: &mut Window, _: &mut App) -> impl IntoElement {
        let anchor = self.anchor;
        let appearance = self.appearance;
        let style = self.style;
        let children = self.children;
        let content = self.content;

        BasePopover::new(self.id)
            .anchor(anchor)
            .mouse_button(self.mouse_button)
            .default_open(self.default_open)
            .overlay_closable(self.overlay_closable)
            .content(move |state, window, cx| {
                Self::render_popover_content(anchor, appearance, window, cx)
                    .when_some(content, |this, content| {
                        this.child((content)(state, window, cx))
                    })
                    .children(children)
                    .refine_style(&style)
            })
            .when_some(self.trigger, |this, trigger| this.trigger_with(trigger))
            .when_some(self.open, |this, open| this.open(open))
            .when_some(self.tracked_focus_handle, |this, handle| {
                this.track_focus(&handle)
            })
            .when_some(self.on_open_change, |this, callback| {
                this.on_open_change(move |open, window, cx| callback(open, window, cx))
            })
            .into_any_element()
    }
}