use crate::shell::{CosmicMappedRenderElement, WorkspaceRenderElement};

use smithay::{
    backend::renderer::{
        element::{Element, RenderElement, UnderlyingStorage},
        glow::{GlowFrame, GlowRenderer},
        Frame, ImportAll, ImportMem, Renderer,
    },
    utils::{Buffer as BufferCoords, Physical, Point, Rectangle, Scale},
};

#[cfg(feature = "debug")]
use smithay::backend::renderer::{
    element::texture::TextureRenderElement, gles::GlesTexture, multigpu::Error as MultiError,
};

use super::{cursor::CursorRenderElement, GlMultiFrame, GlMultiRenderer};

pub enum CosmicElement<R>
where
    R: AsGlowRenderer + Renderer + ImportAll + ImportMem,
    <R as Renderer>::TextureId: 'static,
    CosmicMappedRenderElement<R>: RenderElement<R>,
{
    Workspace(WorkspaceRenderElement<R>),
    Cursor(CursorRenderElement<R>),
    MoveGrab(CosmicMappedRenderElement<R>),
    #[cfg(feature = "debug")]
    Egui(TextureRenderElement<GlesTexture>),
}

impl<R> Element for CosmicElement<R>
where
    R: AsGlowRenderer + Renderer + ImportAll + ImportMem,
    <R as Renderer>::TextureId: 'static,
    CosmicMappedRenderElement<R>: RenderElement<R>,
{
    fn id(&self) -> &smithay::backend::renderer::element::Id {
        match self {
            CosmicElement::Workspace(elem) => elem.id(),
            CosmicElement::Cursor(elem) => elem.id(),
            CosmicElement::MoveGrab(elem) => elem.id(),
            #[cfg(feature = "debug")]
            CosmicElement::Egui(elem) => elem.id(),
        }
    }

    fn current_commit(&self) -> smithay::backend::renderer::utils::CommitCounter {
        match self {
            CosmicElement::Workspace(elem) => elem.current_commit(),
            CosmicElement::Cursor(elem) => elem.current_commit(),
            CosmicElement::MoveGrab(elem) => elem.current_commit(),
            #[cfg(feature = "debug")]
            CosmicElement::Egui(elem) => elem.current_commit(),
        }
    }

    fn src(&self) -> Rectangle<f64, smithay::utils::Buffer> {
        match self {
            CosmicElement::Workspace(elem) => elem.src(),
            CosmicElement::Cursor(elem) => elem.src(),
            CosmicElement::MoveGrab(elem) => elem.src(),
            #[cfg(feature = "debug")]
            CosmicElement::Egui(elem) => elem.src(),
        }
    }

    fn geometry(&self, scale: Scale<f64>) -> Rectangle<i32, Physical> {
        match self {
            CosmicElement::Workspace(elem) => elem.geometry(scale),
            CosmicElement::Cursor(elem) => elem.geometry(scale),
            CosmicElement::MoveGrab(elem) => elem.geometry(scale),
            #[cfg(feature = "debug")]
            CosmicElement::Egui(elem) => elem.geometry(scale),
        }
    }

    fn location(&self, scale: Scale<f64>) -> Point<i32, Physical> {
        match self {
            CosmicElement::Workspace(elem) => elem.location(scale),
            CosmicElement::Cursor(elem) => elem.location(scale),
            CosmicElement::MoveGrab(elem) => elem.location(scale),
            #[cfg(feature = "debug")]
            CosmicElement::Egui(elem) => elem.location(scale),
        }
    }

    fn transform(&self) -> smithay::utils::Transform {
        match self {
            CosmicElement::Workspace(elem) => elem.transform(),
            CosmicElement::Cursor(elem) => elem.transform(),
            CosmicElement::MoveGrab(elem) => elem.transform(),
            #[cfg(feature = "debug")]
            CosmicElement::Egui(elem) => elem.transform(),
        }
    }

    fn damage_since(
        &self,
        scale: Scale<f64>,
        commit: Option<smithay::backend::renderer::utils::CommitCounter>,
    ) -> Vec<Rectangle<i32, Physical>> {
        match self {
            CosmicElement::Workspace(elem) => elem.damage_since(scale, commit),
            CosmicElement::Cursor(elem) => elem.damage_since(scale, commit),
            CosmicElement::MoveGrab(elem) => elem.damage_since(scale, commit),
            #[cfg(feature = "debug")]
            CosmicElement::Egui(elem) => elem.damage_since(scale, commit),
        }
    }

    fn opaque_regions(&self, scale: Scale<f64>) -> Vec<Rectangle<i32, Physical>> {
        match self {
            CosmicElement::Workspace(elem) => elem.opaque_regions(scale),
            CosmicElement::Cursor(elem) => elem.opaque_regions(scale),
            CosmicElement::MoveGrab(elem) => elem.opaque_regions(scale),
            #[cfg(feature = "debug")]
            CosmicElement::Egui(elem) => elem.opaque_regions(scale),
        }
    }
}

impl RenderElement<GlowRenderer> for CosmicElement<GlowRenderer> {
    fn draw<'frame>(
        &self,
        frame: &mut <GlowRenderer as Renderer>::Frame<'frame>,
        src: Rectangle<f64, BufferCoords>,
        dst: Rectangle<i32, Physical>,
        damage: &[Rectangle<i32, Physical>],
    ) -> Result<(), <GlowRenderer as Renderer>::Error> {
        match self {
            CosmicElement::Workspace(elem) => elem.draw(frame, src, dst, damage),
            CosmicElement::Cursor(elem) => elem.draw(frame, src, dst, damage),
            CosmicElement::MoveGrab(elem) => elem.draw(frame, src, dst, damage),
            #[cfg(feature = "debug")]
            CosmicElement::Egui(elem) => {
                RenderElement::<GlowRenderer>::draw(elem, frame, src, dst, damage)
            }
        }
    }

    fn underlying_storage(&self, renderer: &mut GlowRenderer) -> Option<UnderlyingStorage> {
        match self {
            CosmicElement::Workspace(elem) => elem.underlying_storage(renderer),
            CosmicElement::Cursor(elem) => elem.underlying_storage(renderer),
            CosmicElement::MoveGrab(elem) => elem.underlying_storage(renderer),
            #[cfg(feature = "debug")]
            CosmicElement::Egui(elem) => elem.underlying_storage(renderer),
        }
    }
}

impl<'a, 'b> RenderElement<GlMultiRenderer<'a, 'b>> for CosmicElement<GlMultiRenderer<'a, 'b>> {
    fn draw<'frame>(
        &self,
        frame: &mut GlMultiFrame<'a, 'b, 'frame>,
        src: Rectangle<f64, BufferCoords>,
        dst: Rectangle<i32, Physical>,
        damage: &[Rectangle<i32, Physical>],
    ) -> Result<(), <GlMultiRenderer<'a, 'b> as Renderer>::Error> {
        match self {
            CosmicElement::Workspace(elem) => elem.draw(frame, src, dst, damage),
            CosmicElement::Cursor(elem) => elem.draw(frame, src, dst, damage),
            CosmicElement::MoveGrab(elem) => elem.draw(frame, src, dst, damage),
            #[cfg(feature = "debug")]
            CosmicElement::Egui(elem) => {
                let elem = {
                    let glow_frame = frame.glow_frame_mut();
                    RenderElement::<GlowRenderer>::draw(elem, glow_frame, src, dst, damage)
                        .map_err(|err| MultiError::Render(err))
                };
                elem
            }
        }
    }

    fn underlying_storage(
        &self,
        renderer: &mut GlMultiRenderer<'a, 'b>,
    ) -> Option<UnderlyingStorage> {
        match self {
            CosmicElement::Workspace(elem) => elem.underlying_storage(renderer),
            CosmicElement::Cursor(elem) => elem.underlying_storage(renderer),
            CosmicElement::MoveGrab(elem) => elem.underlying_storage(renderer),
            #[cfg(feature = "debug")]
            CosmicElement::Egui(elem) => {
                let glow_renderer = renderer.glow_renderer_mut();
                match elem.underlying_storage(glow_renderer) {
                    Some(UnderlyingStorage::Wayland(buffer)) => {
                        Some(UnderlyingStorage::Wayland(buffer))
                    }
                    _ => None,
                }
            }
        }
    }
}

impl<R> From<WorkspaceRenderElement<R>> for CosmicElement<R>
where
    R: Renderer + ImportAll + ImportMem + AsGlowRenderer,
    <R as Renderer>::TextureId: 'static,
    CosmicMappedRenderElement<R>: RenderElement<R>,
{
    fn from(elem: WorkspaceRenderElement<R>) -> Self {
        Self::Workspace(elem)
    }
}

impl<R> From<CursorRenderElement<R>> for CosmicElement<R>
where
    R: Renderer + ImportAll + ImportMem + AsGlowRenderer,
    <R as Renderer>::TextureId: 'static,
    CosmicMappedRenderElement<R>: RenderElement<R>,
{
    fn from(elem: CursorRenderElement<R>) -> Self {
        Self::Cursor(elem)
    }
}

impl<R> From<CosmicMappedRenderElement<R>> for CosmicElement<R>
where
    R: Renderer + ImportAll + ImportMem + AsGlowRenderer,
    <R as Renderer>::TextureId: 'static,
    CosmicMappedRenderElement<R>: RenderElement<R>,
{
    fn from(elem: CosmicMappedRenderElement<R>) -> Self {
        Self::MoveGrab(elem)
    }
}

#[cfg(feature = "debug")]
impl<R> From<TextureRenderElement<GlesTexture>> for CosmicElement<R>
where
    R: Renderer + ImportAll + ImportMem + AsGlowRenderer,
    <R as Renderer>::TextureId: 'static,
    CosmicMappedRenderElement<R>: RenderElement<R>,
{
    fn from(elem: TextureRenderElement<GlesTexture>) -> Self {
        Self::Egui(elem)
    }
}

pub trait AsGlowRenderer
where
    Self: Renderer,
{
    fn glow_renderer(&self) -> &GlowRenderer;
    fn glow_renderer_mut(&mut self) -> &mut GlowRenderer;
}

impl AsGlowRenderer for GlowRenderer {
    fn glow_renderer(&self) -> &GlowRenderer {
        self
    }
    fn glow_renderer_mut(&mut self) -> &mut GlowRenderer {
        self
    }
}

impl<'a, 'b> AsGlowRenderer for GlMultiRenderer<'a, 'b> {
    fn glow_renderer(&self) -> &GlowRenderer {
        self.as_ref()
    }
    fn glow_renderer_mut(&mut self) -> &mut GlowRenderer {
        self.as_mut()
    }
}

pub trait AsGlowFrame<'a>
where
    Self: Frame,
{
    fn glow_frame(&self) -> &GlowFrame<'a>;
    fn glow_frame_mut(&mut self) -> &mut GlowFrame<'a>;
}

impl<'frame> AsGlowFrame<'frame> for GlowFrame<'frame> {
    fn glow_frame(&self) -> &GlowFrame<'frame> {
        self
    }
    fn glow_frame_mut(&mut self) -> &mut GlowFrame<'frame> {
        self
    }
}

impl<'renderer, 'alloc, 'frame> AsGlowFrame<'frame> for GlMultiFrame<'renderer, 'alloc, 'frame> {
    fn glow_frame(&self) -> &GlowFrame<'frame> {
        self.as_ref()
    }
    fn glow_frame_mut(&mut self) -> &mut GlowFrame<'frame> {
        self.as_mut()
    }
}