/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

extern crate gleam;
extern crate glutin;
extern crate webrender;
extern crate winit;

#[path = "common/boilerplate.rs"]
mod boilerplate;

use crate::boilerplate::Example;
use gleam::gl;
use webrender::api::*;
use webrender::render_api::*;
use webrender::api::units::*;


fn init_gl_texture(
    id: gl::GLuint,
    internal: gl::GLenum,
    external: gl::GLenum,
    bytes: &[u8],
    gl: &dyn gl::Gl,
) {
    gl.bind_texture(gl::TEXTURE_2D, id);
    gl.tex_parameter_i(gl::TEXTURE_2D, gl::TEXTURE_MAG_FILTER, gl::LINEAR as gl::GLint);
    gl.tex_parameter_i(gl::TEXTURE_2D, gl::TEXTURE_MIN_FILTER, gl::LINEAR as gl::GLint);
    gl.tex_parameter_i(gl::TEXTURE_2D, gl::TEXTURE_WRAP_S, gl::CLAMP_TO_EDGE as gl::GLint);
    gl.tex_parameter_i(gl::TEXTURE_2D, gl::TEXTURE_WRAP_T, gl::CLAMP_TO_EDGE as gl::GLint);
    gl.tex_image_2d(
        gl::TEXTURE_2D,
        0,
        internal as gl::GLint,
        100,
        100,
        0,
        external,
        gl::UNSIGNED_BYTE,
        Some(bytes),
    );
    gl.bind_texture(gl::TEXTURE_2D, 0);
}

struct YuvImageProvider {
    texture_ids: Vec<gl::GLuint>,
}

impl YuvImageProvider {
    fn new(gl: &dyn gl::Gl) -> Self {
        let texture_ids = gl.gen_textures(4);

        init_gl_texture(texture_ids[0], gl::RED, gl::RED, &[127; 100 * 100], gl);
        init_gl_texture(texture_ids[1], gl::RG8, gl::RG, &[0; 100 * 100 * 2], gl);
        init_gl_texture(texture_ids[2], gl::RED, gl::RED, &[127; 100 * 100], gl);
        init_gl_texture(texture_ids[3], gl::RED, gl::RED, &[127; 100 * 100], gl);

        YuvImageProvider {
            texture_ids
        }
    }
}

impl ExternalImageHandler for YuvImageProvider {
    fn lock(
        &mut self,
        key: ExternalImageId,
        _channel_index: u8,
        _rendering: ImageRendering
    ) -> ExternalImage {
        let id = self.texture_ids[key.0 as usize];
        ExternalImage {
            uv: TexelRect::new(0.0, 0.0, 1.0, 1.0),
            source: ExternalImageSource::NativeTexture(id),
        }
    }
    fn unlock(&mut self, _key: ExternalImageId, _channel_index: u8) {
    }
}

struct App {
    texture_id: gl::GLuint,
    current_value: u8,
}

impl Example for App {
    fn render(
        &mut self,
        api: &mut RenderApi,
        builder: &mut DisplayListBuilder,
        txn: &mut Transaction,
        _device_size: DeviceIntSize,
        pipeline_id: PipelineId,
        _document_id: DocumentId,
    ) {
        let bounds = LayoutRect::new(LayoutPoint::zero(), LayoutSize::new(500.0, 500.0));
        let space_and_clip = SpaceAndClipInfo::root_scroll(pipeline_id);

        builder.push_simple_stacking_context(
            bounds.origin,
            space_and_clip.spatial_id,
            PrimitiveFlags::IS_BACKFACE_VISIBLE,
        );

        let yuv_chanel1 = api.generate_image_key();
        let yuv_chanel2 = api.generate_image_key();
        let yuv_chanel2_1 = api.generate_image_key();
        let yuv_chanel3 = api.generate_image_key();
        txn.add_image(
            yuv_chanel1,
            ImageDescriptor::new(100, 100, ImageFormat::R8, ImageDescriptorFlags::IS_OPAQUE),
            ImageData::External(ExternalImageData {
                id: ExternalImageId(0),
                channel_index: 0,
                image_type: ExternalImageType::TextureHandle(
                    ImageBufferKind::Texture2D,
                ),
            }),
            None,
        );
        txn.add_image(
            yuv_chanel2,
            ImageDescriptor::new(100, 100, ImageFormat::RG8, ImageDescriptorFlags::IS_OPAQUE),
            ImageData::External(ExternalImageData {
                id: ExternalImageId(1),
                channel_index: 0,
                image_type: ExternalImageType::TextureHandle(
                    ImageBufferKind::Texture2D,
                ),
            }),
            None,
        );
        txn.add_image(
            yuv_chanel2_1,
            ImageDescriptor::new(100, 100, ImageFormat::R8, ImageDescriptorFlags::IS_OPAQUE),
            ImageData::External(ExternalImageData {
                id: ExternalImageId(2),
                channel_index: 0,
                image_type: ExternalImageType::TextureHandle(
                    ImageBufferKind::Texture2D,
                ),
            }),
            None,
        );
        txn.add_image(
            yuv_chanel3,
            ImageDescriptor::new(100, 100, ImageFormat::R8, ImageDescriptorFlags::IS_OPAQUE),
            ImageData::External(ExternalImageData {
                id: ExternalImageId(3),
                channel_index: 0,
                image_type: ExternalImageType::TextureHandle(
                    ImageBufferKind::Texture2D,
                ),
            }),
            None,
        );

        let info = CommonItemProperties::new(
            LayoutRect::new(LayoutPoint::new(100.0, 0.0), LayoutSize::new(100.0, 100.0)),
            space_and_clip,
        );
        builder.push_yuv_image(
            &info,
            bounds,
            YuvData::NV12(yuv_chanel1, yuv_chanel2),
            ColorDepth::Color8,
            YuvColorSpace::Rec601,
            ColorRange::Limited,
            ImageRendering::Auto,
        );

        let info = CommonItemProperties::new(
            LayoutRect::new(LayoutPoint::new(300.0, 0.0), LayoutSize::new(100.0, 100.0)),
            space_and_clip,
        );
        builder.push_yuv_image(
            &info,
            bounds,
            YuvData::PlanarYCbCr(yuv_chanel1, yuv_chanel2_1, yuv_chanel3),
            ColorDepth::Color8,
            YuvColorSpace::Rec601,
            ColorRange::Limited,
            ImageRendering::Auto,
        );

        builder.pop_stacking_context();
    }

    fn on_event(
        &mut self,
        _event: winit::WindowEvent,
        _api: &mut RenderApi,
        _document_id: DocumentId,
    ) -> bool {
        false
    }

    fn get_image_handler(
        &mut self,
        gl: &dyn gl::Gl,
    ) -> Option<Box<dyn ExternalImageHandler>> {
        let provider = YuvImageProvider::new(gl);
        self.texture_id = provider.texture_ids[0];
        Some(Box::new(provider))
    }

    fn draw_custom(&mut self, gl: &dyn gl::Gl) {
        init_gl_texture(self.texture_id, gl::RED, gl::RED, &[self.current_value; 100 * 100], gl);
        self.current_value = self.current_value.wrapping_add(1);
    }
}

fn main() {
    let mut app = App {
        texture_id: 0,
        current_value: 0,
    };

    let opts = webrender::RendererOptions {
        ..Default::default()
    };

    boilerplate::main_wrapper(&mut app, Some(opts));
}