// Copyright (C) 2022 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "DisplayGl.h"

#include "DisplaySurfaceGl.h"
#include "OpenGLESDispatch/DispatchTables.h"
#include "OpenGLESDispatch/EGLDispatch.h"
#include "TextureDraw.h"
#include "host-common/logging.h"

namespace gfxstream {
namespace gl {
namespace {

std::shared_future<void> getCompletedFuture() {
    std::shared_future<void> completedFuture =
        std::async(std::launch::deferred, [] {}).share();
    completedFuture.wait();
    return completedFuture;
}

}  // namespace

std::shared_future<void> DisplayGl::post(const Post& post) {
    const auto* surface = getBoundSurface();
    if (!surface) {
        return getCompletedFuture();
    }
    if (post.layers.empty()) {
        clear();
        return getCompletedFuture();
    }
    const auto* surfaceGl = static_cast<const DisplaySurfaceGl*>(surface->getImpl());

    bool hasDrawLayer = false;
    for (const PostLayer& layer : post.layers) {
        if (layer.layerOptions) {
            if (!hasDrawLayer) {
                mTextureDraw->prepareForDrawLayer();
                hasDrawLayer = true;
            }
            layer.colorBuffer->glOpPostLayer(*layer.layerOptions, post.frameWidth,
                                             post.frameHeight);
        } else if (layer.overlayOptions) {
            if (hasDrawLayer) {
                ERR("Cannot mix colorBuffer.postLayer with postWithOverlay!");
            }
            layer.colorBuffer->glOpPostViewportScaledWithOverlay(
                layer.overlayOptions->rotation, layer.overlayOptions->dx, layer.overlayOptions->dy);
        }
    }
    if (hasDrawLayer) {
        mTextureDraw->cleanupForDrawLayer();
    }

    s_egl.eglSwapBuffers(surfaceGl->mDisplay, surfaceGl->mSurface);

    return getCompletedFuture();
}

void DisplayGl::viewport(int width, int height) {
    mViewportWidth = width;
    mViewportHeight = height;
    s_gles2.glViewport(0, 0, mViewportWidth, mViewportHeight);
}

void DisplayGl::clear() {
    const auto* surface = getBoundSurface();
    if (!surface) {
        return;
    }
    const auto* surfaceGl = static_cast<const DisplaySurfaceGl*>(surface->getImpl());
#ifndef __linux__
    s_gles2.glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
    s_egl.eglSwapBuffers(surfaceGl->mDisplay, surfaceGl->mSurface);
#endif
}

}  // namespace gl
}  // namespace gfxstream