// Copyright 2020 The Dawn Authors
//
// 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 <cstdlib>
#include <utility>

#include "GLFW/glfw3.h"
#include "dawn/common/Platform.h"
#include "dawn/utils/GLFWUtils.h"

#if defined(DAWN_PLATFORM_WINDOWS)
#define GLFW_EXPOSE_NATIVE_WIN32
#elif defined(DAWN_USE_X11)
#define GLFW_EXPOSE_NATIVE_X11
#endif
#include "GLFW/glfw3native.h"

namespace utils {

void SetupGLFWWindowHintsForBackend(wgpu::BackendType type) {
    if (type == wgpu::BackendType::OpenGL) {
        // Ask for OpenGL 4.4 which is what the GL backend requires for compute shaders and
        // texture views.
        glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 4);
        glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 4);
        glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GLFW_TRUE);
        glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
    } else if (type == wgpu::BackendType::OpenGLES) {
        glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
        glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 1);
        glfwWindowHint(GLFW_CLIENT_API, GLFW_OPENGL_ES_API);
        glfwWindowHint(GLFW_CONTEXT_CREATION_API, GLFW_EGL_CONTEXT_API);
    } else {
        // Without this GLFW will initialize a GL context on the window, which prevents using
        // the window with other APIs (by crashing in weird ways).
        glfwWindowHint(GLFW_CLIENT_API, GLFW_NO_API);
    }
}

wgpu::Surface CreateSurfaceForWindow(const wgpu::Instance& instance, GLFWwindow* window) {
    std::unique_ptr<wgpu::ChainedStruct> chainedDescriptor =
        SetupWindowAndGetSurfaceDescriptor(window);

    wgpu::SurfaceDescriptor descriptor;
    descriptor.nextInChain = chainedDescriptor.get();
    wgpu::Surface surface = instance.CreateSurface(&descriptor);

    return surface;
}

#if defined(DAWN_PLATFORM_WINDOWS)
std::unique_ptr<wgpu::ChainedStruct> SetupWindowAndGetSurfaceDescriptor(GLFWwindow* window) {
    std::unique_ptr<wgpu::SurfaceDescriptorFromWindowsHWND> desc =
        std::make_unique<wgpu::SurfaceDescriptorFromWindowsHWND>();
    desc->hwnd = glfwGetWin32Window(window);
    desc->hinstance = GetModuleHandle(nullptr);
    return std::move(desc);
}
#elif defined(DAWN_USE_X11)
std::unique_ptr<wgpu::ChainedStruct> SetupWindowAndGetSurfaceDescriptor(GLFWwindow* window) {
    std::unique_ptr<wgpu::SurfaceDescriptorFromXlibWindow> desc =
        std::make_unique<wgpu::SurfaceDescriptorFromXlibWindow>();
    desc->display = glfwGetX11Display();
    desc->window = glfwGetX11Window(window);
    return std::move(desc);
}
#elif defined(DAWN_ENABLE_BACKEND_METAL)
// SetupWindowAndGetSurfaceDescriptor defined in GLFWUtils_metal.mm
#else
std::unique_ptr<wgpu::ChainedStruct> SetupWindowAndGetSurfaceDescriptor(GLFWwindow*) {
    return nullptr;
}
#endif

}  // namespace utils