// Copyright (C) 2016 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.
#pragma once

#include "RenderChannel.h"
#include "render_api_platform_types.h"
#include "base/Stream.h"
#include "base/ring_buffer.h"
#include "host-common/address_space_graphics_types.h"
#include "host-common/virtio_gpu_ops.h"
#include "snapshot/common.h"

#include <functional>
#include <memory>
#include <string>

namespace android_studio {
    class EmulatorGLESUsages;
}

namespace emugl {

// Renderer - an object that manages a single OpenGL window used for drawing
// and is able to create individual render channels for that window.
//
class Renderer {
public:
    // createRenderChannel - create a separate channel for the rendering data.
    // This call instantiates a new object that waits for the serialized data
    // from the guest, deserializes it, executes the passed GL commands and
    // returns the results back.
    // |loadStream| - if not NULL, RenderChannel uses it to load saved state
    //   asynchronously on its own thread. |loadStream| can be used right after
    //   the call as all the required data is copied here synchronously.
    virtual RenderChannelPtr createRenderChannel(
            android::base::Stream* loadStream = nullptr) = 0;

    // analog of createRenderChannel, but for the address space graphics device
    virtual void* addressSpaceGraphicsConsumerCreate(
        struct asg_context,
        android::emulation::asg::ConsumerCallbacks) = 0;
    virtual void addressSpaceGraphicsConsumerDestroy(void*) = 0;

    // getHardwareStrings - describe the GPU hardware and driver.
    // The underlying GL's vendor/renderer/version strings are returned to the
    // caller.
    struct HardwareStrings {
        std::string vendor;
        std::string renderer;
        std::string version;
    };
    virtual HardwareStrings getHardwareStrings() = 0;

    // A per-frame callback can be registered with setPostCallback(); to remove
    // it pass an empty callback. While a callback is registered, the renderer
    // will call it just before each new frame is displayed, providing a copy of
    // the framebuffer contents.
    //
    // The callback will be called from one of the renderer's threads, so will
    // probably need synchronization on any data structures it modifies. The
    // pixels buffer may be overwritten as soon as the callback returns; it
    // doesn't need to be synchronized, but if the callback needs the pixels
    // afterwards it must copy them.
    //
    // The pixels buffer is intentionally not const: the callback may modify the
    // data without copying to another buffer if it wants, e.g. in-place RGBA to
    // RGB conversion, or in-place y-inversion.
    //
    // Parameters are:
    //   displayId      Default is 0. Can also be 1 to 10 if multi display
    //                  configured.
    //   width, height  Dimensions of the image, in pixels. Rows are tightly
    //                  packed; there is no inter-row padding.
    //   ydir           Indicates row order: 1 means top-to-bottom order, -1
    //                  means bottom-to-top order.
    //   format, type   Format and type GL enums, as used in glTexImage2D() or
    //                  glReadPixels(), describing the pixel format.
    //   pixels         The framebuffer image.
    //
    // In the first implementation, ydir is always -1 (bottom to top), format
    // and type are always GL_RGBA and GL_UNSIGNED_BYTE, and the width and
    // height will always be the same as the ones used to create the renderer.
    using OnPostCallback = void (*)(void* context,
                                    uint32_t displayId,
                                    int width,
                                    int height,
                                    int ydir,
                                    int format,
                                    int type,
                                    unsigned char* pixels);
    virtual void setPostCallback(OnPostCallback onPost,
                                 void* context,
                                 bool useBgraReadback,
                                 uint32_t displayId) = 0;

    // Async readback API
    virtual bool asyncReadbackSupported() = 0;

    // Separate callback to get RGBA Pixels in async readback mode.
    using ReadPixelsCallback = void (*)(void* pixels, uint32_t bytes, uint32_t displayId);
    virtual ReadPixelsCallback getReadPixelsCallback() = 0;

    using FlushReadPixelPipeline = void(*)(int displayId);
    // Flushes the pipeline by duplicating the last frame and informing
    // the async callback that a new frame is available if no reads are
    // active
    virtual FlushReadPixelPipeline getFlushReadPixelPipeline() = 0;


    // showOpenGLSubwindow -
    //     Create or modify a native subwindow which is a child of 'window'
    //     to be used for framebuffer display. If a subwindow already exists,
    //     its properties will be updated to match the given parameters.
    //     wx,wy is the top left corner of the rendering subwindow.
    //     ww,wh are the dimensions of the rendering subwindow.
    //     fbw,fbh are the dimensions of the underlying guest framebuffer.
    //     dpr is the device pixel ratio, which is needed for higher density
    //     displays like retina.
    //     zRot is the rotation to apply on the framebuffer display image.
    //
    //     Return true on success, false on failure, which can happen when using
    //     a software-only renderer like OSMesa. In this case, the client should
    //     call setPostCallback to get the content of each new frame when it is
    //     posted, and will be responsible for displaying it.
    virtual bool showOpenGLSubwindow(FBNativeWindowType window,
                                     int wx,
                                     int wy,
                                     int ww,
                                     int wh,
                                     int fbw,
                                     int fbh,
                                     float dpr,
                                     float zRot,
                                     bool deleteExisting,
                                     bool hideWindow) = 0;

    // destroyOpenGLSubwindow -
    //   destroys the created native subwindow. Once destroyed,
    //   Framebuffer content will not be visible until a new
    //   subwindow will be created.
    virtual bool destroyOpenGLSubwindow() = 0;

    // setOpenGLDisplayRotation -
    //    set the framebuffer display image rotation in units
    //    of degrees around the z axis
    virtual void setOpenGLDisplayRotation(float zRot) = 0;

    // setOpenGLDisplayTranslation
    //    change what coordinate of the guest framebuffer will be displayed at
    //    the corner of the GPU sub-window. Specifically, |px| and |py| = 0
    //    means
    //    align the bottom-left of the framebuffer with the bottom-left of the
    //    sub-window, and |px| and |py| = 1 means align the top right of the
    //    framebuffer with the top right of the sub-window. Intermediate values
    //    interpolate between these states.
    virtual void setOpenGLDisplayTranslation(float px, float py) = 0;

    // repaintOpenGLDisplay -
    //    causes the OpenGL subwindow to get repainted with the
    //    latest framebuffer content.
    virtual void repaintOpenGLDisplay() = 0;

    // hasGuestPostedAFrame / resetGuestPostedAFrame -
    //     for liveness checking; queries whether or not the guest
    //     has successfully issued a framebuffer post to the emulator,
    //     and a method to reset that state.
    virtual bool hasGuestPostedAFrame() = 0;
    virtual void resetGuestPostedAFrame() = 0;

    // setScreenMask -
    //    provide the image that should be overlayed on the
    //    device screen to mask that screen
    virtual void setScreenMask(int width, int height, const unsigned char* rgbaData) = 0;

    // setMultiDisplay
    //    add/modify/del multi-display window
    virtual void setMultiDisplay(uint32_t id,
                                 int32_t x,
                                 int32_t y,
                                 uint32_t w,
                                 uint32_t h,
                                 uint32_t dpi,
                                 bool add) = 0;
    // setMultiDisplayColorBuffer
    //    bind ColorBuffer to the display
    virtual void setMultiDisplayColorBuffer(uint32_t id, uint32_t cb) = 0;

    // cleanupProcGLObjects -
    //    clean up all per-process resources when guest process exits (or is
    // killed). Such resources include color buffer handles and EglImage handles.
    virtual void cleanupProcGLObjects(uint64_t puid) = 0;

    // Wait for cleanupProcGLObjects to finish.
    virtual void waitForProcessCleanup() = 0;

    virtual struct AndroidVirtioGpuOps* getVirtioGpuOps(void) = 0;

    // Stops all channels and render threads. The renderer cannot be used after
    // stopped.
    virtual void stop(bool wait) = 0;

    // Waits for all channels to finish and deletes all render threads.
    // The renderer can still be used after finish().
    virtual void finish() = 0;

    // Pauses all channels to prepare for snapshot saving.
    virtual void pauseAllPreSave() = 0;

    // Resumes all channels after snapshot saving or loading.
    virtual void resumeAll() = 0;

    virtual void save(android::base::Stream* stream,
                      const android::snapshot::ITextureSaverPtr& textureSaver) = 0;
    virtual bool load(android::base::Stream* stream,
                      const android::snapshot::ITextureLoaderPtr& textureLoader) = 0;
    // Fill GLES usage protobuf
    virtual void fillGLESUsages(android_studio::EmulatorGLESUsages*) = 0;
    virtual void getScreenshot(unsigned int nChannels, unsigned int* width,
        unsigned int* height, std::vector<unsigned char>& pixels, int displayId = 0,
        int desiredWidth = 0, int desiredHeight = 0,
        int desiredRotation = 0) = 0;
    virtual void snapshotOperationCallback(
            int snapshotterOp,
            int snapshotterStage) = 0;

protected:
    ~Renderer() = default;
};

using RendererPtr = std::shared_ptr<Renderer>;

}  // namespace emugl