/*
 * Copyright 2019 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.
 */

/**
 * @defgroup swappy_common Swappy common tools
 * Tools to be used with Swappy for OpenGL or Swappy for Vulkan.
 * @{
 */

#pragma once

#include <android/native_window.h>
#include <stdint.h>

#include "common/gamesdk_common.h"

/** @brief Swap interval for 60fps, in nanoseconds. */
#define SWAPPY_SWAP_60FPS (16666667L)

/** @brief Swap interval for 30fps, in nanoseconds. */
#define SWAPPY_SWAP_30FPS (33333333L)

/** @brief Swap interval for 20fps, in nanoseconds. */
#define SWAPPY_SWAP_20FPS (50000000L)

/**
 * The longest duration, in refresh periods, represented by the statistics.
 * @see SwappyStats
 */
#define MAX_FRAME_BUCKETS 6

/** @cond INTERNAL */

#define SWAPPY_SYSTEM_PROP_KEY_DISABLE "swappy.disable"

// Internal macros to track Swappy version, do not use directly.
#define SWAPPY_MAJOR_VERSION 2
#define SWAPPY_MINOR_VERSION 0
#define SWAPPY_BUGFIX_VERSION 0
#define SWAPPY_PACKED_VERSION                                                  \
    ANDROID_GAMESDK_PACKED_VERSION(SWAPPY_MAJOR_VERSION, SWAPPY_MINOR_VERSION, \
                                   SWAPPY_BUGFIX_VERSION)

// Internal macros to generate a symbol to track Swappy version, do not use
// directly.
#define SWAPPY_VERSION_CONCAT_NX(PREFIX, MAJOR, MINOR, BUGFIX, GITCOMMIT) \
    PREFIX##_##MAJOR##_##MINOR##_##BUGFIX##_##GITCOMMIT
#define SWAPPY_VERSION_CONCAT(PREFIX, MAJOR, MINOR, BUGFIX, GITCOMMIT) \
    SWAPPY_VERSION_CONCAT_NX(PREFIX, MAJOR, MINOR, BUGFIX, GITCOMMIT)
#define SWAPPY_VERSION_SYMBOL                                          \
    SWAPPY_VERSION_CONCAT(Swappy_version, SWAPPY_MAJOR_VERSION,        \
                          SWAPPY_MINOR_VERSION, SWAPPY_BUGFIX_VERSION, \
                          AGDK_GIT_COMMIT)

// Define this to 1 to enable all logging from Swappy, by default it is
// disabled in a release build and enabled in a debug build.
#ifndef ENABLE_SWAPPY_LOGGING
#define ENABLE_SWAPPY_LOGGING 0
#endif
/** @endcond */

/** @brief Id of a thread returned by an external thread manager. */
typedef uint64_t SwappyThreadId;

/**
 * @brief A structure enabling you to set how Swappy starts and joins threads by
 * calling
 * ::Swappy_setThreadFunctions.
 *
 * Usage of this functionality is optional.
 */
typedef struct SwappyThreadFunctions {
    /** @brief Thread start callback.
     *
     * This function is called by Swappy to start thread_func on a new thread.
     * @param user_data A value to be passed the thread function.
     * If the thread was started, this function should set the thread_id and
     * return 0. If the thread was not started, this function should return a
     * non-zero value.
     */
    int (*start)(SwappyThreadId* thread_id, void* (*thread_func)(void*),
                 void* user_data);

    /** @brief Thread join callback.
     *
     * This function is called by Swappy to join the thread with given id.
     */
    void (*join)(SwappyThreadId thread_id);

    /** @brief Thread joinable callback.
     *
     * This function is called by Swappy to discover whether the thread with the
     * given id is joinable.
     */
    bool (*joinable)(SwappyThreadId thread_id);
} SwappyThreadFunctions;

#ifdef __cplusplus
extern "C" {
#endif

/**
 * @brief Return the version of the Swappy library at runtime.
 */
uint32_t Swappy_version();

/**
 * @brief Call this before any other functions in order to use a custom thread
 * manager.
 *
 * Usage of this function is entirely optional. Swappy uses std::thread by
 * default.
 *
 */
void Swappy_setThreadFunctions(const SwappyThreadFunctions* thread_functions);

/**
 * @brief Return the full version of the Swappy library at runtime, e.g.
 * "1.9.0_8a85ab7c46"
 */
const char* Swappy_versionString();

/**
 * @brief Swappy frame statistics, collected if toggled on with
 * ::SwappyGL_enableStats or ::SwappyVk_enableStats.
 */
typedef struct SwappyStats {
    /** @brief Total frames swapped by swappy */
    uint64_t totalFrames;

    /** @brief Histogram of the number of screen refreshes a frame waited in the
     * compositor queue after rendering was completed.
     *
     * For example:
     *     if a frame waited 2 refresh periods in the compositor queue after
     * rendering was done, the frame will be counted in idleFrames[2]
     */
    uint64_t idleFrames[MAX_FRAME_BUCKETS];

    /** @brief Histogram of the number of screen refreshes passed between the
     * requested presentation time and the actual present time.
     *
     * For example:
     *     if a frame was presented 2 refresh periods after the requested
     * timestamp swappy set, the frame will be counted in lateFrames[2]
     */
    uint64_t lateFrames[MAX_FRAME_BUCKETS];

    /** @brief Histogram of the number of screen refreshes passed between two
     * consecutive frames
     *
     * For example:
     *     if frame N was presented 2 refresh periods after frame N-1
     *     frame N will be counted in offsetFromPreviousFrame[2]
     */
    uint64_t offsetFromPreviousFrame[MAX_FRAME_BUCKETS];

    /** @brief Histogram of the number of screen refreshes passed between the
     * call to Swappy_recordFrameStart and the actual present time.
     *
     * For example:
     *     if a frame was presented 2 refresh periods after the call to
     * `Swappy_recordFrameStart` the frame will be counted in latencyFrames[2]
     */
    uint64_t latencyFrames[MAX_FRAME_BUCKETS];
} SwappyStats;


#ifdef __cplusplus
}  // extern "C"
#endif

/**
 * Pointer to a function that can be attached to SwappyTracer::preWait
 * @param userData Pointer to arbitrary data, see SwappyTracer::userData.
 */
typedef void (*SwappyPreWaitCallback)(void*);

/**
 * Pointer to a function that can be attached to SwappyTracer::postWait.
 * @param userData Pointer to arbitrary data, see SwappyTracer::userData.
 * @param cpu_time_ns Time for CPU processing of this frame in nanoseconds.
 * @param gpu_time_ns Time for GPU processing of previous frame in nanoseconds.
 */
typedef void (*SwappyPostWaitCallback)(void*, int64_t cpu_time_ns,
                                       int64_t gpu_time_ns);

/**
 * Pointer to a function that can be attached to SwappyTracer::preSwapBuffers.
 * @param userData Pointer to arbitrary data, see SwappyTracer::userData.
 */
typedef void (*SwappyPreSwapBuffersCallback)(void*);

/**
 * Pointer to a function that can be attached to SwappyTracer::postSwapBuffers.
 * @param userData Pointer to arbitrary data, see SwappyTracer::userData.
 * @param desiredPresentationTimeMillis The target time, in milliseconds, at
 * which the frame would be presented on screen.
 */
typedef void (*SwappyPostSwapBuffersCallback)(
    void*, int64_t desiredPresentationTimeMillis);

/**
 * Pointer to a function that can be attached to SwappyTracer::startFrame.
 * @param userData Pointer to arbitrary data, see SwappyTracer::userData.
 * @param desiredPresentationTimeMillis The time, in milliseconds, at which the
 * frame is scheduled to be presented.
 */
typedef void (*SwappyStartFrameCallback)(void*, int currentFrame,
                                         int64_t desiredPresentationTimeMillis);

/**
 * Pointer to a function that can be attached to
 * SwappyTracer::swapIntervalChanged. Call ::SwappyGL_getSwapIntervalNS or
 * ::SwappyVk_getSwapIntervalNS to get the latest swapInterval.
 * @param userData Pointer to arbitrary data, see SwappyTracer::userData.
 */
typedef void (*SwappySwapIntervalChangedCallback)(void*);

/**
 * @brief Collection of callbacks to be called each frame to trace execution.
 *
 * Injection of these is optional.
 */
typedef struct SwappyTracer {
    /**
     * Callback called before waiting to queue the frame to the composer.
     */
    SwappyPreWaitCallback preWait;

    /**
     * Callback called after wait to queue the frame to the composer is done.
     */
    SwappyPostWaitCallback postWait;

    /**
     * Callback called before calling the function to queue the frame to the
     * composer.
     */
    SwappyPreSwapBuffersCallback preSwapBuffers;

    /**
     * Callback called after calling the function to queue the frame to the
     * composer.
     */
    SwappyPostSwapBuffersCallback postSwapBuffers;

    /**
     * Callback called at the start of a frame.
     */
    SwappyStartFrameCallback startFrame;

    /**
     * Pointer to some arbitrary data that will be passed as the first argument
     * of callbacks.
     */
    void* userData;

    /**
     * Callback called when the swap interval was changed.
     */
    SwappySwapIntervalChangedCallback swapIntervalChanged;
} SwappyTracer;

/** @} */