// Copyright 2016 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef GARNET_LIB_MAGMA_SRC_SYS_DRIVER_MAGMA_SYSTEM_CONNECTION_H_
#define GARNET_LIB_MAGMA_SRC_SYS_DRIVER_MAGMA_SYSTEM_CONNECTION_H_

#include "magma_system_buffer.h"
#include "magma_system_context.h"
#include "magma_util/macros.h"
#include "magma_util/platform/platform_connection.h"
#include "msd.h"

#include <memory>
#include <unordered_map>

using msd_connection_unique_ptr_t =
    std::unique_ptr<msd_connection_t, decltype(&msd_connection_close)>;

static inline msd_connection_unique_ptr_t MsdConnectionUniquePtr(msd_connection_t* conn)
{
    return msd_connection_unique_ptr_t(conn, &msd_connection_close);
}

class MagmaSystemDevice;

class MagmaSystemConnection : private MagmaSystemContext::Owner,
                              public magma::PlatformConnection::Delegate {
public:
    MagmaSystemConnection(std::weak_ptr<MagmaSystemDevice> device,
                          msd_connection_unique_ptr_t msd_connection_t);

    ~MagmaSystemConnection() override;

    // Create a buffer from the handle and add it to the map,
    // on success |id_out| contains the id to be used to query the map
    bool ImportBuffer(uint32_t handle, uint64_t* id_out) override;
    // This removes the reference to the shared_ptr in the map
    // other instances remain valid until deleted
    // Returns false if no buffer with the given |id| exists in the map
    bool ReleaseBuffer(uint64_t id) override;

    bool ImportObject(uint32_t handle, magma::PlatformObject::Type object_type) override;
    bool ReleaseObject(uint64_t object_id, magma::PlatformObject::Type object_type) override;

    // Attempts to locate a buffer by |id| in the buffer map and return it.
    // Returns nullptr if the buffer is not found
    std::shared_ptr<MagmaSystemBuffer> LookupBuffer(uint64_t id);

    // Returns the msd_semaphore for the given |id| if present in the semaphore map.
    std::shared_ptr<MagmaSystemSemaphore> LookupSemaphore(uint64_t id);

    magma::Status ExecuteCommandBuffer(uint32_t command_buffer_handle,
                                       uint32_t context_id) override;

    bool CreateContext(uint32_t context_id) override;
    bool DestroyContext(uint32_t context_id) override;
    MagmaSystemContext* LookupContext(uint32_t context_id);

    bool MapBufferGpu(uint64_t buffer_id, uint64_t gpu_va, uint64_t page_offset,
                      uint64_t page_count, uint64_t flags) override;
    bool UnmapBufferGpu(uint64_t buffer_id, uint64_t gpu_va) override;
    bool CommitBuffer(uint64_t buffer_id, uint64_t page_offset, uint64_t page_count) override;
    void SetNotificationCallback(msd_connection_notification_callback_t callback,
                                 void* token) override;

    uint32_t GetDeviceId();

    msd_connection_t* msd_connection() { return msd_connection_.get(); }

    magma::Status ExecuteImmediateCommands(uint32_t context_id, uint64_t commands_size,
                                           void* commands, uint64_t semaphore_count,
                                           uint64_t* semaphore_ids) override;

private:
    struct BufferReference {
        uint64_t refcount = 1;
        std::shared_ptr<MagmaSystemBuffer> buffer;
    };
    struct SemaphoreReference {
        uint64_t refcount = 1;
        std::shared_ptr<MagmaSystemSemaphore> semaphore;
    };

    // MagmaSystemContext::Owner
    std::shared_ptr<MagmaSystemBuffer> LookupBufferForContext(uint64_t id) override
    {
        return LookupBuffer(id);
    }
    std::shared_ptr<MagmaSystemSemaphore> LookupSemaphoreForContext(uint64_t id) override
    {
        return LookupSemaphore(id);
    }

    std::weak_ptr<MagmaSystemDevice> device_;
    msd_connection_unique_ptr_t msd_connection_;
    std::unordered_map<uint32_t, std::unique_ptr<MagmaSystemContext>> context_map_;
    std::unordered_map<uint64_t, BufferReference> buffer_map_;
    std::unordered_map<uint64_t, SemaphoreReference> semaphore_map_;
};

#endif // GARNET_LIB_MAGMA_SRC_SYS_DRIVER_MAGMA_SYSTEM_CONNECTION_H_