// 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 MSD_INTEL_CONNECTION_H
#define MSD_INTEL_CONNECTION_H

#include "command_buffer.h"
#include "engine_command_streamer.h"
#include "magma_util/macros.h"
#include "msd.h"
#include "msd_intel_pci_device.h"
#include <memory>

class ClientContext;

class MsdIntelConnection : PerProcessGtt::Owner {
public:
    class Owner : public PerProcessGtt::Owner {
    public:
        virtual ~Owner() = default;

        virtual magma::Status SubmitCommandBuffer(std::unique_ptr<CommandBuffer> cmd_buf) = 0;
        virtual void DestroyContext(std::shared_ptr<ClientContext> client_context) = 0;
        virtual void ReleaseBuffer(std::shared_ptr<AddressSpace> address_space,
                                   std::shared_ptr<MsdIntelBuffer> buffer) = 0;
    };

    static std::unique_ptr<MsdIntelConnection> Create(Owner* owner, msd_client_id_t client_id);

    virtual ~MsdIntelConnection() {}

    std::shared_ptr<PerProcessGtt> per_process_gtt() { return ppgtt_; }

    msd_client_id_t client_id() { return client_id_; }

    magma::Status SubmitCommandBuffer(std::unique_ptr<CommandBuffer> cmd_buf)
    {
        return owner_->SubmitCommandBuffer(std::move(cmd_buf));
    }

    void ReleaseBuffer(std::shared_ptr<MsdIntelBuffer> buffer)
    {
        owner_->ReleaseBuffer(ppgtt_, std::move(buffer));
    }

    void DestroyContext(std::shared_ptr<ClientContext> client_context)
    {
        return owner_->DestroyContext(std::move(client_context));
    }

    void SetNotificationCallback(msd_connection_notification_callback_t callback, void* token)
    {
        notifications_.Set(callback, token);
    }

    // Called by the device thread when command buffers complete.
    void SendNotification(const std::vector<uint64_t>& buffer_ids)
    {
        notifications_.SendBufferIds(buffer_ids);
    }

    void SendContextKilled() { notifications_.SendContextKilled(); }

private:
    // PerProcessGtt::Owner
    magma::PlatformBusMapper* GetBusMapper() override { return owner_->GetBusMapper(); }

    MsdIntelConnection(Owner* owner, std::shared_ptr<PerProcessGtt> ppgtt,
                       msd_client_id_t client_id)
        : owner_(owner), ppgtt_(std::move(ppgtt)), client_id_(client_id)
    {
    }

    static const uint32_t kMagic = 0x636f6e6e; // "conn" (Connection)

    Owner* owner_;
    std::shared_ptr<PerProcessGtt> ppgtt_;
    msd_client_id_t client_id_;

    class Notifications {
    public:
        void SendBufferIds(const std::vector<uint64_t>& buffer_ids)
        {
            std::lock_guard<std::mutex> lock(mutex_);
            if (callback_ && token_) {
                msd_notification_t notification = {};
                notification.type = MSD_CONNECTION_NOTIFICATION_CHANNEL_SEND;
                const uint32_t max = MSD_CHANNEL_SEND_MAX_SIZE / sizeof(uint64_t);

                uint32_t dst_index = 0;
                for (uint32_t src_index = 0; src_index < buffer_ids.size();) {
                    reinterpret_cast<uint64_t*>(notification.u.channel_send.data)[dst_index++] =
                        buffer_ids[src_index++];
                    if (dst_index == max || src_index == buffer_ids.size()) {
                        notification.u.channel_send.size = dst_index * sizeof(uint64_t);
                        dst_index = 0;
                        callback_(token_, &notification);
                    }
                }
            }
        }

        void SendContextKilled()
        {
            std::lock_guard<std::mutex> lock(mutex_);
            if (callback_ && token_) {
                msd_notification_t notification = {};
                notification.type = MSD_CONNECTION_NOTIFICATION_CONTEXT_KILLED;
                callback_(token_, &notification);
            }
        }

        void Set(msd_connection_notification_callback_t callback, void* token)
        {
            std::lock_guard<std::mutex> lock(mutex_);
            callback_ = callback;
            token_ = token;
        }

    private:
        msd_connection_notification_callback_t callback_ = nullptr;
        void* token_ = nullptr;
        std::mutex mutex_;
    };

    Notifications notifications_;
};

class MsdIntelAbiConnection : public msd_connection_t {
public:
    MsdIntelAbiConnection(std::shared_ptr<MsdIntelConnection> ptr) : ptr_(std::move(ptr))
    {
        magic_ = kMagic;
    }

    static MsdIntelAbiConnection* cast(msd_connection_t* connection)
    {
        DASSERT(connection);
        DASSERT(connection->magic_ == kMagic);
        return static_cast<MsdIntelAbiConnection*>(connection);
    }

    std::shared_ptr<MsdIntelConnection> ptr() { return ptr_; }

private:
    std::shared_ptr<MsdIntelConnection> ptr_;
    static const uint32_t kMagic = 0x636f6e6e; // "conn" (Connection)
};

#endif // MSD_INTEL_CONNECTION_H