// MIT License
//
// Copyright (c) 2023 ROCm Developer Tools
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.

#pragma once

#include <rocprofiler/fwd.h>
#include <rocprofiler/registration.h>
#include <rocprofiler/rocprofiler.h>

#include "lib/common/container/stable_vector.hpp"
#include "lib/common/synchronized.hpp"
#include "lib/rocprofiler/context/domain.hpp"
#include "lib/rocprofiler/counters/core.hpp"
#include "lib/rocprofiler/external_correlation.hpp"

#include <array>
#include <atomic>
#include <cstddef>
#include <cstdint>
#include <optional>

namespace rocprofiler
{
namespace context
{
using external_cid_cb_t = uint64_t (*)(rocprofiler_service_callback_tracing_kind_t,
                                       uint32_t,
                                       uint64_t);

constexpr auto null_user_data = rocprofiler_user_data_t{.value = 0};
struct correlation_id
{
    // reference count starts at 5:
    // - decrement after begin callback/buffer API
    // - decrement after end callback/buffer API
    // - decrement after kernel dispatch/HW counters
    // - if PC sampling is not enabled, we can "retire" correlation id at ref count at 2
    // - if PC sampling is enabled, we decrement after each HSA buffer flush once ref count hits 2
    //   - after the kernel dispatch completes, we know no more PC samples will be generated and
    //     thus, after two HSA buffer flushes, we will have received all the PC samples for
    //     the
    correlation_id(uint32_t _cnt, rocprofiler_thread_id_t _tid, uint64_t _internal) noexcept
    : ref_count{_cnt}
    , thread_idx{_tid}
    , internal{_internal}
    {}

    correlation_id()                              = default;
    ~correlation_id()                             = default;
    correlation_id(correlation_id&& val) noexcept = delete;
    correlation_id(const correlation_id&)         = delete;

    correlation_id& operator=(const correlation_id&) = delete;
    correlation_id& operator=(correlation_id&&) noexcept = delete;

    std::atomic<uint32_t>   ref_count  = {};
    rocprofiler_thread_id_t thread_idx = 0;
    uint64_t                internal   = 0;
};

correlation_id*
get_correlation_id(rocprofiler_thread_id_t tid, uint64_t internal_id);

// latest correlation id for thread
correlation_id*
get_latest_correlation_id();

void
pop_latest_correlation_id(const correlation_id*);

/// permits tools opportunity to modify the correlation id based on the domain, op, and
/// the rocprofiler generated correlation id
struct correlation_tracing_service
{
    external_correlation::external_correlation external_correlator = {};
    static correlation_id*                     construct(uint32_t init_ref_count);
};

struct callback_tracing_service
{
    struct callback_data
    {
        rocprofiler_callback_tracing_cb_t callback = nullptr;
        void*                             data     = nullptr;
    };

    using domain_t         = rocprofiler_service_callback_tracing_kind_t;
    using callback_array_t = std::array<callback_data, domain_info<domain_t>::last>;

    domain_context<domain_t> domains       = {};
    callback_array_t         callback_data = {};
};

struct buffer_tracing_service
{
    using domain_t       = rocprofiler_service_buffer_tracing_kind_t;
    using buffer_array_t = std::array<rocprofiler_buffer_id_t, domain_info<domain_t>::last>;

    domain_context<domain_t> domains     = {};
    buffer_array_t           buffer_data = {};
};

struct counter_collection_service
{
    // Contains a vector of counter collection instances associated with this context.
    // Each instance is assocated with an agent and a counter collection profile.
    // Contains callback information along with other data needed to collect/process
    // counters.
    std::vector<std::shared_ptr<counters::counter_callback_info>> callbacks{};
    // A flag to state wether or not the counter set is currently enabled. This is primarily
    // to protect against multithreaded calls to enable a context (and enabling already enabled
    // counters).
    common::Synchronized<bool> enabled{false};
};

struct context
{
    // size is used to ensure that we never read past the end of the version
    size_t                                      size               = 0;
    uint64_t                                    context_idx        = 0;  // context id
    uint32_t                                    client_idx         = 0;  // tool id
    correlation_tracing_service                 correlation_tracer = {};
    std::unique_ptr<callback_tracing_service>   callback_tracer    = {};
    std::unique_ptr<buffer_tracing_service>     buffered_tracer    = {};
    std::unique_ptr<counter_collection_service> counter_collection = {};
};

// set the client index needs to be called before allocate_context()
void push_client(uint32_t);

// remove the client index
void pop_client(uint32_t);

/// @brief creates a context struct and returns a handle for locating the context struct
///
std::optional<rocprofiler_context_id_t>
allocate_context();

/// \brief rocprofiler validates context, checks for conflicts, etc. Ensures that
///  the contexturation is valid *in isolation*, e.g. it may check that the user
///  set the compat_version field and that required context fields, such as buffer
///  are set. This function will be called before \ref start_context
///  but is provided to help the user validate one or more contexts without starting
///  them
///
/// \param [in] cfg contexturation to validate
rocprofiler_status_t
validate_context(const context* cfg);

/// \brief rocprofiler activates contexturation and provides a context identifier
/// \param [in] id the context identifier to start.
rocprofiler_status_t
start_context(rocprofiler_context_id_t id);

/// \brief disable the contexturation.
rocprofiler_status_t stop_context(rocprofiler_context_id_t);

using unique_context_vec_t = common::container::stable_vector<std::unique_ptr<context>, 8>;
using active_context_vec_t = common::container::stable_vector<std::atomic<const context*>, 8>;

unique_context_vec_t&
get_registered_contexts();

using context_filter_t = bool (*)(const context*);

inline bool
default_context_filter(const context* val)
{
    return (val != nullptr);
}

std::vector<const context*>&
get_active_contexts(std::vector<const context*>& data,
                    context_filter_t             filter = default_context_filter);

std::vector<const context*>
get_active_contexts(context_filter_t filter = default_context_filter);

void deactivate_client_contexts(rocprofiler_client_id_t);

// should only be called if the client failed to initialize
void deregister_client_contexts(rocprofiler_client_id_t);
}  // namespace context
}  // namespace rocprofiler