/*
 * Copyright (c) 2023 Huawei Device Co., Ltd.
 * 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.
 */
#include <pthread.h>
#include <random>
#include "ffrt_inner.h"
#include "core/task_io.h"
#ifdef FFRT_CO_BACKTRACE_OH_ENABLE
#include <dlfcn.h>
#include "libunwind.h"
#endif
#include "util/slab.h"
#include "util/ffrt_facade.h"
#ifdef FFRT_IO_TASK_SCHEDULER
#include "util/spmc_queue.h"

#define ENABLE_LOCAL_QUEUE

namespace {
const int INSERT_GLOBAL_QUEUE_FREQ = 5;
}

namespace ffrt {
static void work_finish_callable(ffrt_executor_io_task* task)
{
    task->status = ExecTaskStatus::ET_FINISH;
    task->work.destroy(task->work.data);

#ifdef FFRT_BBOX_ENABLE
    TaskDoneCounterInc();
#endif

    delete task;
}

static void io_ffrt_executor_task_func(ffrt_executor_task_t* data, ffrt_qos_t qos)
{
    ffrt_executor_io_task* task = static_cast<ffrt_executor_io_task*>(data);
    task->status = ExecTaskStatus::ET_EXECUTING;
    ffrt_coroutine_ptr_t coroutine = task->work.exec;
    ffrt_coroutine_ret_t ret = coroutine(task->work.data);
    if (ret == ffrt_coroutine_ready) {
        FFRT_EXECUTOR_TASK_FINISH_MARKER(task);
        work_finish_callable(task);
        return;
    }

    FFRT_EXECUTOR_TASK_BLOCK_MARKER(task);
    task->status = ffrt::ExecTaskStatus::ET_PENDING;
#ifdef FFRT_BBOX_ENABLE
    TaskPendingCounterInc();
#endif
}

static pthread_once_t once = PTHREAD_ONCE_INIT;

static void ffrt_executor_io_task_init()
{
    ffrt_executor_task_register_func(io_ffrt_executor_task_func, ffrt_io_task);
}
} /* namespace ffrt */

#ifdef __cplusplus
extern "C" {
#endif

API_ATTRIBUTE((visibility("default")))
void ffrt_submit_coroutine(void* co, ffrt_coroutine_ptr_t exec, ffrt_function_t destroy,
    const ffrt_deps_t* in_deps, const ffrt_deps_t* out_deps, const ffrt_task_attr_t* attr)
{
    FFRT_COND_DO_ERR((exec==nullptr), return, "input invalid, exec==nullptr");
    pthread_once(&ffrt::once, ffrt::ffrt_executor_io_task_init);

    ffrt::task_attr_private *p = reinterpret_cast<ffrt::task_attr_private *>(const_cast<ffrt_task_attr_t *>(attr));
    ffrt::QoS qos = (p == nullptr ? ffrt::QoS() : ffrt::QoS(p->qos_map));

    ffrt::ffrt_executor_io_task* task = new ffrt::ffrt_executor_io_task(qos);
    task->work.exec = exec;
    task->work.destroy = destroy;
    task->work.data = co;
    task->status = ffrt::ExecTaskStatus::ET_READY;

    ffrt_executor_task_submit((ffrt_executor_task_t*)task, attr);
}

API_ATTRIBUTE((visibility("default")))
void* ffrt_get_current_task()
{
    return reinterpret_cast<void*>(ffrt::ExecuteCtx::Cur()->exec_task);
}

// API used to schedule stackless coroutine task
API_ATTRIBUTE((visibility("default")))
void ffrt_wake_coroutine(void* task)
{
    if (task == nullptr) {
        FFRT_LOGE("Task is nullptr");
        return;
    }

#ifdef FFRT_BBOX_ENABLE
    TaskWakeCounterInc();
#endif

    ffrt::ffrt_executor_io_task* wakedTask = static_cast<ffrt::ffrt_executor_io_task*>(task);
    wakedTask->status = ffrt::ExecTaskStatus::ET_READY;

    // in self-wakeup scenario, tasks are placed in local fifo to delay scheduling, implementing the veild funtion
    bool selfAwake = (ffrt::ExecuteCtx::Cur()->exec_task == task);
    if (!selfAwake && ffrt::ExecuteCtx::Cur()->PushTaskToPriorityStack(wakedTask)) {
        return;
    }

    if (selfAwake || rand() % INSERT_GLOBAL_QUEUE_FREQ) {
        if (ffrt::ExecuteCtx::Cur()->localFifo != nullptr &&
            ffrt::ExecuteCtx::Cur()->localFifo->PushTail(task) == 0) {
            ffrt::ExecuteUnit::Instance().NotifyLocalTaskAdded(wakedTask->qos);
            return;
            }
    }

    ffrt::LinkedList* node = (ffrt::LinkedList *)(&wakedTask->wq);
    if (!ffrt::FFRTScheduler::Instance()->InsertNode(node, wakedTask->qos)) {
        FFRT_LOGE("Submit IO task failed");
    }
}

API_ATTRIBUTE((visibility("default")))
void ffrt_task_attr_set_coroutine_type(ffrt_task_attr_t* attr, ffrt_coroutine_t coroutine_type)
{
    if (!attr) {
        FFRT_LOGE("attr should be a valid address");
        return;
    }
    return;
}

API_ATTRIBUTE((visibility("default")))
ffrt_coroutine_t ffrt_task_attr_get_coroutine_type(const ffrt_task_attr_t* attr)
{
    if (!attr) {
        FFRT_LOGE("attr should be a valid address");
        return ffrt_coroutine_with_stack;
    }
    return ffrt_coroutine_stackless;
}
#ifdef __cplusplus
}
#endif

#endif