/**
 * MIT License
 *
 * Copyright (c) 2025 Huawei Technologies Co., Ltd. All rights reserved.
 *
 * 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.
 * */
#ifndef UNIFIEDCACHE_TASK_MANAGER_H
#define UNIFIEDCACHE_TASK_MANAGER_H

#include <unordered_map>
#include "status/status.h"
#include "task_queue.h"
#include "task_set.h"

namespace UC {

class TaskManager {
    using TaskPtr = std::shared_ptr<Task>;
    using WaiterPtr = std::shared_ptr<TaskWaiter>;
    using TaskPair = std::pair<TaskPtr, WaiterPtr>;
    using QueuePtr = std::shared_ptr<TaskQueue>;

public:
    virtual ~TaskManager() = default;
    virtual Status Submit(Task&& task, size_t& taskId) noexcept
    {
        taskId = task.Id();
        const auto taskStr = task.Str();
        TaskPtr taskPtr = nullptr;
        WaiterPtr waiterPtr = nullptr;
        try {
            taskPtr = std::make_shared<Task>(std::move(task));
            waiterPtr = std::make_shared<TaskWaiter>(0, task.StartTp());
        } catch (const std::exception& e) {
            UC_ERROR("Failed({}) to submit task({}).", e.what(), taskStr);
            return Status::OutOfMemory();
        }
        std::lock_guard<std::mutex> lg(mutex_);
        const auto& [iter, success] =
            tasks_.emplace(taskId, std::make_pair(std::move(taskPtr), std::move(waiterPtr)));
        if (!success) {
            UC_ERROR("Failed to submit task({}).", taskStr);
            return Status::OutOfMemory();
        }
        auto shards = iter->second.first->Split(queues_.size(), iter->second.second);
        for (auto& shard : shards) {
            auto& q = queues_[qIndex_++];
            if (qIndex_ == queues_.size()) { qIndex_ = 0; }
            q->Push(shard);
        }
        return Status::OK();
    }
    virtual Status Wait(const size_t taskId) noexcept
    {
        TaskPtr task = nullptr;
        WaiterPtr waiter = nullptr;
        {
            std::lock_guard<std::mutex> lg(mutex_);
            auto iter = tasks_.find(taskId);
            if (iter == tasks_.end()) {
                UC_ERROR("Not found task by id({}).", taskId);
                return Status::NotFound();
            }
            task = iter->second.first;
            waiter = iter->second.second;
            tasks_.erase(iter);
        }
        if (!waiter->Wait(timeoutMs_)) {
            UC_ERROR("Task({}) timeout({}).", task->Str(), timeoutMs_);
            failureSet_.Insert(taskId);
            waiter->Wait();
        }
        auto failure = failureSet_.Contains(taskId);
        if (failure) {
            failureSet_.Remove(taskId);
            UC_ERROR("Task({}) failed.", task->Str());
            return Status::Error();
        }
        return Status::OK();
    }
    virtual Status Check(const size_t taskId, bool& finish) noexcept
    {
        std::lock_guard<std::mutex> lg(mutex_);
        auto iter = tasks_.find(taskId);
        if (iter == tasks_.end()) {
            UC_ERROR("Not found task by id({}).", taskId);
            return Status::NotFound();
        }
        finish = iter->second.second->Finish();
        return Status::OK();
    }

protected:
    std::mutex mutex_;
    std::unordered_map<size_t, TaskPair> tasks_;
    size_t qIndex_{0};
    std::vector<QueuePtr> queues_;
    size_t timeoutMs_{0};
    TaskSet failureSet_;
};

}  // namespace UC

#endif
