/**
 * Copyright (c) 2025 Huawei Technologies Co., Ltd.
 * This program is free software, you can redistribute it and/or modify it under the terms and conditions of
 * CANN Open Software License Agreement Version 2.0 (the "License").
 * Please refer to the License for details. You may not use this file except in compliance with the License.
 * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND, EITHER EXPRESS OR IMPLIED,
 * INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT, MERCHANTABILITY, OR FITNESS FOR A PARTICULAR PURPOSE.
 * See LICENSE in the root of the software repository for the full text of the License.
 */

/*!
 * \file sk_lock_detector.h
 * \brief
 */

#ifndef __SK_LOCK_DETECTOR_H__
#define __SK_LOCK_DETECTOR_H__

#include <vector>
#include <algorithm>
#include <unordered_map>
#include <set>
#include "sk_types.h"
#include "sk_node.h"
#include "sk_graph.h"
#include "sk_scope_info.h"
#include "acl/acl.h"

class SuperKernelOptionsManager;

/*!
 * \enum DeadlockFailReason
 * \brief Detailed failure reasons for deadlock detection
 */
enum class DeadlockFailReason : uint8_t {
    NOT_FIND_DEADLOCK = 0,
    KERNEL_INSUFFICIENT_CORES,      ///< Kernel node requires more cores than available
    NOTIFY_NOT_IN_GRAPH,       ///< Wait node's notify not found in graph
    NOTIFY_AFTER_SK_RANGE,     ///< Notify node is after SK range
    NOTIFY_INVALID,         ///< Deadlock detected in wait node's pre-path
    NOTIFY_INSUFFICIENT_CORES,      ///< Notify node in other SK that requires more cores than available
    FIRST_WAIT,                ///< First wait node in the graph is locked
    NO_SUPPORT_NODE,            ///< Not support node type in waiting for nodes
};
/*!
 * \brief Convert DeadlockFailReason to string
 */
inline const char* DeadlockFailReasonToStr(DeadlockFailReason reason)
{
    switch (reason) {
        case DeadlockFailReason::NOT_FIND_DEADLOCK:
            return "not find deadlock";
        case DeadlockFailReason::KERNEL_INSUFFICIENT_CORES:
            return "The wait node depends on a kernel node that requires more cores than available";
        case DeadlockFailReason::NOTIFY_INSUFFICIENT_CORES:
            return "The wait node depends on a notify node which has fused in other SK that it requires more cores";
        case DeadlockFailReason::NOTIFY_NOT_IN_GRAPH:
            return "The wait node depends on a notify node that it is not in graph";
        case DeadlockFailReason::NOTIFY_AFTER_SK_RANGE:
            return "The wait node depends on a notify node that it is after SK range";
        case DeadlockFailReason::NOTIFY_INVALID:
            return "In check deadlock of this wait node, get invalid notify node";
        case DeadlockFailReason::FIRST_WAIT:
            return "The wait node is first node in scope";
        case DeadlockFailReason::NO_SUPPORT_NODE:
            return "The wait node waiting for unsupport node type";
        default:
            return "UNKNOWN REASON";
    }
}

/**
 * @class LockDetector
 * @brief 死锁检测器，用于检测SuperKernel融合时是否会引入死锁
 *
 * 该类通过分析节点的核心使用情况和依赖关系，判断是否可以将节点融合到SuperKernel中。
 */
class LockDetector {
public:
    /**
     * @brief 构造函数，传入图对象
     * @param graph 图对象引用
     */
    explicit LockDetector(SuperKernelGraph& graph)
    {
        Init(graph);
    }

    LockDetector(SuperKernelGraph& graph, const SuperKernelOptionsManager& opts) : opts_(&opts)
    {
        Init(graph);
    }

    ~LockDetector()
    {
        if (graph_ != nullptr) {
            Reset();
        }
    }

    static aclError GetDeviceCores();

    /**
     * @brief 重置检测器状态
     */
    void Reset();

    /**
     * @brief 获取最近一次检测到的死锁原因
     */
    DeadlockFailReason GetDeadlockReason() const { return deadlockReason_; }

    /**
     * @brief 判断节点是否可融合到SuperKernel中
     * @param curNode 待检测的节点
     * @return true 可融合，false 不可融合（会导致死锁）
     */
    bool IsFusible(SuperKernelBaseNode& curNode);

    /**
     * @brief 设置scope中Notify节点的expand number
     * @param scope Scope信息
     *
     * 该函数遍历scope中的所有节点，找出最大的vec/cube num，
     * 并将其设置到所有Notify节点上。
     */
    void SetNotifyNodesExpandNumForScope(SuperKernelScopeInfo& scope);

    /**
     * @brief 重置scope中Notify节点的expand number为0
     * @param scope Scope信息
     *
     * 该函数将scope中所有Notify节点的expandVecNum和expandCubeNum重置为0，
     * 用于在死锁检测Pass结束时复原节点状态，使得Pass可重入。
     */
    void ResetNotifyExpandNumForScope(SuperKernelScopeInfo& scope);

private:
    void Init(SuperKernelGraph& graph);

    std::pair<uint64_t, uint64_t> GetAvailableCores(bool isSuperKernel) const;

    bool IsInSKStream(const SuperKernelBaseNode& node);

    void UpdateNodeInfo(const SuperKernelBaseNode& node);

    void UpdateSKRangeInStream(const SuperKernelBaseNode& node);

    bool IsBeforeSKRange(const SuperKernelBaseNode& node);

    bool IsAfterSKRange(const SuperKernelBaseNode& node);

    bool HasIntersection(const std::unordered_set<uint32_t>& lhsStreams, const std::unordered_set<uint32_t>& rhsStreams);

    bool HasDeadlock(SuperKernelBaseNode* curNode);

    bool CheckKernelNodeDeadlock(SuperKernelBaseNode* preNode);

    bool CheckWaitNodeDeadlock(SuperKernelBaseNode* preNode);

    bool CheckNotifyNodeDeadlock(SuperKernelBaseNode* preNode);

    bool GetWaitNodeFusibleStatus(SuperKernelBaseNode& curNode);

    bool CheckNotifyInSKStream(SuperKernelBaseNode& curNode, SuperKernelBaseNode& notifyNode);

    bool GetFusibleStatus(SuperKernelBaseNode& curNode);
    bool ShouldBypassValueWaitDeadlock(const SuperKernelBaseNode& curNode) const;

    bool HasEnoughCores(const SuperKernelBaseNode* curNode, bool isSuperKernel);

    void RollbackVisitedState(std::vector<uint64_t>& visitedNodes);

    std::vector<uint64_t> nodes; // visited nodes
    std::vector<uint64_t> tempVisitedNodes; // temporary visited nodes for HasDeadlock
    uint32_t depOpCubeNum;       // visited op cube num outside superkernel
    uint32_t depOpVecNum;        // visited op vec num outside superkernel
    uint32_t superKernelCubeNum; // fused op cube num in superkernel
    uint32_t superKernelVecNum;  // fused op vec num in superkernel
    static int64_t deviceRealCubeNum;
    static int64_t deviceRealVecNum;
    std::unordered_set<uint32_t> skStreamIds;
    uint32_t nodeNum;
    uint32_t kernelNodeNum;
    std::unordered_map<uint32_t, std::pair<uint64_t, uint64_t>> skRangeInStream;
    SuperKernelGraph* graph_;  // 存储graph指针，用于析构时调用Reset
    const SuperKernelOptionsManager* opts_ = nullptr;
    DeadlockFailReason deadlockReason_ = DeadlockFailReason::NOT_FIND_DEADLOCK;  // 当前检测到的死锁原因
};

#endif // __SK_LOCK_DETECTOR_H__