// Licensed to the Apache Software Foundation (ASF) under one

// or more contributor license agreements.  See the NOTICE file

// distributed with this work for additional information

// regarding copyright ownership.  The ASF licenses this file

// to you 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.

#pragma once

#include <cstdint>

#include <memory>

#include <mutex>

#include <string>

#include <vector>

#include "common/status.h"

#include "pipeline/dependency.h"

#include "pipeline/exec/operator.h"

#include "pipeline/exec/spill_utils.h"

#include "pipeline/pipeline.h"

#include "util/runtime_profile.h"

#include "util/stopwatch.hpp"

#include "vec/core/block.h"

namespace doris {

class QueryContext;

class RuntimeState;

namespace pipeline {

class PipelineFragmentContext;

} // namespace pipeline

} // namespace doris

namespace doris::pipeline {

class MultiCoreTaskQueue;

class PriorityTaskQueue;

class Dependency;

class PipelineTask : public std::enable_shared_from_this<PipelineTask> {

public:

    PipelineTask(PipelinePtr& pipeline, uint32_t task_id, RuntimeState* state,

                 std::shared_ptr<PipelineFragmentContext> fragment_context,

                 RuntimeProfile* parent_profile,

                 std::map<int, std::pair<std::shared_ptr<BasicSharedState>,

                                         std::vector<std::shared_ptr<Dependency>>>>

                         shared_state_map,

                 int task_idx);

    virtual ~PipelineTask();

    Status prepare(const std::vector<TScanRangeParams>& scan_range, const int sender_id,

                   const TDataSink& tsink);

    virtual Status execute(bool* done);

    // if the pipeline create a bunch of pipeline task

    // must be call after all pipeline task is finish to release resource

    virtual Status close(Status exec_status, bool close_sink = true);

    virtual std::weak_ptr<PipelineFragmentContext>& fragment_context() { return _fragment_context; }

    int get_thread_id(int num_threads) const {

        return _thread_id == -1 ? _thread_id : _thread_id % num_threads;

    }

    virtual PipelineTask& set_thread_id(int thread_id) {

        _thread_id = thread_id;

        if (thread_id != _thread_id) {

            COUNTER_UPDATE(_core_change_times, 1);

        }

        return *this;

    }

    virtual Status finalize();

    std::string debug_string();

    std::shared_ptr<BasicSharedState> get_source_shared_state() {

        return _op_shared_states.contains(_source->operator_id())

                       ? _op_shared_states[_source->operator_id()]

                       : nullptr;

    }

    /**

     * Pipeline task is blockable means it will be blocked in the next run. So we should put it into

     * the blocking task scheduler.

     */

    virtual bool is_blockable() const;

    /**

     * `shared_state` is shared by different pipeline tasks. This function aims to establish

     * connections across related tasks.

     *

     * There are 2 kinds of relationships to share state by tasks.

     * 1. For regular operators, for example, Aggregation, we use the AggSinkOperator to create a

     *    shared state and then inject it into downstream task which contains the corresponding

     *    AggSourceOperator.

     * 2. For multiple-sink-single-source operator, for example, Set operations, the shared state is

     *    created once and shared by multiple sink operators and single source operator. For this

     *    case, we use the first sink operator create shared state and then inject into all of other

     *    tasks.

     */

    bool inject_shared_state(std::shared_ptr<BasicSharedState> shared_state);

    std::shared_ptr<BasicSharedState> get_sink_shared_state() { return _sink_shared_state; }

    BasicSharedState* get_op_shared_state(int id) {

        if (!_op_shared_states.contains(id)) {

            return nullptr;

        }

        return _op_shared_states[id].get();

    }

    Status wake_up(Dependency* dep);

    DataSinkOperatorPtr sink() const { return _sink; }

    int task_id() const { return _index; };

    virtual bool is_finalized() const { return _exec_state == State::FINALIZED; }

    void set_wake_up_early(PipelineId wake_by = -1) {

        _wake_up_early = true;

        _wake_by = wake_by;

    }

    // Execution phase should be terminated. This is called if this task is canceled or waken up early.

    void terminate();

    // 1 used for update priority queue

    // note(wb) an ugly implementation, need refactor later

    // 1.1 pipeline task

    void inc_runtime_ns(uint64_t delta_time) { this->_runtime += delta_time; }

    uint64_t get_runtime_ns() const { return this->_runtime; }

    // 1.2 priority queue's queue level

    void update_queue_level(int queue_level) { this->_queue_level = queue_level; }

    int get_queue_level() const { return this->_queue_level; }

    void put_in_runnable_queue() {

        _schedule_time++;

        _wait_worker_watcher.start();

    }

    void pop_out_runnable_queue() { _wait_worker_watcher.stop(); }

    bool is_running() { return _running.load(); }

    virtual bool set_running(bool running) {

        bool old_value = !running;

        _running.compare_exchange_weak(old_value, running);

        return old_value;

    }

    virtual RuntimeState* runtime_state() const { return _state; }

    virtual std::string task_name() const {

        return fmt::format("task{}({})", _index, _pipeline->_name);

    }

    [[nodiscard]] Status do_revoke_memory(const std::shared_ptr<SpillContext>& spill_context);

    // TODO: Maybe we do not need this safe code anymore

    void stop_if_finished();

    virtual PipelineId pipeline_id() const { return _pipeline->id(); }

    [[nodiscard]] size_t get_revocable_size() const;

    [[nodiscard]] Status revoke_memory(const std::shared_ptr<SpillContext>& spill_context);

    Status blocked(Dependency* dependency) {

        DCHECK_EQ(_blocked_dep, nullptr) << "task: " << debug_string();

        _blocked_dep = dependency;

        return _state_transition(PipelineTask::State::BLOCKED);

    }

protected:

    // Only used for RevokableTask

    PipelineTask() : _index(0) {}

private:

    friend class HybridTaskScheduler;

    void _stop_accepting_submit();

    // Whether this task is blocked before execution (FE 2-phase commit trigger, runtime filters)

    bool _wait_to_start();

    // Whether this task is blocked during execution (read dependency, write dependency)

    bool _is_blocked();

    // Whether this task is blocked after execution (pending finish dependency)

    bool _is_pending_finish();

    Status _extract_dependencies();

    void _init_profile();

    void _fresh_profile_counter();

    Status _open();

    Status _prepare();

    // Operator `op` try to reserve memory before executing. Return false if reserve failed

    // otherwise return true.

    bool _try_to_reserve_memory(const size_t reserve_size, OperatorBase* op);

    const TUniqueId _query_id;

    const uint32_t _index;

    PipelinePtr _pipeline;

    bool _opened;

    RuntimeState* _state = nullptr;

    int _thread_id = -1;

    uint32_t _schedule_time = 0;

    std::unique_ptr<vectorized::Block> _block;

    std::weak_ptr<PipelineFragmentContext> _fragment_context;

    // used for priority queue

    // it may be visited by different thread but there is no race condition

    // so no need to add lock

    uint64_t _runtime = 0;

    // it's visited in one thread, so no need to thread synchronization

    // 1 get task, (set _queue_level/_core_id)

    // 2 exe task

    // 3 update task statistics(update _queue_level/_core_id)

    int _queue_level = 0;

    RuntimeProfile* _parent_profile = nullptr;

    std::unique_ptr<RuntimeProfile> _task_profile;

    RuntimeProfile::Counter* _task_cpu_timer = nullptr;

    RuntimeProfile::Counter* _prepare_timer = nullptr;

    RuntimeProfile::Counter* _open_timer = nullptr;

    RuntimeProfile::Counter* _exec_timer = nullptr;

    RuntimeProfile::Counter* _get_block_timer = nullptr;

    RuntimeProfile::Counter* _get_block_counter = nullptr;

    RuntimeProfile::Counter* _sink_timer = nullptr;

    RuntimeProfile::Counter* _close_timer = nullptr;

    RuntimeProfile::Counter* _schedule_counts = nullptr;

    MonotonicStopWatch _wait_worker_watcher;

    RuntimeProfile::Counter* _wait_worker_timer = nullptr;

    // TODO we should calculate the time between when really runnable and runnable

    RuntimeProfile::Counter* _yield_counts = nullptr;

    RuntimeProfile::Counter* _core_change_times = nullptr;

    RuntimeProfile::Counter* _memory_reserve_times = nullptr;

    RuntimeProfile::Counter* _memory_reserve_failed_times = nullptr;

    Operators _operators; // left is _source, right is _root

    OperatorXBase* _source;

    OperatorXBase* _root;

    DataSinkOperatorPtr _sink;

    // `_read_dependencies` is stored as same order as `_operators`

    std::vector<std::vector<Dependency*>> _read_dependencies;

    std::vector<Dependency*> _write_dependencies;

    std::vector<Dependency*> _finish_dependencies;

    std::vector<Dependency*> _execution_dependencies;

    // All shared states of this pipeline task.

    std::map<int, std::shared_ptr<BasicSharedState>> _op_shared_states;

    std::shared_ptr<BasicSharedState> _sink_shared_state;

    std::vector<TScanRangeParams> _scan_ranges;

    std::map<int,

             std::pair<std::shared_ptr<BasicSharedState>, std::vector<std::shared_ptr<Dependency>>>>

            _shared_state_map;

    int _task_idx;

    bool _dry_run = false;

    MOCK_REMOVE(const)

    unsigned long long _exec_time_slice = config::pipeline_task_exec_time_slice * NANOS_PER_MILLIS;

    Dependency* _blocked_dep = nullptr;

    Dependency* _memory_sufficient_dependency;

    std::mutex _dependency_lock;

    // Guards _accept_submit and keeps HybridTaskScheduler::submit() from reading _sink/_operators

    // in is_blockable() while terminal close/finalize is closing the submit gate.

    std::mutex _blockable_check_lock;

    bool _accept_submit = true;

    std::atomic<bool> _running {false};

    std::atomic<bool> _eos {false};

    std::atomic<bool> _wake_up_early {false};

    // PipelineTask maybe hold by TaskQueue

    std::shared_ptr<MemTrackerLimiter> _query_mem_tracker;

    /**

         *

         * INITED -----> RUNNABLE -------------------------+----> FINISHED ---+---> FINALIZED

         *                   ^                             |                  |

         *                   |                             |                  |

         *                   +----------- BLOCKED <--------+------------------+

         */

    enum class State : int {

        INITED,

        RUNNABLE,

        BLOCKED,

        FINISHED,

        FINALIZED,

    };

    const std::vector<std::set<State>> LEGAL_STATE_TRANSITION = {

            {},                                               // Target state is INITED

            {State::INITED, State::RUNNABLE, State::BLOCKED}, // Target state is RUNNABLE

            {State::RUNNABLE, State::FINISHED},               // Target state is BLOCKED

            {State::RUNNABLE},                                // Target state is FINISHED

            {State::INITED, State::FINISHED}};                // Target state is FINALIZED

    std::string _to_string(State state) const {

        switch (state) {

        case State::INITED:

            return "INITED";

        case State::RUNNABLE:

            return "RUNNABLE";

        case State::BLOCKED:

            return "BLOCKED";

        case State::FINISHED:

            return "FINISHED";

        case State::FINALIZED:

            return "FINALIZED";

        default:

            __builtin_unreachable();

        }

    }

    Status _state_transition(State new_state);

    std::atomic<State> _exec_state = State::INITED;

    MonotonicStopWatch _state_change_watcher;

    std::atomic<bool> _spilling = false;

    const std::string _pipeline_name;

    int _wake_by = -1;

};

using PipelineTaskSPtr = std::shared_ptr<PipelineTask>;

} // namespace doris::pipeline