#pragma once

#include <iostream>
#include <atomic.hpp>
#include <support.hpp>

namespace tpcc {
namespace solutions {

class PetersonLock {
  public:
    void Lock(const size_t thread_index) {
      const size_t another_thread = 1 - thread_index;
      flag[thread_index].store(true);
      victim.store(thread_index);
      while(flag[another_thread].load() && victim.load() == thread_index) {};
    }

    void Unlock(const size_t thread_index) {
      flag[thread_index].store(false);
    }
  private:
    std::atomic<bool> flag[2];
    std::atomic<size_t> victim;
};

class TournamentTreeLock {
  public:
    explicit TournamentTreeLock(const size_t num_threads) {
    }

    void Lock(const size_t thread_index) {
      pt.Lock(thread_index);
    }

    void Unlock(size_t thread_index) {
      pt.Unlock(thread_index);
    }

  private:
  // Tree navigation

    size_t GetParent(size_t node_index) const {
      if(node_index % 2 == 0) {
        return (node_index-2)/2;
      }
      else return (node_index-1)/2;
    }

    size_t GetLeftChild(size_t node_index) const {
      return 2*node_index+1;
    }

    size_t GetRightChild(size_t node_index) const {
      return 2*node_index+2;
    }

    size_t GetThreadLeaf(size_t thread_index) const {
      return 0;
    }

  private:
    PetersonLock pt;
};

} // namespace solutions
} // namespace tpcc