// eqpalg/utility/expression_engine.cpp
#include <eqpalg/utility/expression_engine.h>
#include <glob/SingletonTemplate.h>
#include <eqpalg/gb_item_memory.h>
#include <mix_cc/type/mix_time.h>
#include <log4cplus/LOG.h>

ExpressionEngine::ExpressionEngine(std::map<std::string, double>& mm_vars,
                                   std::vector<std::string>& m_tags)
    : mm_vars_(mm_vars), m_tags_(m_tags) {}

// 惰性初始化 VarsCache（首次变量刷新时调用）
static void ensureVarCache(VarsCache& vc, size_t tag_count) {
  if (vc.tag_num == 0 && tag_count > 0) {
    vc.init(tag_count, 6);
  }
}

int ExpressionEngine::registerExpression(const std::string& name,
                                          const std::string& raw_exp_str) {
  if (exps_.count(name)) return 0;  // 已注册，幂等

  auto& entry = exps_[name];
  entry.raw_str = raw_exp_str;

  // 通过 FunVars 替换状态函数（KeepC/KeepT/RiseEdge/Detect）为 funN 变量
  auto [ok, processed] = fun_vars_.add_exp_str(raw_exp_str, &mm_vars_);
  if (!ok) return -1;
  entry.processed_str = processed;

  // 编译表达式
  try {
    entry.ptr = std::make_unique<MExp>(processed, &mm_vars_);
  } catch (const std::exception& e) {
    return -1;
  }

  // 从表达式中提取 hold(n,T) 模式
  initHoldExpStr(processed);

  return 0;
}

int ExpressionEngine::registerRawExpression(const std::string& name,
                                             const std::string& raw_exp_str) {
  if (exps_.count(name)) return 0;

  auto& entry = exps_[name];
  entry.raw_str = raw_exp_str;
  entry.processed_str = raw_exp_str;

  try {
    entry.ptr = std::make_unique<MExp>(raw_exp_str, &mm_vars_);
  } catch (const std::exception& e) {
    return -1;
  }
  return 0;
}

double ExpressionEngine::evaluate(const std::string& name) {
  auto it = exps_.find(name);
  if (it == exps_.end()) return 0.0;
  return it->second.ptr->evaluate();
}

bool ExpressionEngine::evaluateBool(const std::string& name) {
  return static_cast<bool>(evaluate(name));
}

int ExpressionEngine::initHoldExpStr(const std::string& exp_str) {
  return 0;  // stub — Task 5 will implement
}

void ExpressionEngine::refreshFromMemory(
    const TimePoint& now_time,
    mix_cc::time_range_t& query_time_range) {

  ensureVarCache(var_cache_, m_tags_.size());

  for (size_t i = 0; i < m_tags_.size(); i++) {
    double current =
        SingletonTemplate<GlobaltemSharedMemory>::GetInstance()[m_tags_[i]];

    // pN = 旧 tagN
    mm_vars_[var_cache_.p_keys[i]] = mm_vars_[var_cache_.tag_keys[i]];
    // tagN = 当前值
    mm_vars_[var_cache_.tag_keys[i]] = current;

    // pvN 历史移位
    for (size_t j = PV_NUM - 1; j > 0; j--) {
      mm_vars_[var_cache_.pv_keys[i][j]] =
          mm_vars_[var_cache_.pv_keys[i][j - 1]];
    }
    mm_vars_[var_cache_.pv_keys[i][0]] = current;
  }

  mm_vars_["now"] = std::chrono::duration_cast<std::chrono::milliseconds>(
                        now_time.time_since_epoch())
                        .count();

  fun_vars_.refresh_fun_vars(false, &mm_vars_);
  query_time_range.set_right(now_time);
  refreshHoldVars();
}

void ExpressionEngine::refreshFromIhdRow(
    int row,
    const Eigen::Matrix<double, Eigen::Dynamic, Eigen::Dynamic>& queried_data,
    const std::vector<TimePoint>& queried_time,
    TimePoint& now_time,
    mix_cc::time_range_t& query_time_range) {

  if (queried_data.rows() == 0 || queried_data.cols() == 0) return;
  if (row < 0 || row >= queried_data.rows()) return;
  if (static_cast<int>(m_tags_.size()) > queried_data.cols()) return;

  ensureVarCache(var_cache_, m_tags_.size());

  for (size_t i = 0; i < m_tags_.size(); i++) {
    // pN = 旧 tagN
    mm_vars_[var_cache_.p_keys[i]] = mm_vars_[var_cache_.tag_keys[i]];
    // tagN = 当前行数据
    mm_vars_[var_cache_.tag_keys[i]] = queried_data(row, i);

    // pvN 历史移位
    for (size_t j = PV_NUM - 1; j > 0; j--) {
      mm_vars_[var_cache_.pv_keys[i][j]] =
          mm_vars_[var_cache_.pv_keys[i][j - 1]];
    }
    mm_vars_[var_cache_.pv_keys[i][0]] =
        mm_vars_[var_cache_.tag_keys[i]];
  }

  mm_vars_["now"] =
      mix_cc::mix_time_t(queried_time[row]).to_milliseconds();

  now_time = queried_time[row];
  query_time_range.set_right(queried_time[row]);

  fun_vars_.refresh_fun_vars(false, &mm_vars_);
  refreshHoldVars();
}

void ExpressionEngine::refreshHoldVars() {
  // stub — Task 5 will implement
}