// sherpa-onnx/csrc/context-graph-test.cc
//
// Copyright (c)  2023  Xiaomi Corporation

#include "sherpa-onnx/csrc/context-graph.h"

#include <chrono>  // NOLINT
#include <map>
#include <random>
#include <string>
#include <vector>

#include "gtest/gtest.h"
#include "sherpa-onnx/csrc/macros.h"

namespace sherpa_onnx {

TEST(ContextGraph, TestBasic) {
  std::vector<std::string> contexts_str(
      {"S", "HE", "SHE", "SHELL", "HIS", "HERS", "HELLO", "THIS", "THEM"});
  std::vector<std::vector<int32_t>> contexts;
  for (int32_t i = 0; i < contexts_str.size(); ++i) {
    contexts.emplace_back(contexts_str[i].begin(), contexts_str[i].end());
  }
  auto context_graph = ContextGraph(contexts, 1);

  auto queries = std::map<std::string, float>{
      {"HEHERSHE", 14}, {"HERSHE", 12}, {"HISHE", 9},
      {"SHED", 6},      {"SHELF", 6},   {"HELL", 2},
      {"HELLO", 7},     {"DHRHISQ", 4}, {"THEN", 2}};

  for (const auto &iter : queries) {
    float total_scores = 0;
    auto state = context_graph.Root();
    for (auto q : iter.first) {
      auto res = context_graph.ForwardOneStep(state, q);
      total_scores += res.first;
      state = res.second;
    }
    auto res = context_graph.Finalize(state);
    EXPECT_EQ(res.second->token, -1);
    total_scores += res.first;
    EXPECT_EQ(total_scores, iter.second);
  }
}

TEST(ContextGraph, Benchmark) {
  std::random_device rd;
  std::mt19937 mt(rd());
  std::uniform_int_distribution<int32_t> char_dist(0, 25);
  std::uniform_int_distribution<int32_t> len_dist(3, 8);
  for (int32_t num = 10; num <= 10000; num *= 10) {
    std::vector<std::vector<int32_t>> contexts;
    for (int32_t i = 0; i < num; ++i) {
      std::vector<int32_t> tmp;
      int32_t word_len = len_dist(mt);
      for (int32_t j = 0; j < word_len; ++j) {
        tmp.push_back(char_dist(mt));
      }
      contexts.push_back(std::move(tmp));
    }
    auto start = std::chrono::high_resolution_clock::now();
    auto context_graph = ContextGraph(contexts, 1);
    auto stop = std::chrono::high_resolution_clock::now();
    auto duration =
        std::chrono::duration_cast<std::chrono::microseconds>(stop - start);
    SHERPA_ONNX_LOGE("Construct context graph for %d item takes %ld us.", num,
                     duration.count());
  }
}

}  // namespace sherpa_onnx