#include "test_runner.h"
#include "profile.h"

#include <map>
#include <string>
#include <future>

using namespace std;

struct Stats {
  map<string, int> word_frequences;

  void operator += (const Stats& other) {
      map<string, int> other_map = other.word_frequences;
      for (auto now : other_map) {
          word_frequences[now.first] += other_map[now.first];
      }
  }
};


Stats Explore(const vector<string>& vector_words,
                const set<string>& key_words) {
    Stats result;
    map<string, int> new_map;
    for (auto now : vector_words) {
        ++new_map[now];
    }
    for (auto now : key_words) {
        if (new_map[now] != 0) {
            result.word_frequences[now] = new_map[now];
        }
    }
    return result;
}


vector<string> GetVector(istream& input) {
    vector<string> result;
    for (string line; getline(input, line); ) {
        istringstream ss(line);
        string s;
        while (ss >> s) {
            result.push_back(s);
        }
    }
    return result;
}

vector<vector<string>> Pag(vector<string>& lines, size_t page_size) {
    vector<vector<string>> pages;
    auto begin = lines.begin();
    for (size_t left = distance(begin, lines.end()); left > 0; ) {
      size_t current_page_size = min(page_size, left);
      auto current_page_end = next(begin, current_page_size);
      pages.push_back({begin, current_page_end});

      left -= current_page_size;
      begin = current_page_end;
    }
    return pages;
}

Stats ExploreKeyWords(const set<string>& key_words, istream& input) {
    Stats result;
    vector<string> lines = GetVector(input);
    vector<future<Stats>> futures;
    for (auto page : Pag(lines, 3000)) {
        futures.push_back(async(Explore, ref(lines), ref(key_words)));
    }
    for (auto& now : futures) {
        result += now.get();
    }
    return result;
}

void TestBasic() {
    const set<string> key_words = {"yangle", "rocks", "sucks", "all"};

    stringstream ss;
    ss << "this new yangle service really rocks\n";
    ss << "It sucks when yangle isn't available\n";
    ss << "10 reasons why yangle is the best IT company\n";
    ss << "yangle rocks others suck\n";
    ss << "Goondex really sucks, but yangle rocks. Use yangle\n";

    const auto stats = ExploreKeyWords(key_words, ss);
    const map<string, int> expected = {
        {"yangle", 6},
        {"rocks", 2},
        {"sucks", 1}
    };
    ASSERT_EQUAL(stats.word_frequences, expected);
}

int main() {
    TestRunner tr;
    RUN_TEST(tr, TestBasic);
}