//
//  stream_fluent.t.h
//  stream
//
//  Created by Sam Jaffe on 1/28/17.
//

#pragma once

#include <cxxtest/TestSuite.h>

#include <vector>

#include "streams.hpp"
#include "streams/fluent.hpp"

class stream_fluent_TestSuite : public CxxTest::TestSuite {
public:
  using int_t = int const &;
  using vec_t = std::vector<int>;
public:
  void test_collect_arg_preserves() {
    vec_t v{1, 2, 3, 4, 5};
    auto s = stream::make_stream(v);
    std::set<int> o{};
    s > o;
    for ( int i : v ) {
      TS_ASSERT_EQUALS(o.count( i ), 1);
    }
  }
  
  void test_map_identity() {
    vec_t v{1, 2, 3, 4, 5};
    auto identity = [](int_t i) { return i; };
    auto s = stream::make_stream(v) | identity;
    vec_t o{s.begin(), s.end()};
    TS_ASSERT_EQUALS(v, o);
  }
  
  void test_map_change() {
    vec_t v{1, 2, 3, 4, 5};
    vec_t expected{3, 5, 7, 9, 11};
    auto fmap = [](int_t i) { return 2*i+1; };
    auto s = stream::make_stream(v) | fmap;
    vec_t o{s.begin(), s.end()};
    TS_ASSERT_EQUALS(expected, o);
  }
  
  void test_filter_noop() {
    vec_t v{1, 2, 3, 4, 5};
    auto pass = [](int_t) { return true; };
    auto s = stream::make_stream(v) | pass;
    vec_t o{s.begin(), s.end()};
    TS_ASSERT_EQUALS(v, o);
  }
  
  void test_filter_value() {
    vec_t v{1, 2, 3, 4, 5};
    vec_t expected{2, 4};
    auto even = [](int_t i) { return i%2 == 0; };
    auto s = stream::make_stream(v) | even;
    vec_t o{s.begin(), s.end()};
    TS_ASSERT_EQUALS(expected, o);
  }
  
  void test_accumulate() {
    vec_t v{1, 2, 3, 4, 5};
    auto even = [](int_t i) { return i%2 == 0; };
    auto sum =[](int_t lhs, int_t rhs) { return lhs + rhs; };
    auto s = stream::make_stream(v) | even;
    TS_ASSERT_EQUALS( 6 , s > sum );
  }
  
  void test_flatmap_joins_lists() {
    vec_t vv{1, 2, 3, 4, 5};
    auto next3 = [](int_t i) { return vec_t{i, i+1, i+2}; };
    vec_t expected{1, 2, 3, 2, 3, 4, 3, 4, 5, 4, 5, 6, 5, 6, 7};
    auto s = stream::make_stream(vv) || next3;
    vec_t o{s.begin(), s.end()};
    TS_ASSERT_EQUALS(expected, o);
  }
};