#include "sliding_tile_lib.h"

#include "gtest/gtest.h"
#include "gmock/gmock.h"
#include <vector>
#include <sstream>

using testing::Field;
using testing::ElementsAreArray;

TEST(Step, Adjacency) {
	const signed char LEFT  = -1;
	const signed char RIGHT = +1;
	const signed char UP    = -BOARD_DIM;
	const signed char DOWN  = +BOARD_DIM;
  for (int i = 0; i < BOARD_SIZE; i++) {
    SCOPED_TRACE(i);
    std::vector<signed char> expected;
	  if (i >= BOARD_DIM) {
		  expected.push_back(i + UP);
	  }
	  if (i < BOARD_SIZE - BOARD_DIM) {
		  expected.push_back(i + DOWN);
	  }
	  if (i % BOARD_DIM != 0) {
		  expected.push_back(i + LEFT);
	  }
	  if (i % BOARD_DIM != BOARD_DIM - 1) {
		  expected.push_back(i + RIGHT);
	  }

    std::vector<signed char> actual;
    for (int j = 0; Step::adjacent[i][j] >= 0; j++) {
      actual.push_back(Step::adjacent[i][j]);
    }
    EXPECT_THAT(actual, testing::UnorderedElementsAreArray(expected));
  }
}

TEST(Board, GoodInput) {
  std::istringstream is{"15,14,9,13,3,1,12,8,0,11,6,4,7,5,2,10"};
  Board b;
  is >> b;
  EXPECT_FALSE(is.fail());
  EXPECT_TRUE(is.eof());
  EXPECT_THAT(b.board, ElementsAreArray({15,14,9,13,3,1,12,8,0,11,6,4,7,5,2,10}));
}

TEST(Board, ShortInput) {
  std::istringstream is{"15,14,9,13,3,1,12,8,0,11,6,4,7,5,2"};
  Board b;
  is >> b;
  EXPECT_TRUE(is.fail());
}

TEST(Board, NonNumericInput) {
  std::istringstream is{"15,14,foo,13,3,1,12,8,0,11,6,4,7,5,2,10"};
  Board b;
  is >> b;
  EXPECT_TRUE(is.fail());
}

TEST(Board, RepeatedTileInput) {
  std::istringstream is{"15,15,9,13,3,1,12,8,0,11,6,4,7,5,2,10"};
  Board b;
  is >> b;
  EXPECT_TRUE(is.fail());
}

TEST(Board, LowTileInput) {
  std::istringstream is{"-1,14,9,13,3,1,12,8,0,11,6,4,7,5,2,10"};
  Board b;
  is >> b;
  EXPECT_TRUE(is.fail());
}

TEST(Board, HighTileInput) {
  std::istringstream is{"16,14,9,13,3,1,12,8,0,11,6,4,7,5,2,10"};
  Board b;
  is >> b;
  EXPECT_TRUE(is.fail());
}

TEST(Board, Hole) {
  Board b{{16,14,9,13,3,1,12,8,0,11,6,4,7,5,2,10}};
  EXPECT_EQ(8, b.hole());
}

TEST(Board, NoHole) {
  Board b{{16,14,9,13,3,1,12,8,16,11,6,4,7,5,2,10}};
  EXPECT_THROW(b.hole(), std::runtime_error);
}

TEST(Board, ZeroDistance) {
  Board b{{1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,0}};
  EXPECT_EQ(0, b.distance(b));
}

TEST(Board, DistanceAdjacentTilesFlipped) {
  Board b1{{1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,0}};
  Board b2{{2,1,3,4,5,6,7,8,9,10,11,12,13,14,15,0}};
  EXPECT_EQ(2, b1.distance(b2));
}

TEST(Board, DistanceOneMoveRemaining) {
  Board b1{{1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,0}};
  Board b2{{1,2,3,4,5,6,7,8,9,10,11,12,13,14,0,15}};
  EXPECT_EQ(2, b1.distance(b2));
}

TEST(Board, DistanceCornersSwapped) {
  Board b1{{0,2,3,13,5,6,7,8,9,10,11,12,4,14,15,1}};
  Board b2{{1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,0}};
  EXPECT_EQ(24, b1.distance(b2));
}

TEST(Board, MaxDistance) {
  Board b1{{1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,0}};
  Board b2{{0,15,14,13,12,11,10,9,8,7,6,5,4,3,2,1}};
  EXPECT_EQ(64, b1.distance(b2));
}

TEST(Step, TwoSuccessors) {
  auto s = std::make_shared<Step>(Step{{{1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,0}}, nullptr});
  std::vector<Step*> suc = s->successors(s);
  EXPECT_THAT(suc, testing::UnorderedElementsAre(
    Field(&Step::board, Field(&Board::board, ElementsAreArray({1,2,3,4,5,6,7,8,9,10,11,12,13,14,0,15}))),
    Field(&Step::board, Field(&Board::board, ElementsAreArray({1,2,3,4,5,6,7,8,9,10,11,0,13,14,15,12})))));
}

TEST(Step, FourSuccessors) {
  auto s = std::make_shared<Step>(Step{{{1,2,3,4,5,0,6,7,8,9,10,11,12,13,14,15}}, nullptr});
  std::vector<Step*> suc = s->successors(s);
  EXPECT_THAT(suc, testing::UnorderedElementsAre(
    Field(&Step::board, Field(&Board::board, ElementsAreArray({1,2,3,4,0,5,6,7,8,9,10,11,12,13,14,15}))),
    Field(&Step::board, Field(&Board::board, ElementsAreArray({1,2,3,4,5,6,0,7,8,9,10,11,12,13,14,15}))),
    Field(&Step::board, Field(&Board::board, ElementsAreArray({1,0,3,4,5,2,6,7,8,9,10,11,12,13,14,15}))),
    Field(&Step::board, Field(&Board::board, ElementsAreArray({1,2,3,4,5,9,6,7,8,0,10,11,12,13,14,15})))));
}

TEST(Step, Output) {
  auto s1 = std::make_shared<Step>(Step{{{1,2,3,4,5,7,11,8,9,6,0,12,13,10,14,15}}, nullptr});
  auto s2 = std::make_shared<Step>(Step{{{1,2,3,4,5,7,0,8,9,6,11,12,13,10,14,15}}, s1});
  auto s3 = std::make_shared<Step>(Step{{{1,2,3,4,5,0,7,8,9,6,11,12,13,10,14,15}}, s2});
  auto s4 = std::make_shared<Step>(Step{{{1,2,3,4,5,6,7,8,9,0,11,12,13,10,14,15}}, s3});
  auto s5 = std::make_shared<Step>(Step{{{1,2,3,4,5,6,7,8,9,10,11,12,13,0,14,15}}, s4});
  auto s6 = std::make_shared<Step>(Step{{{1,2,3,4,5,6,7,8,9,10,11,12,13,14,0,15}}, s5});
  auto s7 = std::make_shared<Step>(Step{{{1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,0}}, s6});
  std::ostringstream actual;
  actual << *s7;
  std::ostringstream expected;
  expected << "11 down" << std::endl
           << "7 right" << std::endl
           << "6 up"    << std::endl
           << "10 up"   << std::endl
           << "14 left" << std::endl
           << "15 left" << std::endl;
  EXPECT_EQ(expected.str(), actual.str());
}