#ifndef GENERATOR_H_811386CE
#define GENERATOR_H_811386CE

#include <string>
#include <random>
#include <map>
#include <tuple>
#include <memory>
#include <verbly.h>
#include <hkutil/string.h>

enum Height {
  kTop,
  kMiddle,
  kBottom,
  kHeightCount
};

enum Colour {
  kWhite,
  kBlack,
  kRed,
  kBlue,
  kPurple,
  kBrown,
  kYellow,
  kGreen,
  kOrange,
  kColourCount
};

enum FilterDirection {
  kTowardSolution,
  kTowardQuestion
};

enum PalindromeQuery {
  kPalindromeUnspecified,
  kForcePalindrome,
  kRejectPalindrome
};

struct GenerateOptions {
  bool obscure_hint = false;
  int max_answer_len = 0;
  int max_hint_len = 0;
  int exact_len = 0;
  int max_len_diff = -1; // supported by single, double, paired, cohinted
  bool multiword = false;
  bool save_for_later = false;
  bool reuse_solution = false; // supported by single, double, and stack
  std::string unique_pool; // supported by single, double, and stack
  PalindromeQuery palindrome = kPalindromeUnspecified; // only important for middle black. supported by single and paired
  std::string copy_to; // supported by single and paired
  std::string copy_to2; // supported by paired
  std::string copy_hidden; // supported by single mid white
  bool force_two_words = false;
  bool must_be_broad = false; // the solution must also be gettable by bottom white/red/blue. supported by single and double
  bool allow_top_expansion = false; // this disables the triviality check that top puzzles can't also apply to middle
};

class Wanderlust {
public:
  Wanderlust(const std::string& words_filename, const std::string& puzzles_filename) {
    std::ifstream words_file(words_filename);
    std::string line;
    while (std::getline(words_file, line)) {
      words_.push_back(line);
    }

    std::ifstream puzzles_file(puzzles_filename);
    while (std::getline(puzzles_file, line)) {
      std::string line2;
      if (!std::getline(puzzles_file, line2)) {
        throw std::invalid_argument("Wanderlust file is malformed.");
      }

      puzzles_.emplace_back(line, line2);
    }
  }

  std::tuple<std::string, std::string> GetPuzzle(std::mt19937& rng) const {
    return puzzles_.at(std::uniform_int_distribution<int>(0, puzzles_.size()-1)(rng));
  }

  const std::string& GetWord(std::mt19937& rng) const {
    return words_.at(std::uniform_int_distribution<int>(0, words_.size()-1)(rng));
  }

private:
  std::vector<std::tuple<std::string, std::string>> puzzles_;
  std::vector<std::string> words_;
};

class CrossTower {
public:
  explicit CrossTower(std::string filename) {
    std::ifstream file(filename);
    std::string line;
    while (std::getline(file, line)) {
      sets_.push_back(hatkirby::split<std::vector<std::string>>(line, " "));
    }
  }

  std::vector<std::vector<std::string>> GetPuzzleSet(std::mt19937& rng) const {
    std::vector<std::vector<std::string>> result = sets_;
    std::shuffle(result.begin(), result.end(), rng);
    result.resize(4);

    for (std::vector<std::string>& set : result) {
      std::shuffle(set.begin(), set.end(), rng);
    }

    return result;
  }

private:
  std::vector<std::vector<std::string>> sets_;
};

class Generator {
public:

  explicit Generator(unsigned int seed) : seed_(seed), rng_(seed) {
    database_ = std::make_unique<verbly::database>("/Users/hatkirby/Dropbox/Programming/verbly-datafiles/d1.3_lingo7");
    wanderlust_ = std::make_unique<Wanderlust>("../wanderlust_words.txt", "../wanderlust_puzzles.txt");
    cross_tower_ = std::make_unique<CrossTower>("../cross_tower.txt");
  }

  // Querying
  bool IsPanelRandomized(const std::string& name) const {
    return panels_.count(name);
  }

  const std::tuple<std::string, std::string>& GetPanel(const std::string& name) const {
    return panels_.at(name);
  }

  // Sets the panel's question and answer to static values.
  void GenerateStaticPanel(std::string name, std::string question, std::string answer = "");

  // Generates a one-block puzzle with the given height and colour.
  void GenerateSinglePanel(std::string name, Height height, Colour colour, GenerateOptions options = {});

  // Generates a one-block puzzle with the given height and colour, where there is a panel on two faces of the block.
  // Both puzzles will have the same answer.
  void GenerateDoublePanel(std::string name1, std::string name2, Height height, Colour colour, GenerateOptions options = {});

  // Generates two puzzles with the same hint but different answers.
  void GenerateCohintedPanels(std::string name1, std::string name2, Height height, Colour colour, GenerateOptions options = {});

  // Generates two panels at once, where the question for one is the answer to the other.
  // Colour must be white, black, or yellow.
  // Middle white is a special case; the puzzles will be antonyms of one another.
  void GeneratePairedPanels(std::string name1, std::string name2, Height height, Colour colour, GenerateOptions options = {});

  // Generates a vertical stack of panels that all have the same answer.
  // If a name is left blank, that height will be ignored.
  void GeneratePanelStack(std::string top_name, Colour top_colour, std::string middle_name, Colour middle_colour, std::string bottom_name, Colour bottom_colour, GenerateOptions options = {});

  // Generate an orange puzzle, with a number for the hint.
  void GenerateOrangeNumberPanel(std::string name);

  // Generate an orange puzzle, with a word for the hint.
  void GenerateOrangeWordPanel(std::string name);

  // Generate an orange puzzle, with an addition problem for the hint.
  void GenerateOrangeAdditionPanel(std::string name);

  // Generates the ONE ROAD MANY TURNS panel by combining the solutions to four other panels.
  void GenerateOneRoadManyTurns(std::string order_name, std::string part1_name, std::string part2_name, std::string part3_name, std::string part4_name);

  // Generates a hybrid puzzle where the solution is two words and each word is provided by a different colour/height puzzle.
  void GenerateComboPanel(std::string name, Height left_height, Colour left_colour, Height right_height, Colour right_colour, GenerateOptions options = {});

  // Generates the cross tower sets-of-four puzzles.
  void GenerateCrossTower(
    std::string north_tower_name,
    std::string south_tower_name,
    std::string east_tower_name,
    std::string west_tower_name,
    std::string north_lookout_name,
    std::string south_lookout_name,
    std::string east_lookout_name,
    std::string west_lookout_name,
    std::string north_other_name1,
    std::string north_other_name2,
    std::string north_other_name3,
    std::string south_other_name1,
    std::string south_other_name2,
    std::string south_other_name3,
    std::string east_other_name1,
    std::string east_other_name2,
    std::string east_other_name3,
    std::string west_other_name1,
    std::string west_other_name2,
    std::string west_other_name3);

private:

  verbly::filter MakeHintFilter(verbly::filter subfilter, Height height, Colour colour, FilterDirection filter_direction) const;

  bool GenerateSinglePanelImpl(std::string name, Height height, Colour colour, GenerateOptions options);

  bool GenerateDoublePanelImpl(std::string name1, std::string name2, Height height, Colour colour, GenerateOptions options);

  bool GenerateCohintedPanelsImpl(std::string name1, std::string name2, Height height, Colour colour, GenerateOptions options);

  bool GeneratePairedPanelsImpl(std::string name1, std::string name2, Height height, Colour colour, GenerateOptions options);

  bool GeneratePanelStackImpl(std::string top_name, Colour top_colour, std::string middle_name, Colour middle_colour, std::string bottom_name, Colour bottom_colour, GenerateOptions options);

  bool GenerateComboPanelImpl(std::string name, Height left_height, Colour left_colour, Height right_height, Colour right_colour, GenerateOptions options);

  void SavePanel(std::string name, std::string question, std::string answer, GenerateOptions options = {});

  verbly::filter GetWordFilter(FilterDirection direction, GenerateOptions options) const;

  bool IsClueTrivial(Height height, Colour colour, const verbly::form& clue, const verbly::form& solution, GenerateOptions options = {}) const;

  unsigned int seed_;
  std::mt19937 rng_;
  std::unique_ptr<verbly::database> database_;
  std::unique_ptr<Wanderlust> wanderlust_;
  std::unique_ptr<CrossTower> cross_tower_;

  // name, question, answer
  std::map<std::string, std::tuple<std::string, std::string>> panels_;

  std::vector<std::string> reusable_;
  std::map<std::string, std::set<std::string>> pools_;
};

#endif /* end of include guard: GENERATOR_H_811386CE */