#include "board.hpp"
#include <cctype>
#include <cstdio>
#include <print>
#include <string>

bool WHITE = true;
bool BLACK = false;

void setBoardFen(std::string fen, board *b) {
  // example fen rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1
  int file = 0;
  int rank = 0;

  std::string castle = "";

  enum parserState {
    POSITION,
    TURN,
    CASTLE,
    ENPASSANT,
    CLOCK1,
    CLOCK2,
  };
  parserState state = POSITION;

  for (int i = 0; i < fen.length(); i++) {
    std::printf("state: %d\n", state);
    std::printf("doing: %c\n", fen[i]);
    if (fen[i] == ' ') {
      if (state == POSITION) {
        state = TURN;
        continue;
      }
      if (state == TURN) {
        state = CASTLE;
        continue;
      }
      if (state == CASTLE) {
        state = ENPASSANT;
        continue;
      }
      if (state == ENPASSANT) {
        state = CLOCK1;
        continue;
      }
      if (state == CLOCK1) {
        state = CLOCK2;
        continue;
      }
    }
    if (state == ENPASSANT) {
      continue;
    }
    if (state == CASTLE) {
      if (fen[i] == '-') {
        castle = "-";
        continue;
      }
      if (toupper(fen[i]) == 'K') {
        castle += fen[i];
        continue;
      }
      if (toupper(fen[i]) == 'Q') {
        castle += fen[i];
        continue;
      }
    }
    if (state == TURN) {
      if (toupper(fen[i]) == 'W') {
        b->turn = WHITE;
        continue;
      }
      if (toupper(fen[i]) == 'B') {
        b->turn = BLACK;
        continue;
      }
    }
    if (state == POSITION) {
      if (isdigit(fen[i])) {
        int move = fen[i] - '0';
        file += move;
        if (file > 8) {
          std::println("Fatal: file was to big");
          return; // malformed rank
        }
        continue;
      }
      if (fen[i] == '/') {
        file = 0;
        rank++;
        if (rank > 8) {
          std::println("Fatal: rank was to big");
          return; // malformed rank
        }
        continue;
      }
      if (toupper(fen[i]) == 'N') {
        Piece piece = createPiece(KNIGHT, isupper(fen[i]));
        b->pieces[rank * 8 + file] = piece;
        file++;
        continue;
      }
      if (toupper(fen[i]) == 'R') {
        Piece piece = createPiece(ROOK, isupper(fen[i]));
        b->pieces[rank * 8 + file] = piece;
        file++;
        continue;
      }
      if (toupper(fen[i]) == 'Q') {
        Piece piece = createPiece(QUEEN, isupper(fen[i]));
        b->pieces[rank * 8 + file] = piece;
        file++;
        continue;
      }
      if (toupper(fen[i]) == 'B') {
        Piece piece = createPiece(BISHOP, isupper(fen[i]));
        b->pieces[rank * 8 + file] = piece;
        file++;
        continue;
      }
      if (toupper(fen[i]) == 'P') {
        Piece piece = createPiece(PAWN, isupper(fen[i]));
        b->pieces[rank * 8 + file] = piece;
        file++;
        continue;
      }
      if (toupper(fen[i]) == 'K') {
        Piece piece = createPiece(KING, isupper(fen[i]));
        b->pieces[rank * 8 + file] = piece;
        file++;
        continue;
      }
    }
    break;
  }
  b->castle = castle.empty() ? "-" : castle;
}