#include <assert.h>
#include <ctype.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include "moves.h"
#include "types.h"
#include "help.h"
#include "eval.h"
#include "main.h"

#define BUFF_SIZE 4096

game *fenGame(char *str);
void playMoves(game *g, char *moves);
long long *findSet(game *g, long long bit);
long long *charToSet(game *g, char c);

int cmain() {
  setbuf(stdin, NULL);
  setbuf(stdout, NULL);
  game *g = NULL;

  char line[BUFF_SIZE];
  char *lineRest, *token;
  char ltz[] = "abcdefgh";
  int cnt = 0;
  while (1) {
    if(!fgets(line, sizeof(line), stdin))
      return 0;
    size_t len = strlen(line);
    if (len - 1)
      line[len - 1] = '\0';
    token = strtok_r(line, " ", &lineRest);
    if (!strcmp("uci", token)) {
      printf("id name RatChess 0.0\n");
      printf("id author rat<3\n");
      printf("uciok\n");
    } else if (!strcmp("quit", token)) {
      return 0;
    } else if (!strcmp("setoption", token)) {
    } else if (!strcmp("position", token)) {
      token = strtok_r(lineRest, " ", &lineRest);
      if (!strcmp("fen", token)) {
        g = fenGame(lineRest + 1);
        for (int i = 0; i < 6; i++)
          token = strtok_r(lineRest, " ", &lineRest);
      } else {
        g = fenGame("rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1");
      }
      playMoves(g, lineRest);
    } else if (!strcmp("ucinewgame", token)) {
    } else if (!strcmp("isready", token)) {
      printf("readyok\n");
    } else if (!strcmp("go", token)) {
      uciGo(g);
    }
  }
}

void uciGo(game *g){
  char ltz[] = "abcdefgh";
  static move mov[1500];//big dumb buffer
  size_t cnt = 0;
  cnt += pawnMove(g,mov);
  cnt += knightMove(g,(mov+cnt));
  cnt += rookMove(g,(mov+cnt));
  cnt += bishopMove(g,(mov+cnt));
  cnt += kingMove(g,(mov+cnt));
  cnt += queenMove(g,(mov+cnt));
  move *m = findBest(mov,cnt,g);
  if(m == NULL){
    printf("bestmove 0000\n");
    return;
  }

  char *end = "";
  int yTo, xTo, yFrom, xFrom;
  xTo = m->To % 8;
  yTo = m->To / 8 + 1;
  xFrom = m->From % 8;
  yFrom = m->From / 8 + 1;

  long long bit = 1LL << m->From;
  if (m->Promo) {
    end = "q\n";
  } else {
    end = "\n";
  }
  printf("bestmove %c%d%c%d%s", ltz[xFrom], yFrom, ltz[xTo], yTo, end);
}


game *fenGame(char *str) {
  int rank = 7;
  int file = 0;
  size_t pos = 0;
  game *g;
  g = malloc(sizeof(game));
  memset(g, 0, sizeof(game));

  while (str[pos] != '\0' && str[pos] != ' ') {
    char current_char = *str;

    if (isdigit(*str)) {
      int empty_squares = *str - '0';
      file += empty_squares;
      str++;
      continue;
    }

    if (current_char == '/') {
      rank--;
      file = 0;
      str++;
      continue;
    }

    long long bit = 1ULL << (rank * 8 + file);
    long long *set = charToSet(g, *str);
    if (set)
      *set |= bit;
    file++;
    str++;
  }
  str++;
  g->whiteToMove = (*str == 'w') ? true : false;
  return g;
}

void playMoves(game *g, char *moves) {
  char *moveStr;
  moveStr = strtok_r(moves, " ", &moves);
  moveStr = strtok_r(moves, " ", &moves);
  while (moveStr) {
    move m;
    m.From = (moveStr[0]-'a') + (moveStr[1]-'1')*8;
    m.To = (moveStr[2]-'a') + (moveStr[3]-'1')*8;
    m.Promo = (strlen(moveStr) == 5) ? moveStr[4] : 0;
    makeMove(g, &m);
    moveStr = strtok_r(moves, " ", &moves);
  }
}