#include <string.h>
#include <assert.h>
#include "response.h"

enum {
  STATE_INITIAL,
  STATE_IDLE,
  STATE_SYNC,
  STATE_PING,
  STATE_ACTIVE,
  STATE_HALT,
};
int current_state = STATE_INITIAL;
int debug = false;

void todo() {
  assert(0);
}

void handle_uci(ucicmd cmd) {
  if (current_state == STATE_INITIAL) {
    return handle_initial(cmd);
  }
  if (current_state == STATE_IDLE) {
    return handle_idle(cmd);
  }
  if (current_state == STATE_SYNC) {
    return handle_sync(cmd);
  }
  if (current_state == STATE_PING) {
    return handle_ping(cmd);
  }
  if (current_state == STATE_ACTIVE) {
    return handle_active(cmd);
  }
  return handle_halt(cmd);
}

void handle_initial(ucicmd cmd) {
  if (cmd.empty || strcmp(cmd.root, "uci") != 0) return;
  printf("uciok\n");
  current_state = STATE_IDLE;
}

void handle_idle(ucicmd cmd) {
  if (cmd.empty) return;
  if (strcmp(cmd.root, "debug") == 0) {
    debug = strcmp(ucicmd_get_arg(cmd, 0), "on") == 0;
  } else if (strcmp(cmd.root, "setoption") == 0) {
  } else if (strcmp(cmd.root, "ucinewgame") == 0) {
  } else if (strcmp(cmd.root, "position") == 0) {
  } else if (strcmp(cmd.root, "stop") == 0) {
  } else if (strcmp(cmd.root, "quit") == 0) {
    free(cmd.args);
    exit(0);
  } else if (strcmp(cmd.root, "isready") == 0) {
    current_state = STATE_SYNC;
  } else if (strcmp(cmd.root, "go") == 0) {
    current_state = STATE_ACTIVE;
  } else {
    printf("Invalid command: %s\n", cmd.root);
  }
}

void handle_sync(ucicmd cmd) {
  // when i come up with some info to give: 
  // printf("info\n");
  printf("readyok\n");
  current_state = STATE_IDLE;
}

void handle_ping(ucicmd cmd) {
  // when i come up with some info to give: 
  // printf("info\n");
  //
  // if (TODO) {
  //   printf("bestmove\n");
  //   current_state = STATE_IDLE;
  // }
  printf("readyok\n");
  current_state = STATE_ACTIVE;
}

void handle_active(ucicmd cmd) {
  if (cmd.empty) {
    return;
  }
  // TODO: this section will call the engine to analysis
  if (strcmp(cmd.root, "isready") == 0) {
    current_state = STATE_PING;
  } else if (strcmp(cmd.root, "stop") == 0) {
    current_state = STATE_HALT;
  } else {
    printf("Invalid command: %s\n", cmd.root);
  }
}

void handle_halt(ucicmd cmd) {
  // when i come up with some info to give: 
  // printf("info\n");
  printf("bestmove 0000\n"); // TODO: idk get it rn
  current_state = STATE_IDLE;
}