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

void apply_option(uci_state *state, char *name, char *buffer) {
  int settings_count = sizeof(state->option_settings)/sizeof(option_setting_t);
  for (int i = 0; i < settings_count; i++) {
    option_setting_t setting = state->option_settings[i];

    if (strcmp(setting.option_name, name)) continue;
    if (OPTION_SPIN == setting.type) {
      option_spin_setting_t data = setting.data.spin;
      int num = atoi(buffer);
      if (num < data.min) return;
      if (num > data.max) return;
      *setting.value.spin = num;
    } else if (OPTION_COMBO == setting.type) {
      option_combo_setting_t data = setting.data.combo;
      for (int j = 0; j < data.count; j++) {
        if (strcmp(data.combination[i], buffer)) continue;
        *setting.value.combo = j;
      }
    } else if (OPTION_CHECK == setting.type) {
      *setting.value.check = strcmp(buffer, "true") == 0;
    } else if (OPTION_STRING == setting.type) {
      free(setting.value.string->data);
      setting.value.string->length = strlen(buffer);
      setting.value.string->data = malloc(setting.value.string->length);
      memcpy(setting.value.string->data, buffer, setting.value.string->length);
    } else if (OPTION_BUTTON == setting.type) {
      *setting.value.button = true;
    } else { assert(0); }
    return;
  }
  printf("invalid option\n");
}

// examples from uci_min.txt
// option name Nullmove type check default true\n
// option name Selectivity type spin default 2 min 0 max 4\n
// option name Style type combo default Normal var Solid var Normal var Risky\n
// option name NalimovPath type string default c:\\n
// option name Clear Hash type button\n
void print_setting(option_setting_t setting) {
  printf("option name %s type ", setting.option_name);
  // accidently did the yoda style if statement, i am keeping it
  if (OPTION_SPIN == setting.type) {
    option_spin_setting_t data = setting.data.spin;
    printf(
      "spin default %d min %d max %d\n",
      data.default_value,
      data.min,
      data.max
    );
  } else if (OPTION_COMBO == setting.type) {
    option_combo_setting_t data = setting.data.combo;
    printf("combo default %s", data.combination[data.default_index]);
    for (int i = 0; i < data.count; i++) {
      printf(" var %s", data.combination[i]);
    }
    printf("\n");
  } else if (OPTION_CHECK == setting.type) {
    printf("check default %d\n", setting.data.check_default);
  } else if (OPTION_STRING == setting.type) {
    printf("string default %s\n", setting.data.string_default);
  } else if (OPTION_BUTTON == setting.type) {
    printf("button\n");
  } else { assert(0); }
}

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

void todo() {
  assert(0);
}

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

void handle_initial(uci_state *state, ucicmd cmd) {
  if (cmd.empty || strcmp(cmd.root, "uci") != 0) return;
  printf("id name %s\n", state->name);
  printf("id author %s\n", state->author);
  int settings_count = sizeof(state->option_settings)/sizeof(option_setting_t);
  for (int i = 0; i < settings_count; i++) {
    print_setting(state->option_settings[i]);
  }
  printf("uciok\n");
  current_state = STATE_IDLE;
}

void handle_idle(uci_state *state, ucicmd cmd) {
  if (cmd.empty) return;
  if (strcmp(cmd.root, "debug") == 0) {
    state->debug = strcmp(ucicmd_get_arg(cmd, 0), "on") == 0;
  } else if (strcmp(cmd.root, "setoption") == 0) {
    char buffer[2048] = {0};
    char name[64] = {0};
    char *cursor = name;
    for (int i = 1; i < cmd.args_count; i++) {
      assert((long)cursor - (long)buffer < 2048);
      char *arg = ucicmd_get_arg(cmd, i);
      if (strcmp(arg, "value") == 0) {
        *(--cursor) = 0;
        cursor = buffer;
        continue;
      }
      cursor = stpncpy(cursor, arg, MAX_TOKEN_SIZE);
      *(cursor++) = ' ';
    }
    *(--cursor) = 0;
    apply_option(state, name, buffer);
  } 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(uci_state *state, ucicmd cmd) {
  // when i come up with some info to give: 
  // printf("info\n");
  printf("readyok\n");
  current_state = STATE_IDLE;
}

void handle_ping(uci_state *state, 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(uci_state *state, 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(uci_state *state, 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;
}