'use strict';

const fs = require('fs');
const path = require('path');
const RandomBot = require('./RandomBot');
const LLMBot = require('./LLMBot');

const NAMES_PATH = path.join(__dirname, 'bot_names.txt');
const FALLBACK_NAMES = ['DefaultBot', 'BackupBot', 'SpareBot', 'ExtraBot'];

function readNames() {
  try {
    const names = fs
      .readFileSync(NAMES_PATH, 'utf8')
      .split('\n')
      .map((name) => name.trim())
      .filter((name) => name.length > 0);
    return names.length ? names : FALLBACK_NAMES;
  } catch (err) {
    console.warn(`[BotFactory] Could not read ${NAMES_PATH}: ${err.message}`);
    return FALLBACK_NAMES;
  }
}

class BotFactory {
  /**
   * Create a bot instance. LLM bots fall back to RandomBot when the LLM
   * client cannot be constructed (missing API key/config) so a game can
   * always start.
   */
  static createBot(type = 'llm') {
    switch (String(type).toLowerCase()) {
      case 'random':
        return new RandomBot();
      case 'llm':
        try {
          return new LLMBot();
        } catch (err) {
          console.warn(
            `[BotFactory] LLM bot unavailable (${err.message}); using RandomBot instead.`
          );
          return new RandomBot();
        }
      default:
        throw new Error(`Unknown bot type: ${type}`);
    }
  }

  /**
   * Pick a random bot name, avoiding names already used in the room.
   */
  static generateBotName(exclude = []) {
    const names = readNames();
    const taken = new Set(
      (Array.isArray(exclude) ? exclude : [exclude])
        .filter(Boolean)
        .map((name) => String(name).toLowerCase())
    );

    const available = names.filter((name) => !taken.has(name.toLowerCase()));
    const pool = available.length ? available : names;
    const pick = pool[Math.floor(Math.random() * pool.length)] || FALLBACK_NAMES[0];

    // If every themed name is taken, disambiguate with a number.
    if (taken.has(pick.toLowerCase())) {
      let suffix = 2;
      while (taken.has(`${pick}${suffix}`.toLowerCase())) suffix += 1;
      return `${pick}${suffix}`;
    }
    return pick;
  }

  static getAvailableBotTypes() {
    return ['llm', 'random'];
  }
}

module.exports = BotFactory;