telegram-bot-workers/src/tools/weather-tool.ts

// Weather Tool - wttr.in integration
import type { Env } from '../types';
import { retryWithBackoff } from '../utils/retry';
import { ERROR_MESSAGES } from '../constants/messages';

// wttr.in API 응답 타입 정의
interface WttrCurrentCondition {
  temp_C: string;
  FeelsLikeC: string;
  weatherDesc: Array<{ value: string }>;
  humidity: string;
  windspeedKmph: string;
  winddir16Point: string;
  uvIndex: string;
  visibility: string;
}

interface WttrWeatherDay {
  date: string;
  maxtempC: string;
  mintempC: string;
  hourly: Array<{
    time: string;
    tempC: string;
    weatherDesc: Array<{ value: string }>;
    chanceofrain: string;
  }>;
}

interface WttrResponse {
  current_condition: WttrCurrentCondition[];
  weather: WttrWeatherDay[];
  nearest_area: Array<{
    areaName: Array<{ value: string }>;
    country: Array<{ value: string }>;
  }>;
}

export const weatherTool = {
  type: 'function',
  function: {
    name: 'get_weather',
    description: '특정 도시의 현재 날씨 정보를 가져옵니다',
    parameters: {
      type: 'object',
      properties: {
        city: {
          type: 'string',
          description: '도시 이름 (예: Seoul, Tokyo, New York)',
        },
      },
      required: ['city'],
    },
  },
};

export async function executeWeather(args: { city: string }, env?: Env): Promise<string> {
  const city = args.city || 'Seoul';
  try {
    const wttrUrl = env?.WTTR_IN_URL || 'https://wttr.in';
    const response = await retryWithBackoff(
      () => fetch(`${wttrUrl}/${encodeURIComponent(city)}?format=j1`),
      { maxRetries: 2, initialDelayMs: 500 }
    );

    if (!response.ok) {
      throw new Error(`API 응답 실패: ${response.status}`);
    }

    const data = await response.json() as WttrResponse;

    // 안전한 접근 - 데이터 유효성 확인
    if (!data.current_condition?.[0]) {
      return `${ERROR_MESSAGES.WEATHER_SERVICE_UNAVAILABLE}: ${city}`;
    }

    const current = data.current_condition[0];

    // weatherDesc 배열 존재 확인
    if (!current.weatherDesc?.[0]?.value) {
      return `날씨 정보가 불완전합니다: ${city}`;
    }

    return `🌤 ${city} 날씨
온도: ${current.temp_C}°C (체감 ${current.FeelsLikeC}°C)
상태: ${current.weatherDesc[0].value}
습도: ${current.humidity}%
풍속: ${current.windspeedKmph} km/h`;
  } catch (error) {
    return `${ERROR_MESSAGES.WEATHER_SERVICE_UNAVAILABLE}: ${city}`;
  }
}