🦉 iOS 기반 주식 시세 조회 앱

// StockManager.swift
import Foundation

typealias StockData = (String, Double, String)

class StockManager {
    private let apiKey = "YOUR_API_KEY"
    private var retryCount = 0

    func fetchStockData(symbol: String, completion: @escaping (Result<StockData, Error>) -> Void) {
        // 기본 URL 구성
        guard var urlComponents = URLComponents(string: "https://api.example.com/stock") else {
            completion(.failure(NetworkError.invalidURL))
            return
        }

        // 쿼리 파라미터 추가
        urlComponents.queryItems = [
            URLQueryItem(name: "symbol", value: symbol),
            URLQueryItem(name: "api_key", value: apiKey)
        ]

        guard let url = urlComponents.url else {
            completion(.failure(NetworkError.invalidURL))
            return
        }

        // 네트워크 요청 실행
        URLSession.shared.dataTask(with: url) { data, response, error in
            
            // 오류 처리
            if let error = error {
                self.retryCount += 1
                if self.retryCount < 3 {
                    print("재시도 시도 $self.retryCount회")
                    DispatchQueue.global().asyncAfter(deadline: .now() + 2) {
                        self.fetchStockData(symbol: symbol, completion: completion)
                    }
                    return
                }
                completion(.failure(error))
                return
            }

            // 응답 처리
            guard let data = data else {
                completion(.failure(NetworkError.emptyResponse))
                return
            }

            do {
                // JSON 파싱
                let json = try JSONSerialization.jsonObject(with: data, options: []) as? [String: Any]
                guard let price = json?["price"] as? Double,
                      let currency = json?["currency"] as? String else {
                    completion(.failure(NetworkError.invalidFormat))
                    return
                }

                // 성공 처리
                completion(.success((symbol, price, currency)))
            } catch {
                completion(.failure(error))
            }
        }.resume()
    }
}

// NetworkError.swift
enum NetworkError: Error {
    case invalidURL
    case emptyResponse
    case invalidFormat
}