import Foundation

/// 固件信息
public struct FirmwareInfo: Codable, Equatable {
    public let version: String
    public let fileUrl: String
    public let description: String?
    public let fileSize: String?
    public let fileMd5: String?
    public let identifier: String?
    public let status: String?
}

struct FirmwareResponse: Codable {
    let success: Bool
    let data: FirmwareInfo?
}

/// 固件服务内部实现
final class FirmwareService {
    private let config: DuooomiBleConfig
    private let latestPath = "api/auth/loomart/firmware/latest-published"

    init(config: DuooomiBleConfig) {
        self.config = config
    }

    func fetchLatest(
        identifier: String? = nil,
        status: String? = nil,
        completion: @escaping (Result<FirmwareInfo?, Error>) -> Void
    ) {
        let id = (identifier ?? config.firmwareIdentifier).trimmingCharacters(in: .whitespacesAndNewlines)
        let st = status ?? config.firmwareStatus
        guard !id.isEmpty else {
            completion(.failure(DuooomiBleError.transferFailed("Invalid firmware identifier")))
            return
        }

        let urlString = "\(config.apiHost)/\(latestPath)"
        guard var comps = URLComponents(string: urlString) else {
            completion(.failure(DuooomiBleError.transferFailed("Invalid firmware URL")))
            return
        }
        comps.queryItems = [
            URLQueryItem(name: "identifier", value: id),
            URLQueryItem(name: "status", value: st)
        ]
        guard let url = comps.url else {
            completion(.failure(DuooomiBleError.transferFailed("Invalid firmware URL")))
            return
        }

        var req = URLRequest(url: url)
        req.httpMethod = "GET"
        req.setValue(config.apiKey, forHTTPHeaderField: "x-api-key")
        req.setValue("application/json", forHTTPHeaderField: "accept")

        URLSession.shared.dataTask(with: req) { data, resp, error in
            if let error = error {
                completion(.failure(error))
                return
            }
            guard let http = resp as? HTTPURLResponse else {
                completion(.failure(DuooomiBleError.transferFailed("Invalid response")))
                return
            }
            guard (200...299).contains(http.statusCode) else {
                completion(.failure(DuooomiBleError.transferFailed("HTTP \(http.statusCode)")))
                return
            }
            guard let data = data else {
                completion(.failure(DuooomiBleError.transferFailed("Empty response")))
                return
            }

            do {
                let decoded = try JSONDecoder().decode(FirmwareResponse.self, from: data)
                completion(.success(decoded.data))
            } catch {
                completion(.failure(error))
            }
        }.resume()
    }
}