import Foundation

/// Shared error type for Lilith agent API operations
public enum APIError: LocalizedError, Sendable {
    case unauthorized
    case forbidden
    case notFound
    case serverError(statusCode: Int, message: String?)
    case networkError(underlying: Error)
    case decodingError(underlying: Error)
    case invalidURL(String)
    case missingAuthToken
    case registrationFailed(reason: String)
    case verificationPending

    public var errorDescription: String? {
        switch self {
        case .unauthorized:
            return "Authentication required. Please re-authenticate."
        case .forbidden:
            return "Access denied. Insufficient permissions."
        case .notFound:
            return "Resource not found."
        case .serverError(let statusCode, let message):
            return "Server error (\(statusCode)): \(message ?? "Unknown error")"
        case .networkError(let underlying):
            return "Network error: \(underlying.localizedDescription)"
        case .decodingError(let underlying):
            return "Failed to decode response: \(underlying.localizedDescription)"
        case .invalidURL(let url):
            return "Invalid URL: \(url)"
        case .missingAuthToken:
            return "No authentication token available. Please register this device."
        case .registrationFailed(let reason):
            return "Device registration failed: \(reason)"
        case .verificationPending:
            return "Device verification is pending. Please approve in the web dashboard."
        }
    }

    public var isRetryable: Bool {
        switch self {
        case .networkError:
            return true
        case .serverError(let code, _) where code >= 500:
            return true
        default:
            return false
        }
    }
}