Errors

public enum EncoreError: Error, LocalizedError, Sendable {
    case transport(TransportError)      // "The road is broken" — connectivity
    case `protocol`(ProtocolError)      // "The language failed" — HTTP/API
    case integration(IntegrationError)  // "SDK misused" — config/programmer error
    case domain(String)                 // Client business-rule violation (message only)

    public enum TransportError: Error, Sendable {
        case network(Error)       // No connectivity, timeout, connection failed
        case persistence(Error)   // Local storage read/write failure
    }

    public enum ProtocolError: Error, Sendable {
        case http(status: Int, message: String?)        // Non-2xx, body unreadable
        case api(status: Int, code: String?, message: String) // Structured server error
        case decoding(Error)                              // 2xx body didn't match schema
    }

    public enum IntegrationError: Error, Sendable {
        case notConfigured    // configure() not called before use
        case invalidApiKey    // Empty / malformed API key
        case invalidURL       // Failed to construct a request URL
    }
}

if let underlying = encoreError.underlying {
    // The original URLSession / decoding error, when one exists.
}

func cancelTapped() {
    Task {
        do {
            let result = try await Encore.placement("cancel_flow").show()
            switch result {
            case .granted(let entitlement):
                applyEntitlement(entitlement)
            case .notGranted:
                // User dismissed or no offers — proceed with the original action.
                proceedWithCancellation()
            }
        } catch let error as EncoreError {
            switch error {
            case .integration(.notConfigured):
                assertionFailure("Call Encore.shared.configure(apiKey:) at launch")
            case .transport(.network(let underlying)):
                Logger.log("Network error: \(underlying.localizedDescription)")
            case .protocol(.api(_, let code, let message)):
                Logger.log("API error (\(code ?? "unknown")): \(message)")
            default:
                Logger.log(error.errorDescription ?? "Encore error")
            }
            // Always let the user proceed.
            proceedWithCancellation()
        } catch {
            proceedWithCancellation()
        }
    }
}