import Foundation

// MARK: - BlindBox Async Polling Sequences

enum BlindBoxPolling {
    /// Poll a single blind box until it becomes "Unopened".
    /// Yields once when ready, then finishes.
    static func singleBox(boxId: String, intervalSeconds: Double = 2.0) -> AsyncThrowingStream<BlindBoxData, Error> {
        AsyncThrowingStream { continuation in
            let task = Task {
                while !Task.isCancelled {
                    do {
                        let result = try await BlindBoxApi.shared.getBlindBox(boxId: boxId)
                        if let data = result {
                            if data.status.lowercased() == "unopened" {
                                continuation.yield(data)
                                continuation.finish()
                                break
                            }
                        }
                        try await Task.sleep(nanoseconds: UInt64(intervalSeconds * 1_000_000_000))
                    } catch is CancellationError {
                        continuation.finish()
                        break
                    } catch {
                        continuation.finish(throwing: error)
                        break
                    }
                }
            }
            continuation.onTermination = { @Sendable _ in
                task.cancel()
            }
        }
    }

    /// Poll blind box list and yield first unopened box when available.
    /// Yields once when found, then finishes.
    static func firstUnopened(intervalSeconds: Double = 2.0) -> AsyncThrowingStream<BlindBoxData, Error> {
        AsyncThrowingStream { continuation in
            let task = Task {
                while !Task.isCancelled {
                    do {
                        let list = try await BlindBoxApi.shared.getBlindBoxList()
                        if let item = list?.first(where: { $0.status.lowercased() == "unopened" }) {
                            continuation.yield(item)
                            continuation.finish()
                            break
                        }
                        try await Task.sleep(nanoseconds: UInt64(intervalSeconds * 1_000_000_000))
                    } catch is CancellationError {
                        continuation.finish()
                        break
                    } catch {
                        continuation.finish(throwing: error)
                        break
                    }
                }
            }
            continuation.onTermination = { @Sendable _ in
                task.cancel()
            }
        }
    }
}