import Foundation

// MARK: - Binding (BLE 协议层硬绑/硬解 + 解绑端的软解；OTA 检查/对账/软绑搬到 +Firmware)

extension DuooomiBleSDK {

    /// 硬绑：BLE 协议层把当前用户绑定到设备（命令 0x0F），完成后同步拉一次版本号。
    ///
    /// **作用域**：只做 BLE 通道的绑定 + `getDeviceVersion`。
    /// 软绑 / 升级对账上报 / 拉最新固件 → 全部移到 `fetchLatestFirmware(sn:currentVersion:userId:)` 内部串。
    ///
    /// 完成后 SDK 状态变化：
    /// - `sdk.sn` 写入设备序列号
    /// - `sdk.version` 写入当前固件版本（getVersion 失败时保持空，但 bind 不算失败）
    /// - `sdk.isActivated = true`，delegate `didChangeActivation(true)` 回调
    ///
    /// - Parameters:
    ///   - userId: 当前用户 ID（写入 BLE BIND payload 的 `bindUserId` 字段，不依赖登录态 token）
    ///   - completion: 回调 `Result<BindingResponse, Error>`
    ///     - 成功：`BindingResponse(success: 1, sn, contents)`
    ///     - 失败：`.notConnected` / `.alreadyBoundByOtherUser`(success≠1) / `.timeout(.bindDevice)`
    /// - Note: `bind` / `unbind` / `setPlayMode` 共享 `0x0F` / `0x12` opId 通道，**不能并发**。
    public func bind(userId: String, completion: @escaping (Result<BindingResponse, Error>) -> Void) {
        guard ensureConnected(completion: completion) else { return }
        BleLog.d("Sending bind (userId=\(userId))", "Command")

        sendAsyncAndWait(commandType: .bindDevice, completion: { [weak self] result in
            guard let self = self else { return }
            switch result {
            case .failure(let error):
                completion(.failure(error))
            case .success(let data):
                do {
                    let resp = try self.decodeResponse(BindingResponse.self, from: data)
                    self.isActivated = resp.success == 1
                    if resp.success != 1 {
                        BleLog.w("Hard bind failed: success=0", "Command")
                        completion(.failure(DuooomiBleError.alreadyBoundByOtherUser))
                        return
                    }
                    self.sn = resp.sn
                    BleLog.i("Hard bind success: sn=\(resp.sn)", "Command")
                    // 同步拉版本，让后续 fetchLatestFirmware 的对账上报有 currentVersion 可用
                    self.getVersion { _ in
                        completion(.success(resp))
                    }
                } catch {
                    completion(.failure(error))
                }
            }
        }, send: { done in
            self.deviceInfoService.bindDevice(userId: userId, completion: done)
        })
    }

    /// 解绑：硬解绑（BLE 0x12）→ 软解绑（shipment-sn HTTP）。SDK 内部完成全套。
    ///
    /// 软解失败仅打 warn 不阻断硬解结果回传——对端云记录如果残留，由后续 bind 自然修正。
    ///
    /// 完成后 SDK 状态变化：
    /// - `sdk.sn` 清空
    /// - `sdk.isActivated = false`，delegate `didChangeActivation(false)` 回调
    ///
    /// - Parameters:
    ///   - userId: 当前用户 ID（写入 BLE UNBIND payload + 软解请求体的 `bindUserId`）
    ///   - completion: 回调 `Result<UnbindResponse, Error>`
    ///     - 成功：`UnbindResponse(success: 1)`（软解失败也算成功）
    ///     - 失败：`.notConnected` / `.unbindFailed`(BLE 层 success≠1) / `.timeout(.unbindDevice)`
    /// - Note: `bind` / `unbind` / `setPlayMode` 共享 `0x0F` / `0x12` opId 通道，**不能并发**。
    public func unbind(userId: String, completion: @escaping (Result<UnbindResponse, Error>) -> Void) {
        guard ensureConnected(completion: completion) else { return }
        let cachedSn = self.sn
        BleLog.d("Sending unbind (userId=\(userId))", "Command")

        sendAsyncAndWait(commandType: .unbindDevice, completion: { [weak self] result in
            guard let self = self else { return }
            switch result {
            case .failure(let error):
                completion(.failure(error))
            case .success(let data):
                do {
                    let resp = try self.decodeResponse(UnbindResponse.self, from: data)
                    if resp.success == 1 {
                        self.isActivated = false
                        self.sn = ""
                        BleLog.i("Hard unbind success", "Command")
                        if !cachedSn.isEmpty {
                            self.shipmentService.unbind(sn: cachedSn, bindUserId: userId) { softResult in
                                if case .failure(let err) = softResult {
                                    BleLog.w("Soft unbind failed (ignored): \(err.localizedDescription)", "Command")
                                }
                                completion(.success(resp))
                            }
                        } else {
                            completion(.success(resp))
                        }
                    } else {
                        BleLog.w("Unbind failed", "Command")
                        completion(.failure(DuooomiBleError.unbindFailed))
                    }
                } catch {
                    completion(.failure(error))
                }
            }
        }, send: { done in
            self.deviceInfoService.unbindDevice(userId: userId, completion: done)
        })
    }
}