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// Lead Maintainer: Virgil Security Inc. <support@virgilsecurity.com>
//

import VirgilSDK
import VirgilCrypto

/// Class for Pythia BrainKey
@objc(VSYBrainKey) open class BrainKey: NSObject {
    /// PythiaClientProtocol implementation
    @objc public let client: PythiaClientProtocol
    /// PythiaCryptoProtocol implementation
    @objc public let pythiaCrypto: PythiaCryptoProtocol

    /// Initializer
    ///
    /// - Parameter context: BrainKey context
    @objc public init(context: BrainKeyContext) {
        self.client = context.client
        self.pythiaCrypto = context.pythiaCrypto
    }

    /// Generates key pair based on given password and brainkeyId
    ///
    /// - Parameters:
    ///   - password: password from which key pair will be generated
    ///   - brainKeyId: optional brainKey identifier (in case one wants to generate several key pairs from 1 password)
    /// - Returns: GenericOperation with VirgilKeyPair
    open func generateKeyPair(password: String, brainKeyId: String? = nil) -> GenericOperation<VirgilKeyPair> {
        CallbackOperation { _, completion in
            do {
                let blindedResult = try self.pythiaCrypto.blind(password: password)

                let seed = try self.client.generateSeed(blindedPassword: blindedResult.blindedPassword,
                                                        brainKeyId: brainKeyId)

                let deblindedPassword = try self.pythiaCrypto.deblind(transformedPassword: seed,
                                                                      blindingSecret: blindedResult.blindingSecret)

                let keyPair = try self.pythiaCrypto.generateKeyPair(usingSeed: deblindedPassword)

                completion(keyPair, nil)
            }
            catch {
                completion(nil, error)
                return
            }
        }
    }
}
