session-ios/SessionMessagingKit/Sending & Receiving/Notifications/Models/UnsubscribeRequest.swift

// Copyright © 2023 Rangeproof Pty Ltd. All rights reserved.

import Foundation
import SessionSnodeKit
import SessionUtilitiesKit

extension PushNotificationAPI {
    class UnsubscribeRequest: AuthenticatedRequest {
        private enum CodingKeys: String, CodingKey {
            case service
            case serviceInfo = "service_info"
        }
        
        /// Dict of service-specific data; typically this includes just a "token" field with a device-specific token, but different services in the
        /// future may have different input requirements.
        private let serviceInfo: ServiceInfo
        
        override var verificationBytes: [UInt8] {
            /// A signature is signed using the account's Ed25519 private key (or Ed25519 subkey, if using
            /// subkey authentication with a `subkey_tag`, for future closed group subscriptions), and signs the value:
            /// `"UNSUBSCRIBE" || HEX(ACCOUNT) || SIG_TS`
            ///
            /// Where `SIG_TS` is the `sig_ts` value as a base-10 string and must be within 24 hours of the current time.
            "UNSUBSCRIBE".bytes
                .appending(contentsOf: authMethod.sessionId.hexString.bytes)
                .appending(contentsOf: "\(timestamp)".data(using: .ascii)?.bytes)
        }
        
        // MARK: - Initialization
        
        init(
            serviceInfo: ServiceInfo,
            authMethod: AuthenticationMethod,
            timestamp: TimeInterval
        ) {
            self.serviceInfo = serviceInfo
            
            super.init(
                authMethod: authMethod,
                timestamp: Int64(timestamp)   // Server expects rounded seconds
            )
        }
        
        // MARK: - Coding
        
        override public func encode(to encoder: Encoder) throws {
            var container: KeyedEncodingContainer<CodingKeys> = encoder.container(keyedBy: CodingKeys.self)
            
            try container.encode(Service.apns, forKey: .service)
            try container.encode(serviceInfo, forKey: .serviceInfo)
            
            try super.encode(to: encoder)
        }
    }
}