ZcashLightClientKit/ZcashLightClientKit/Transaction/TransactionEncoder.swift

//
//  TransactionEncoder.swift
//  ZcashLightClientKit
//
//  Created by Francisco Gindre on 11/20/19.
//

import Foundation

typealias TransactionEncoderResultBlock = (_ result: Result<EncodedTransaction,Error>) -> Void

public enum TransactionEncoderError: Error {
    case notFound(transactionId: Int)
    case NotEncoded(transactionId: Int)
    case missingParams
    case spendingKeyWrongNetwork
    case couldNotExpand(txId: Data)
}

protocol TransactionEncoder {
    
    /**
    Creates a transaction, throwing an exception whenever things are missing. When the provided wallet implementation
    doesn't throw an exception, we wrap the issue into a descriptive exception ourselves (rather than using
    double-bangs for things).
     Blocking
     
     - Parameters:
     - Parameter spendingKey: a string containing the spending key
     - Parameter zatoshi: the amount to send in zatoshis
     - Parameter to: string containing the recipient address
     - Parameter memo: string containing the memo (optional)
     - Parameter accountIndex: index of the account that will be used to send the funds
     
     - Throws: a TransactionEncoderError
    */
    func createTransaction(spendingKey: String, zatoshi: Int, to: String, memo: String?, from accountIndex: Int) throws -> EncodedTransaction
    
    /**
    Creates a transaction, throwing an exception whenever things are missing. When the provided wallet implementation
    doesn't throw an exception, we wrap the issue into a descriptive exception ourselves (rather than using
    double-bangs for things).
     Non-blocking
     
     - Parameters:
    - Parameter spendingKey: a string containing the spending key
    - Parameter zatoshi: the amount to send in zatoshis
    - Parameter to: string containing the recipient address
    - Parameter memo: string containing the memo (optional)
    - Parameter accountIndex: index of the account that will be used to send the funds
    - Parameter result: a non escaping closure that receives a Result containing either an EncodedTransaction or a TransactionEncoderError
    */
    func createTransaction(spendingKey: String, zatoshi: Int, to: String, memo: String?, from accountIndex: Int, result: @escaping TransactionEncoderResultBlock)
    
    /**
        Fetch the Transaction Entity from the encoded representation
     - Parameter encodedTransaction: The encoded transaction to expand
     - Returns: a TransactionEntity based on the given Encoded Transaction
     - Throws: a TransactionEncoderError
     */
    func expandEncodedTransaction(_ encodedTransaction: EncodedTransaction) throws -> TransactionEntity
}