// Copyright © 2017-2020 Trust Wallet.

//

// This file is part of Trust. The full Trust copyright notice, including

// terms governing use, modification, and redistribution, is contained in the

// file LICENSE at the root of the source code distribution tree.

#pragma once

#include "Transaction.h"

#include "TransactionBuilder.h"

#include "TransactionInput.h"

#include "../Bitcoin/Amount.h"

#include "../Bitcoin/Script.h"

#include "../Bitcoin/TransactionPlan.h"

#include "../Hash.h"

#include "../PrivateKey.h"

#include "../Result.h"

#include "../proto/Bitcoin.pb.h"

#include "../proto/Decred.pb.h"

#include <memory>

#include <string>

#include <vector>

namespace TW::Decred {

/// Helper class that performs Decred transaction signing.

class Signer {

private:

/// Private key and redeem script provider for signing.

Bitcoin::Proto::SigningInput input;

public:

/// Transaction plan.

Bitcoin::TransactionPlan plan;

/// Transaction being signed.

Transaction transaction;

private:

/// List of signed inputs.

std::vector<TransactionInput> signedInputs;

public:

/// Initializes a transaction signer.

Signer() = default;

/// Initializes a transaction signer with signing input.

explicit Signer(Bitcoin::Proto::SigningInput&& input)

: input(input), plan(TransactionBuilder::plan(input)) {

transaction = TransactionBuilder::build(plan, input.to_address(), input.change_address());

}

/// Initializes a transaction signer with signing input, a transaction, and

/// a hash type.

Signer(Bitcoin::Proto::SigningInput&& input, const Bitcoin::TransactionPlan& plan)

: input(input), plan(plan) {

transaction = TransactionBuilder::build(plan, input.to_address(), input.change_address());

}

/// Signs the transaction.

///

/// \returns the signed transaction or an error.

Result<Transaction> sign();

/// Signs a particular input.

///

/// \returns the signed transaction script.

Result<Bitcoin::Script> sign(Bitcoin::Script script, size_t index);

private:

Result<std::vector<Data>> signStep(Bitcoin::Script script, size_t index);

Data createSignature(const Transaction& transaction, const Bitcoin::Script& script,

const Data& key, size_t index);

Data pushAll(const std::vector<Data>& results);

/// Returns the private key for the given public key hash.

Data keyForPublicKeyHash(const Data& hash) const;

/// Returns the redeem script for the given script hash.

Data scriptForScriptHash(const Data& hash) const;

};

} // namespace TW::Decred

/// Wrapper for C interface.

struct TWDecredSigner {

TW::Decred::Signer impl;

};