// 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 "../Data.h"

#include <TrustWalletCore/TWBitcoinOpCodes.h>

#include <TrustWalletCore/TWCoinType.h>

#include <string>

#include <vector>

namespace TW::Bitcoin {

class Script {

public:

/// Script raw bytes.

Data bytes;

/// Initializes an empty script.

Script() = default;

/// Initializes a script with a collection of raw bytes.

template <typename It>

Script(It begin, It end) : bytes(begin, end) {}

/// Initializaes a script with a collection of raw bytes by moving.

explicit Script(Data&& bytes) : bytes(bytes) {}

/// Whether the script is empty.

bool empty() const { return bytes.empty(); }

/// Returns the script's script hash.

Data hash() const;

/// Determines whether this is a pay-to-script-hash (P2SH) script.

bool isPayToScriptHash() const;

/// Determines whether this is a pay-to-witness-script-hash (P2WSH) script.

bool isPayToWitnessScriptHash() const;

/// Determines whether this is a witness programm script.

bool isWitnessProgram() const;

/// Matches the script to a pay-to-public-key (P2PK) script.

bool matchPayToPubkey(Data& publicKey) const;

/// Matches the script to a pay-to-public-key-hash (P2PKH).

bool matchPayToPubkeyHash(Data& keyHash) const;

/// Matches the script to a pay-to-script-hash (P2SH).

bool matchPayToScriptHash(Data& scriptHash) const;

/// Matches the script to a pay-to-witness-public-key-hash (P2WPKH).

bool matchPayToWitnessPublicKeyHash(Data& keyHash) const;

/// Matches the script to a pay-to-witness-script-hash (P2WSH).

bool matchPayToWitnessScriptHash(Data& scriptHash) const;

/// Matches the script to a multisig script.

bool matchMultisig(std::vector<Data>& publicKeys, int& required) const;

/// Builds a pay-to-public-key-hash (P2PKH) script from a public key hash.

static Script buildPayToPublicKeyHash(const Data& hash);

/// Builds a pay-to-script-hash (P2SH) script from a script hash.

static Script buildPayToScriptHash(const Data& scriptHash);

/// Builds a pay-to-witness-program script, P2WSH or P2WPKH.

static Script buildPayToWitnessProgram(const Data& program);

/// Builds a pay-to-witness-public-key-hash (P2WPKH) script from a public

/// key hash.

static Script buildPayToWitnessPubkeyHash(const Data& hash);

/// Builds a pay-to-witness-script-hash (P2WSH) script from a script hash.

static Script buildPayToWitnessScriptHash(const Data& scriptHash);

/// Builds a pay-to-public-key-hash (P2PKH) script appropriate for the given

/// address.

static Script buildForAddress(const std::string& address, enum TWCoinType coin);

/// Encodes the script.

void encode(Data& data) const;

/// Encodes a small integer

static uint8_t encodeNumber(int n) {

assert(n >= 0 && n <= 16);

if (n == 0) {

return OP_0;

}

return OP_1 + uint8_t(n - 1);

}

private:

/// Extracts a single opcode at the given index including its operand.

///

/// \param index [in/out] index where the operation starts, on return the

/// index of the next operation. \param opcode [out] the opcode. \param

/// operand [out] the opcode's operand. \returns whether an opcode was

/// available.

bool getScriptOp(size_t& index, uint8_t& opcode, Data& operand) const;

};

inline bool operator==(const Script& lhs, const Script& rhs) {

return lhs.bytes == rhs.bytes;

}

inline bool operator!=(const Script& lhs, const Script& rhs) {

return !(lhs == rhs);

}

} // namespace TW::Bitcoin

/// Wrapper for C interface.

struct TWBitcoinScript {

TW::Bitcoin::Script impl;

};