// Copyright (c) 2023 The Bitcoin Core developers

// Distributed under the MIT software license, see the accompanying

// file COPYING or https://www.opensource.org/licenses/mit-license.php.

#ifndef BITCOIN_ADDRESSTYPE_H

#define BITCOIN_ADDRESSTYPE_H

#include <attributes.h>

#include <pubkey.h>

#include <script/script.h>

#include <uint256.h>

#include <util/check.h>

#include <util/hash_type.h>

#include <algorithm>

#include <variant>

#include <vector>

class CNoDestination

{

private:

    CScript m_script;

public:

    CNoDestination() = default;

    explicit CNoDestination(const CScript& script) : m_script(script) {}

    const CScript& GetScript() const LIFETIMEBOUND { return m_script; }

    friend bool operator==(const CNoDestination& a, const CNoDestination& b) { return a.GetScript() == b.GetScript(); }

    friend bool operator<(const CNoDestination& a, const CNoDestination& b) { return a.GetScript() < b.GetScript(); }

};

struct PubKeyDestination {

private:

    CPubKey m_pubkey;

public:

    explicit PubKeyDestination(const CPubKey& pubkey) : m_pubkey(pubkey) {}

    const CPubKey& GetPubKey() const LIFETIMEBOUND { return m_pubkey; }

    friend bool operator==(const PubKeyDestination& a, const PubKeyDestination& b) { return a.GetPubKey() == b.GetPubKey(); }

    friend bool operator<(const PubKeyDestination& a, const PubKeyDestination& b) { return a.GetPubKey() < b.GetPubKey(); }

};

struct PKHash : public BaseHash<uint160>

{

    PKHash() : BaseHash() {}

    explicit PKHash(const uint160& hash) : BaseHash(hash) {}

    explicit PKHash(const CPubKey& pubkey);

    explicit PKHash(const CKeyID& pubkey_id);

};

CKeyID ToKeyID(const PKHash& key_hash);

struct WitnessV0KeyHash;

struct ScriptHash : public BaseHash<uint160>

{

    ScriptHash() : BaseHash() {}

    // These don't do what you'd expect.

    // Use ScriptHash(GetScriptForDestination(...)) instead.

    explicit ScriptHash(const WitnessV0KeyHash& hash) = delete;

    explicit ScriptHash(const PKHash& hash) = delete;

    explicit ScriptHash(const uint160& hash) : BaseHash(hash) {}

    explicit ScriptHash(const CScript& script);

    explicit ScriptHash(const CScriptID& script);

};

CScriptID ToScriptID(const ScriptHash& script_hash);

struct WitnessV0ScriptHash : public BaseHash<uint256>

{

    WitnessV0ScriptHash() : BaseHash() {}

    explicit WitnessV0ScriptHash(const uint256& hash) : BaseHash(hash) {}

    explicit WitnessV0ScriptHash(const CScript& script);

};

struct WitnessV0KeyHash : public BaseHash<uint160>

{

    WitnessV0KeyHash() : BaseHash() {}

    explicit WitnessV0KeyHash(const uint160& hash) : BaseHash(hash) {}

    explicit WitnessV0KeyHash(const CPubKey& pubkey);

    explicit WitnessV0KeyHash(const PKHash& pubkey_hash);

};

CKeyID ToKeyID(const WitnessV0KeyHash& key_hash);

struct WitnessV1Taproot : public XOnlyPubKey

{

    WitnessV1Taproot() : XOnlyPubKey() {}

    explicit WitnessV1Taproot(const XOnlyPubKey& xpk) : XOnlyPubKey(xpk) {}

};

//! CTxDestination subtype to encode any future Witness version

struct WitnessUnknown

{

private:

    unsigned int m_version;

    std::vector<unsigned char> m_program;

public:

    WitnessUnknown(unsigned int version, const std::vector<unsigned char>& program) : m_version(version), m_program(program) {}

    WitnessUnknown(int version, const std::vector<unsigned char>& program) : m_version(static_cast<unsigned int>(version)), m_program(program) {}

    unsigned int GetWitnessVersion() const { return m_version; }

    const std::vector<unsigned char>& GetWitnessProgram() const LIFETIMEBOUND { return m_program; }

    friend bool operator==(const WitnessUnknown& w1, const WitnessUnknown& w2) {

        if (w1.GetWitnessVersion() != w2.GetWitnessVersion()) return false;

        return w1.GetWitnessProgram() == w2.GetWitnessProgram();

    }

    friend bool operator<(const WitnessUnknown& w1, const WitnessUnknown& w2) {

        if (w1.GetWitnessVersion() < w2.GetWitnessVersion()) return true;

        if (w1.GetWitnessVersion() > w2.GetWitnessVersion()) return false;

        return w1.GetWitnessProgram() < w2.GetWitnessProgram();

    }

};

struct PayToAnchor : public WitnessUnknown

{

    PayToAnchor() : WitnessUnknown(1, {0x4e, 0x73}) {

        Assume(CScript::IsPayToAnchor(1, {0x4e, 0x73}));

    };

};

/**

 * A txout script categorized into standard templates.

 *  * CNoDestination: Optionally a script, no corresponding address.

 *  * PubKeyDestination: TxoutType::PUBKEY (P2PK), no corresponding address

 *  * PKHash: TxoutType::PUBKEYHASH destination (P2PKH address)

 *  * ScriptHash: TxoutType::SCRIPTHASH destination (P2SH address)

 *  * WitnessV0ScriptHash: TxoutType::WITNESS_V0_SCRIPTHASH destination (P2WSH address)

 *  * WitnessV0KeyHash: TxoutType::WITNESS_V0_KEYHASH destination (P2WPKH address)

 *  * WitnessV1Taproot: TxoutType::WITNESS_V1_TAPROOT destination (P2TR address)

 *  * PayToAnchor: TxoutType::ANCHOR destination (P2A address)

 *  * WitnessUnknown: TxoutType::WITNESS_UNKNOWN destination (P2W??? address)

 *  A CTxDestination is the internal data type encoded in a bitcoin address

 */

using CTxDestination = std::variant<CNoDestination, PubKeyDestination, PKHash, ScriptHash, WitnessV0ScriptHash, WitnessV0KeyHash, WitnessV1Taproot, PayToAnchor, WitnessUnknown>;

/** Check whether a CTxDestination corresponds to one with an address. */

bool IsValidDestination(const CTxDestination& dest);

/**

 * Parse a scriptPubKey for the destination.

 *

 * For standard scripts that have addresses (and P2PK as an exception), a corresponding CTxDestination

 * is assigned to addressRet.

 * For all other scripts. addressRet is assigned as a CNoDestination containing the scriptPubKey.

 *

 * Returns true for standard destinations with addresses - P2PKH, P2SH, P2WPKH, P2WSH, P2TR and P2W??? scripts.

 * Returns false for non-standard destinations and those without addresses - P2PK, bare multisig, null data, and nonstandard scripts.

 */

bool ExtractDestination(const CScript& scriptPubKey, CTxDestination& addressRet);

/**

 * Generate a Bitcoin scriptPubKey for the given CTxDestination. Returns a P2PKH

 * script for a CKeyID destination, a P2SH script for a CScriptID, and an empty

 * script for CNoDestination.

 */

CScript GetScriptForDestination(const CTxDestination& dest);

#endif // BITCOIN_ADDRESSTYPE_H