// Copyright (c) 2011-2022 The Bitcoin Core developers

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

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

#ifndef BITCOIN_WALLET_COINCONTROL_H

#define BITCOIN_WALLET_COINCONTROL_H

#include <outputtype.h>

#include <policy/feerate.h>

#include <policy/fees.h>

#include <primitives/transaction.h>

#include <script/keyorigin.h>

#include <script/signingprovider.h>

#include <algorithm>

#include <map>

#include <optional>

#include <set>

namespace wallet {

const int DEFAULT_MIN_DEPTH = 0;

const int DEFAULT_MAX_DEPTH = 9999999;

const int DEFAULT_WALLET_TX_VERSION = CTransaction::CURRENT_VERSION;

//! Default for -avoidpartialspends

static constexpr bool DEFAULT_AVOIDPARTIALSPENDS = false;

class PreselectedInput

{

private:

    //! The previous output being spent by this input

    std::optional<CTxOut> m_txout;

    //! The input weight for spending this input

    std::optional<int64_t> m_weight;

    //! The sequence number for this input

    std::optional<uint32_t> m_sequence;

    //! The scriptSig for this input

    std::optional<CScript> m_script_sig;

    //! The scriptWitness for this input

    std::optional<CScriptWitness> m_script_witness;

    //! The position in the inputs vector for this input

    std::optional<unsigned int> m_pos;

public:

    /**

     * Set the previous output for this input.

     * Only necessary if the input is expected to be an external input.

     */

    void SetTxOut(const CTxOut& txout);

    /** Retrieve the previous output for this input. */

    CTxOut GetTxOut() const;

    /** Return whether the previous output is set for this input. */

    bool HasTxOut() const;

    /** Set the weight for this input. */

    void SetInputWeight(int64_t weight);

    /** Retrieve the input weight for this input. */

    std::optional<int64_t> GetInputWeight() const;

    /** Set the sequence for this input. */

    void SetSequence(uint32_t sequence);

    /** Retrieve the sequence for this input. */

    std::optional<uint32_t> GetSequence() const;

    /** Set the scriptSig for this input. */

    void SetScriptSig(const CScript& script);

    /** Set the scriptWitness for this input. */

    void SetScriptWitness(const CScriptWitness& script_wit);

    /** Return whether either the scriptSig or scriptWitness are set for this input. */

    bool HasScripts() const;

    /** Retrieve both the scriptSig and the scriptWitness. */

    std::pair<std::optional<CScript>, std::optional<CScriptWitness>> GetScripts() const;

    /** Store the position of this input. */

    void SetPosition(unsigned int pos);

    /** Retrieve the position of this input. */

    std::optional<unsigned int> GetPosition() const;

};

/** Coin Control Features. */

class CCoinControl

{

public:

    //! Custom change destination, if not set an address is generated

    CTxDestination destChange = CNoDestination();

    //! Override the default change type if set, ignored if destChange is set

    std::optional<OutputType> m_change_type;

    //! If false, only safe inputs will be used

    bool m_include_unsafe_inputs = false;

    //! If true, the selection process can add extra unselected inputs from the wallet

    //! while requires all selected inputs be used

    bool m_allow_other_inputs = true;

    //! Override automatic min/max checks on fee, m_feerate must be set if true

    bool fOverrideFeeRate = false;

    //! Override the wallet's m_pay_tx_fee if set

    std::optional<CFeeRate> m_feerate;

    //! Override the default confirmation target if set

    std::optional<unsigned int> m_confirm_target;

    //! Override the wallet's m_signal_rbf if set

    std::optional<bool> m_signal_bip125_rbf;

    //! Avoid partial use of funds sent to a given address

    bool m_avoid_partial_spends = DEFAULT_AVOIDPARTIALSPENDS;

    //! Forbids inclusion of dirty (previously used) addresses

    bool m_avoid_address_reuse = false;

    //! Fee estimation mode to control arguments to estimateSmartFee

    FeeEstimateMode m_fee_mode = FeeEstimateMode::UNSET;

    //! Minimum chain depth value for coin availability

    int m_min_depth = DEFAULT_MIN_DEPTH;

    //! Maximum chain depth value for coin availability

    int m_max_depth = DEFAULT_MAX_DEPTH;

    //! SigningProvider that has pubkeys and scripts to do spend size estimation for external inputs

    FlatSigningProvider m_external_provider;

    //! Version

    uint32_t m_version = DEFAULT_WALLET_TX_VERSION;

    //! Locktime

    std::optional<uint32_t> m_locktime;

    //! Caps weight of resulting tx

    std::optional<int> m_max_tx_weight{std::nullopt};

    CCoinControl();

    /**

     * Returns true if there are pre-selected inputs.

     */

    bool HasSelected() const;

    /**

     * Returns true if the given output is pre-selected.

     */

    bool IsSelected(const COutPoint& outpoint) const;

    /**

     * Returns true if the given output is selected as an external input.

     */

    bool IsExternalSelected(const COutPoint& outpoint) const;

    /**

     * Returns the external output for the given outpoint if it exists.

     */

    std::optional<CTxOut> GetExternalOutput(const COutPoint& outpoint) const;

    /**

     * Lock-in the given output for spending.

     * The output will be included in the transaction even if it's not the most optimal choice.

     */

    PreselectedInput& Select(const COutPoint& outpoint);

    /**

     * Unselects the given output.

     */

    void UnSelect(const COutPoint& outpoint);

    /**

     * Unselects all outputs.

     */

    void UnSelectAll();

    /**

     * List the selected inputs.

     */

    std::vector<COutPoint> ListSelected() const;

    /**

     * Set an input's weight.

     */

    void SetInputWeight(const COutPoint& outpoint, int64_t weight);

    /**

     * Returns the input weight.

     */

    std::optional<int64_t> GetInputWeight(const COutPoint& outpoint) const;

    /** Retrieve the sequence for an input */

    std::optional<uint32_t> GetSequence(const COutPoint& outpoint) const;

    /** Retrieves the scriptSig and scriptWitness for an input. */

    std::pair<std::optional<CScript>, std::optional<CScriptWitness>> GetScripts(const COutPoint& outpoint) const;

    bool HasSelectedOrder() const

    {

        return m_selection_pos > 0;

    }

    std::optional<unsigned int> GetSelectionPos(const COutPoint& outpoint) const

    {

        const auto it = m_selected.find(outpoint);

        if (it == m_selected.end()) {

            return std::nullopt;

        }

        return it->second.GetPosition();

    }

private:

    //! Selected inputs (inputs that will be used, regardless of whether they're optimal or not)

    std::map<COutPoint, PreselectedInput> m_selected;

    unsigned int m_selection_pos{0};

};

} // namespace wallet

#endif // BITCOIN_WALLET_COINCONTROL_H