//------------------------------------------------------------------------------
/*
    This file is part of rippled: https://github.com/ripple/rippled
    Copyright (c) 2022 Ripple Labs Inc.

    Permission to use, copy, modify, and/or distribute this software for any
    purpose  with  or without fee is hereby granted, provided that the above
    copyright notice and this permission notice appear in all copies.

    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
//==============================================================================

#ifndef RIPPLE_PROTOCOL_STXATTESTATIONS_H_INCLUDED
#define RIPPLE_PROTOCOL_STXATTESTATIONS_H_INCLUDED

#include <xrpl/basics/Buffer.h>
#include <xrpl/basics/Expected.h>
#include <xrpl/protocol/AccountID.h>
#include <xrpl/protocol/Issue.h>
#include <xrpl/protocol/PublicKey.h>
#include <xrpl/protocol/SField.h>
#include <xrpl/protocol/STBase.h>
#include <xrpl/protocol/STXChainBridge.h>
#include <xrpl/protocol/SecretKey.h>
#include <xrpl/protocol/TER.h>

#include <boost/container/flat_set.hpp>
#include <boost/container/vector.hpp>

#include <cstddef>
#include <type_traits>
#include <unordered_map>
#include <vector>

namespace ripple {

namespace Attestations {

struct AttestationBase
{
    // Account associated with the public key
    AccountID attestationSignerAccount;
    // Public key from the witness server attesting to the event
    PublicKey publicKey;
    // Signature from the witness server attesting to the event
    Buffer signature;
    // Account on the sending chain that triggered the event (sent the
    // transaction)
    AccountID sendingAccount;
    // Amount transfered on the sending chain
    STAmount sendingAmount;
    // Account on the destination chain that collects a share of the attestation
    // reward
    AccountID rewardAccount;
    // Amount was transfered on the locking chain
    bool wasLockingChainSend;

    explicit AttestationBase(
        AccountID attestationSignerAccount_,
        PublicKey const& publicKey_,
        Buffer signature_,
        AccountID const& sendingAccount_,
        STAmount const& sendingAmount_,
        AccountID const& rewardAccount_,
        bool wasLockingChainSend_);

    AttestationBase(AttestationBase const&) = default;

    virtual ~AttestationBase() = default;

    AttestationBase&
    operator=(AttestationBase const&) = default;

    // verify that the signature attests to the data.
    bool
    verify(STXChainBridge const& bridge) const;

protected:
    explicit AttestationBase(STObject const& o);
    explicit AttestationBase(Json::Value const& v);

    [[nodiscard]] static bool
    equalHelper(AttestationBase const& lhs, AttestationBase const& rhs);

    [[nodiscard]] static bool
    sameEventHelper(AttestationBase const& lhs, AttestationBase const& rhs);

    void
    addHelper(STObject& o) const;

private:
    [[nodiscard]] virtual std::vector<std::uint8_t>
    message(STXChainBridge const& bridge) const = 0;
};

// Attest to a regular cross-chain transfer
struct AttestationClaim : AttestationBase
{
    std::uint64_t claimID;
    std::optional<AccountID> dst;

    explicit AttestationClaim(
        AccountID attestationSignerAccount_,
        PublicKey const& publicKey_,
        Buffer signature_,
        AccountID const& sendingAccount_,
        STAmount const& sendingAmount_,
        AccountID const& rewardAccount_,
        bool wasLockingChainSend_,
        std::uint64_t claimID_,
        std::optional<AccountID> const& dst_);

    explicit AttestationClaim(
        STXChainBridge const& bridge,
        AccountID attestationSignerAccount_,
        PublicKey const& publicKey_,
        SecretKey const& secretKey_,
        AccountID const& sendingAccount_,
        STAmount const& sendingAmount_,
        AccountID const& rewardAccount_,
        bool wasLockingChainSend_,
        std::uint64_t claimID_,
        std::optional<AccountID> const& dst_);

    explicit AttestationClaim(STObject const& o);
    explicit AttestationClaim(Json::Value const& v);

    [[nodiscard]] STObject
    toSTObject() const;

    // return true if the two attestations attest to the same thing
    [[nodiscard]] bool
    sameEvent(AttestationClaim const& rhs) const;

    [[nodiscard]] static std::vector<std::uint8_t>
    message(
        STXChainBridge const& bridge,
        AccountID const& sendingAccount,
        STAmount const& sendingAmount,
        AccountID const& rewardAccount,
        bool wasLockingChainSend,
        std::uint64_t claimID,
        std::optional<AccountID> const& dst);

    [[nodiscard]] bool
    validAmounts() const;

private:
    [[nodiscard]] std::vector<std::uint8_t>
    message(STXChainBridge const& bridge) const override;

    friend bool
    operator==(AttestationClaim const& lhs, AttestationClaim const& rhs);
};

struct CmpByClaimID
{
    bool
    operator()(AttestationClaim const& lhs, AttestationClaim const& rhs) const
    {
        return lhs.claimID < rhs.claimID;
    }
};

// Attest to a cross-chain transfer that creates an account
struct AttestationCreateAccount : AttestationBase
{
    // createCount on the sending chain. This is the value of the `CreateCount`
    // field of the bridge on the sending chain when the transaction was
    // executed.
    std::uint64_t createCount;
    // Account to create on the destination chain
    AccountID toCreate;
    // Total amount of the reward pool
    STAmount rewardAmount;

    explicit AttestationCreateAccount(STObject const& o);

    explicit AttestationCreateAccount(Json::Value const& v);

    explicit AttestationCreateAccount(
        AccountID attestationSignerAccount_,
        PublicKey const& publicKey_,
        Buffer signature_,
        AccountID const& sendingAccount_,
        STAmount const& sendingAmount_,
        STAmount const& rewardAmount_,
        AccountID const& rewardAccount_,
        bool wasLockingChainSend_,
        std::uint64_t createCount_,
        AccountID const& toCreate_);

    explicit AttestationCreateAccount(
        STXChainBridge const& bridge,
        AccountID attestationSignerAccount_,
        PublicKey const& publicKey_,
        SecretKey const& secretKey_,
        AccountID const& sendingAccount_,
        STAmount const& sendingAmount_,
        STAmount const& rewardAmount_,
        AccountID const& rewardAccount_,
        bool wasLockingChainSend_,
        std::uint64_t createCount_,
        AccountID const& toCreate_);

    [[nodiscard]] STObject
    toSTObject() const;

    // return true if the two attestations attest to the same thing
    [[nodiscard]] bool
    sameEvent(AttestationCreateAccount const& rhs) const;

    friend bool
    operator==(
        AttestationCreateAccount const& lhs,
        AttestationCreateAccount const& rhs);

    [[nodiscard]] static std::vector<std::uint8_t>
    message(
        STXChainBridge const& bridge,
        AccountID const& sendingAccount,
        STAmount const& sendingAmount,
        STAmount const& rewardAmount,
        AccountID const& rewardAccount,
        bool wasLockingChainSend,
        std::uint64_t createCount,
        AccountID const& dst);

    [[nodiscard]] bool
    validAmounts() const;

private:
    [[nodiscard]] std::vector<std::uint8_t>
    message(STXChainBridge const& bridge) const override;
};

struct CmpByCreateCount
{
    bool
    operator()(
        AttestationCreateAccount const& lhs,
        AttestationCreateAccount const& rhs) const
    {
        return lhs.createCount < rhs.createCount;
    }
};

};  // namespace Attestations

// Result when checking when two attestation match.
enum class AttestationMatch {
    // One of the fields doesn't match, and it isn't the dst field
    nonDstMismatch,
    // all of the fields match, except the dst field
    matchExceptDst,
    // all of the fields match
    match
};

struct XChainClaimAttestation
{
    using TSignedAttestation = Attestations::AttestationClaim;
    static SField const& ArrayFieldName;

    AccountID keyAccount;
    PublicKey publicKey;
    STAmount amount;
    AccountID rewardAccount;
    bool wasLockingChainSend;
    std::optional<AccountID> dst;

    struct MatchFields
    {
        STAmount amount;
        bool wasLockingChainSend;
        std::optional<AccountID> dst;
        MatchFields(TSignedAttestation const& att);
        MatchFields(
            STAmount const& a,
            bool b,
            std::optional<AccountID> const& d)
            : amount{a}, wasLockingChainSend{b}, dst{d}
        {
        }
    };

    explicit XChainClaimAttestation(
        AccountID const& keyAccount_,
        PublicKey const& publicKey_,
        STAmount const& amount_,
        AccountID const& rewardAccount_,
        bool wasLockingChainSend_,
        std::optional<AccountID> const& dst);

    explicit XChainClaimAttestation(
        STAccount const& keyAccount_,
        PublicKey const& publicKey_,
        STAmount const& amount_,
        STAccount const& rewardAccount_,
        bool wasLockingChainSend_,
        std::optional<STAccount> const& dst);

    explicit XChainClaimAttestation(TSignedAttestation const& claimAtt);

    explicit XChainClaimAttestation(STObject const& o);

    explicit XChainClaimAttestation(Json::Value const& v);

    AttestationMatch
    match(MatchFields const& rhs) const;

    [[nodiscard]] STObject
    toSTObject() const;

    friend bool
    operator==(
        XChainClaimAttestation const& lhs,
        XChainClaimAttestation const& rhs);
};

struct XChainCreateAccountAttestation
{
    using TSignedAttestation = Attestations::AttestationCreateAccount;
    static SField const& ArrayFieldName;

    AccountID keyAccount;
    PublicKey publicKey;
    STAmount amount;
    STAmount rewardAmount;
    AccountID rewardAccount;
    bool wasLockingChainSend;
    AccountID dst;

    struct MatchFields
    {
        STAmount amount;
        STAmount rewardAmount;
        bool wasLockingChainSend;
        AccountID dst;

        MatchFields(TSignedAttestation const& att);
    };

    explicit XChainCreateAccountAttestation(
        AccountID const& keyAccount_,
        PublicKey const& publicKey_,
        STAmount const& amount_,
        STAmount const& rewardAmount_,
        AccountID const& rewardAccount_,
        bool wasLockingChainSend_,
        AccountID const& dst_);

    explicit XChainCreateAccountAttestation(TSignedAttestation const& claimAtt);

    explicit XChainCreateAccountAttestation(STObject const& o);

    explicit XChainCreateAccountAttestation(Json::Value const& v);

    [[nodiscard]] STObject
    toSTObject() const;

    AttestationMatch
    match(MatchFields const& rhs) const;

    friend bool
    operator==(
        XChainCreateAccountAttestation const& lhs,
        XChainCreateAccountAttestation const& rhs);
};

// Attestations from witness servers for a particular claimid and bridge.
// Only one attestation per signature is allowed.
template <class TAttestation>
class XChainAttestationsBase
{
public:
    using AttCollection = std::vector<TAttestation>;

private:
    // Set a max number of allowed attestations to limit the amount of memory
    // allocated and processing time. This number is much larger than the actual
    // number of attestation a server would ever expect.
    static constexpr std::uint32_t maxAttestations = 256;
    AttCollection attestations_;

protected:
    // Prevent slicing to the base class
    ~XChainAttestationsBase() = default;

public:
    XChainAttestationsBase() = default;
    XChainAttestationsBase(XChainAttestationsBase const& rhs) = default;
    XChainAttestationsBase&
    operator=(XChainAttestationsBase const& rhs) = default;

    explicit XChainAttestationsBase(AttCollection&& sigs);

    explicit XChainAttestationsBase(Json::Value const& v);

    explicit XChainAttestationsBase(STArray const& arr);

    [[nodiscard]] STArray
    toSTArray() const;

    typename AttCollection::const_iterator
    begin() const;

    typename AttCollection::const_iterator
    end() const;

    typename AttCollection::iterator
    begin();

    typename AttCollection::iterator
    end();

    template <class F>
    std::size_t
    erase_if(F&& f);

    std::size_t
    size() const;

    bool
    empty() const;

    AttCollection const&
    attestations() const;

    template <class T>
    void
    emplace_back(T&& att);
};

template <class TAttestation>
[[nodiscard]] inline bool
operator==(
    XChainAttestationsBase<TAttestation> const& lhs,
    XChainAttestationsBase<TAttestation> const& rhs)
{
    return lhs.attestations() == rhs.attestations();
}

template <class TAttestation>
inline typename XChainAttestationsBase<TAttestation>::AttCollection const&
XChainAttestationsBase<TAttestation>::attestations() const
{
    return attestations_;
};

template <class TAttestation>
template <class T>
inline void
XChainAttestationsBase<TAttestation>::emplace_back(T&& att)
{
    attestations_.emplace_back(std::forward<T>(att));
};

template <class TAttestation>
template <class F>
inline std::size_t
XChainAttestationsBase<TAttestation>::erase_if(F&& f)
{
    return std::erase_if(attestations_, std::forward<F>(f));
}

template <class TAttestation>
inline std::size_t
XChainAttestationsBase<TAttestation>::size() const
{
    return attestations_.size();
}

template <class TAttestation>
inline bool
XChainAttestationsBase<TAttestation>::empty() const
{
    return attestations_.empty();
}

class XChainClaimAttestations final
    : public XChainAttestationsBase<XChainClaimAttestation>
{
    using TBase = XChainAttestationsBase<XChainClaimAttestation>;
    using TBase::TBase;
};

class XChainCreateAccountAttestations final
    : public XChainAttestationsBase<XChainCreateAccountAttestation>
{
    using TBase = XChainAttestationsBase<XChainCreateAccountAttestation>;
    using TBase::TBase;
};

}  // namespace ripple

#endif  // STXCHAINATTESTATIONS_H_
