#include "../pchheader.hpp"
#include "../conf.hpp"
#include "../crypto.hpp"
#include "../util.hpp"
#include "../hplog.hpp"
#include "../p2p/p2p.hpp"
#include "p2pmsg_container_generated.h"
#include "p2pmsg_content_generated.h"
#include "common_helpers.hpp"
#include "p2pmsg_helpers.hpp"

namespace fbschema::p2pmsg
{

/**
 * This section contains Flatbuffer message reading/writing helpers.
 * These helpers are mainly used by peer_session_handler.
 * 
 * All Flatbuffer peer messages are 'Container' messages. 'Container' message is a bucket
 * which some common headers (version, singature etc..) and the message 'Content' (Proposal, NPL etc..).
 * 
 * Therefore, when constructing peer messages, we have to first construct 'Content' message and then
 * place the 'Content' inside a 'Conatiner. 'Content' and 'Container' messages are constructed using
 * Flatbuffer builders.
 * 
 * Reading is also 2 steps because of this. We have first interprit the 'Container' message from the
 * received data and then interprit the 'Content' portion of it separately to read the actual content.
 */

//---Message validation helpers---/

/**
 * Verifies Conatiner message structure and outputs faltbuffer Container pointer to access the given buffer.
 * 
 * @param container_ref A pointer reference to assign the pointer to the Container object.
 * @param container_buf The buffer containing the data that should be validated and interpreted
 *                      via the container pointer.
 * @return 0 on successful verification. -1 for failure.
 */
int validate_and_extract_container(const Container **container_ref, std::string_view container_buf)
{
    //Accessing message buffer
    const uint8_t *container_buf_ptr = reinterpret_cast<const uint8_t *>(container_buf.data());
    const size_t container_buf_size = container_buf.length();

    //Defining Flatbuffer verifier (default max depth = 64, max_tables = 1000000,)
    flatbuffers::Verifier container_verifier(container_buf_ptr, container_buf_size);

    //Verify container message using flatbuffer verifier
    if (!VerifyContainerBuffer(container_verifier))
    {
        LOG_DBG << "Flatbuffer verify: Bad peer message container.";
        return -1;
    }

    //Get message container
    const Container *container = GetContainer(container_buf_ptr);

    //check protocol version of message whether it is greater than minimum supported protocol version.
    const uint16_t version = container->version();
    if (version < util::MIN_PEERMSG_VERSION)
    {
        LOG_DBG << "Peer message is from unsupported protocol version (" << version << ").";
        return -1;
    }

    //check message timestamp.
    const int64_t time_now = util::get_epoch_milliseconds();
    if (container->timestamp() < (time_now - conf::cfg.roundtime * 4))
    {
        LOG_DBG << "Peer message is too old.";
        return -1;
    }

    //Assign container and content out params.
    *container_ref = container;
    return 0;
}

/**
 * Validates the container message signing keys to see if the message is from a trusted source (UNL).
 * @return 0 on successful verification. -1 for failure.
 */
int validate_container_trust(const Container *container)
{
    std::string_view msg_pubkey = flatbuff_bytes_to_sv(container->pubkey());
    std::string_view msg_sig = flatbuff_bytes_to_sv(container->signature());

    if (msg_pubkey.empty() || msg_sig.empty())
    {
        LOG_DBG << "Peer message key pair incomplete. Trust verification failed.";
        return -1;
    }

    //validate if the message is not from a node of current node's unl list.
    if (!conf::cfg.unl.count(std::string(msg_pubkey)))
    {
        LOG_DBG << "Peer message pubkey verification failed. Not in UNL.";
        return -1;
    }

    //verify message signature.
    //this is performed towards end since this is bit expensive
    std::string_view msg_content = flatbuff_bytes_to_sv(container->content());

    if (crypto::verify(msg_content, msg_sig, msg_pubkey) != 0)
    {
        LOG_DBG << "Peer message signature verification failed.";
        return -1;
    }

    return 0;
}

/**
 * Verifies the Content message structure and outputs faltbuffer Content pointer to access the given buffer.
 * 
 * @param content_ref A pointer reference to assign the pointer to the Content object.
 * @param content_ptr Pointer to the the buffer containing the data that should validated and interpreted
 *                      via the container pointer.
 * @param content_size Data buffer size.
 * @return 0 on successful verification. -1 for failure.
 */
int validate_and_extract_content(const Content **content_ref, const uint8_t *content_ptr, const flatbuffers::uoffset_t content_size)
{
    //Defining Flatbuffer verifier for message content verification.
    //Since content is also serialised by using Flatbuffer we can verify it using Flatbuffer.
    flatbuffers::Verifier content_verifier(content_ptr, content_size);

    //verify content message using flatbuffer verifier.
    if (!VerifyContainerBuffer(content_verifier))
    {
        LOG_DBG << "Flatbuffer verify: Bad content.";
        return -1;
    }

    *content_ref = GetContent(content_ptr);
    return 0;
}

//---Message reading helpers---/

std::string_view get_peerid_from_msg(const PeerId_Notify_Message &msg)
{
    return flatbuff_bytes_to_sv(msg.peerid());
}

/**
 * Creates a non-unl proposal stuct from the given non-unl proposal message.
 * @param The Flatbuffer non-unl poporal received from the peer.
 * @return A non-unl proposal struct representing the message.
 */
const p2p::nonunl_proposal create_nonunl_proposal_from_msg(const NonUnl_Proposal_Message &msg, const uint64_t timestamp)
{
    p2p::nonunl_proposal nup;

    if (msg.usermessages())
        nup.user_messages = flatbuf_usermsgsmap_to_usermsgsmap(msg.usermessages());

    return nup;
}

/**
 * Creates a history response stuct from the given histrory response message.
 * @param msg Flatbuffer History response message received from the peer.
 * @return A History response struct representing the message.
 */
const p2p::history_response create_history_response_from_msg(const History_Response_Message &msg)
{
    p2p::history_response hr;

    if (msg.hist_ledgers())
        hr.hist_ledgers = flatbuf_historyledgermap_to_historyledgermap(msg.hist_ledgers());

    if (msg.error())
        hr.error = (p2p::LEDGER_RESPONSE_ERROR)msg.error();

    return hr;
}

/**
 * Creates a proposal stuct from the given proposal message.
 * @param The Flatbuffer poposal received from the peer.
 * @return A proposal struct representing the message.
 */
const p2p::proposal create_proposal_from_msg(const Proposal_Message &msg, const flatbuffers::Vector<uint8_t> *pubkey, const uint64_t timestamp, const flatbuffers::Vector<uint8_t> *lcl)
{
    p2p::proposal p;

    p.pubkey = flatbuff_bytes_to_sv(pubkey);
    p.timestamp = timestamp;
    p.time = msg.time();
    p.stage = msg.stage();
    p.lcl = flatbuff_bytes_to_sv(lcl);
    p.curr_hash_state = flatbuff_bytes_to_sv(msg.curr_state_hash());

    if (msg.users())
        p.users = flatbuf_bytearrayvector_to_stringlist(msg.users());

    if (msg.hash_inputs())
        p.hash_inputs = flatbuf_bytearrayvector_to_stringlist(msg.hash_inputs());

    if (msg.hash_outputs())
        p.hash_outputs = flatbuf_bytearrayvector_to_stringlist(msg.hash_outputs());

    return p;
}

/**
 * Creates a history request struct from the given history request message.
 * @param msg Flatbuffer History request message received from the peer.
 * @return A History request struct representing the message.
 */
const p2p::history_request create_history_request_from_msg(const History_Request_Message &msg)
{
    p2p::history_request hr;

    if (msg.minimum_lcl())
        hr.minimum_lcl = flatbuff_bytes_to_sv(msg.minimum_lcl());

    if (msg.required_lcl())
        hr.required_lcl = flatbuff_bytes_to_sv(msg.required_lcl());

    return hr;
}

/**
 * Creates a state request struct from the given state request message.
 * @param msg Flatbuffer State request message received from the peer.
 * @return A State request struct representing the message.
 */
const p2p::state_request create_state_request_from_msg(const State_Request_Message &msg)
{
    p2p::state_request sr;

    sr.block_id = msg.block_id();
    sr.is_file = msg.is_file();
    sr.parent_path = flatbuff_str_to_sv(msg.parent_path());
    sr.expected_hash = flatbuff_bytes_to_hash(msg.expected_hash());

    return sr;
}

/**
 * Creates a block response struct from the given block response message.
 * @param msg Flatbuffer block response message received from the peer.
 * @return A Block response struct representing the message.
 */
const p2p::block_response create_block_response_from_msg(const Block_Response &msg)
{
    p2p::block_response br;

    br.path = flatbuff_str_to_sv(msg.path());
    br.block_id = msg.block_id();
    br.data = flatbuff_bytes_to_sv(msg.data());
    return br;
}

//---Message creation helpers---//

void create_msg_from_peerid(flatbuffers::FlatBufferBuilder &container_builder, std::string_view peerid)
{
    flatbuffers::FlatBufferBuilder builder(1024);

    const flatbuffers::Offset<PeerId_Notify_Message> peerid_msg =
        CreatePeerId_Notify_Message(
            builder,
            sv_to_flatbuff_bytes(builder, peerid));

    const flatbuffers::Offset<Content> message = CreateContent(builder, Message_PeerId_Notify_Message, peerid_msg.Union());
    builder.Finish(message); // Finished building message content to get serialised content.

    // Now that we have built the content message,
    // we need to sign it and place it inside a container message.
    create_containermsg_from_content(container_builder, builder, nullptr, false);
}

void create_msg_from_nonunl_proposal(flatbuffers::FlatBufferBuilder &container_builder, const p2p::nonunl_proposal &nup)
{
    flatbuffers::FlatBufferBuilder builder(1024);

    const flatbuffers::Offset<NonUnl_Proposal_Message> nupmsg =
        CreateNonUnl_Proposal_Message(
            builder,
            usermsgsmap_to_flatbuf_usermsgsmap(builder, nup.user_messages));

    const flatbuffers::Offset<Content> message = CreateContent(builder, Message_NonUnl_Proposal_Message, nupmsg.Union());
    builder.Finish(message); // Finished building message content to get serialised content.

    // Now that we have built the content message,
    // we need to sign it and place it inside a container message.
    create_containermsg_from_content(container_builder, builder, nullptr, false);
}

/**
 * Create proposal peer message from the given proposal struct.
 * @param container_builder Flatbuffer builder for the container message.
 * @param p The proposal struct to be placed in the container message.
 */
void create_msg_from_proposal(flatbuffers::FlatBufferBuilder &container_builder, const p2p::proposal &p)
{
    // todo:get a average propsal message size and allocate content builder based on that.
    flatbuffers::FlatBufferBuilder builder(1024);

    const flatbuffers::Offset<Proposal_Message> proposal =
        CreateProposal_Message(
            builder,
            p.stage,
            p.time,
            stringlist_to_flatbuf_bytearrayvector(builder, p.users),
            stringlist_to_flatbuf_bytearrayvector(builder, p.hash_inputs),
            stringlist_to_flatbuf_bytearrayvector(builder, p.hash_outputs),
            sv_to_flatbuff_bytes(builder, p.curr_hash_state));

    const flatbuffers::Offset<Content> message = CreateContent(builder, Message_Proposal_Message, proposal.Union());
    builder.Finish(message); // Finished building message content to get serialised content.

    // Now that we have built the content message,
    // we need to sign it and place it inside a container message.
    create_containermsg_from_content(container_builder, builder, p.lcl, true);
}

/**
 * Ctreat npl message from the given npl output srtuct.
 * @param container_builder Flatbuffer builder for the container message.
 * @param n The npl struct to be placed in the container message.
 * @param lcl Lcl value to be passed in the container message.
 */
void create_msg_from_npl_output(flatbuffers::FlatBufferBuilder &container_builder, const p2p::npl_message &n, std::string_view lcl)
{
    flatbuffers::FlatBufferBuilder builder(1024);

    const flatbuffers::Offset<Npl_Message> npl =
        CreateNpl_Message(
            builder,
            sv_to_flatbuff_bytes(builder, n.data));

    const flatbuffers::Offset<Content> message = CreateContent(builder, Message_Npl_Message, npl.Union());
    builder.Finish(message); // Finished building message content to get serialised content.

    // Now that we have built the content message,
    // we need to sign it and place it inside a container message.
    create_containermsg_from_content(container_builder, builder, lcl, true);
}

/**
 * Create history request message from the given history request struct.
 * @param container_builder Flatbuffer builder for the container message.
 * @param hr The History request struct to be placed in the container message.
 */
void create_msg_from_history_request(flatbuffers::FlatBufferBuilder &container_builder, const p2p::history_request &hr)
{
    flatbuffers::FlatBufferBuilder builder(1024);

    flatbuffers::Offset<History_Request_Message> hrmsg =
        CreateHistory_Request_Message(
            builder,
            sv_to_flatbuff_bytes(builder, hr.minimum_lcl),
            sv_to_flatbuff_bytes(builder, hr.required_lcl));

    flatbuffers::Offset<Content> message = CreateContent(builder, Message_History_Request_Message, hrmsg.Union());
    builder.Finish(message); // Finished building message content to get serialised content.

    // Now that we have built the content message,
    // we need to sign it and place it inside a container message.
    create_containermsg_from_content(container_builder, builder, nullptr, true);
}

/**
 * Create history response message from the given history response struct.
 * @param container_builder Flatbuffer builder for the container message.
 * @param hr The History response struct to be placed in the container message.
 */
void create_msg_from_history_response(flatbuffers::FlatBufferBuilder &container_builder, const p2p::history_response &hr)
{
    flatbuffers::FlatBufferBuilder builder(1024);

    flatbuffers::Offset<History_Response_Message> hrmsg =
        CreateHistory_Response_Message(
            builder,
            historyledgermap_to_flatbuf_historyledgermap(builder, hr.hist_ledgers),
            (Ledger_Response_Error)hr.error);

    flatbuffers::Offset<Content> message = CreateContent(builder, Message_History_Response_Message, hrmsg.Union());
    builder.Finish(message); // Finished building message content to get serialised content.

    // Now that we have built the content message,
    // we need to sign it and place it inside a container message.
    create_containermsg_from_content(container_builder, builder, nullptr, true);
}

/**
 * Create state request message from the given state request struct.
 * @param container_builder Flatbuffer builder for the container message.
 * @param sr The state request struct to be placed in the container message.
 */
void create_msg_from_state_request(flatbuffers::FlatBufferBuilder &container_builder, const p2p::state_request &hr, std::string_view lcl)
{
    flatbuffers::FlatBufferBuilder builder(1024);

    flatbuffers::Offset<State_Request_Message> srmsg =
        CreateState_Request_Message(
            builder,
            sv_to_flatbuff_str(builder, hr.parent_path),
            hr.is_file,
            hr.block_id,
            hash_to_flatbuff_bytes(builder, hr.expected_hash));

    flatbuffers::Offset<Content> message = CreateContent(builder, Message_State_Request_Message, srmsg.Union());
    builder.Finish(message); // Finished building message content to get serialised content.

    // Now that we have built the content message,
    // we need to sign it and place it inside a container message.
    create_containermsg_from_content(container_builder, builder, lcl, true);
}

/**
 * Create content response message from the given content response.
 * @param container_builder Flatbuffer builder for the container message.
 * @param path The path of the directory.
 * @param fs_entries File or directory entries in the given parent path.
 * @param expected_hash The exptected hash of the requested path.
 * @param lcl Lcl to be include in the container msg.
 */
void create_msg_from_fsentry_response(flatbuffers::FlatBufferBuilder &container_builder, const std::string_view path, std::unordered_map<std::string, p2p::state_fs_hash_entry> &fs_entries, hasher::B2H expected_hash, std::string_view lcl)
{
    flatbuffers::FlatBufferBuilder builder(1024);

    const flatbuffers::Offset<Fs_Entry_Response> resp =
        CreateFs_Entry_Response(
            builder,
            sv_to_flatbuff_str(builder, path),
            statefshashentry_to_flatbuff_statefshashentry(builder, fs_entries));

    const flatbuffers::Offset<State_Response_Message> st_resp = CreateState_Response_Message(
        builder, State_Response_Fs_Entry_Response,
        resp.Union(),
        hash_to_flatbuff_bytes(builder, expected_hash));

    flatbuffers::Offset<Content> message = CreateContent(builder, Message_State_Response_Message, st_resp.Union());
    builder.Finish(message); // Finished building message content to get serialised content.

    // Now that we have built the content message,
    // we need to sign it and place it inside a container message.
    create_containermsg_from_content(container_builder, builder, lcl, true);
}

/**
 * Create content response message from the given content response.
 * @param container_builder Flatbuffer builder for the container message.
 * @param path The path of the directory.
 * @param hashmap Hashmap of the file
 * @param lcl Lcl to be include in the container msg.
 */
void create_msg_from_filehashmap_response(flatbuffers::FlatBufferBuilder &container_builder, std::string_view path, std::vector<uint8_t> &hashmap, std::size_t file_length, hasher::B2H expected_hash, std::string_view lcl)
{
    // todo:get a average propsal message size and allocate content builder based on that.
    flatbuffers::FlatBufferBuilder builder(1024);

    std::string_view hashmap_sv(reinterpret_cast<const char *>(hashmap.data()), hashmap.size());

    const flatbuffers::Offset<File_HashMap_Response> resp =
        CreateFile_HashMap_Response(
            builder,
            sv_to_flatbuff_str(builder, path),
            file_length,
            sv_to_flatbuff_bytes(builder, hashmap_sv));

    const flatbuffers::Offset<State_Response_Message> st_resp = CreateState_Response_Message(
        builder,
        State_Response_File_HashMap_Response,
        resp.Union(),
        hash_to_flatbuff_bytes(builder, expected_hash));

    flatbuffers::Offset<Content> message = CreateContent(builder, Message_State_Response_Message, st_resp.Union());
    builder.Finish(message); // Finished building message content to get serialised content.

    // Now that we have built the content message,
    // we need to sign it and place it inside a container message.
    create_containermsg_from_content(container_builder, builder, lcl, true);
}

/**
 * Create content response message from the given content response.
 * @param container_builder Flatbuffer builder for the container message.
 * @param block_resp Block response struct to place in the message
 * @param lcl Lcl to be include in the container message.
 */
void create_msg_from_block_response(flatbuffers::FlatBufferBuilder &container_builder, p2p::block_response &block_resp, std::string_view lcl)
{
    // todo:get a average propsal message size and allocate content builder based on that.
    flatbuffers::FlatBufferBuilder builder(1024);

    const flatbuffers::Offset<Block_Response> resp =
        CreateBlock_Response(
            builder,
            sv_to_flatbuff_str(builder, block_resp.path),
            block_resp.block_id,
            sv_to_flatbuff_bytes(builder, block_resp.data));

    const flatbuffers::Offset<State_Response_Message> st_resp = CreateState_Response_Message(
        builder,
        State_Response_Block_Response,
        resp.Union(),
        hash_to_flatbuff_bytes(builder, block_resp.hash));

    flatbuffers::Offset<Content> message = CreateContent(builder, Message_State_Response_Message, st_resp.Union());
    builder.Finish(message); // Finished building message content to get serialised content.

    // Now that we have built the content message,
    // we need to sign it and place it inside a container message.
    create_containermsg_from_content(container_builder, builder, lcl, true);
}

void create_msg_from_state_error_response(flatbuffers::FlatBufferBuilder &container_builder, std::string_view lcl)
{
    // todo:get a average propsal message size and allocate content builder based on that.
    flatbuffers::FlatBufferBuilder builder(1024);

    const flatbuffers::Offset<State_Response_Message> st_resp = CreateState_Response_Message(builder, State_Response_NONE, 0, true);

    flatbuffers::Offset<Content> message = CreateContent(builder, Message_State_Response_Message, st_resp.Union());
    builder.Finish(message); // Finished building message content to get serialised content.

    // Now that we have built the content message,
    // we need to sign it and place it inside a container message.
    create_containermsg_from_content(container_builder, builder, lcl, true);
}

/**
 * Creates a Flatbuffer container message from the given Content message.
 * @param container_builder The Flatbuffer builder to which the final container message should be written to.
 * @param content_builder The Flatbuffer builder containing the content message that should be placed
 *                        inside the container message.
 * @param sign Whether to sign the message content.
 */
void create_containermsg_from_content(
    flatbuffers::FlatBufferBuilder &container_builder, const flatbuffers::FlatBufferBuilder &content_builder, std::string_view lcl, const bool sign)
{
    const uint8_t *content_buf = content_builder.GetBufferPointer();
    const flatbuffers::uoffset_t content_size = content_builder.GetSize();

    // Create container message content from serialised content from previous step.
    const flatbuffers::Offset<flatbuffers::Vector<uint8_t>> content = container_builder.CreateVector(content_buf, content_size);

    flatbuffers::Offset<flatbuffers::Vector<uint8_t>> pubkey_offset = 0;
    flatbuffers::Offset<flatbuffers::Vector<uint8_t>> sig_offset = 0;

    flatbuffers::Offset<flatbuffers::Vector<uint8_t>> lcl_offset = 0;

    if (sign)
    {
        // Sign message content with this node's private key.
        std::string_view content_to_sign(reinterpret_cast<const char *>(content_buf), content_size);

        sig_offset = sv_to_flatbuff_bytes(container_builder, crypto::sign(content_to_sign, conf::cfg.seckey));
        pubkey_offset = sv_to_flatbuff_bytes(container_builder, conf::cfg.pubkey);
    }

    if (!lcl.empty())
        lcl_offset = sv_to_flatbuff_bytes(container_builder, lcl);

    const flatbuffers::Offset<Container> container_message = CreateContainer(
        container_builder,
        util::PEERMSG_VERSION,
        util::get_epoch_milliseconds(),
        pubkey_offset,
        lcl_offset,
        sig_offset,
        content);

    // Finish building message container to get serialised message.
    container_builder.Finish(container_message);
}

//---Conversion helpers from flatbuffers data types to std data types---//

const std::unordered_map<std::string, const std::list<usr::user_submitted_message>>
flatbuf_usermsgsmap_to_usermsgsmap(const flatbuffers::Vector<flatbuffers::Offset<UserSubmittedMessageGroup>> *fbvec)
{
    std::unordered_map<std::string, const std::list<usr::user_submitted_message>> map;
    map.reserve(fbvec->size());
    for (const UserSubmittedMessageGroup *group : *fbvec)
    {
        std::list<usr::user_submitted_message> msglist;

        for (const auto msg : *group->messages())
        {
            msglist.push_back(usr::user_submitted_message(
                flatbuff_bytes_to_sv(msg->content()),
                flatbuff_bytes_to_sv(msg->signature())));
        }

        map.emplace(flatbuff_bytes_to_sv(group->pubkey()), std::move(msglist));
    }
    return map;
}

//---Conversion helpers from std data types to flatbuffers data types---//
//---These are used in constructing Flatbuffer messages using builders---//

const flatbuffers::Offset<flatbuffers::Vector<flatbuffers::Offset<UserSubmittedMessageGroup>>>
usermsgsmap_to_flatbuf_usermsgsmap(flatbuffers::FlatBufferBuilder &builder, const std::unordered_map<std::string, const std::list<usr::user_submitted_message>> &map)
{
    std::vector<flatbuffers::Offset<UserSubmittedMessageGroup>> fbvec;
    fbvec.reserve(map.size());
    for (const auto &[pubkey, msglist] : map)
    {
        std::vector<flatbuffers::Offset<UserSubmittedMessage>> fbmsgsvec;
        for (const usr::user_submitted_message &msg : msglist)
        {
            fbmsgsvec.push_back(CreateUserSubmittedMessage(
                builder,
                sv_to_flatbuff_bytes(builder, msg.content),
                sv_to_flatbuff_bytes(builder, msg.sig)));
        }

        fbvec.push_back(CreateUserSubmittedMessageGroup(
            builder,
            sv_to_flatbuff_bytes(builder, pubkey),
            builder.CreateVector(fbmsgsvec)));
    }
    return builder.CreateVector(fbvec);
}

const std::map<uint64_t, const p2p::history_ledger>
flatbuf_historyledgermap_to_historyledgermap(const flatbuffers::Vector<flatbuffers::Offset<HistoryLedgerPair>> *fbvec)
{
    std::map<uint64_t, const p2p::history_ledger> map;

    for (const HistoryLedgerPair *pair : *fbvec)
    {
        std::list<usr::user_submitted_message> msglist;

        p2p::history_ledger ledger;

        ledger.lcl = flatbuff_bytes_to_sv(pair->ledger()->lcl());
        auto raw = pair->ledger()->raw_ledger();
        ledger.raw_ledger = std::vector<uint8_t>(raw->begin(), raw->end());

        map.emplace(pair->seq_no(), std::move(ledger));
    }
    return map;
}

const flatbuffers::Offset<flatbuffers::Vector<flatbuffers::Offset<HistoryLedgerPair>>>
historyledgermap_to_flatbuf_historyledgermap(flatbuffers::FlatBufferBuilder &builder, const std::map<uint64_t, const p2p::history_ledger> &map)
{
    std::vector<flatbuffers::Offset<HistoryLedgerPair>> fbvec;
    fbvec.reserve(map.size());
    for (auto const &[seq_no, ledger] : map)
    {
        flatbuffers::Offset<HistoryLedger> history_ledger = CreateHistoryLedger(
            builder,
            sv_to_flatbuff_bytes(builder, ledger.state),
            sv_to_flatbuff_bytes(builder, ledger.lcl),
            builder.CreateVector(ledger.raw_ledger));

        fbvec.push_back(CreateHistoryLedgerPair(
            builder,
            seq_no,
            history_ledger));
    }
    return builder.CreateVector(fbvec);
}

void flatbuf_statefshashentry_to_statefshashentry(std::unordered_map<std::string, p2p::state_fs_hash_entry> &fs_entries, const flatbuffers::Vector<flatbuffers::Offset<State_FS_Hash_Entry>> *fhashes)
{

    for (const State_FS_Hash_Entry *f_hash : *fhashes)
    {
        p2p::state_fs_hash_entry h;

        h.is_file = f_hash->is_file();
        h.hash = flatbuff_bytes_to_hash(f_hash->hash());
        fs_entries.emplace(flatbuff_str_to_sv(f_hash->path()), std::move(h));
    }
}

flatbuffers::Offset<flatbuffers::Vector<flatbuffers::Offset<State_FS_Hash_Entry>>>
statefshashentry_to_flatbuff_statefshashentry(flatbuffers::FlatBufferBuilder &builder, std::unordered_map<std::string, p2p::state_fs_hash_entry> &fs_entries)
{
    std::vector<flatbuffers::Offset<State_FS_Hash_Entry>> fbvec;
    fbvec.reserve(fs_entries.size());
    for (auto const &[path, fs_entry] : fs_entries)
    {
        flatbuffers::Offset<State_FS_Hash_Entry> state_fs_entry = CreateState_FS_Hash_Entry(
            builder,
            sv_to_flatbuff_str(builder, path),
            fs_entry.is_file,
            hash_to_flatbuff_bytes(builder, fs_entry.hash));

        fbvec.push_back(state_fs_entry);
    }
    return builder.CreateVector(fbvec);
}

} // namespace fbschema::p2pmsg