// SPDX-License-Identifier: GPL-2.0-only
/*
 * Digital Voice Modem - Common Library
 * GPLv2 Open Source. Use is subject to license terms.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 *  Copyright (C) 2016 Jonathan Naylor, G4KLX
 *  Copyright (C) 2017-2022,2024,2025 Bryan Biedenkapp, N2PLL
 *  Copyright (c) 2024 Patrick McDonnell, W3AXL
 *  Copyright (c) 2024 Caleb, KO4UYJ
 *
 */
#include "PeerListLookup.h"
#include "Log.h"

using namespace lookups;

#include <fstream>
#include <algorithm>

// ---------------------------------------------------------------------------
//  Static Class Members
// ---------------------------------------------------------------------------

std::mutex PeerListLookup::s_mutex;
bool PeerListLookup::s_locked = false;

// ---------------------------------------------------------------------------
//  Macros
// ---------------------------------------------------------------------------

// Lock the table.
#define __LOCK_TABLE()                          \
    std::lock_guard<std::mutex> lock(s_mutex);  \
    s_locked = true;

// Unlock the table.
#define __UNLOCK_TABLE() s_locked = false;

// Spinlock wait for table to be read unlocked.
#define __SPINLOCK()                            \
    if (s_locked) {                             \
        while (s_locked)                        \
            Thread::sleep(2U);                  \
    }

// ---------------------------------------------------------------------------
//  Public Class Members
// ---------------------------------------------------------------------------

/* Initializes a new instance of the PeerListLookup class. */

PeerListLookup::PeerListLookup(const std::string& filename, uint32_t reloadTime, bool peerAcl) : LookupTable(filename, reloadTime),
    m_acl(peerAcl)
{
    /* stub */
}

/* Clears all entries from the list. */

void PeerListLookup::clear()
{
    __LOCK_TABLE();

    m_table.clear();

    __UNLOCK_TABLE();
}

/* Adds a new entry to the list. */

void PeerListLookup::addEntry(uint32_t id, PeerId entry)
{
    __LOCK_TABLE();

    try {
        PeerId _entry = m_table.at(id);
        // if either the alias or the enabled flag doesn't match, update the entry
        if (_entry.peerId() == id) {
            _entry = entry;
            m_table[id] = _entry;
        }
    } catch (...) {
        m_table[id] = entry;
    }

    __UNLOCK_TABLE();
}

/* Removes an existing entry from the list. */

void PeerListLookup::eraseEntry(uint32_t id)
{
    __LOCK_TABLE();

    try {
        PeerId entry = m_table.at(id);  // this value will get discarded
        (void)entry;                    // but some variants of C++ mark the unordered_map<>::at as nodiscard
        m_table.erase(id);
    } catch (...) {
        /* stub */
    }

    __UNLOCK_TABLE();
}

/* Finds a table entry in this lookup table. */

PeerId PeerListLookup::find(uint32_t id)
{
    PeerId entry;

    __SPINLOCK();

    try {
        entry = m_table.at(id);
    } catch (...) {
        entry = PeerId(0U, "", "", true);
    }

    return entry;
}

/* Commit the table. */

void PeerListLookup::commit(bool quiet)
{
    save(quiet);
}

/* Gets whether the lookup is enabled. */

bool PeerListLookup::getACL() const
{
    return m_acl;
}

/* Checks if a peer ID is in the list. */

bool PeerListLookup::isPeerInList(uint32_t id) const
{
    __SPINLOCK();

    if (m_table.find(id) != m_table.end()) {
        return true;
    }

    return false;
}

/* Checks if a peer ID is allowed based on the mode and enabled flag. */

bool PeerListLookup::isPeerAllowed(uint32_t id) const
{
    if (!m_acl) {
        return true; // if not enabled, allow all peers
    }

    return isPeerInList(id);
}

/* Gets the entire peer ID table. */

std::vector<PeerId> PeerListLookup::tableAsList() const
{
    std::vector<PeerId> ret = std::vector<PeerId>();

    __LOCK_TABLE();

    for (auto entry : m_table) {
        ret.push_back(entry.second);
    }

    __UNLOCK_TABLE();
    return ret;
}

// ---------------------------------------------------------------------------
//  Private Class Members
// ---------------------------------------------------------------------------

/* Loads the table from the passed lookup table file. */

bool PeerListLookup::load()
{
    if (m_filename.empty()) {
        return false;
    }

    std::ifstream file(m_filename, std::ifstream::in);
    if (file.fail()) {
        LogError(LOG_HOST, "Cannot open the peer ID lookup file - %s", m_filename.c_str());
        return false;
    }

    clear();

    __LOCK_TABLE();

    // read lines from file
    std::string line;
    while (std::getline(file, line)) {
        if (line.length() > 0) {
            // Skip comments with #
            if (line.at(0) == '#')
                continue;

            // tokenize line
            std::vector<std::string> parsed;
            std::stringstream ss(line);
            std::string field;
            char delim = ',';

            while (std::getline(ss, field, delim))
                parsed.push_back(field);

            // parse tokenized line
            uint32_t id = ::atoi(parsed[0].c_str());

            // parse optional alias field (at end of line to avoid breaking change with existing lists)
            std::string alias = "";
            if (parsed.size() >= 4)
                alias = parsed[3].c_str();

            // parse peer link flag
            bool peerReplica = false;
            if (parsed.size() >= 3)
                peerReplica = ::atoi(parsed[2].c_str()) == 1;

            // parse can request keys flag
            bool canRequestKeys = false;
            if (parsed.size() >= 5)
                canRequestKeys = ::atoi(parsed[4].c_str()) == 1;

            // parse can issue inhibit flag
            bool canIssueInhibit = false;
            if (parsed.size() >= 6)
                canIssueInhibit = ::atoi(parsed[5].c_str()) == 1;

            // parse can issue inhibit flag
            bool hasCallPriority = false;
            if (parsed.size() >= 7)
                hasCallPriority = ::atoi(parsed[6].c_str()) == 1;

            // parse jitter buffer enabled flag
            bool jitterBufferEnabled = false;
            if (parsed.size() >= 8)
                jitterBufferEnabled = ::atoi(parsed[7].c_str()) == 1;

            // parse jitter buffer max size
            uint16_t jitterBufferMaxSize = DEFAULT_JITTER_MAX_SIZE;
            if (parsed.size() >= 9)
                jitterBufferMaxSize = (uint16_t)::atoi(parsed[8].c_str());

            // parse jitter buffer max wait time
            uint32_t jitterBufferMaxWait = DEFAULT_JITTER_MAX_WAIT;
            if (parsed.size() >= 10)
                jitterBufferMaxWait = (uint32_t)::atoi(parsed[9].c_str());

            // parse optional password
            std::string password = "";
            if (parsed.size() >= 2)
                password = parsed[1].c_str();

            // load into table
            PeerId entry = PeerId(id, alias, password, false);
            entry.peerReplica(peerReplica);
            entry.canRequestKeys(canRequestKeys);
            entry.canIssueInhibit(canIssueInhibit);
            entry.hasCallPriority(hasCallPriority);
            entry.jitterBufferEnabled(jitterBufferEnabled);
            entry.jitterBufferMaxSize(jitterBufferMaxSize);
            entry.jitterBufferMaxWait(jitterBufferMaxWait);

            m_table[id] = entry;

            // log depending on what was loaded
            LogInfoEx(LOG_HOST, "Loaded peer ID %u%s into peer ID lookup table, %s%s%s%s%s%s", id,
                (!alias.empty() ? (" (" + alias + ")").c_str() : ""),
                (!password.empty() ? "using unique peer password" : "using master password"),
                (peerReplica) ? ", Replication Enabled" : "",
                (canRequestKeys) ? ", Can Request Keys" : "",
                (canIssueInhibit) ? ", Can Issue Inhibit" : "",
                (hasCallPriority) ? ", Has Call Priority" : "",
                (jitterBufferEnabled) ? ", Jitter Buffer Enabled" : "");
        }
    }

    file.close();
    __UNLOCK_TABLE();

    size_t size = m_table.size();
    if (size == 0U)
        return false;

    uint64_t now = std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::system_clock::now().time_since_epoch()).count();
    m_lastLoadTime = now;

    LogInfoEx(LOG_HOST, "Loaded %lu entries into peer list lookup table", size);
    return true;
}

/* Saves the table to the passed lookup table file. */

bool PeerListLookup::save(bool quiet)
{
    if (m_filename.empty()) {
        return false;
    }

    std::ofstream file(m_filename, std::ofstream::out);
    if (file.fail()) {
        LogError(LOG_HOST, "Cannot open the peer ID lookup file - %s", m_filename.c_str());
        return false;
    }

    if (!quiet)
        LogInfoEx(LOG_HOST, "Saving peer lookup file to %s", m_filename.c_str());

    // Counter for lines written
    unsigned int lines = 0;

    std::lock_guard<std::mutex> lock(s_mutex);

    // String for writing
    std::string line;
    // iterate over each entry in the RID lookup and write it to the open file
    for (auto& entry: m_table) {
        // get the parameters
        uint32_t peerId = entry.first;
        std::string alias = entry.second.peerAlias();
        std::string password = entry.second.peerPassword();

        // format into a string
        line = std::to_string(peerId) + ",";

        // add the password if we have one
        if (password.length() > 0) {
            line += password;
        }
        line += ",";

        // add peer replication flag
        bool peerReplica = entry.second.peerReplica();
        if (peerReplica) {
            line += "1,";
        } else {
            line += "0,";
        }

        // add alias if we have one
        if (alias.length() > 0) {
            line += alias;
            line += ",";
        } else {
            line += ",";
        }

        // add canRequestKeys flag
        bool canRequestKeys = entry.second.canRequestKeys();
        if (canRequestKeys) {
            line += "1,";
        } else {
            line += "0,";
        }

        // add canIssueInhibit flag
        bool canIssueInhibit = entry.second.canIssueInhibit();
        if (canIssueInhibit) {
            line += "1,";
        } else {
            line += "0,";
        }

        // add hasCallPriority flag
        bool hasCallPriority = entry.second.hasCallPriority();
        if (hasCallPriority) {
            line += "1,";
        } else {
            line += "0,";
        }

        // add jitter buffer enabled flag
        bool jitterBufferEnabled = entry.second.jitterBufferEnabled();
        if (jitterBufferEnabled) {
            line += "1,";
        } else {
            line += "0,";
        }

        // add jitter buffer max size
        uint16_t jitterBufferMaxSize = entry.second.jitterBufferMaxSize();
        line += std::to_string(jitterBufferMaxSize) + ",";

        // add jitter buffer max wait time
        uint32_t jitterBufferMaxWait = entry.second.jitterBufferMaxWait();
        line += std::to_string(jitterBufferMaxWait);

        line += "\n";
        file << line;
        lines++;
    }

    file.close();

    if (lines != m_table.size())
        return false;

    if (!quiet)
        LogInfoEx(LOG_HOST, "Saved %u entries to lookup table file %s", lines, m_filename.c_str());

    return true;
}