/***
    This file is part of snapcast
    Copyright (C) 2014-2021  Johannes Pohl

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
***/

#include "config.hpp"
#include "common/aixlog.hpp"
#include "common/snap_exception.hpp"
#include "common/str_compat.hpp"
#include "common/utils/file_utils.hpp"
#include <cerrno>
#include <fcntl.h>
#include <fstream>
#include <sys/stat.h>
#include <sys/types.h>

using namespace std;



Config::~Config()
{
    save();
}


void Config::init(const std::string& root_directory, const std::string& user, const std::string& group)
{
    string dir;
    if (!root_directory.empty())
        dir = root_directory;
    else if (getenv("HOME") == nullptr)
        dir = "/var/lib/snapserver/";
    else
        dir = string(getenv("HOME")) + "/.config/snapserver/";

    if (!dir.empty() && (dir.back() != '/'))
        dir += "/";

    // if (dir.find("/var/lib/snapserver") == string::npos)
    //     dir += ".config/snapserver/";

    int status = utils::file::mkdirRecursive(dir.c_str(), S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH);
    if ((status != 0) && (errno != EEXIST))
        throw SnapException("failed to create settings directory: \"" + dir + "\": " + cpt::to_string(errno));

    filename_ = dir + "server.json";
    LOG(NOTICE) << "Settings file: \"" << filename_ << "\"\n";

    int fd;
    if ((fd = open(filename_.c_str(), O_RDWR | O_CREAT, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH)) == -1)
    {
        if (errno == EACCES)
            throw std::runtime_error("failed to open file \"" + filename_ + "\", permission denied (error " + cpt::to_string(errno) + ")");
        else
            throw std::runtime_error("failed to open file \"" + filename_ + "\", error " + cpt::to_string(errno));
    }
    close(fd);

    if (!user.empty() && !group.empty())
    {
        try
        {
            utils::file::do_chown(dir, user, group);
            utils::file::do_chown(filename_, user, group);
        }
        catch (const std::exception& e)
        {
            LOG(ERROR) << "Exception in chown: " << e.what() << "\n";
        }
    }

    try
    {
        ifstream ifs(filename_, std::ifstream::in);
        if (ifs.good() && (ifs.peek() != std::ifstream::traits_type::eof()))
        {
            json j;
            ifs >> j;
            if (j.count("ConfigVersion") != 0u)
            {
                json jGroups = j["Groups"];
                for (const auto& jGroup : jGroups)
                {
                    GroupPtr group = make_shared<Group>();
                    group->fromJson(jGroup);
                    // if (client->id.empty() || getClientInfo(client->id))
                    //     continue;
                    groups.push_back(group);
                }
            }
        }
    }
    catch (const std::exception& e)
    {
        LOG(ERROR) << "Error reading config: " << e.what() << "\n";
    }
}


void Config::save()
{
    std::lock_guard<std::recursive_mutex> lock(mutex_);
    if (filename_.empty())
        init();
    std::ofstream ofs(filename_.c_str(), std::ofstream::out | std::ofstream::trunc);
    json clients = {{"ConfigVersion", 2}, {"Groups", getGroups()}};
    // ofs << std::setw(4) << clients;
    ofs << clients;
    ofs.close();
}


ClientInfoPtr Config::getClientInfo(const std::string& clientId) const
{
    if (clientId.empty())
        return nullptr;

    std::lock_guard<std::recursive_mutex> lock(mutex_);
    for (const auto& group : groups)
    {
        for (auto client : group->clients)
        {
            if (client->id == clientId)
                return client;
        }
    }

    return nullptr;
}


GroupPtr Config::addClientInfo(ClientInfoPtr client)
{
    std::lock_guard<std::recursive_mutex> lock(mutex_);
    GroupPtr group = getGroupFromClient(client);
    if (!group)
    {
        group = std::make_shared<Group>();
        group->addClient(client);
        groups.push_back(group);
    }
    return group;
}


GroupPtr Config::addClientInfo(const std::string& clientId)
{
    std::lock_guard<std::recursive_mutex> lock(mutex_);
    ClientInfoPtr client = getClientInfo(clientId);
    if (!client)
        client = make_shared<ClientInfo>(clientId);
    return addClientInfo(client);
}


GroupPtr Config::getGroup(const std::string& groupId) const
{
    std::lock_guard<std::recursive_mutex> lock(mutex_);
    for (const auto& group : groups)
    {
        if (group->id == groupId)
            return group;
    }

    return nullptr;
}


GroupPtr Config::getGroupFromClient(const std::string& clientId)
{
    std::lock_guard<std::recursive_mutex> lock(mutex_);
    for (const auto& group : groups)
    {
        for (const auto& c : group->clients)
        {
            if (c->id == clientId)
                return group;
        }
    }
    return nullptr;
}


GroupPtr Config::getGroupFromClient(ClientInfoPtr client)
{
    return getGroupFromClient(client->id);
}


json Config::getServerStatus(const json& streams) const
{
    std::lock_guard<std::recursive_mutex> lock(mutex_);
    Host host;
    host.update();
    // TODO: Set MAC and IP
    Snapserver snapserver("Snapserver", VERSION);
    json serverStatus = {{"server",
                          {{"host", host.toJson()}, // getHostName()},
                           {"snapserver", snapserver.toJson()}}},
                         {"groups", getGroups()},
                         {"streams", streams}};

    return serverStatus;
}



json Config::getGroups() const
{
    std::lock_guard<std::recursive_mutex> lock(mutex_);
    json result = json::array();
    for (const auto& group : groups)
        result.push_back(group->toJson());
    return result;
}


void Config::remove(ClientInfoPtr client)
{
    std::lock_guard<std::recursive_mutex> lock(mutex_);
    auto group = getGroupFromClient(client);
    if (!group)
        return;
    group->removeClient(client);
    if (group->empty())
        remove(group);
}


void Config::remove(GroupPtr group, bool force)
{
    std::lock_guard<std::recursive_mutex> lock(mutex_);
    if (!group)
        return;

    if (group->empty() || force)
        groups.erase(std::remove(groups.begin(), groups.end(), group), groups.end());
}


std::mutex& Config::getMutex()
{
    return client_mutex_;
}

/*
GroupPtr Config::removeFromGroup(const std::string& groupId, const std::string& clientId)
{
        GroupPtr group = getGroup(groupId);
        if (!group || (group->id != groupId))
                return group;

        auto client = getClientInfo(clientId);
        if (client)
                group->clients.erase(std::remove(group->clients.begin(), group->clients.end(), client), group->clients.end());

        addClientInfo(clientId);
        return group;
}


GroupPtr Config::setGroupForClient(const std::string& groupId, const std::string& clientId)
{
        GroupPtr oldGroup = getGroupFromClient(clientId);
        if (oldGroup && (oldGroup->id == groupId))
                return oldGroup;

        GroupPtr newGroup = getGroup(groupId);
        if (!newGroup)
                return nullptr;

        auto client = getClientInfo(clientId);
        if (!client)
                return nullptr;

        if (oldGroup)
                removeFromGroup(oldGroup->id, clientId);

        newGroup->addClient(client);
        return newGroup;
}
*/