// Squawk messenger.
// Copyright (C) 2019  Yury Gubich <blue@macaw.me>
//
// 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/>.

#ifndef CORE_TABLE_HPP
#define CORE_TABLE_HPP

#include "table.h"
#include "exceptions.h"

template<class K, class V>
DataBase::Table<K, V>::Table(const std::string& p_name, DataBase* parent):
    _Table(p_name, parent),
    keySerializer(new Serializer<K>()),
    valueSerializer(new Serializer<V>())
{
}

template<class K, class V>
DataBase::Table<K, V>::~Table() {
    delete valueSerializer;
    delete keySerializer;
}

template<class K, class V>
void DataBase::Table<K, V>::addRecord(const K& key, const V& value) {
    if (!db->opened) {
        throw Closed("addRecord", db->name, name);
    }

    MDB_val lmdbKey = keySerializer->setData(key);
    MDB_val lmdbData = valueSerializer->setData(value);
    MDB_txn *txn;
    mdb_txn_begin(db->environment, NULL, 0, &txn);
    int rc;
    rc = mdb_put(txn, dbi, &lmdbKey, &lmdbData, MDB_NOOVERWRITE);
    if (rc != 0) {
        mdb_txn_abort(txn);
        if (rc == MDB_KEYEXIST) {
            throw Exist(toString(key), db->name, name);
        } else {
            throw Unknown(db->name, mdb_strerror(rc), name);
        }
    } else {
        mdb_txn_commit(txn);
    }
}



template<class K, class V>
void DataBase::Table<K, V>::changeRecord(const K& key, const V& value) {
    if (!db->opened) {
        throw Closed("changeRecord", db->name, name);
    }

    MDB_val lmdbKey = keySerializer->setData(key);
    MDB_val lmdbData = valueSerializer->setData(value);
    MDB_txn *txn;
    mdb_txn_begin(db->environment, NULL, 0, &txn);
    int rc;
    rc = mdb_put(txn, dbi, &lmdbKey, &lmdbData, 0);
    if (rc != 0) {
        mdb_txn_abort(txn);
        if (rc) {
            throw Unknown(db->name, mdb_strerror(rc), name);
        }
    } else {
        mdb_txn_commit(txn);
    }
}

template<class K, class V>
V DataBase::Table<K, V>::getRecord(const K& key) const {
    if (!db->opened) {
        throw Closed("getRecord", db->name, name);
    }

    MDB_val lmdbKey = keySerializer->setData(key);
    MDB_val lmdbData;

    MDB_txn *txn;
    int rc;
    mdb_txn_begin(db->environment, NULL, MDB_RDONLY, &txn);
    rc = mdb_get(txn, dbi, &lmdbKey, &lmdbData);
    if (rc) {
        mdb_txn_abort(txn);
        if (rc == MDB_NOTFOUND) {
            throw NotFound(toString(key), db->name, name);
        } else {
            throw Unknown(db->name, mdb_strerror(rc), name);
        }
    } else {
        V value = valueSerializer->deserialize(lmdbData);
        mdb_txn_abort(txn);

        return value;
    }
}

template<class K, class V>
void DataBase::Table<K, V>::removeRecord(const K& key) {
    if (!db->opened) {
        throw Closed("removeRecord", db->name, name);
    }

    MDB_val lmdbKey = keySerializer->setData(key);

    MDB_txn *txn;
    int rc;
    mdb_txn_begin(db->environment, NULL, 0, &txn);
    rc = mdb_del(txn, dbi, &lmdbKey, NULL);
    if (rc) {
        mdb_txn_abort(txn);
        if (rc == MDB_NOTFOUND) {
            throw NotFound(toString(key), db->name, name);
        } else {
            throw Unknown(db->name, mdb_strerror(rc), name);
        }
    } else {
        mdb_txn_commit(txn);
    }
}

template<class K, class V>
int DataBase::Table<K, V>::createTable(MDB_txn* transaction) {
    return makeTable<K>(transaction);
}

template<class K>
inline int DataBase::_Table::makeTable(MDB_txn* transaction) {
    return mdb_dbi_open(transaction, name.c_str(), MDB_CREATE, &dbi);
}

template<>
inline int DataBase::_Table::makeTable<uint32_t>(MDB_txn* transaction) {
    return mdb_dbi_open(transaction, name.c_str(), MDB_CREATE | MDB_INTEGERKEY, &dbi);
}

template<class T>
inline std::string DataBase::_Table::toString(const T& value) {
    return std::to_string(value);
}

template<>
inline std::string DataBase::_Table::toString(const QString& value) {
    return value.toStdString();
}

#endif //CORE_TABLE_HPP