// 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 LMDBDATABASE_STORAGE_HPP
#define LMDBDATABASE_STORAGE_HPP

#include "storage.h"
#include "exceptions.h"

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

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

template<class K, class V>
void LMDBDataBase::Storage<K, V>::addRecord(const K& key, const V& value) {
    ensureOpened(addRecordMethodName);

    TransactionID txn = beginTransaction();
    MDB_val lmdbKey = keySerializer->setData(key);
    MDB_val lmdbData = valueSerializer->setData(value);

    int rc = mdb_put(txn, dbi, &lmdbKey, &lmdbData, MDB_NOOVERWRITE);
    if (rc != MDB_SUCCESS)
        throwDuplicateOrUnknown(rc, txn, toString(key));

    commitTransaction(txn);
}

template<class K, class V>
bool LMDBDataBase::Storage<K, V>::forceRecord(const K& key, const V& value) {
    ensureOpened(forceRecordMethodName);

    bool added;
    TransactionID txn = beginTransaction();
    MDB_val lmdbKey = keySerializer->setData(key);
    MDB_val lmdbData;

    int rc = mdb_get(txn, dbi, &lmdbKey, &lmdbData);
    switch (rc) {
        case MDB_SUCCESS:
            added = false;
            break;
        case MDB_NOTFOUND:
            added = true;
            break;
        default:
            added = false;
            throwUnknown(rc, txn);
    }

    lmdbData = valueSerializer->setData(value);
    rc = mdb_put(txn, dbi, &lmdbKey, &lmdbData, 0);
    if (rc != MDB_SUCCESS)
        throwUnknown(rc, txn);

    commitTransaction(txn);

    return added;
}

template<class K, class V>
void LMDBDataBase::Storage<K, V>::changeRecord(const K& key, const V& value) {
    ensureOpened(changeRecordMethodName);

    TransactionID txn = beginTransaction();
    MDB_val lmdbKey = keySerializer->setData(key);
    MDB_val lmdbData = valueSerializer->setData(value);

    int rc = mdb_put(txn, dbi, &lmdbKey, &lmdbData, 0);
    if (rc != MDB_SUCCESS)
        throwUnknown(rc, txn);

    commitTransaction(txn);
}

template<class K, class V>
V LMDBDataBase::Storage<K, V>::getRecord(const K& key) const {
    ensureOpened(getRecordMethodName);

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

    int rc = mdb_get(txn, dbi, &lmdbKey, &lmdbData);
    if (rc != MDB_SUCCESS)
        throwNotFoundOrUnknown(rc, txn, toString(key));

    V value = valueSerializer->deserialize(lmdbData);
    abortTransaction(txn);

    return value;
}

template<class K, class V>
bool LMDBDataBase::Storage<K, V>::checkRecord(const K& key) const {
    ensureOpened(checkRecordMethodName);

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

    int rc = mdb_get(txn, dbi, &lmdbKey, &lmdbData);
    abortTransaction(txn);

    if (rc == MDB_SUCCESS)
        return true;

    if (rc != MDB_NOTFOUND)
        throwUnknown(rc);

    return false;
}

template<class K, class V>
std::map<K, V> LMDBDataBase::Storage<K, V>::readAll() const {
    ensureOpened(readAllMethodName);

    TransactionID txn = beginReadOnlyTransaction();
    std::map<K, V> result;
    MDB_cursor* cursor;
    MDB_val lmdbKey, lmdbData;

    int rc = mdb_cursor_open(txn, dbi, &cursor);
    if (rc != MDB_SUCCESS)
        throwUnknown(rc, txn);

    rc = mdb_cursor_get(cursor, &lmdbKey, &lmdbData, MDB_FIRST);
    while (rc == MDB_SUCCESS) {
        K key = keySerializer->deserialize(lmdbKey);
        V value = valueSerializer->deserialize(lmdbData);
        result.insert(std::make_pair(key, value));
        rc = mdb_cursor_get(cursor, &lmdbKey, &lmdbData, MDB_NEXT);
    }

    abortTransaction(txn);
    if (rc != MDB_NOTFOUND)
        throwUnknown(rc);

    return result;
}

template<class K, class V>
void LMDBDataBase::Storage<K, V>::replaceAll(const std::map<K, V>& data) {
    ensureOpened(replaceAllMethodName);

    TransactionID txn = beginTransaction();
    int rc = drop(txn);
    if (rc != MDB_SUCCESS)
        throwUnknown(rc, txn);

    MDB_val lmdbKey, lmdbData;
    for (const std::pair<const K, V>& pair : data) {
        lmdbKey = keySerializer->setData(pair.first);
        lmdbData = valueSerializer->setData(pair.second);

        rc = mdb_put(txn, dbi, &lmdbKey, &lmdbData, MDB_NOOVERWRITE);
        if (rc != MDB_SUCCESS)
            throwUnknown(rc, txn);
    }
    commitTransaction(txn);
}

template<class K, class V>
uint32_t LMDBDataBase::Storage<K, V>::addRecords(const std::map<K, V>& data, bool overwrite) {
    ensureOpened(addRecordsMethodName);

    TransactionID txn = beginTransaction();
    MDB_val lmdbKey, lmdbData;
    int rc;

    for (const std::pair<const K, V>& pair : data) {
        lmdbKey = keySerializer->setData(pair.first);
        lmdbData = valueSerializer->setData(pair.second);

        rc = mdb_put(txn, dbi, &lmdbKey, &lmdbData, overwrite ? 0 : MDB_NOOVERWRITE);
        if (rc != MDB_SUCCESS)
            throwUnknown(rc, txn);
    }

    MDB_stat stat;
    rc = mdb_stat(txn, dbi, &stat);
    if (rc != MDB_SUCCESS)
        throwUnknown(rc, txn);

    uint32_t amount = stat.ms_entries;
    commitTransaction(txn);

    return amount;
}

template<class K, class V>
void LMDBDataBase::Storage<K, V>::removeRecord(const K& key) {
    ensureOpened(removeRecordMethodName);

    TransactionID txn = beginTransaction();
    MDB_val lmdbKey = keySerializer->setData(key);
    int rc = mdb_del(txn, dbi, &lmdbKey, NULL);
    if (rc != MDB_SUCCESS)
        throwNotFoundOrUnknown(rc, txn, toString(key));

    commitTransaction(txn);
}

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

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

template<>
inline int LMDBDataBase::StorageBase::makeTable<uint64_t>(MDB_txn* transaction) {
    return mdb_dbi_open(transaction, name.c_str(), MDB_CREATE | MDB_INTEGERKEY, &dbi);
}

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

template<>
inline int LMDBDataBase::StorageBase::makeTable<uint16_t>(MDB_txn* transaction) {
    return mdb_dbi_open(transaction, name.c_str(), MDB_CREATE | MDB_INTEGERKEY, &dbi);
}

template<>
inline int LMDBDataBase::StorageBase::makeTable<uint8_t>(MDB_txn* transaction) {
    return mdb_dbi_open(transaction, name.c_str(), MDB_CREATE | MDB_INTEGERKEY, &dbi);
}

template<>
inline int LMDBDataBase::StorageBase::makeTable<int64_t>(MDB_txn* transaction) {
    return mdb_dbi_open(transaction, name.c_str(), MDB_CREATE | MDB_INTEGERKEY, &dbi);
}

template<>
inline int LMDBDataBase::StorageBase::makeTable<int32_t>(MDB_txn* transaction) {
    return mdb_dbi_open(transaction, name.c_str(), MDB_CREATE | MDB_INTEGERKEY, &dbi);
}

template<>
inline int LMDBDataBase::StorageBase::makeTable<int16_t>(MDB_txn* transaction) {
    return mdb_dbi_open(transaction, name.c_str(), MDB_CREATE | MDB_INTEGERKEY, &dbi);
}

template<>
inline int LMDBDataBase::StorageBase::makeTable<int8_t>(MDB_txn* transaction) {
    return mdb_dbi_open(transaction, name.c_str(), MDB_CREATE | MDB_INTEGERKEY, &dbi);
}

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

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

template<>
inline std::string LMDBDataBase::StorageBase::toString(const std::string& value) {
    return value;
}

#endif //LMDBDATABASE_STORAGE_HPP