// 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/>.

#include "storage.h"

LMDBDataBase::StorageBase::StorageBase(const std::string& p_name, DataBase* parent):
    dbi(),
    db(parent),
    name(p_name)
{}

LMDBDataBase::StorageBase::~StorageBase() {}

void LMDBDataBase::StorageBase::drop() {
    ensureOpened(dropMethodName);

    MDB_txn *txn;
    int rc = mdb_txn_begin(db->environment, NULL, 0, &txn);
    if (rc) {
        mdb_txn_abort(txn);
        throw Unknown(db->name, mdb_strerror(rc), name);
    }
    rc = drop(txn);
    if (rc) {
        mdb_txn_abort(txn);
        throw Unknown(db->name, mdb_strerror(rc), name);
    }

    mdb_txn_commit(txn);
}

int LMDBDataBase::StorageBase::drop(MDB_txn* transaction) {
    return mdb_drop(transaction, dbi, 0);
}

const std::string & LMDBDataBase::StorageBase::dbName() const {
    return db->name;}

bool LMDBDataBase::StorageBase::isDBOpened() const {
    return db->opened;}

void LMDBDataBase::StorageBase::ensureOpened(const std::string& methodName) const {
    if (!db->opened)
        throw Closed(methodName, db->name, name);
}

uint32_t LMDBDataBase::StorageBase::count() const {
    ensureOpened(countMethodName);

    MDB_txn *txn;
    MDB_stat stat;
    int rc = mdb_txn_begin(db->environment, NULL, MDB_RDONLY, &txn);
    if (rc) {
        mdb_txn_abort(txn);
        throw Unknown(db->name, mdb_strerror(rc), name);
    }

    rc = mdb_stat(txn, dbi, &stat);
    if (rc) {
        mdb_txn_abort(txn);
        throw Unknown(db->name, mdb_strerror(rc), name);
    }
    uint32_t amount = stat.ms_entries;
    mdb_txn_abort(txn);
    return amount;
}

void LMDBDataBase::StorageBase::throwDuplicateOrUnknown(int rc, TransactionID txn, const std::string& key) const {
    abortTransaction(txn);
    if (rc == MDB_KEYEXIST)
        throwDuplicate(key);
    else
        throwUnknown(rc);
}

void LMDBDataBase::StorageBase::throwNotFoundOrUnknown(int rc, LMDBDataBase::TransactionID txn, const std::string& key) const {
    abortTransaction(txn);
    if (rc == MDB_NOTFOUND)
        throwNotFound(key);
    else
        throwUnknown(rc);
}

void LMDBDataBase::StorageBase::throwUnknown(int rc, LMDBDataBase::TransactionID txn) const {
    abortTransaction(txn);
    throwUnknown(rc);
}

void LMDBDataBase::StorageBase::throwUnknown(int rc) const {
    throw Unknown(db->name, mdb_strerror(rc), name);}

void LMDBDataBase::StorageBase::throwDuplicate(const std::string& key) const {
    throw Exist(key, db->name, name);}

void LMDBDataBase::StorageBase::throwNotFound(const std::string& key) const {
    throw NotFound(key, db->name, name);}

LMDBDataBase::TransactionID LMDBDataBase::StorageBase::beginReadOnlyTransaction() const {
    return db->beginReadOnlyTransaction(name);}

LMDBDataBase::TransactionID LMDBDataBase::StorageBase::beginTransaction() const {
    return db->beginTransaction(name);}

void LMDBDataBase::StorageBase::abortTransaction(LMDBDataBase::TransactionID id) const {
    db->abortTransaction(id);}

void LMDBDataBase::StorageBase::commitTransaction(LMDBDataBase::TransactionID id) const {
    db->commitTransaction(id);}