* Geekttrss is a RSS feed reader application on the Android Platform.

 *

 *

 * This file is part of Geekttrss.

 *

 * Geekttrss 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.

 *

 * Geekttrss 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 Geekttrss.  If not, see <http://www.gnu.org/licenses/>.

 */

package com.geekorum.ttrss.data

import androidx.room.Dao

import androidx.room.Delete

import androidx.room.Insert

import androidx.room.OnConflictStrategy

import androidx.room.Query

import kotlinx.coroutines.runBlocking

/**

 * Dao to read/modify transactions.

 */

@Dao

abstract class TransactionsDao {

    @Insert(onConflict = OnConflictStrategy.REPLACE)

    abstract suspend fun insertTransaction(transaction: Transaction)

    @Delete

    abstract suspend fun deleteTransactions(transactions: Collection<Transaction>)

    @Query("SELECT * FROM transactions WHERE article_id=:articleId AND field=:field")

    abstract suspend fun getTransactionForArticleAndType(articleId: Long, field: String): List<Transaction>

    /**

     * Insert a unique transaction for a [Transaction.articleId] [Transaction.field] pair.

     *

     * @param transaction

     */

    @androidx.room.Transaction

    open fun insertUniqueTransaction(transaction: Transaction) = runBlocking {

        val existingTransactions = getTransactionForArticleAndType(transaction.articleId, transaction.field)

        deleteTransactions(existingTransactions)

        insertTransaction(transaction)

    }

}