<?xml version="1.0" encoding="utf-8"?>
<databaseChangeLog
    xmlns="http://www.liquibase.org/xml/ns/dbchangelog"
    xmlns:ext="http://www.liquibase.org/xml/ns/dbchangelog-ext"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.liquibase.org/xml/ns/dbchangelog http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-3.5.xsd
                        http://www.liquibase.org/xml/ns/dbchangelog-ext http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-ext.xsd">

    <!-- Table for historical Asset data. -->
    <changeSet id="20190507193200-1" author="mhierweck,mhoennig" dbms="postgresql">
        <createTable tableName="asset_history">

            <!-- history-related columns -->

            <column name="history_id" type="bigint" autoIncrement="true">
                <constraints primaryKey="true" unique="true" nullable="false"/>
            </column>

            <column name="history_transaction" type="bigint">
                <constraints nullable="false" />
            </column>

            <column name="history_tombstone" type="bool">
                <constraints nullable="false" />
            </column>

            <!-- id-column like in base table, but no primary key nor unique -->
            <column name="id" type="bigint">
                <constraints primaryKey="true" nullable="false"/>
            </column>

            <!-- all following columns like in base table, dropping unique constraints -->
            <column name="document_date" type="date">
                <constraints nullable="false" />
            </column>

            <column name="value_date" type="date">
                <constraints nullable="false" />
            </column>

            <column name="action" type="varchar(255)">
                <constraints nullable="false" />
            </column>

            <column name="amount" type="decimal(10,2)">
                <constraints nullable="false" />
            </column>

            <column name="remark" type="varchar(160)">
                <constraints nullable="true" />
            </column>

            <column name="membership_id" type="bigint">
                <constraints nullable="false" />
            </column>

        </createTable>

    </changeSet>

    <changeSet id="20190507193200-2" author="mhierweck,mhoennig" dbms="postgresql">

        <addForeignKeyConstraint baseColumnNames="history_transaction"
                                 baseTableName="asset_history"
                                 constraintName="fk_asset_history_transaction"
                                 referencedColumnNames="history_transaction"
                                 referencedTableName="history"/>

    </changeSet>

    <changeSet id="20190507193200-3" author="mhierweck,mhoennig" dbms="postgresql">
        <createProcedure>
            CREATE TRIGGER asset_historicize
            AFTER INSERT OR DELETE OR UPDATE ON asset
            FOR EACH ROW EXECUTE PROCEDURE historicize();
        </createProcedure>
        <rollback>
            DROP TRIGGER asset_historicize
        </rollback>
    </changeSet>

    <changeSet id="20190507193200-4" author="mhierweck,mhoennig" dbms="postgresql">
        <createView viewName="asset_history_view" replaceIfExists="true">
            SELECT *
                FROM asset_history
               WHERE history_id IN (
                    SELECT max(history_id) AS history_id
                      FROM asset_history
                     WHERE history_transaction &lt;= current_setting('history.transaction')::bigint
                     GROUP BY id) -- assets are not deletable, thus id is enough
        </createView>
    </changeSet>

</databaseChangeLog>


