/**
 *
 * Copyright (c) 2006-2017, Speedment, Inc. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); You may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at:
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
package com.speedment.runtime.core.internal.db;

import com.speedment.common.injector.Injector;
import static com.speedment.common.injector.State.CREATED;
import static com.speedment.common.injector.State.INITIALIZED;
import com.speedment.common.injector.annotation.ExecuteBefore;
import com.speedment.common.injector.annotation.Inject;
import com.speedment.common.injector.annotation.WithState;
import static com.speedment.common.invariant.LongRangeUtil.requireNonNegative;
import com.speedment.runtime.config.Column;
import com.speedment.runtime.core.component.DbmsHandlerComponent;
import com.speedment.runtime.core.db.DatabaseNamingConvention;
import com.speedment.runtime.core.db.DbmsColumnHandler;
import com.speedment.runtime.core.db.DbmsType;
import com.speedment.runtime.core.db.metadata.TypeInfoMetaData;
import java.util.Collections;
import java.util.List;
import static java.util.Objects.requireNonNull;
import java.util.Optional;
import java.util.Set;

/**
 *
 * @author Emil Forslund
 * @since 3.0.0
 */
public abstract class AbstractDbmsType implements DbmsType {

    private static final DbmsColumnHandler DEFAULT_COLUMN_HANDLER = () -> Column::isAutoIncrement;

    @Inject
    private Injector injector;

    @ExecuteBefore(INITIALIZED)
    void install(@WithState(CREATED) DbmsHandlerComponent component) {
        component.install(this);
    }

    @Override
    public String getResultSetTableSchema() {
        return "TABLE_SCHEM";
    }

    @Override
    public String getSchemaTableDelimiter() {
        return ".";
    }

    @Override
    public boolean isSupported() {
        return isSupported(getDriverName());
    }

    protected boolean isSupported(String driverName) {
        requireNonNull(driverName);
        try {
            Class.forName(
                driverName,
                true,
                injector.classLoader()
            );
            return true;
        } catch (final ClassNotFoundException ex) {
            try {
                // Some JavaEE servers, noteabley Tomcat, runs the driver on the
                // standard classloader.  This is the reason we need to check an
                // extra time.
                Class.forName(driverName);
                return true;
            } catch (final ClassNotFoundException ex2) {
            }
        }
        return false;
    }

    @Override
    public DatabaseNamingConvention getDatabaseNamingConvention() {
        return new DefaultDatabaseNamingConvention();
    }

    @Override
    public Set<TypeInfoMetaData> getDataTypes() {
        return Collections.emptySet();
    }

    @Override
    public Optional<String> getDefaultDbmsName() {
        return Optional.empty();
    }

    @Override
    public String getInitialQuery() {
        return "select 1 from dual";
    }

    @Override
    public DbmsColumnHandler getColumnHandler() {
        return DEFAULT_COLUMN_HANDLER;
    }

    @Override
    public SkipLimitSupport getSkipLimitSupport() {
        return SkipLimitSupport.STANDARD;
    }

    @Override
    public String applySkipLimit(String originalSql, List<Object> params, long skip, long limit) {
        requireNonNegative(skip);
        requireNonNegative(limit);

        if (skip == 0 && limit == Long.MAX_VALUE) {
            return originalSql;
        }

        final StringBuilder sb = new StringBuilder(originalSql);
        if (limit == Long.MAX_VALUE) {
            sb.append(" LIMIT 223372036854775807"); // Some big number that does not overflow
        } else {
            sb.append(" LIMIT ?");
            params.add(limit);
        }

        if (skip > 0) {
            sb.append(" OFFSET ?");
            params.add(skip);
        }

        return sb.toString();

    }

    @Override
    public SubSelectAlias getSubSelectAlias() {
        return SubSelectAlias.REQUIRED;
    }

    @Override
    public SortByNullOrderInsertion getSortByNullOrderInsertion() {
        return SortByNullOrderInsertion.PRE;
    }

}