/*
 * 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 org.jdbi.v3.sqlobject.statement;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import java.lang.reflect.Method;
import java.lang.reflect.Type;

import org.jdbi.v3.core.Handle;
import org.jdbi.v3.core.generic.GenericTypes;
import org.jdbi.v3.core.statement.Call;
import org.jdbi.v3.core.statement.OutParameters;
import org.jdbi.v3.sqlobject.SqlMethodAnnotation;

/**
 * Support for stored proc invocation. Return value must be either null or OutParameters at present.
 */
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.METHOD})
@SqlMethodAnnotation(SqlCall.Impl.class)
public @interface SqlCall {
    String value() default "";

    class Impl extends CustomizingStatementHandler<Call> {
        private final boolean returnOutParams;

        public Impl(Class<?> sqlObjectType, Method method) {
            super(sqlObjectType, method);

            Type returnType = GenericTypes.resolveType(method.getGenericReturnType(), sqlObjectType);
            Class<?> returnClass = GenericTypes.getErasedType(returnType);
            if (Void.TYPE.equals(returnClass)) {
                returnOutParams = false;
            } else if (OutParameters.class.isAssignableFrom(returnClass)) {
                returnOutParams = true;
            } else {
                throw new IllegalArgumentException("@SqlCall methods may only return null or OutParameters at present");
            }
        }

        @Override
        Call createStatement(Handle handle, String locatedSql) {
            return handle.createCall(locatedSql);
        }

        @Override
        void configureReturner(Call c, SqlObjectStatementConfiguration cfg) {
            cfg.setReturner(() -> {
                OutParameters ou = c.invoke();
                if (returnOutParams) {
                    return ou;
                } else {
                    return null;
                }
            });
        }
    }
}