/*
 * Copyright 2012-present the original author or authors.
 *
 * 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
 *
 *      https://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.springframework.boot.autoconfigure.r2dbc;

import java.util.function.Supplier;

import io.r2dbc.spi.ConnectionFactoryOptions;
import io.r2dbc.spi.ConnectionFactoryOptions.Builder;

import org.springframework.beans.factory.BeanCreationException;
import org.springframework.boot.r2dbc.EmbeddedDatabaseConnection;
import org.springframework.util.StringUtils;

/**
 * Initialize a {@link Builder} based on {@link R2dbcProperties}.
 *
 * @author Stephane Nicoll
 * @author Moritz Halbritter
 * @author Andy Wilkinson
 * @author Phillip Webb
 */
class ConnectionFactoryOptionsInitializer {

	/**
	 * Initialize a {@link Builder ConnectionFactoryOptions.Builder} using the specified
	 * properties.
	 * @param properties the properties to use to initialize the builder
	 * @param connectionDetails the connection details to use to initialize the builder
	 * @param embeddedDatabaseConnection the embedded connection to use as a fallback
	 * @return an initialized builder
	 * @throws ConnectionFactoryBeanCreationException if no suitable connection could be
	 * determined
	 */
	ConnectionFactoryOptions.Builder initialize(R2dbcProperties properties, R2dbcConnectionDetails connectionDetails,
			Supplier<EmbeddedDatabaseConnection> embeddedDatabaseConnection) {
		if (connectionDetails != null) {
			return connectionDetails.getConnectionFactoryOptions().mutate();
		}
		EmbeddedDatabaseConnection embeddedConnection = embeddedDatabaseConnection.get();
		if (embeddedConnection != EmbeddedDatabaseConnection.NONE) {
			return initializeEmbeddedOptions(properties, embeddedConnection);
		}
		throw connectionFactoryBeanCreationException("Failed to determine a suitable R2DBC Connection URL", null,
				embeddedConnection);
	}

	private Builder initializeEmbeddedOptions(R2dbcProperties properties,
			EmbeddedDatabaseConnection embeddedDatabaseConnection) {
		String url = embeddedDatabaseConnection.getUrl(determineEmbeddedDatabaseName(properties));
		if (url == null) {
			throw connectionFactoryBeanCreationException("Failed to determine a suitable R2DBC Connection URL", url,
					embeddedDatabaseConnection);
		}
		Builder builder = ConnectionFactoryOptions.parse(url).mutate();
		String username = determineEmbeddedUsername(properties);
		if (StringUtils.hasText(username)) {
			builder.option(ConnectionFactoryOptions.USER, username);
		}
		if (StringUtils.hasText(properties.getPassword())) {
			builder.option(ConnectionFactoryOptions.PASSWORD, properties.getPassword());
		}
		return builder;
	}

	private String determineEmbeddedDatabaseName(R2dbcProperties properties) {
		String databaseName = determineDatabaseName(properties);
		return (databaseName != null) ? databaseName : "testdb";
	}

	private String determineDatabaseName(R2dbcProperties properties) {
		if (properties.isGenerateUniqueName()) {
			return properties.determineUniqueName();
		}
		if (StringUtils.hasLength(properties.getName())) {
			return properties.getName();
		}
		return null;
	}

	private String determineEmbeddedUsername(R2dbcProperties properties) {
		String username = ifHasText(properties.getUsername());
		return (username != null) ? username : "sa";
	}

	private ConnectionFactoryBeanCreationException connectionFactoryBeanCreationException(String message,
			String r2dbcUrl, EmbeddedDatabaseConnection embeddedDatabaseConnection) {
		return new ConnectionFactoryBeanCreationException(message, r2dbcUrl, embeddedDatabaseConnection);
	}

	private String ifHasText(String candidate) {
		return (StringUtils.hasText(candidate)) ? candidate : null;
	}

	static class ConnectionFactoryBeanCreationException extends BeanCreationException {

		private final String url;

		private final EmbeddedDatabaseConnection embeddedDatabaseConnection;

		ConnectionFactoryBeanCreationException(String message, String url,
				EmbeddedDatabaseConnection embeddedDatabaseConnection) {
			super(message);
			this.url = url;
			this.embeddedDatabaseConnection = embeddedDatabaseConnection;
		}

		String getUrl() {
			return this.url;
		}

		EmbeddedDatabaseConnection getEmbeddedDatabaseConnection() {
			return this.embeddedDatabaseConnection;
		}

	}

}
