/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.epam.dlab.core;

import com.epam.dlab.exceptions.AdapterException;
import com.epam.dlab.model.aws.ReportLine;
import com.fasterxml.jackson.annotation.JsonIgnore;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.google.common.base.MoreObjects.ToStringHelper;
import org.bson.Document;

import java.util.List;

/**
 * Abstract module for read/write adapter.
 * See description of {@link ModuleBase} how to create your own adapter.
 */
public abstract class AdapterBase extends ModuleBase {
	public enum Mode {READ, WRITE}

	;

	/**
	 * Flag the header of common format should be written to target.
	 */
	@JsonProperty
	private boolean writeHeader = true;


	/**
	 * The mode of adapter read or write.
	 */
	@JsonIgnore
	private Mode mode;


	/**
	 * Default constructor for deserialization.
	 */
	public AdapterBase() {
	}

	/**
	 * Instantiate adapter for reading or writing.
	 *
	 * @param mode the mode of adapter.
	 */
	public AdapterBase(Mode mode) {
		this.mode = mode;
	}


	/**
	 * Return <b>true</b> if the header of common format should be written to target.
	 */
	public boolean isWriteHeader() {
		return writeHeader;
	}

	/**
	 * Set flag the header of common format should be written to target.
	 */
	public void setWriteHeader(boolean writeHeader) {
		this.writeHeader = writeHeader;
	}


	/**
	 * Return the mode of adapter read or write.
	 */
	public Mode getMode() {
		return mode;
	}

	/**
	 * Set the mode of adapter read or write.
	 */
	public void setMode(Mode mode) {
		this.mode = mode;
	}


	/**
	 * Open connection.
	 *
	 * @throws AdapterException if cannot open connection.
	 */
	public abstract void open() throws AdapterException;

	/**
	 * Return <b>true</b> if adapter has the multiply entries of data.
	 */
	public boolean hasMultyEntry() {
		return false;
	}

	/**
	 * Return <b>true</b> if current entry has the data.
	 */
	public boolean hasEntryData() {
		return true;
	}

	/**
	 * Open next entry if exists and return <b>true</b> otherwise return <b>false</b>.
	 *
	 * @throws AdapterException if cannot open entry.
	 */
	public boolean openNextEntry() throws AdapterException {
		return false;
	}

	/**
	 * Close connection.
	 *
	 * @throws AdapterException if cannot close connection.
	 */
	public abstract void close() throws AdapterException;

	/**
	 * Return the current processed entry name.
	 */
	public abstract String getEntryName();

	/**
	 * Read the line of data from adapter and return it.
	 *
	 * @throws AdapterException
	 */
	public abstract String readLine() throws AdapterException;

	/**
	 * Write the header of data to adapter.
	 *
	 * @param header the header of common format.
	 * @throws AdapterException
	 */
	public abstract void writeHeader(List<String> header) throws AdapterException;

	/**
	 * Write the row of data to adapter.
	 *
	 * @param row the row of common format.
	 * @return
	 * @throws AdapterException
	 */
	public abstract Document writeRow(ReportLine row) throws AdapterException;


	@Override
	public ToStringHelper toStringHelper(Object self) {
		return super.toStringHelper(self)
				.add("mode", mode)
				.add("writeHeader", isWriteHeader());
	}
}