/*******************************************************************************
 * Copyright (c) 2016 EclipseSource.
 *
 * Distributed under MIT license
 * See https://github.com/ralfstx/minimal-json/blob/master/LICENSE
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 ******************************************************************************/
package net.sourceforge.plantuml.json;

import java.io.IOException;
import java.io.Writer;
import java.util.Arrays;

/**
 * Enables human readable JSON output by inserting whitespace between
 * values.after commas and colons. Example:
 *
 * <pre>
 * jsonValue.writeTo(writer, PrettyPrint.singleLine());
 * </pre>
 */
public class PrettyPrint extends WriterConfig {

	private final char[] indentChars;

	protected PrettyPrint(char[] indentChars) {
		this.indentChars = indentChars;
	}

	/**
	 * Print every value on a separate line. Use tabs (<code>\t</code>) for
	 * indentation.
	 *
	 * @return A PrettyPrint instance for wrapped mode with tab indentation
	 */
	public static PrettyPrint singleLine() {
		return new PrettyPrint(null);
	}

	/**
	 * Print every value on a separate line. Use the given number of spaces for
	 * indentation.
	 *
	 * @param number the number of spaces to use
	 * @return A PrettyPrint instance for wrapped mode with spaces indentation
	 */
	public static PrettyPrint indentWithSpaces(int number) {
		if (number < 0) {
			throw new IllegalArgumentException("number is negative");
		}
		char[] chars = new char[number];
		Arrays.fill(chars, ' ');
		return new PrettyPrint(chars);
	}

	/**
	 * Do not break lines, but still insert whitespace between values.
	 *
	 * @return A PrettyPrint instance for single-line mode
	 */
	public static PrettyPrint indentWithTabs() {
		return new PrettyPrint(new char[] { '\t' });
	}

	@Override
	protected JsonWriter createWriter(Writer writer) {
		return new PrettyPrintWriter(writer, indentChars);
	}

	private static class PrettyPrintWriter extends JsonWriter {

		private final char[] indentChars;
		private int indent;

		private PrettyPrintWriter(Writer writer, char[] indentChars) {
			super(writer);
			this.indentChars = indentChars;
		}

		@Override
		protected void writeArrayOpen() throws IOException {
			indent++;
			writer.write('[');
			writeNewLine();
		}

		@Override
		protected void writeArrayClose() throws IOException {
			indent--;
			writeNewLine();
			writer.write(']');
		}

		@Override
		protected void writeArraySeparator() throws IOException {
			writer.write(',');
			if (!writeNewLine()) {
				writer.write(' ');
			}
		}

		@Override
		protected void writeObjectOpen() throws IOException {
			indent++;
			writer.write('{');
			writeNewLine();
		}

		@Override
		protected void writeObjectClose() throws IOException {
			indent--;
			writeNewLine();
			writer.write('}');
		}

		@Override
		protected void writeMemberSeparator() throws IOException {
			writer.write(':');
			writer.write(' ');
		}

		@Override
		protected void writeObjectSeparator() throws IOException {
			writer.write(',');
			if (!writeNewLine()) {
				writer.write(' ');
			}
		}

		private boolean writeNewLine() throws IOException {
			if (indentChars == null) {
				return false;
			}
			writer.write('\n');
			for (int i = 0; i < indent; i++) {
				writer.write(indentChars);
			}
			return true;
		}

	}

}
