package net.minecraft.util;

import com.google.common.collect.Lists;
import java.io.IOException;
import java.io.Writer;
import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import org.apache.commons.lang3.StringEscapeUtils;
import org.jetbrains.annotations.Nullable;

public class CsvOutput {
	private static final String LINE_SEPARATOR = "\r\n";
	private static final String FIELD_SEPARATOR = ",";
	private final Writer output;
	private final int columnCount;

	CsvOutput(Writer output, List<String> firstRow) throws IOException {
		this.output = output;
		this.columnCount = firstRow.size();
		this.writeLine(firstRow.stream());
	}

	public static CsvOutput.Builder builder() {
		return new CsvOutput.Builder();
	}

	public void writeRow(Object... data) throws IOException {
		if (data.length != this.columnCount) {
			throw new IllegalArgumentException("Invalid number of columns, expected " + this.columnCount + ", but got " + data.length);
		} else {
			this.writeLine(Stream.of(data));
		}
	}

	private void writeLine(Stream<?> data) throws IOException {
		this.output.write((String)data.map(CsvOutput::getStringValue).collect(Collectors.joining(",")) + "\r\n");
	}

	private static String getStringValue(@Nullable Object value) {
		return StringEscapeUtils.escapeCsv(value != null ? value.toString() : "[null]");
	}

	public static class Builder {
		private final List<String> headers = Lists.<String>newArrayList();

		public CsvOutput.Builder addColumn(String header) {
			this.headers.add(header);
			return this;
		}

		public CsvOutput build(Writer output) throws IOException {
			return new CsvOutput(output, this.headers);
		}
	}
}