/*******************************************************************************
 * Breakout Cave Survey Visualizer
 *
 * Copyright (C) 2014 James Edwards
 *
 * jedwards8 at fastmail dot fm
 *
 * This program is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software
 * Foundation; either version 2 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 51
 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *******************************************************************************/
package org.andork.collect;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Iterator;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.stream.Stream;
import java.util.stream.StreamSupport;

import org.andork.util.IterableUtils;

/**
 * Absolutely the easiest way to read a file or URL line-by-line:
 *
 * <pre>
 * for (String line : new LineIterable("test.txt")) {
 * 	System.out.println(line);
 * }
 * </pre>
 *
 * @author andy.edwards
 */
public class InputStreamLineIterable implements Iterable<String> {
	public static Stream<Matcher> grep(File in, Pattern p) {
		return grep(StreamSupport.stream(LineIterable.linesOf(in).spliterator(), false), p);
	}

	public static Stream<Matcher> grep(InputStream in, Pattern p) {
		return grep(StreamSupport.stream(linesOf(in).spliterator(), false), p);
	}

	public static Stream<Matcher> grep(Stream<String> in, Pattern p) {
		return in.map(s -> {
			Matcher m = p.matcher(s);
			return m.find() ? m : null;
		}).filter(m -> m != null);
	}

	public static Stream<Matcher> grep(String diamondArg, Pattern p) {
		return grep(StreamSupport.stream(perlDiamond(diamondArg).spliterator(), false), p);
	}

	public static Stream<Path> grepFiles(String expr) {
		int starIndex = expr.indexOf('*');
		if (starIndex < 0) {
			return Stream.<Path> builder().add(Paths.get(expr)).build();
		}
		Path basePath = Paths.get(expr.substring(0, starIndex));
		String regex = "^.*" + expr.substring(starIndex).replaceAll("\\*", ".*") + "$";

		try {
			return Files.find(basePath, 10, (path, attributes) -> path.toString().matches(regex));
		} catch (IOException e) {
			e.printStackTrace();
			return Stream.<Path> builder().build();
		}
	}

	public static InputStreamLineIterable linesOf(InputStream in) {
		return new InputStreamLineIterable(in);
	}

	public static Iterable<String> perlDiamond(int startIndex, String... args) {
		if (args.length - startIndex == 0) {
			return new InputStreamLineIterable(System.in);
		} else {
			IterableChain<String> chain = new IterableChain<String>();
			for (int i = startIndex; i < args.length; i++) {
				try {
					FileInputStream in = new FileInputStream(args[i]);
					chain = chain.add(new InputStreamLineIterable(in));
				} catch (Exception ex) {

				}
			}
			return chain;
		}
	}

	public static Iterable<String> perlDiamond(String... args) {
		if (args.length == 0) {
			return new InputStreamLineIterable(System.in);
		} else {
			IterableChain<String> chain = new IterableChain<String>();
			for (String s : args) {
				for (Path path : IterableUtils.iterable(grepFiles(s).iterator())) {
					try {
						FileInputStream in = new FileInputStream(path.toFile());
						chain = chain.add(new InputStreamLineIterable(in));
					} catch (Exception ex) {

					}
				}
			}
			return chain;
		}
	}

	InputStream in;

	public InputStreamLineIterable(InputStream in) {
		this.in = in;
	}

	@Override
	public Iterator<String> iterator() {
		return new LineIterator(in);
	}
}