package net.osmand.util;


import java.io.Closeable;
import java.io.EOFException;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import net.osmand.PlatformUtil;

import org.apache.commons.logging.Log;


/**
 * Basic algorithms that are not in jdk 
 */
public class Algorithms {
	private static final int BUFFER_SIZE = 1024;
	private static final Log log = PlatformUtil.getLog(Algorithms.class);
	
	public static boolean isEmpty(String s){
		return s == null || s.length() == 0;
	}
	
	public static long parseLongSilently(String input, long def) {
		if(input != null && input.length() > 0) {
			try {
				return Long.parseLong(input);
			} catch (NumberFormatException e) {
				return def;
			}
		}
		return def;
	}
	
	public static int findFirstNumberEndIndex(String value) {
		int i = 0;
		boolean valid = false;
		if (value.length() > 0 && value.charAt(0) == '-') {
			i++;
		}
		while (i < value.length() && (Character.isDigit(value.charAt(i)) || value.charAt(i) == '.')) {
			i++;
			valid = true;
		}
		if (valid) {
			return i;
		} else {
			return -1;
		}
	}
	
	/**
	 * Determine whether a file is a ZIP File.
	 */
	public static boolean isZipFile(File file) throws IOException {
		if (file.isDirectory()) {
			return false;
		}
		if (!file.canRead()) {
			throw new IOException("Cannot read file " + file.getAbsolutePath());
		}
		if (file.length() < 4) {
			return false;
		}
		FileInputStream in = new FileInputStream(file);
		int test = readInt(in);
		in.close();
		return test == 0x504b0304;
	}
	
	private static final int readInt(InputStream in) throws IOException {
        int ch1 = in.read();
        int ch2 = in.read();
        int ch3 = in.read();
        int ch4 = in.read();
        if ((ch1 | ch2 | ch3 | ch4) < 0)
            throw new EOFException();
        return ((ch1 << 24) + (ch2 << 16) + (ch3 << 8) + ch4);
    }
	
	public static String capitalizeFirstLetterAndLowercase(String s) {
		if (s != null && s.length() > 1) {
			// not very efficient algorithm
			return Character.toUpperCase(s.charAt(0)) + s.substring(1).toLowerCase();
		} else {
			return s;
		}
	}
	
	
	public static boolean objectEquals(Object a, Object b){
		if(a == null){
			return b == null;
		} else {
			return a.equals(b);
		}
	}
	
	public static int extractFirstIntegerNumber(String s) {
		int i = 0;
		for (int k = 0; k < s.length(); k++) {
			if (Character.isDigit(s.charAt(k))) {
				i = i * 10 + (s.charAt(k) - '0');
			} else {
				break;
			}
		}
		return i;
	}
	
	public static String extractIntegerSuffix(String s) {
		int k = 0;
		for (; k < s.length(); k++) {
			if (!Character.isDigit(s.charAt(k))) {
				return s.substring(k);
			}
		}
		return "";
	}
	
	
	public static void streamCopy(InputStream in, OutputStream out) throws IOException{
		byte[] b = new byte[BUFFER_SIZE];
		int read;
		while ((read = in.read(b)) != -1) {
			out.write(b, 0, read);
		}
	}
	
	public static void oneByteStreamCopy(InputStream in, OutputStream out) throws IOException{
		int read;
		while ((read = in.read()) != -1) {
			out.write(read);
		}
	}
	
	public static void closeStream(Closeable stream){
		try {
			if(stream != null){
				stream.close();
			}
		} catch(IOException e){
			log.warn("Closing stream warn", e); //$NON-NLS-1$
		}
	}
	
	public static void updateAllExistingImgTilesToOsmandFormat(File f){
		if(f.isDirectory()){
			for(File c : f.listFiles()){
				updateAllExistingImgTilesToOsmandFormat(c);
			}
		} else if(f.getName().endsWith(".png") || f.getName().endsWith(".jpg")){ //$NON-NLS-1$ //$NON-NLS-2$
			f.renameTo(new File(f.getAbsolutePath() + ".tile")); //$NON-NLS-1$
		} else if(f.getName().endsWith(".andnav2")) { //$NON-NLS-1$
			f.renameTo(new File(f.getAbsolutePath().substring(0, f.getAbsolutePath().length() - ".andnav2".length()) + ".tile")); //$NON-NLS-1$ //$NON-NLS-2$
		}
			
	}
	
	public static boolean removeAllFiles(File f) {
		if (f == null) {
			return false;
		}
		if (f.isDirectory()) {
			File[] fs = f.listFiles();
			if(fs != null) {
			  for (File c : fs) {
			   removeAllFiles(c);
			  }
			}
			return f.delete();
		} else {
			return f.delete();
		}
	}
	
	
	public static long parseLongFromBytes(byte[] bytes, int offset) {
		long o= 0xff & bytes[offset + 7];
		o = o << 8 | (0xff & bytes[offset + 6]);
		o = o << 8 | (0xff & bytes[offset + 5]);
		o = o << 8 | (0xff & bytes[offset + 4]);
		o = o << 8 | (0xff & bytes[offset + 3]);
		o = o << 8 | (0xff & bytes[offset + 2]);
		o = o << 8 | (0xff & bytes[offset + 1]);
		o = o << 8 | (0xff & bytes[offset]);
		return o;
	}
	
	
	
	public static void putLongToBytes(byte[] bytes, int offset, long l){
		bytes[offset] = (byte) (l & 0xff);
		l >>= 8;
		bytes[offset + 1] = (byte) (l & 0xff);
		l >>= 8;
		bytes[offset + 2] = (byte) (l & 0xff);
		l >>= 8;
		bytes[offset + 3] = (byte) (l & 0xff);
		l >>= 8;
		bytes[offset + 4] = (byte) (l & 0xff);
		l >>= 8;
		bytes[offset + 5] = (byte) (l & 0xff);
		l >>= 8;
		bytes[offset + 6] = (byte) (l & 0xff);
		l >>= 8;
		bytes[offset + 7] = (byte) (l & 0xff);
	}
	
	
	public static int parseIntFromBytes(byte[] bytes, int offset) {
		int o = (0xff & bytes[offset + 3]) << 24;
		o |= (0xff & bytes[offset + 2]) << 16;
		o |= (0xff & bytes[offset + 1]) << 8;
		o |= (0xff & bytes[offset]);
		return o;
	}
	
	public static void putIntToBytes(byte[] bytes, int offset, int l){
		bytes[offset] = (byte) (l & 0xff);
		l >>= 8;
		bytes[offset + 1] = (byte) (l & 0xff);
		l >>= 8;
		bytes[offset + 2] = (byte) (l & 0xff);
		l >>= 8;
		bytes[offset + 3] = (byte) (l & 0xff);
	}
	
	
	public static void writeLongInt(OutputStream stream, long l) throws IOException {
		stream.write((int) (l & 0xff));
		l >>= 8;
		stream.write((int) (l & 0xff));
		l >>= 8;
		stream.write((int) (l & 0xff));
		l >>= 8;
		stream.write((int) (l & 0xff));
		l >>= 8;
		stream.write((int) (l & 0xff));
		l >>= 8;
		stream.write((int) (l & 0xff));
		l >>= 8;
		stream.write((int) (l & 0xff));
		l >>= 8;
		stream.write((int) (l & 0xff));
	}
	
	public static void writeInt(OutputStream stream, int l) throws IOException {
		stream.write(l & 0xff);
		l >>= 8;
		stream.write(l & 0xff);
		l >>= 8;
		stream.write(l & 0xff);
		l >>= 8;
		stream.write(l & 0xff);
	}
	

	public static void writeSmallInt(OutputStream stream, int l) throws IOException {
		stream.write(l & 0xff);
		l >>= 8;
		stream.write(l & 0xff);
		l >>= 8;
	}
	
	public static int parseSmallIntFromBytes(byte[] bytes, int offset) {
		int s = (0xff & bytes[offset + 1]) << 8;
		s |= (0xff & bytes[offset]);
		return s;
	}
	
	public static void putSmallIntBytes(byte[] bytes, int offset, int s){
		bytes[offset] = (byte) (s & 0xff);
		s >>= 8;
		bytes[offset + 1] = (byte) (s & 0xff);
		s >>= 8;
	}

	public static boolean containsDigit(String name) {
		for (int i = 0; i < name.length(); i++) {
			if (Character.isDigit(name.charAt(i))) {
				return true;
			}
		}
		return false;
	}
	

	public static String formatDuration(int seconds) {
		String sec;
		if (seconds % 60 < 10) {
			sec = "0" + (seconds % 60);
		} else {
			sec = (seconds % 60) + "";
		}
		int minutes = seconds / 60;
		if (minutes < 60) {
			return minutes + ":" + sec;
		} else {
			String min;
			if (minutes % 60 < 10) {
				min = "0" + (minutes % 60);
			} else {
				min = (minutes % 60) + "";
			}
			int hours = minutes / 60;
			return hours + ":" + min + ":" + sec;
		}
	}
	
	public static <T extends Enum<T> > T parseEnumValue(T[] cl, String val, T defaultValue){
		for(int i = 0; i< cl.length; i++) {
			if(cl[i].name().equalsIgnoreCase(val)) {
				return cl[i];
			}
		}
		return defaultValue;
	}
	
}