package net.osmand.util;


import java.io.BufferedReader;
import java.io.Closeable;
import java.io.EOFException;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;

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 boolean stringsEqual(String s1, String s2) {
		if (s1 == null && s2 == null) {
			return true;
		} else if (s1 == null) {
			return false;
		} else if (s2 == null) {
			return false;
		} else {
			return s2.equals(s1);
		}
	}

	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 String getFileNameWithoutExtension(File f) {
		String name = f.getName();
		int i = name.indexOf('.');
		if(i >= 0) {
			name = name.substring(0, i);
		}
		return name;
	}
	
	
	
	public static File[] getSortedFilesVersions(File dir){
		File[] listFiles = dir.listFiles();
		if (listFiles != null) {
			Arrays.sort(listFiles, getFileVersionComparator());
		}
		return listFiles;
	}

	public static Comparator<File> getFileVersionComparator() {
		return new Comparator<File>() {
			@Override
			public int compare(File o1, File o2) {
				return -simplifyFileName(o1.getName()).compareTo(simplifyFileName(o2.getName()));
			}
			
			public String simplifyFileName(String fn) {
				String lc = fn.toLowerCase();
				if (lc.indexOf(".") != -1) {
					lc = lc.substring(0, lc.indexOf("."));
				}
				if (lc.endsWith("_2")) {
					lc = lc.substring(0, lc.length() - "_2".length());
				}
				boolean hasTimestampEnd = false;
				for(int i = 0; i < lc.length(); i++) {
					if(lc.charAt(i) >= '0' && lc.charAt(i) <= '9') {
						hasTimestampEnd = true;
						break;
					}
				}
				if(!hasTimestampEnd) {
					lc += "_00_00_00";
				}
				return lc;
			}
		};
	}
	
	private static final char CHAR_TOSPLIT = 0x01;

	public static Map<String, String> decodeMap(String s) {
		if (isEmpty(s)) {
			return Collections.emptyMap();
		}
		Map<String, String> names = new HashMap<String, String>();
		String[] split = s.split(CHAR_TOSPLIT + "");
		// last split is an empty string
		for (int i = 1; i < split.length; i += 2) {
			names.put(split[i - 1], split[i]);
		}
		return names;
	}
	
	public static String encodeMap(Map<String, String> names) {
		if (names != null) {
			Iterator<Entry<String, String>> it = names.entrySet().iterator();
			StringBuilder bld = new StringBuilder();
			while (it.hasNext()) {
				Entry<String, String> e = it.next();
				bld.append(e.getKey()).append(CHAR_TOSPLIT)
						.append(e.getValue().replace(CHAR_TOSPLIT, (char)(CHAR_TOSPLIT + 1)));
				bld.append(CHAR_TOSPLIT);
			}
			return bld.toString();
		}
		return "";
	}
	
	public static int findFirstNumberEndIndex(String value) {
		int i = 0;
		boolean valid = false;
		if (value.length() > 0 && value.charAt(0) == '-') {
			i++;
		}
		while (i < value.length() && (isDigit(value.charAt(i)) || value.charAt(i) == '.')) {
			i++;
			valid = true;
		}
		if (valid) {
			return i;
		} else {
			return -1;
		}
	}
	
	public static boolean isDigit(char charAt) {
		return charAt >= '0' && charAt <= '9';
	}

	/**
	 * 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);
		}
	}
	
	
	/**
     	* Parse the color string, and return the corresponding color-int.
     	* If the string cannot be parsed, throws an IllegalArgumentException
     	* exception. Supported formats are:
     	* #RRGGBB
     	* #AARRGGBB
     	* 'red', 'blue', 'green', 'black', 'white', 'gray', 'cyan', 'magenta',
     	* 'yellow', 'lightgray', 'darkgray'
     	*/
    	public static int parseColor(String colorString) {
        	if (colorString.charAt(0) == '#') {
            	// Use a long to avoid rollovers on #ffXXXXXX
            	long color = Long.parseLong(colorString.substring(1), 16);
            	if (colorString.length() == 7) {
	                // Set the alpha value
        	        color |= 0x00000000ff000000;
            	} else if (colorString.length() != 9) {
                	throw new IllegalArgumentException("Unknown color " + colorString); //$NON-NLS-1$
            	}
            	return (int)color;
        	}
        	throw new IllegalArgumentException("Unknown color " + colorString); //$NON-NLS-1$
    	}
	
    	
	public static int extractFirstIntegerNumber(String s) {
		int i = 0;
		for (int k = 0; k < s.length(); k++) {
			if (isDigit(s.charAt(k))) {
				i = i * 10 + (s.charAt(k) - '0');
			} else {
				break;
			}
		}
		return i;
	}
	
	public static int extractIntegerNumber(String s) {
		int i = 0;
		int k = 0;
		for (k = 0; k < s.length(); k++) {
			if (isDigit(s.charAt(k))) {
				break;
			}
		}
		for (; k < s.length(); k++) {
			if (isDigit(s.charAt(k))) {
				i = i * 10 + (s.charAt(k) - '0');
			} else {
				break;
			}
		}
		return i;
	}
	
	public static String extractIntegerPrefix(String s) {
		int k = 0;
		for (; k < s.length(); k++) {
			if (Character.isDigit(s.charAt(k))) {
				return s.substring(0, k);
			}
		}
		return "";
	}
	
	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 fileCopy(File src, File dst) throws IOException {
		FileOutputStream fout = new FileOutputStream(dst);
		try {
			FileInputStream fin = new FileInputStream(src);
			try {
				Algorithms.streamCopy(fin, fout);
			} finally {
				fin.close();
			}
		} finally {
			fout.close();
		}
	}
	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 StringBuilder readFromInputStream(InputStream i) throws IOException {
		StringBuilder responseBody = new StringBuilder();
		responseBody.setLength(0);
		if (i != null) {
			BufferedReader in = new BufferedReader(new InputStreamReader(i, "UTF-8"), 256); //$NON-NLS-1$
			String s;
			boolean f = true;
			while ((s = in.readLine()) != null) {
				if (!f) {
					responseBody.append("\n"); //$NON-NLS-1$
				} else {
					f = false;
				}
				responseBody.append(s);
			}
		}
		return responseBody;
	}
	
	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;
	}

	public static String colorToString(int color) {
		if ((0xFF000000 & color) == 0xFF000000) {
			return "#" + format(6, Integer.toHexString(color & 0x00FFFFFF)); //$NON-NLS-1$
		} else {
			return "#" + format(8, Integer.toHexString(color)); //$NON-NLS-1$
		}
	}

	private static String format(int i, String hexString) {
		while(hexString.length() < i) {
			hexString = "0" + hexString;
		}
		return hexString;
	}
}