package jxl.biff;

import common.Logger;
import jxl.WorkbookSettings;

public class EncodedURLHelper {
  private static Logger logger = Logger.getLogger(EncodedURLHelper.class);
  
  private static byte msDosDriveLetter = 1;
  
  private static byte sameDrive = 2;
  
  private static byte endOfSubdirectory = 3;
  
  private static byte parentDirectory = 4;
  
  private static byte unencodedUrl = 5;
  
  public static byte[] getEncodedURL(String s, WorkbookSettings ws) {
    if (s.startsWith("http:"))
      return getURL(s, ws); 
    return getFile(s, ws);
  }
  
  private static byte[] getFile(String s, WorkbookSettings ws) {
    ByteArray byteArray = new ByteArray();
    int pos = 0;
    if (s.charAt(1) == ':') {
      byteArray.add(msDosDriveLetter);
      byteArray.add((byte)s.charAt(0));
      pos = 2;
    } else if (s.charAt(pos) == '\\' || s.charAt(pos) == '/') {
      byteArray.add(sameDrive);
    } 
    while (s.charAt(pos) == '\\' || s.charAt(pos) == '/')
      pos++; 
    while (pos < s.length()) {
      int nextSepIndex1 = s.indexOf('/', pos);
      int nextSepIndex2 = s.indexOf('\\', pos);
      int nextSepIndex = 0;
      String nextFileNameComponent = null;
      if (nextSepIndex1 != -1 && nextSepIndex2 != -1) {
        nextSepIndex = Math.min(nextSepIndex1, nextSepIndex2);
      } else if (nextSepIndex1 == -1 || nextSepIndex2 == -1) {
        nextSepIndex = Math.max(nextSepIndex1, nextSepIndex2);
      } 
      if (nextSepIndex == -1) {
        nextFileNameComponent = s.substring(pos);
        pos = s.length();
      } else {
        nextFileNameComponent = s.substring(pos, nextSepIndex);
        pos = nextSepIndex + 1;
      } 
      if (!nextFileNameComponent.equals("."))
        if (nextFileNameComponent.equals("..")) {
          byteArray.add(parentDirectory);
        } else {
          byteArray.add(StringHelper.getBytes(nextFileNameComponent, ws));
        }  
      if (pos < s.length())
        byteArray.add(endOfSubdirectory); 
    } 
    return byteArray.getBytes();
  }
  
  private static byte[] getURL(String s, WorkbookSettings ws) {
    ByteArray byteArray = new ByteArray();
    byteArray.add(unencodedUrl);
    byteArray.add((byte)s.length());
    byteArray.add(StringHelper.getBytes(s, ws));
    return byteArray.getBytes();
  }
}