import java.io.*;
import java.util.ArrayList;


public class ByteFixer {
	private File fin ;
	private ArrayList<Byte> Queue;
	private byte[] OverrunByte;
	private DataInputStream reader;
	public ByteFixer(String FileName)	{
		Queue = new ArrayList<Byte>();
		fin = new File(FileName);
		try{
			reader = new DataInputStream(new FileInputStream(fin));
		} catch(FileNotFoundException e){
			System.err.println("Input file not found");
			return;
		}
	}

	public void close(){
		try {
			reader.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
	public void fixCharacter() throws UnsupportedEncodingException{
		
		boolean done_ansel_quick_fix = false;
		
		
		if (Queue.size() == 1) {
			byte first_char = Queue.get(0);
			if (first_char == 0xB0) {
				done_ansel_quick_fix = true;
				Queue.set(0,(byte)'`');
			}
			else if (first_char == 0xFE) {
				done_ansel_quick_fix = true;
				Queue.set(0,(byte)'\'');
			}
		}

		if (done_ansel_quick_fix) {
			return;
		}
		
		//Copy Queue to byte array
		byte[] Character = new byte[Queue.size()];
		for(int i=0; i < Queue.size(); i++)
			Character[i]=Queue.get(i);
		
		//Convert to ISO8859 
		String str = new String(Character,"ISO-8859-1");
		
		byte[] UTF8 = str.getBytes("UTF-8");
		
		System.err.println("FIXED TO: " + new String(UTF8, "UTF-8"));
		
		Queue = new ArrayList<Byte>();
		for(int i=0; i < UTF8.length; i++)
			Queue.add(UTF8[i]);
		return;
	}
	
	public byte[] getNextCharacter(){
		
		int head;
		
		if(OverrunByte!=null){
			byte[] Queue_Bytes = new byte[1];
			Queue_Bytes[0] = OverrunByte[0];
			OverrunByte = null;
			return Queue_Bytes;
		}
		
		try{
			 head = reader.readUnsignedByte();
			 if((head & 0x80)==0){
				 //Simple ASCII case, 1-byte sequence
				 Queue.add((byte)head);
			 }
			 else{
				 //If >1-byte sequence
				 
				 Queue.add((byte)head);
				 
				 if ((head & 0xC0) != 0xC0) {
					 // Isn't the start of a valid UTF-8 sequence
					 fixCharacter();
				 }
				 else {
					 head = head << 1;
					 while((head & 0x80)!=0){
						 int next = reader.readUnsignedByte();
						 if((next & 0xC0)==0x80)
							 Queue.add((byte)next);
						 else{
							 //If sequence end
							 String s = Integer.toBinaryString(next);
							 System.err.println("Encountered non-UTF8 character " + s);
							 //Convert to UTF8
							 fixCharacter();
							 //Save overrun byte
							 OverrunByte = new byte[1];
							 OverrunByte[0] = (byte)next;
							 break;
						 }
						 head = head << 1;
					 }
				 }
			 }
		}catch(EOFException e){
			System.out.println("End of file reached");
			return null;
		}catch(Exception e){
			e.printStackTrace();
		}
		//Copy Queue to byte array
		byte[] Queue_Bytes = new byte[Queue.size()];
		for(int i=0; i < Queue.size(); i++){
			Queue_Bytes[i] = Queue.get(i);
		}
		//Reset queue to be empty
		Queue = new ArrayList<Byte>();
		return Queue_Bytes;
	}
	
}