package org.cl0zzzy.rtmp;

import java.util.ArrayList;
import java.util.Arrays;

public class AMF {
	
	private ArrayList<AMFObject> AMFMessage = new ArrayList<AMFObject>();
	private byte[] amf;
	
	public boolean next = false;
	public byte[] nextArr;
	
	public AMF( byte[] amf ) {
		this.amf = amf;
		this.decodeAMF();
	}
	
	private AMFResult decodeNumber( int i ) {
		byte[] number = new byte[8];
		number[0] = amf[i+1];
		number[1] = amf[i+2];
		number[2] = amf[i+3];
		number[3] = amf[i+4];
		number[4] = amf[i+5];
		number[5] = amf[i+6];
		number[6] = amf[i+7];
		number[7] = amf[i+8];
		AMFResult result = new AMFResult();
		result.value = this.numberToDouble( Util.bytesToHex( number ) );
		result.index = i+8;
		return result;
	}
	
	private AMFResult decodeString( int i ) {
		byte[] stringLength = new byte[2];
		stringLength[0] = amf[i+1];
		stringLength[1] = amf[i+2];
		int length = Integer.parseInt( Util.bytesToHex(stringLength), 16 );
		ArrayList<Byte> str = new ArrayList<Byte>();
		for( int u = (i+3); u < (i+3+length); u++ ) {
			str.add( amf[u] );
		}
		AMFResult result = new AMFResult();
		byte[] _a = new byte[str.size()];
		int j = 0;
		for(Byte b : str) {
			_a[j++] = b.byteValue();
		}
		try { result.value = new String( _a, "UTF-8" ); } catch( Exception e ) { e.printStackTrace(); }
		result.index = i+2+length;
		return result;
	}
	
	private AMFResult decodeECMA( int i ) {
		AMFEcmaArray ecma = new AMFEcmaArray();
		if( amf[i] == AMFObject.AMF_ECMA_ARRAY_START && 
				amf[i+1] == 0x00 && 
				amf[i+2] == 0x00 &&
				amf[i+3] == 0x00 &&
				amf[i+4] == 0x00 &&
				amf[i+5] == 0x00 && 
				amf[i+6] == 0x00 &&
				amf[i+7] == AMFObject.AMF_OBJECT_END ) {
			i = i + 7;
			AMFResult result = new AMFResult();
			result.value = ecma;
			result.index = i;
			return result;
		}
		i+=5;
		int index = 0;
		while( true ) {
			if( amf[i] == 0x00 && amf[i+1] == 0x00 && amf[i+2] == 0x09 ) {
				i = i + 2;
				break;
			}
			i+=3;
			
			int __index = index;
			__index = __index - ( __index % 10 );
			if( __index > 0 ) {
				int len = String.valueOf(__index).substring(1).length();
				i += len;
			}
			Result res = this.decodeOne(i);
			AMFObject value = new AMFObject( amf[i], res.val );
			ecma.add(value);
			i = res.i;
			i++;
			index++;
		}
		AMFResult result = new AMFResult();
		result.value = ecma;
		result.index = i;
		return result;
	}
	
	private AMFResult decodeObj( int i ) {
		i++;
		AMFObjectArray array = new AMFObjectArray();
		while( true ) {
			if( amf[i] == 0x00 && amf[i+1] == 0x00 && amf[i+2] == 0x09 ) {
				i = i + 2;
				break;
			}
			byte[] length = new byte[2];
			length[0] = amf[i];
			length[1] = amf[i+1];
			
			int decimal = Integer.parseInt( Util.bytesToHex(length), 16 );
			String key = "";
			for( int u = i+2; u < (i+2+decimal); u++ ) {
				key = key + new String( new byte[] {amf[u]} );
			}
			
			Result res = this.decodeOne(i+2+decimal);
			AMFObject obj = new AMFObject( amf[i+2+decimal], res.val );
			array.add(key, obj);
			i = res.i + 1;
		}
		
		
		AMFResult result = new AMFResult();
		result.value = array;
		result.index = i;
		return result;
	}
	
	private Result decodeOne( int i ) {
		Object val = null;
		if( amf[i] == AMFObject.AMF_NUMBER ) {
			AMFResult result = this.decodeNumber(i);
			val = result.value;
			i = result.index;
		} else if( amf[i] == AMFObject.AMF_STRING ) {
			AMFResult result = this.decodeString(i);
			val = result.value;
			i = result.index;
		} else if( amf[i] == AMFObject.AMF_BOOLEAN ) {
			if( amf[i+1] == 0x00 ) {
				val = false;
			} else {
				val = true;
			}
			i++;
		} else if( amf[i] == AMFObject.AMF_OBJECT_START ) {
			AMFResult result = this.decodeObj(i);
			val = result.value;
			i = result.index;
		} else if( amf[i] == AMFObject.AMF_NULL ) {
			val = null;
		} else if( amf[i] == AMFObject.AMF_ECMA_ARRAY_START ) {
			AMFResult result = this.decodeECMA(i);
			val = result.value;
			i = result.index;
		} else if( amf[i] == AMFObject.AMF_DATE ) {
			val = "Date";
			i = i + 10;
		} else if( amf[i] == (byte) 0x43 || amf[i] == (byte) 0x83 ){
			val = "end";
			next = true;
			nextArr = Arrays.copyOfRange(amf, i, amf.length);
		}
		Result res = new Result();
		res.i = i;
		res.val = val;
		return res;
	}
	
	private void decodeAMF() {
		for( int i = 0; i < amf.length; i++ ) {
			Object val = null;
			int _i = i;
			Result res = this.decodeOne( i );
			i = res.i;
			val = res.val;
			if( val != null && val.equals("end") ) {
				break;
			}
			if( amf[_i] != AMFObject.AMF_BOOLEAN &&
					amf[_i] != AMFObject.AMF_ECMA_ARRAY_START &&
					amf[_i] != AMFObject.AMF_NUMBER &&
					amf[_i] != AMFObject.AMF_OBJECT_START &&
					amf[_i] != AMFObject.AMF_STRING ) {
				amf[_i] = AMFObject.AMF_NULL;
			}
			AMFObject value = new AMFObject( amf[_i], val );
			AMFMessage.add(value);
		}
	}
	
	public int getLength() {
		return this.AMFMessage.size();
	}
	
	public AMFObject get( int index ) {
		return this.AMFMessage.get(index);
	}
	
	private double numberToDouble( String hexString ) {
		long longHex = parseUnsignedHex(hexString);
        return Double.longBitsToDouble(longHex);
	}
	
	private long parseUnsignedHex(String text) {
        if (text.length() == 16) {
            return (parseUnsignedHex(text.substring(0, 1)) << 60)
                    | parseUnsignedHex(text.substring(1));
        }
        return Long.parseLong(text, 16);
    }
}