package se.lth.cs.nlp.opinions;

import java.io.Serializable;
import java.util.Arrays;

import se.lth.cs.nlp.nlputils.ml_long.SymbolEncoder;

public class FeatureTemplate implements Serializable {

	static final long serialVersionUID = 0L;
	
	static final int OUTSIDE_LABEL = 1;
	
	public long id; // set externally
	
	// components of the template are represented as int pairs
	// [column, row, width, max]
	// the output column has number 0
	private int[][] fs;
	private long[] offs;
	
	private String templateString;
	
	public FeatureTemplate(String s, int maxOffset) {
		s = s.trim();
		if(s.length() == 0)
			throw new IllegalArgumentException("empty string");
		templateString = s;
		String[] ts = s.split("\\s+");

		fs = new int[ts.length][];
		for(int i = 0; i < fs.length; i++) {
			fs[i] = parsePart(ts[i]);
		}
		offs = new long[ts.length];
		long offset = 0;
		for(int i = 0; i < fs.length; i++) {
			offs[i] = offset;
			offset += fs[i][2];
		}
		if(offset >= maxOffset)
			throw new IllegalArgumentException("too wide");
		
        //System.out.println("fs = " + Arrays.deepToString(fs));
        //System.out.println("offs = " + Arrays.toString(offs));
		
	}
	
	private int[] parsePart(String s) {
		s = s.trim();
		String[] ss = s.split(":");
		if(ss.length != 2)
			throw new IllegalArgumentException("Illegal feature " + s);
		int width = Integer.parseInt(ss[1]);
		String s1 = ss[0];
		if(s1.length() < 2)
			throw new IllegalArgumentException("Illegal feature " + s);
		if(s1.charAt(1) != '[') 
			throw new IllegalArgumentException("Illegal feature " + s);
		if(s1.charAt(s1.length() - 1) != ']')
			throw new IllegalArgumentException("Illegal feature " + s);
		int[] out = new int[4];
		out[2] = width;
		out[3] = (1 << width) - 1;
		String s2 = s1.substring(2, s1.length()-1);
		if(s1.charAt(0) == 'I') {
			String[] ts = s2.split("\\]\\[");
			if(ts.length != 2)
				throw new IllegalArgumentException("Illegal feature " + s);
			out[0] = Integer.parseInt(ts[0]) + 1;
			out[1] = Integer.parseInt(ts[1]);
		} else if(s1.charAt(0) == 'O') {
			out[1] = Integer.parseInt(s2);
			if(out[1] > 0)
				throw new IllegalArgumentException("Illegal feature " + s);
		} else
			throw new IllegalArgumentException("Illegal feature " + s);
		return out;
	}

	public int getRange() {
		int range = 0;
		for(int i = 0; i < fs.length; i++)
			if(fs[i][0] == 0) {
				int r = -fs[i][1] + 1;
				if(r > range)
					range = r;
			}
		//System.out.println("range returns " + range);
		return range;		
	}
	
	public long encodeFeature(int[][] ifs, int[] ofs, int index) {
		long out = id;
		for(int i = 0; i < fs.length; i++) {
			if(fs[i][0] == 0) {
				int row = -fs[i][1];
				int f = ofs[row];
				if(f < 0 || f > fs[i][3])
					throw new RuntimeException("feature value too large #1 (" + templateString + ")");
				out |= (long) f << offs[i];
			} else {
				int col = fs[i][0] - 1;
				int row = index + fs[i][1];
				int f;
				if(row < 0 || row >= ifs.length)
					f = OUTSIDE_LABEL;
				else {
					f = ifs[row][col];
					if(f < 0 || f > fs[i][3]) {
						for(int j1 = 0; j1 < ifs.length; j1++) {
							for(int j2 = 0; j2 < ifs[j1].length; j2++)
								System.out.print(ifs[j1][j2] + "\t");
							System.out.println();
						}
						throw new RuntimeException("feature value too large #2 (" + f + " / " + fs[i][3] 
						        + ") (" + templateString + ")");
					}
				}
				out |= (long) f << offs[i];
			}
		}
		return out;
	}	
	
	public String featureToString(long l) {
		
		return null;
	}
	
}