package edu.rice.hj.example.cnc.util;

/**
 * @author <a href="http://shams.web.rice.edu/">Shams Imam</a> (shams@rice.edu)
 */
public interface BlockIndices {
    double get(int i, int j);

    double delta(BlockIndices other);


    public static final class DefaultBlockIndices implements BlockIndices {

        public double get(final int i, final int j) {
            return 0;
        }

        public double delta(final BlockIndices other) {
            if (other instanceof DefaultBlockIndices) {
                return 0;
            }
            return other.delta(this);
        }

    }

    public static final class DataBlockIndices implements BlockIndices {

        public final double[][] block;
        public final int startRow;
        public final int endRow;
        public final int startCol;
        public final int endCol;

        public DataBlockIndices(
                final double[][] block,
                final int startRow, final int endRow,
                final int startCol, final int endCol) {

            this.block = block;
            this.startRow = startRow;
            this.endRow = endRow;
            this.startCol = startCol;
            this.endCol = endCol;
        }

        public double get(final int i, final int j) {
            return block[i - startRow][j - startCol];
        }

        public double delta(final BlockIndices other) {

            double localDelta = 0;

            for (int i = startRow; i < endRow; i++) {
                for (int j = startCol; j < endCol; j++) {

                    final double delta = Math.abs(get(i, j) - other.get(i, j));
                    localDelta = Math.max(localDelta, delta);

                }
            }

            return localDelta;
        }
    }
}