/**
 * Copyright 2010-2013 Jingjing Li.
 *
 * This file is part of jplot2d.
 *
 * jplot2d is free software: you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or any later version.
 *
 * jplot2d is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Lesser Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with jplot2d. If not, see .
 */
package org.jplot2d.image;

import java.awt.Dimension;

import org.jplot2d.data.ByteDataBuffer;
import org.jplot2d.data.DoubleDataBuffer;
import org.jplot2d.data.FloatDataBuffer;
import org.jplot2d.data.ImageDataBuffer;
import org.jplot2d.data.IntDataBuffer;
import org.jplot2d.data.ShortDataBuffer;
import org.jplot2d.util.DoubleBottomNFinder;
import org.jplot2d.util.DoubleTopNFinder;
import org.jplot2d.util.FloatBottomNFinder;
import org.jplot2d.util.FloatTopNFinder;
import org.jplot2d.util.IntBottomNFinder;
import org.jplot2d.util.IntTopNFinder;
import org.jplot2d.util.ShortBottomNFinder;
import org.jplot2d.util.ShortTopNFinder;

/**
 * The limits calculator to produce the upper and lower limits to based on the specified percentage. A histogram of the
 * data is created and the limits are set to display the percentage, about the mean value.
 * 
 * @author Jingjing Li
 * 
 */
public class PercentCalculator implements LimitsCalculator {

	private final double percentage;

	public PercentCalculator(double percentage) {
		this.percentage = percentage;
	}

	public double[] calcLimits(ImageDataBuffer[] dbufArray, Dimension[] sizeArray) {

		if (percentage == 100) {
			return MinMaxCalculator.calcMinMax(dbufArray, sizeArray);
		}

		int numberCount = 0;
		for (int a = 0; a < dbufArray.length; a++) {
			numberCount += dbufArray[a].countValid(sizeArray[a].width, sizeArray[a].height);
		}
		if (numberCount == 0) {
			return null;
		} else if (numberCount == 1) {
			return MinMaxCalculator.calcMinMax(dbufArray, sizeArray);
		}

		double cutoff = numberCount * (100 - percentage) / 100.0 / 2.0;

		int maxDataByes = 0;
		for (int i = 0; i < dbufArray.length; i++) {
			int dataBytes = 0;
			if (dbufArray[i] instanceof ByteDataBuffer) {
				dataBytes = 1;
			} else if (dbufArray[i] instanceof ShortDataBuffer) {
				dataBytes = 2;
			} else if (dbufArray[i] instanceof IntDataBuffer) {
				dataBytes = 4;
			} else if (dbufArray[i] instanceof FloatDataBuffer) {
				dataBytes = 6;
			} else if (dbufArray[i] instanceof DoubleDataBuffer) {
				dataBytes = 8;
			}
			if (maxDataByes < dataBytes) {
				maxDataByes = dataBytes;
			}
		}

		switch (maxDataByes) {
		case 1:
			return calcByteLimits(dbufArray, sizeArray, cutoff);
		case 2:
			return calcShortLimits(dbufArray, sizeArray, cutoff);
		case 4:
			return calcIntLimits(dbufArray, sizeArray, cutoff);
		case 6:
			return calcFloatLimits(dbufArray, sizeArray, cutoff);
		case 8:
			return calcDoubleLimits(dbufArray, sizeArray, cutoff);
		default:
			throw new IllegalArgumentException("Unsupported ImageDataBuffer");
		}
	}

	/**
	 * Calculate low & high cut values of the given 2d array. If the array contains no data, null is returned.
	 * 
	 * @param dbufArray
	 * @param sizeArray
	 * @param cutoff
	 *            the number of values that should be cut-off on each side
	 * @return the low & high cut values
	 */
	private static double[] calcByteLimits(ImageDataBuffer[] dbufArray, Dimension[] sizeArray, double cutoff) {

		// the cuts value is between cutoffLess and cutoffMore
		double offsetrate = (int) cutoff + 1 - cutoff;
		int cutoffLess = (int) cutoff + 1;
		int cutoffMore = (int) cutoff + 2;

		// calculate by value index count
		int valueN = 2 << Byte.SIZE;
		int[] valueCounter = new int[valueN];
		for (int a = 0; a < dbufArray.length; a++) {
			ImageDataBuffer dbuf = dbufArray[a];
			int w = sizeArray[a].width;
			int h = sizeArray[a].height;

			if (!dbuf.hasMasks()) {
				for (int i = 0; i < h; i++) {
					for (int j = 0; j < w; j++) {
						byte v = ((ByteDataBuffer) dbuf).get(i, j);
						valueCounter[v - Byte.MIN_VALUE]++;
					}
				}
			} else {
				for (int i = 0; i < h; i++) {
					for (int j = 0; j < w; j++) {
						if (!dbuf.isMasked(i, j)) {
							byte v = ((ByteDataBuffer) dbuf).get(i, j);
							valueCounter[v - Byte.MIN_VALUE]++;
						}
					}
				}
			}
		}

		// calculate low cut
		int bottomMax = -1;
		int bottomMax2nd = -1;
		int cutN = 0;
		for (int i = 0; i < valueN; i++) {
			cutN += valueCounter[i];
			if (cutN >= cutoffMore) {
				bottomMax = i + Byte.MIN_VALUE;
				bottomMax2nd = bottomMax;
				break;
			} else if (cutN >= cutoffLess) {
				bottomMax2nd = i + Byte.MIN_VALUE;
				for (int j = i + 1; j < valueN; j++) {
					if (valueCounter[j] > 0) {
						bottomMax = j + Byte.MIN_VALUE;
						break;
					}
				}
				break;
			}
		}

		double lowCut = bottomMax * (1 - offsetrate) + bottomMax2nd * offsetrate;

		// calculate high cut
		int topMin = -Byte.MIN_VALUE;
		int topMin2nd = -Byte.MIN_VALUE;
		cutN = 0;
		for (int i = valueN - 1; i >= 0; i--) {
			cutN += valueCounter[i];
			if (cutN >= cutoffMore) {
				topMin = i + Byte.MIN_VALUE;
				topMin2nd = topMin;
				break;
			} else if (cutN >= cutoffLess) {
				topMin2nd = i + Byte.MIN_VALUE;
				for (int j = i - 1; j >= 0; j--) {
					if (valueCounter[j] > 0) {
						topMin = j + Byte.MIN_VALUE;
						break;
					}
				}
				break;
			}
		}
		double highCut = topMin * (1 - offsetrate) + topMin2nd * offsetrate;

		return new double[] { lowCut, highCut };
	}

	private static double[] calcShortLimits(ImageDataBuffer[] dbufArray, Dimension[] sizeArray, double cutoff) {

		// the cuts value is between cutoffMore-1 and cutoffMore
		double offsetrate = (int) cutoff + 1 - cutoff;
		int cutoffMore = (int) cutoff + 2;

		short[] lowCuts = new short[cutoffMore];
		short[] highCuts = new short[cutoffMore];

		// fill the cuts array
		int m = -1;
		int n = -1;
		int c = 0;
		for (int a = 0; a < dbufArray.length; a++) {
			ImageDataBuffer dbuf = dbufArray[a];
			int w = sizeArray[a].width;
			int h = sizeArray[a].height;

			if (!dbuf.hasMasks()) {
				for (int i = 0; i < h; i++) {
					for (int j = 0; j < w; j++) {
						short v = dbuf.getShort(i, j);
						lowCuts[c] = v;
						highCuts[c] = v;
						if (++c == cutoffMore) {
							m = i;
							n = j;
							break;
						}
					}
					if (n != -1) {
						break;
					}
				}
			} else {
				for (int i = 0; i < h; i++) {
					for (int j = 0; j < w; j++) {
						if (!dbuf.isMasked(i, j)) {
							short v = dbuf.getShort(i, j);
							lowCuts[c] = v;
							highCuts[c] = v;
							if (++c == cutoffMore) {
								m = i;
								n = j;
								break;
							}
						}
					}
					if (n != -1) {
						break;
					}
				}
			}
		}

		// build the cuts array
		ShortBottomNFinder bf = new ShortBottomNFinder(lowCuts);
		ShortTopNFinder tf = new ShortTopNFinder(highCuts);

		n++;
		for (int a = 0; a < dbufArray.length; a++) {
			ImageDataBuffer dbuf = dbufArray[a];
			int w = sizeArray[a].width;
			int h = sizeArray[a].height;

			if (!dbuf.hasMasks()) {
				for (int i = m; i < h; i++) {
					for (int j = n; j < w; j++) {
						short v = dbuf.getShort(i, j);
						bf.check(v);
						tf.check(v);
					}
					n = 0;
				}
			} else {
				for (int i = m; i < h; i++) {
					for (int j = n; j < w; j++) {
						if (!dbuf.isMasked(i, j)) {
							short v = dbuf.getShort(i, j);
							bf.check(v);
							tf.check(v);
						}
					}
					n = 0;
				}
			}
		}

		double lowCut = bf.getMax() * (1 - offsetrate) + bf.getMax2nd() * offsetrate;
		double highCut = tf.getMin() * (1 - offsetrate) + tf.getMin2nd() * offsetrate;

		return new double[] { lowCut, highCut };
	}

	private static double[] calcIntLimits(ImageDataBuffer[] dbufArray, Dimension[] sizeArray, double cutoff) {

		// the cuts value is between cutoffMore-1 and cutoffMore
		double offsetrate = (int) cutoff + 1 - cutoff;
		int cutoffMore = (int) cutoff + 2;

		int[] lowCuts = new int[cutoffMore];
		int[] highCuts = new int[cutoffMore];

		// fill the cuts array
		int m = -1;
		int n = -1;
		int c = 0;
		for (int a = 0; a < dbufArray.length; a++) {
			ImageDataBuffer dbuf = dbufArray[a];
			int w = sizeArray[a].width;
			int h = sizeArray[a].height;

			if (!dbuf.hasMasks()) {
				for (int i = 0; i < h; i++) {
					for (int j = 0; j < w; j++) {
						int v = dbuf.getInt(i, j);
						lowCuts[c] = v;
						highCuts[c] = v;
						if (++c == cutoffMore) {
							m = i;
							n = j;
							break;
						}
					}
					if (n != -1) {
						break;
					}
				}
			} else {
				for (int i = 0; i < h; i++) {
					for (int j = 0; j < w; j++) {
						if (!dbuf.isMasked(i, j)) {
							int v = dbuf.getInt(i, j);
							lowCuts[c] = v;
							highCuts[c] = v;
							if (++c == cutoffMore) {
								m = i;
								n = j;
								break;
							}
						}
					}
					if (n != -1) {
						break;
					}
				}
			}
		}

		// build the cuts array
		IntBottomNFinder bf = new IntBottomNFinder(lowCuts);
		IntTopNFinder tf = new IntTopNFinder(highCuts);

		n++;
		for (int a = 0; a < dbufArray.length; a++) {
			ImageDataBuffer dbuf = dbufArray[a];
			int w = sizeArray[a].width;
			int h = sizeArray[a].height;

			if (!dbuf.hasMasks()) {
				for (int i = m; i < h; i++) {
					for (int j = n; j < w; j++) {
						int v = dbuf.getInt(i, j);
						bf.check(v);
						tf.check(v);
					}
					n = 0;
				}
			} else {
				for (int i = m; i < h; i++) {
					for (int j = n; j < w; j++) {
						if (!dbuf.isMasked(i, j)) {
							int v = dbuf.getInt(i, j);
							bf.check(v);
							tf.check(v);
						}
					}
					n = 0;
				}
			}
		}

		double lowCut = bf.getMax() * (1 - offsetrate) + bf.getMax2nd() * offsetrate;
		double highCut = tf.getMin() * (1 - offsetrate) + tf.getMin2nd() * offsetrate;

		return new double[] { lowCut, highCut };
	}

	private static double[] calcFloatLimits(ImageDataBuffer[] dbufArray, Dimension[] sizeArray, double cutoff) {

		// the cuts value is between cutoffMore-1 and cutoffMore
		double offsetrate = (int) cutoff + 1 - cutoff;
		int cutoffMore = (int) cutoff + 2;

		float[] lowCuts = new float[cutoffMore];
		float[] highCuts = new float[cutoffMore];

		// fill the cuts array
		int m = -1;
		int n = -1;
		int c = 0;
		for (int a = 0; a < dbufArray.length; a++) {
			ImageDataBuffer dbuf = dbufArray[a];
			int w = sizeArray[a].width;
			int h = sizeArray[a].height;

			if (!dbuf.hasMasks()) {
				for (int i = 0; i < h; i++) {
					for (int j = 0; j < w; j++) {
						float v = dbuf.getFloat(i, j);
						if (v == v && v != Float.POSITIVE_INFINITY && v != Float.NEGATIVE_INFINITY) {
							lowCuts[c] = v;
							highCuts[c] = v;
							if (++c == cutoffMore) {
								m = i;
								n = j;
								break;
							}
						}
					}
					if (n != -1) {
						break;
					}
				}
			} else {
				for (int i = 0; i < h; i++) {
					for (int j = 0; j < w; j++) {
						if (!dbuf.isMasked(i, j)) {
							float v = dbuf.getFloat(i, j);
							if (v == v && v != Float.POSITIVE_INFINITY && v != Float.NEGATIVE_INFINITY) {
								lowCuts[c] = v;
								highCuts[c] = v;
								if (++c == cutoffMore) {
									m = i;
									n = j;
									break;
								}
							}
						}
					}
					if (n != -1) {
						break;
					}
				}
			}
		}

		// build the cuts array
		FloatBottomNFinder bf = new FloatBottomNFinder(lowCuts);
		FloatTopNFinder tf = new FloatTopNFinder(highCuts);

		n++;
		for (int a = 0; a < dbufArray.length; a++) {
			ImageDataBuffer dbuf = dbufArray[a];
			int w = sizeArray[a].width;
			int h = sizeArray[a].height;

			if (!dbuf.hasMasks()) {
				for (int i = m; i < h; i++) {
					for (int j = n; j < w; j++) {
						float v = dbuf.getFloat(i, j);
						if (v == v && v != Float.POSITIVE_INFINITY && v != Float.NEGATIVE_INFINITY) {
							bf.check(v);
							tf.check(v);
						}
					}
					n = 0;
				}
			} else {
				for (int i = m; i < h; i++) {
					for (int j = n; j < w; j++) {
						if (!dbuf.isMasked(i, j)) {
							float v = dbuf.getFloat(i, j);
							if (v == v && v != Float.POSITIVE_INFINITY && v != Float.NEGATIVE_INFINITY) {
								bf.check(v);
								tf.check(v);
							}
						}
					}
					n = 0;
				}
			}
		}

		double lowCut = bf.getMax() * (1 - offsetrate) + bf.getMax2nd() * offsetrate;
		double highCut = tf.getMin() * (1 - offsetrate) + tf.getMin2nd() * offsetrate;

		return new double[] { lowCut, highCut };
	}

	private static double[] calcDoubleLimits(ImageDataBuffer[] dbufArray, Dimension[] sizeArray, double cutoff) {

		// the cuts value is between cutoffMore-1 and cutoffMore
		double offsetrate = (int) cutoff + 1 - cutoff;
		int cutoffMore = (int) cutoff + 2;

		double[] lowCuts = new double[cutoffMore];
		double[] highCuts = new double[cutoffMore];

		// fill the cuts array
		int m = -1;
		int n = -1;
		int c = 0;
		for (int a = 0; a < dbufArray.length; a++) {
			ImageDataBuffer dbuf = dbufArray[a];
			int w = sizeArray[a].width;
			int h = sizeArray[a].height;

			if (!dbuf.hasMasks()) {
				for (int i = 0; i < h; i++) {
					for (int j = 0; j < w; j++) {
						double v = dbuf.getDouble(i, j);
						if (v == v && v != Float.POSITIVE_INFINITY && v != Float.NEGATIVE_INFINITY) {
							lowCuts[c] = v;
							highCuts[c] = v;
							if (++c == cutoffMore) {
								m = i;
								n = j;
								break;
							}
						}
					}
					if (n != -1) {
						break;
					}
				}
			} else {
				for (int i = 0; i < h; i++) {
					for (int j = 0; j < w; j++) {
						if (!dbuf.isMasked(i, j)) {
							double v = dbuf.getDouble(i, j);
							if (v == v && v != Float.POSITIVE_INFINITY && v != Float.NEGATIVE_INFINITY) {
								lowCuts[c] = v;
								highCuts[c] = v;
								if (++c == cutoffMore) {
									m = i;
									n = j;
									break;
								}
							}
						}
					}
					if (n != -1) {
						break;
					}
				}
			}
		}

		// build the cuts array
		DoubleBottomNFinder bf = new DoubleBottomNFinder(lowCuts);
		DoubleTopNFinder tf = new DoubleTopNFinder(highCuts);

		n++;
		for (int a = 0; a < dbufArray.length; a++) {
			ImageDataBuffer dbuf = dbufArray[a];
			int w = sizeArray[a].width;
			int h = sizeArray[a].height;

			if (!dbuf.hasMasks()) {
				for (int i = m; i < h; i++) {
					for (int j = n; j < w; j++) {
						double v = dbuf.getDouble(i, j);
						if (v == v && v != Double.POSITIVE_INFINITY && v != Double.NEGATIVE_INFINITY) {
							bf.check(v);
							tf.check(v);
						}
					}
					n = 0;
				}
			} else {
				for (int i = m; i < h; i++) {
					for (int j = n; j < w; j++) {
						if (!dbuf.isMasked(i, j)) {
							double v = dbuf.getDouble(i, j);
							if (v == v && v != Double.POSITIVE_INFINITY && v != Double.NEGATIVE_INFINITY) {
								bf.check(v);
								tf.check(v);
							}
						}
					}
					n = 0;
				}
			}
		}

		double lowCut = bf.getMax() * (1 - offsetrate) + bf.getMax2nd() * offsetrate;
		double highCut = tf.getMin() * (1 - offsetrate) + tf.getMin2nd() * offsetrate;

		return new double[] { lowCut, highCut };
	}

}