package com.qxueyou.scc.admin.progress.service.impl;


/**
 * ѧϰ½ø¶È¹¤¾ß¼ÆËãÀà
 *
 * @author xiadehu
 *
 */
public class StudyProgressUtils {

	private final static int POS_BEFORE = 0;

	private final static int POS_IN = 1;

	private final static int POS_AFTER = 2;

	/**
	 * еÄѧϰ½ø¶ÈºÍÔ­Óнø¶ÈºÏ²¢¹²ÓÐÁùÖֺϲ¢¶¯×÷
	 */
	private final static int ACTION_INSERT = 0;

	private final static int ACTION_MERGE_01 = 1;

	private final static int ACTION_MERGE_02 = 2;

	private final static int ACTION_MERGE_11 = 3;

	private final static int ACTION_MERGE_12 = 4;

	private final static int ACTION_CONTINUE = 5;

	/**
	 * ºÏ²¢Ñ§Ï°½ø¶È
	 *
	 * @param orig
	 *            ÒÑѧϰ½ø¶È
	 * @param start
	 *            ¿ªÊ¼Î»ÖÃ
	 * @param end
	 *            ½áÊøλÖÃ
	 * @return
	 */
	public static Double[][] merge(Double[][] orig, Double start, Double end) {

		// ÖмäºÏ²¢½á¹û
		Double[][] result = new Double[orig.length + 1][2];

		int j = 0;
		int i = 0;
		boolean breakFlag = false;

		// ÖðÒ»¶Ô±ÈÅжÏÒÑÓÐѧϰ½ø¶È
		for (; i < orig.length; i++) {

			int action = action(orig[i], start, end);

			switch (action) {
			case ACTION_INSERT: {
				result[j++] = new Double[] { start, end };
				result[j++] = orig[i];
				breakFlag = true;
				break;
			}
			case ACTION_MERGE_01: {
				result[j++] = new Double[] { start, orig[i][1] };
				breakFlag = true;
				break;
			}
			case ACTION_MERGE_02:
				break;
			case ACTION_MERGE_11: {
				result[j++] = orig[i];
				breakFlag = true;
				break;
			}
			case ACTION_MERGE_12: {
				start = orig[i][0];
				break;
			}
			case ACTION_CONTINUE: {
				result[j++] = orig[i];
				break;
			}
			}

			if (breakFlag) {
				break;
			}
		}

		// Ìí¼ÓÔ­ÓÐѧϰ½ø¶ÈµÄÊ£Óಿ·Ö
		for (i++; i < orig.length; i++) {
			result[j++] = orig[i];
		}

		// Èç¹û±¾´ÎѧϰÖÕֹλÖó¬³öÒÔÍùËùÓÐѧϰ½ø¶È£¬ÔòÌí¼Óµ½×îºó
		if (orig.length == 0 ) {
			result[j++] = new Double[] { start, end };
		}else if(pos(end, orig[orig.length - 1]) == POS_AFTER){
			result[j++] = new Double[] { start, end };
		}

		// ×îÖպϲ¢½á¹û£¬È¥µôÖмäºÏ²¢½á¹ûµÄ¶à³öΪ¿ÕµÄÔªËØ
		Double[][] finalResult = new Double[j][2];

		for (int k = 0; k < result.length; k++) {
			if (result[k][0] == 0 && result[k][1] == 0 && k>0) {
				break;
			}
			finalResult[k] = result[k];
		}

		return finalResult;

	}

	/**
	 * ͳ¼Æѧϰ½ø¶È
	 *
	 * @param orig
	 *            È«²¿Ñ§Ï°½ø¶È
	 * @return
	 */
	public static Double sum(Double[][] orig) {

		Double sum = 0.0;

		for (Double[] item : orig) {
			sum += (item[1] - item[0] + 1);
		}
		return sum;

	}

	private static int action(Double[] segment, Double start, Double end) {
		int startPos = pos(start, segment);
		int endPos = pos(end, segment);

		if (POS_BEFORE == endPos) {
			return ACTION_INSERT;
		}

		if (POS_BEFORE == startPos && POS_IN == endPos) {
			return ACTION_MERGE_01;
		}

		if (POS_BEFORE == startPos && POS_AFTER == endPos) {
			return ACTION_MERGE_02;
		}

		if (POS_IN == startPos && POS_IN == endPos) {
			return ACTION_MERGE_11;
		}

		if (POS_IN == startPos && POS_AFTER == endPos) {
			return ACTION_MERGE_12;
		}

		if (POS_AFTER == startPos) {
			return ACTION_CONTINUE;
		}

		return 0;

	}

	private static int pos(Double index, Double[] range) {
		if (index < range[0]) {
			return POS_BEFORE;
		}
		if (index >= range[0] && index <= range[1]) {
			return POS_IN;
		}
		return POS_AFTER;
	}



}