package com.cardence.lawshelf.cfr;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.apache.commons.lang.ArrayUtils;
import org.apache.commons.lang.StringUtils;
import org.apache.commons.lang.math.NumberUtils;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.annotation.Lazy;
import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Component;

@Component
@Scope(value = BeanDefinition.SCOPE_SINGLETON)
@Lazy(value = false)
public class CfrSectionTracker implements ApplicationContextAware {

	private static final List<String> HEADING_DELIMITERS = getHeadingSplitDelimiterList();
	private static final List<String> REFERENCE_DELIMITERS = getReferenceSplitDelimiterList();

	private enum SIDE {
		LEFT, RIGHT
	};

	private Map<String, String> childReferenceMapToParentReference;
	private Map<String, String> referenceMapToHeading;
	private Map<String, CfrSection> allCfrSections;

	private static ApplicationContext appctx;
	private static CfrSectionTracker me;

	public static CfrSectionTracker getInstance() {
		if (me == null) {
			me = appctx.getBean(CfrSectionTracker.class);
		}
		return me;
	}

	public void addNewChildHeadingForParentReference(CfrSection section, String parentReference) {
		final String childReference = getChildReference(section);
		this.getAllCfrSections().put(section.getHeading(), section);
		this.getReferenceMapToHeading().put(childReference, section.getHeading());
		this.mapChildReferenceToParentReference(childReference, parentReference);
	}

	private String getChildReference(CfrSection section) {
		try {
			return parseReferenceFromHeading(section.getHeading());
		} catch (Exception e) {
			return section.getCategoryLevel();
		}
	}

	public void mapChildReferenceToParentReference(String childReference, String parentReference) {
		if (StringUtils.isNotBlank(childReference) && StringUtils.isNotBlank(parentReference)) {
			this.getChildReferenceMapToParentReference().put(childReference, parentReference);
		}
	}

	public String getTitleTextForReference(String reference) {
		final String heading = this.getReferenceMapToHeading().get(reference);
		if (heading == null) {
			return null;
		} else {
			return parseTitleFromHeading(heading);
		}
	}

	public String getFullUniqueSourceReferenceForReference(String reference) {
		final String myCategoryLevel = parseCategoryLevelFromReference(reference);
		final String parentReference = this.getChildReferenceMapToParentReference().get(reference);
		if (parentReference == null) {
			return myCategoryLevel;
		} else {
			return appendCategoryLevelToSourceReference(myCategoryLevel,
					getFullUniqueSourceReferenceForReference(parentReference));
		}
	}

	public String getFullUniqueSourceReferenceForReferenceAndCategoryLevel(String reference, String categoryLevel) {
		final String parentReference = this.getChildReferenceMapToParentReference().get(reference);
		if (parentReference == null) {
			return categoryLevel;
		} else {
			return appendCategoryLevelToSourceReference(categoryLevel,
					getFullUniqueSourceReferenceForReference(parentReference));
		}
	}

	public String appendCategoryLevelToSourceReference(String categoryLevel, String sourceReference) {
		return sourceReference + "." + categoryLevel;
	}

	public String getHeadingForReference(String reference) {
		return this.getChildReferenceMapToParentReference().get(reference);
	}

	public static String parseCategoryTypeFromReference(String reference) {
		return translateCategoryTypeText(getLeftSideOfReference(reference));
	}

	public static String translateCategoryTypeText(String originalText) {
		if (StringUtils.isBlank(originalText)) {
			return originalText;
		}

		if (StringUtils.contains(originalText, "\u00A7") || StringUtils.contains(originalText, "&sect;")) {
			return "SECTION";
		}

		return originalText;
	}

	public static String parseCategoryLevelFromReference(String reference) {
		return getRightSideOfReference(reference);
	}

	public static String parseReferenceFromHeading(String heading) {
		return getLeftSideOfHeading(heading);
	}

	public static String parseTitleFromHeading(String heading) {
		return getRightSideOfHeading(heading);
	}

	private Map<String, String> getReferenceMapToHeading() {
		if (this.referenceMapToHeading == null) {
			this.referenceMapToHeading = new HashMap<String, String>();
		}
		return this.referenceMapToHeading;
	}

	private Map<String, String> getChildReferenceMapToParentReference() {
		if (this.childReferenceMapToParentReference == null) {
			this.childReferenceMapToParentReference = new HashMap<String, String>();
		}
		return this.childReferenceMapToParentReference;

	}

	private Map<String, CfrSection> getAllCfrSections() {
		if (this.allCfrSections == null) {
			this.allCfrSections = new HashMap<String, CfrSection>();
		}
		return this.allCfrSections;

	}

	private final static String getLeftSideOfHeading(String heading) {
		return getValueFromStringForSide(getHeadingLeftAndRightSides(heading), SIDE.LEFT);

	}

	private final static String getRightSideOfHeading(String heading) {
		return getValueFromStringForSide(getHeadingLeftAndRightSides(heading), SIDE.RIGHT);
	}

	private final static String getLeftSideOfReference(String reference) {
		return getValueFromStringForSide(getReferenceLeftAndRightSides(reference), SIDE.LEFT);
	}

	private final static String getRightSideOfReference(String reference) {
		return getValueFromStringForSide(getReferenceLeftAndRightSides(reference), SIDE.RIGHT);
	}

	private final static String getValueFromStringForSide(String[] stringParts, SIDE side) {
		int indexOfHeadingSplit = 0;
		switch (side) {
		case LEFT:
			indexOfHeadingSplit = 0;
			break;
		case RIGHT:
			indexOfHeadingSplit = 1;
			break;
		}
		if (stringParts == null) {
			return null;
		} else {
			String s = StringUtils.replace(stringParts[indexOfHeadingSplit], "[", "");
			return StringUtils.trimToEmpty(s);
		}
	}

	private final static String[] getHeadingLeftAndRightSides(String heading) {
		return splitStringWithDelimiters(heading, HEADING_DELIMITERS);
	}

	private final static String[] getReferenceLeftAndRightSides(String reference) {
		return splitStringWithDelimiters(reference, REFERENCE_DELIMITERS);
	}

	private final static String[] splitStringWithDelimiters(String stringToSplit, List<String> delimiters) {
		for (Iterator<String> it = delimiters.iterator(); it.hasNext();) {
			String delim = it.next();
			String[] headingParts = StringUtils.splitByWholeSeparator(stringToSplit, delim);
			if (headingParts != null && headingParts.length == 2) {
				return headingParts;
			} else if (headingParts.length > 2) {
				if (NumberUtils.isDigits("" + headingParts[1].charAt(0))) {
					final String firstPart = headingParts[0] + delim + headingParts[1];
					final String lastPart = StringUtils.join(ArrayUtils.subarray(headingParts, 2, headingParts.length),
							delim);
					return new String[] { firstPart, lastPart };
				} else {
					return new String[] { headingParts[0], StringUtils.substringAfter(stringToSplit, delim) };
				}
			}
		}
		throw new RuntimeException("Cannot split string " + stringToSplit + " into two parts");
	}

	private final static List<String> getHeadingSplitDelimiterList() {
		final ArrayList<String> delimList = new ArrayList<String>();

		// delimList.add("&ndash;"); // en dash
		delimList.add("\u2014"); // em dash
		// delimList.add("&mdash;"); // em dash
		delimList.add("\u2015"); // horizontal bar
		delimList.add("\u2012"); // figure dash
		delimList.add("\u2013"); // en dash

		delimList.add("-");
		delimList.add(" ["); // cfr uses this in reserved columns
		delimList.add("["); // cfr uses this in reserved columns
		return delimList;
	}

	private final static List<String> getReferenceSplitDelimiterList() {
		final ArrayList<String> delimList = new ArrayList<String>();
		delimList.add(" ");
		return delimList;
	}

	public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
		appctx = applicationContext;
	}

}