/*
 * FindBugs - Find bugs in Java programs
 * Copyright (C) 2004, University of Maryland
 *
 * This library 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 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package edu.umd.cs.findbugs.config;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import java.util.StringTokenizer;
import java.util.TreeSet;

import edu.umd.cs.findbugs.BugInstance;
import edu.umd.cs.findbugs.BugPattern;
import edu.umd.cs.findbugs.BugProperty;
import edu.umd.cs.findbugs.Detector;
import edu.umd.cs.findbugs.DetectorFactoryCollection;
import edu.umd.cs.findbugs.I18N;

/**
 * Settings for user filtering of warnings for a project.
 * This includes selecting particular bug categories
 * to view, as well as a minimum warning priority.
 * Includes support for encoding these settings as a String,
 * which can easily be stored as a persistent project property
 * in Eclipse.
 *
 * @see BugInstance
 * @author David Hovemeyer
 */
public class ProjectFilterSettings implements Cloneable {
	/** Text string for high priority. */
	public static final String HIGH_PRIORITY = "High";

	/** Text string for medium priority. */
	public static final String MEDIUM_PRIORITY = "Medium";

	/** Text string for low priority. */
	public static final String LOW_PRIORITY = "Low";

	/** Text string for experimental priority. */
	public static final String EXPERIMENTAL_PRIORITY = "Experimental";

	/** Default warning threshold priority. */
	public static final String DEFAULT_PRIORITY = MEDIUM_PRIORITY;

	/** Map of priority level names to their numeric values.  */
	private static Map<String, Integer> priorityNameToValueMap = new HashMap<String, Integer>();
	static {
		priorityNameToValueMap.put(HIGH_PRIORITY, (Detector.HIGH_PRIORITY));
		priorityNameToValueMap.put(MEDIUM_PRIORITY, (Detector.NORMAL_PRIORITY));
		priorityNameToValueMap.put(LOW_PRIORITY, (Detector.LOW_PRIORITY));
		priorityNameToValueMap.put(EXPERIMENTAL_PRIORITY, (Detector.EXP_PRIORITY));
	}

	/**
	 * The character used for delimiting whole fields in filter settings encoded as strings
	 */
	private static String FIELD_DELIMITER="|";
	/**
	 * The character used for delimiting list items in filter settings encoded as strings
	 */
	private static String LISTITEM_DELIMITER=",";

	// Fields
	private Set<String> activeBugCategorySet; // not used for much: hiddenBugCategorySet has priority.
	private Set<String> hiddenBugCategorySet;
	private String minPriority;
	private int minPriorityAsInt;
	private boolean displayFalseWarnings;

	/**
	 * Constructor.
	 * This is not meant to be called directly; use one of the factory methods instead.
	 */
	private ProjectFilterSettings() {
		DetectorFactoryCollection.instance(); // ensure detectors loaded

		// initially all known bug categories are active
		// using SortedSet to allow better revision control on saved sorted properties
		this.activeBugCategorySet = new TreeSet<String>( I18N.instance().getBugCategories() );
		this.hiddenBugCategorySet = new HashSet<String>();
		activeBugCategorySet.remove("NOISE");
		hiddenBugCategorySet.add("NOISE");
		setMinPriority(DEFAULT_PRIORITY);
		this.displayFalseWarnings = false;
	}

	/**
	 * Factory method to create a default ProjectFilterSettings object.
	 * Uses the default warning priority threshold, and enables
	 * all bug categories.
	 *
	 * @return a default ProjectFilterSettings object
	 */
	public static ProjectFilterSettings createDefault() {
		ProjectFilterSettings result = new ProjectFilterSettings();

		// Set default priority threshold
		result.setMinPriority(DEFAULT_PRIORITY);

		return result;
	}

	/**
	 * Create ProjectFilterSettings from an encoded string.
	 *
	 * @param s the encoded string
	 * @return the ProjectFilterSettings
	 */
	public static ProjectFilterSettings fromEncodedString(String s) {
		ProjectFilterSettings result = new ProjectFilterSettings();

		if (s.length() > 0) {
			int bar = s.indexOf(FIELD_DELIMITER);
			String minPriority;
			if (bar >= 0) {
				minPriority = s.substring(0, bar);
				s = s.substring(bar+1);
			} else {
				minPriority = s;
				s = "";
			}
			if (priorityNameToValueMap.get(minPriority) == null) {
				minPriority = DEFAULT_PRIORITY;
			}
			result.setMinPriority(minPriority);
		}

		if (s.length() > 0) {
			int bar = s.indexOf(FIELD_DELIMITER);
			String categories;
			if (bar >= 0) {
				categories = s.substring(0, bar);
				s = s.substring(bar+1);
			} else {
				categories = s;
				s = "";
			}
			StringTokenizer t = new StringTokenizer(categories, LISTITEM_DELIMITER);
			while (t.hasMoreTokens()) {
				String category = t.nextToken();
				// 'result' probably already contains 'category', since
				// it contains all known bug category keys by default.
				// But add it to the set anyway in case it is an unknown key.
				result.addCategory(category);
			}
		}

		if (s.length() > 0) {
			int bar = s.indexOf(FIELD_DELIMITER);
			String displayFalseWarnings;
			if (bar >= 0) {
				displayFalseWarnings = s.substring(0, bar);
				s = s.substring(bar+1);
			} else {
				displayFalseWarnings = s;
				s = "";
			}
			result.setDisplayFalseWarnings(Boolean.valueOf(displayFalseWarnings).booleanValue());
		}

		if (s.length() > 0) {
			// Can add other fields here...
			assert true;
		}



		return result;

	}


	/**
	 * set the hidden bug categories on the specifed ProjectFilterSettings
	 * from an encoded string
	 *
	 * @param result the ProjectFilterSettings from which to remove bug categories
	 * @param s the encoded string
	 * @see ProjectFilterSettings#hiddenFromEncodedString(ProjectFilterSettings, String)
	 */
	public static void hiddenFromEncodedString(ProjectFilterSettings result, String s) {

		if (s.length() > 0) {
			int bar = s.indexOf(FIELD_DELIMITER);
			String categories;
			if (bar >= 0) {
				categories = s.substring(0, bar);
			} else {
				categories = s;
			}
			StringTokenizer t = new StringTokenizer(categories, LISTITEM_DELIMITER);
			while (t.hasMoreTokens()) {
				String category = t.nextToken();
				result.removeCategory(category);
			}
		}

	}


	/**
	 * Return whether or not a warning should be displayed,
	 * according to the project filter settings.
	 *
	 * @param bugInstance the warning
	 * @return true if the warning should be displayed, false if not
	 */
	public boolean displayWarning(BugInstance bugInstance) {

		int priority = bugInstance.getPriority();
		if (priority > getMinPriorityAsInt()) {
			return false;
		}

		BugPattern bugPattern = bugInstance.getBugPattern();

		// HACK: it is conceivable that the detector plugin which generated
		// this warning is not available any more, in which case we can't
		// find out the category.  Let the warning be visible in this case.
		if (bugPattern != null && !containsCategory(bugPattern.getCategory())) {
			return false;
		}

		if (!displayFalseWarnings) {
			boolean isFalseWarning =
				!Boolean.valueOf(bugInstance.getProperty(BugProperty.IS_BUG, "true")).booleanValue();
			if (isFalseWarning) {
				return false;
			}
		}

		return true;
	}

	/**
	 * Set minimum warning priority threshold.
	 *
	 * @param minPriority the priority threshold: one of "High", "Medium", or "Low"
	 */
	public void setMinPriority(String minPriority) {
		this.minPriority = minPriority;

		Integer value = priorityNameToValueMap.get(minPriority);
		if (value == null) {
			value = priorityNameToValueMap.get(DEFAULT_PRIORITY);
			if (value == null) {
				throw new IllegalStateException();
			}
		}

		this.minPriorityAsInt = value.intValue();

	}

	/**
	 * Get the minimum warning priority threshold.
	 *
	 * @return minimum warning priority threshold: one of "High", "Medium", or "Low"
	 */
	public String getMinPriority() {
		return this.minPriority;
	}

	/**
	 * Return the minimum warning priority threshold as an integer.
	 *
	 * @return the minimum warning priority threshold as an integer
	 */
	public int getMinPriorityAsInt() {
		return minPriorityAsInt;
	}

	/**
	 * Add a bug category to the set of categories to be displayed.
	 *
	 * @param category the bug category: e.g., "CORRECTNESS"
	 */
	public void addCategory(String category) {
		this.hiddenBugCategorySet.remove(category);
		this.activeBugCategorySet.add(category);
	}

	/**
	 * Remove a bug category from the set of categories to be displayed.
	 *
	 * @param category the bug category: e.g., "CORRECTNESS"
	 */
	public void removeCategory(String category) {
		this.hiddenBugCategorySet.add(category);
		this.activeBugCategorySet.remove(category);
	}

	/**
	 * Clear all bug categories from the hidden list.
	 * So the effect is to enable all bug categories.
	 */
	public void clearAllCategories() {
		this.activeBugCategorySet.addAll(hiddenBugCategorySet);
		this.hiddenBugCategorySet.clear();
	}

	/**
	 * Returns false if the given category is hidden
	 * in the project filter settings.
	 *
	 * @param category the category
	 * @return false if the category is hidden, true if not
	 */
	public boolean containsCategory(String category) {
		// do _not_ consult the activeBugCategorySet: if not hidden return true.
		return !hiddenBugCategorySet.contains(category);
	}

	/**
	 * Return set of active (enabled) bug categories.
	 *
	 * Note that bug categories that are not explicity
	 * hidden will appear active even if they are not
	 * members of this set.
	 *
	 * @return the set of active categories
	 */
	public Set<String> getActiveCategorySet() {
		Set<String> result = new TreeSet<String>();
		result.addAll(this.activeBugCategorySet);
		return result;
	}

	/**
	 * Set whether or not false warnings should be displayed.
	 *
	 * @param displayFalseWarnings true if false warnings should be displayed,
	 *                             false if not
	 */
	public void setDisplayFalseWarnings(boolean displayFalseWarnings) {
		this.displayFalseWarnings = displayFalseWarnings;
	}

	/**
	 * Get whether or not false warnings should be displayed.
	 *
	 * @return true if false warnings should be displayed, false if not
	 */
	public boolean displayFalseWarnings() {
		return displayFalseWarnings;
	}

	/**
	 * Create a string containing the encoded form of the hidden bug categories
	 *
	 * @return an encoded string
	 */
	public String hiddenToEncodedString() {
		StringBuilder buf = new StringBuilder();
		// Encode hidden bug categories
		for (Iterator<String> i = hiddenBugCategorySet.iterator(); i.hasNext(); ) {
			buf.append(i.next());
			if (i.hasNext()) {
				buf.append(LISTITEM_DELIMITER);
			}
		}
		buf.append(FIELD_DELIMITER);

		return buf.toString();
	}

	/**
	 * Create a string containing the encoded form of the ProjectFilterSettings.
	 *
	 * @return an encoded string
	 */
	public String toEncodedString() {
		// Priority threshold
		StringBuilder buf = new StringBuilder();
		buf.append(getMinPriority());

		// Encode enabled bug categories. Note that these aren't really used for much.
		// They only come in to play when parsed by a version of FindBugs older than 1.1.
		buf.append(FIELD_DELIMITER);
		for (Iterator<String> i = activeBugCategorySet.iterator(); i.hasNext(); ) {
			buf.append(i.next());
			if (i.hasNext()) {
				buf.append(LISTITEM_DELIMITER);
			}

		}

		// Whether to display false warnings
		buf.append(FIELD_DELIMITER);
		buf.append(displayFalseWarnings ? "true" : "false");

		return buf.toString();
	}

	@Override
		 public String toString() {
		return toEncodedString();
	}

	/* (non-Javadoc)
	 * @see java.lang.Object#equals(java.lang.Object)
	 */
	@Override
		 public boolean equals(Object obj) {
		if (obj == null || obj.getClass() != this.getClass()) {
			return false;
		}
		ProjectFilterSettings other = (ProjectFilterSettings) obj;

		if (!this.getMinPriority().equals(other.getMinPriority())) {
			return false;
		}

		// don't compare the activeBugCategorySet. compare the hiddenBugCategorySet only
		if (!this.hiddenBugCategorySet.equals(other.hiddenBugCategorySet)) {
			return false;
		}

		if (this.displayFalseWarnings != other.displayFalseWarnings) {
			return false;
		}

		return true;
	}


	/* (non-Javadoc)
	 * @see java.lang.Object#clone()
	 */
	@Override
		 public Object clone()  {
		try {
			// Create shallow copy
			ProjectFilterSettings clone = (ProjectFilterSettings) super.clone();

			// Copy field contents
			clone.hiddenBugCategorySet = new HashSet<String>();
			clone.hiddenBugCategorySet.addAll(this.hiddenBugCategorySet);
			clone.activeBugCategorySet = new TreeSet<String>();
			clone.activeBugCategorySet.addAll(this.activeBugCategorySet);
			clone.setMinPriority(this.getMinPriority());
			clone.displayFalseWarnings = this.displayFalseWarnings;

			return clone;
		} catch (CloneNotSupportedException e) {
			// Should not happen!
			throw new AssertionError(e);
		}

	}

	/* (non-Javadoc)
	 * @see java.lang.Object#hashCode()
	 */
	@Override
		 public int hashCode() {
		return minPriority.hashCode()
			+ 1009 * hiddenBugCategorySet.hashCode()
			+ (displayFalseWarnings ? 7919 : 0);
	}

	/**
	 * Convert an integer warning priority threshold value to
	 * a String.
	 */
	public static String getIntPriorityAsString(int prio) {
		String minPriority;
		switch (prio) {
			case Detector.EXP_PRIORITY:
				minPriority = ProjectFilterSettings.EXPERIMENTAL_PRIORITY;
				break;
			case Detector.LOW_PRIORITY:
				minPriority = ProjectFilterSettings.LOW_PRIORITY;
				break;
			case Detector.NORMAL_PRIORITY:
				minPriority = ProjectFilterSettings.MEDIUM_PRIORITY;
				break;
			case Detector.HIGH_PRIORITY:
				minPriority = ProjectFilterSettings.HIGH_PRIORITY;
				break;
			default:
				minPriority = ProjectFilterSettings.DEFAULT_PRIORITY;
				break;
		}
		return minPriority;
	}
}

// vim:ts=4
