/*******************************************************************************
 * Copyright (c) 2000, 2008 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Obeo - code cleanup and tweaking for use within ATL
 *******************************************************************************/
package org.eclipse.m2m.atl.adt.ui.preferences;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Observable;

import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.ProjectScope;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.core.runtime.preferences.DefaultScope;
import org.eclipse.core.runtime.preferences.IEclipsePreferences;
import org.eclipse.core.runtime.preferences.IScopeContext;
import org.eclipse.core.runtime.preferences.InstanceScope;
import org.eclipse.m2m.atl.adt.ui.AtlUIPlugin;

/**
 * The model for the set of profiles which are available in the workbench.
 * 
 */
public abstract class ProfileManager extends Observable {

    public static final class KeySet {

		private final List<String> fKeys;
		private final String fNodeName;

		public KeySet(String nodeName, List<String> keys) {
			fNodeName = nodeName;
			fKeys = keys;
        }

        public String getNodeName() {
	        return fNodeName;
        }

        public List<String> getKeys() {
	        return fKeys;
        }
    }

	/**
     * A prefix which is prepended to every ID of a user-defined profile, in order
     * to differentiate it from a built-in profile.
     */
	public final static String ID_PREFIX= "_"; //$NON-NLS-1$

	/**
	 * Represents a profile with a unique ID, a name and a map
	 * containing the code formatter settings.
	 */
	public static abstract class Profile implements Comparable<Profile> {

		public abstract String getName();
		public abstract Profile rename(String name, ProfileManager manager);

		public abstract Map<String, String> getSettings();
		public abstract void setSettings(Map<String, String> settings);

		public boolean hasEqualSettings(Map<String, String> otherMap, Collection<String> allKeys) {
			Map<String, String> settings = getSettings();
			for (Iterator<String> iter = allKeys.iterator(); iter.hasNext(); ){
				String key = (String) iter.next();
				Object other = otherMap.get(key);
				Object curr = settings.get(key);
				if (other == null) {
					if (curr != null) {
						return false;
					}
				} else if (!other.equals(curr)) {
					return false;
				}
			}
			return true;
		}

		public abstract boolean isProfileToSave();

		public abstract String getID();

		public boolean isSharedProfile() {
			return false;
		}

		public boolean isBuiltInProfile() {
			return false;
		}
	}

	/**
	 * Represents a built-in profile. The state of a built-in profile
	 * cannot be changed after instantiation.
	 */
	public static final class BuiltInProfile extends Profile {
		private final String fName;
		private final String fID;
		private final Map<String, String> fSettings;
		private final int fOrder;

		public BuiltInProfile(String ID, String name, Map<String, String> settings, int order) {
			fName = name;
			fID = ID;
			fSettings = settings;
			fOrder = order;
		}

		public String getName() {
			return fName;
		}

		public Profile rename(String name, ProfileManager manager) {
			final String trimmed = name.trim();
		 	CustomProfile newProfile = new CustomProfile(trimmed, fSettings);
		 	manager.addProfile(newProfile);
			return newProfile;
		}

		public Map<String, String> getSettings() {
			return fSettings;
		}

		public String getID() {
			return fID;
		}

		public boolean isProfileToSave() {
			return false;
		}

		public boolean isBuiltInProfile() {
			return true;
		}

		public int compareTo(Profile o) {
			if (o instanceof BuiltInProfile) {
				return fOrder - ((BuiltInProfile)o).fOrder;
			}
			return -1;
		}

		@Override
		public void setSettings(Map<String, String> settings) {
		}

	}

	/**
	 * Represents a user-defined profile. A custom profile can be modified after instantiation.
	 */
	public static class CustomProfile extends Profile {
		private String fName;
		private Map<String, String> fSettings;
		protected ProfileManager fManager;

		public CustomProfile(String name, Map<String, String> settings) {
			fName = name;
			fSettings = settings;
		}

		public String getName() {
			return fName;
		}

		public Profile rename(String name, ProfileManager manager) {
			final String trimmed = name.trim();
			if (trimmed.equals(getName()))
				return this;

			String oldID = getID(); // remember old id before changing name
			fName = trimmed;

			manager.profileRenamed(this, oldID);
			return this;
		}

		public Map<String, String> getSettings() {
			return fSettings;
		}

		public void setSettings(Map<String, String> settings) {
			if (settings == null)
				throw new IllegalArgumentException();
			fSettings = settings;
			if (fManager != null) {
				fManager.profileChanged(this);
			}
		}

		public String getID() {
			return ID_PREFIX + fName;
		}

		public void setManager(ProfileManager profileManager) {
			fManager = profileManager;
		}

		public ProfileManager getManager() {
			return fManager;
		}

		public boolean isProfileToSave() {
			return true;
		}

		public int compareTo(Profile o) {
			if (o instanceof SharedProfile) {
				return -1;
			}
			if (o instanceof CustomProfile) {
				return getName().compareToIgnoreCase(((Profile)o).getName());
			}
			return 1;
		}

	}

	public final class SharedProfile extends CustomProfile {

		public SharedProfile(String oldName, Map<String, String> options) {
			super(oldName, options);
		}

		public Profile rename(String name, ProfileManager manager) {
			CustomProfile profile = new CustomProfile(name.trim(), getSettings());

			manager.profileReplaced(this, profile);
			return profile;
		}

		public String getID() {
			return SHARED_PROFILE;
		}

		public final int compareTo(Profile o) {
			return 1;
		}

		public boolean isProfileToSave() {
			return false;
		}

		public boolean isSharedProfile() {
			return true;
		}
	}


	/**
	 * The possible events for observers listening to this class.
	 */
	public final static int SELECTION_CHANGED_EVENT = 1;
	public final static int PROFILE_DELETED_EVENT = 2;
	public final static int PROFILE_RENAMED_EVENT = 3;
	public final static int PROFILE_CREATED_EVENT = 4;
	public final static int SETTINGS_CHANGED_EVENT = 5;


	/**
	 * The key of the preference where the selected profile is stored.
	 */
	private final String fProfileKey;

	private final static String SHARED_PROFILE= "org.eclipse.jdt.ui.default.shared"; //$NON-NLS-1$


	/**
	 * A map containing the available profiles, using the IDs as keys.
	 */
	private final Map<String, Profile> fProfiles;

	/**
	 * The available profiles, sorted by name.
	 */
	private final List<Profile> fProfilesByName;


	/**
	 * The currently selected profile.
	 */
	private Profile fSelected;


	/**
	 * The keys of the options to be saved with each profile
	 */
	private final KeySet[] fKeySets;

	private final PreferencesAccess fPreferencesAccess;

	/**
	 * Create and initialize a new profile manager.
	 * @param profiles Initial custom profiles (List of type <code>CustomProfile</code>)
	 */
	public ProfileManager(
			List<Profile> profiles,
			IScopeContext context,
			PreferencesAccess preferencesAccess,
			KeySet[] keySets,
			String profileKey) {

		fPreferencesAccess = preferencesAccess;
		fKeySets = keySets;
		fProfileKey = profileKey;

		fProfiles = new HashMap<String, Profile>();
		fProfilesByName = new ArrayList<Profile>();

		for (final Iterator<Profile> iter = profiles.iterator(); iter.hasNext();) {
			final Profile profile = iter.next();
			if (profile instanceof CustomProfile) {
				((CustomProfile)profile).setManager(this);
			}
			fProfiles.put(profile.getID(), profile);
			fProfilesByName.add(profile);
		}

		Collections.sort(fProfilesByName);

		String profileId = getSelectedProfileId(fPreferencesAccess.getInstanceScope());

		Profile profile = fProfiles.get(profileId);
		if (profile == null) {
			profile = getDefaultProfile();
		}
		fSelected = profile;

		if (context.getName() == ProjectScope.SCOPE) {
			String projProfileId = context.getNode(AtlUIPlugin.getPluginId()).get(AtlCodeFormatterPropertyPage.CURRENT_PROFILE_KEY, null);
			if(projProfileId != null) {
				Profile curr = fProfiles.get(projProfileId);
				if(curr != null)
					fSelected = curr;
			}
		}
	}

	protected String getSelectedProfileId(IScopeContext instanceScope) {
		String profileId = instanceScope.getNode(AtlUIPlugin.getPluginId()).get(fProfileKey, null);
		if (profileId == null) {
			// request from bug 129427
			profileId = new DefaultScope().getNode(AtlUIPlugin.getPluginId()).get(fProfileKey, null);
		}
	    return profileId;
    }

	/**
	 * Notify observers with a message. The message must be one of the following:
	 * @param message Message to send out
	 *
	 * @see #SELECTION_CHANGED_EVENT
	 * @see #PROFILE_DELETED_EVENT
	 * @see #PROFILE_RENAMED_EVENT
	 * @see #PROFILE_CREATED_EVENT
	 * @see #SETTINGS_CHANGED_EVENT
	 */
	protected void notifyObservers(int message) {
		setChanged();
		notifyObservers(new Integer(message));
	}

	public static boolean hasProjectSpecificSettings(IScopeContext context, KeySet[] keySets) {
		for (int i= 0; i < keySets.length; i++) {
	        KeySet keySet = keySets[i];
	        IEclipsePreferences preferences = context.getNode(keySet.getNodeName());
	        for (final Iterator<String> keyIter = keySet.getKeys().iterator(); keyIter.hasNext();) {
	            final String key = keyIter.next();
	            Object val = preferences.get(key, null);
	            if (val != null) {
	            	return true;
	            }
            }
        }
		return false;
	}

	public boolean hasProjectSpecificSettings(IScopeContext context) {
		return hasProjectSpecificSettings(context, fKeySets);
	}

	private boolean updatePreferences(IEclipsePreferences prefs, List<String> keys, Map<String, String> profileOptions) {
		boolean hasChanges= false;
		for (final Iterator<String> keyIter = keys.iterator(); keyIter.hasNext(); ) {
			final String key = keyIter.next();
			final String oldVal = prefs.get(key, null);
			final String val = profileOptions.get(key);
			if (val == null) {
				if (oldVal != null) {
					prefs.remove(key);
					hasChanges = true;
				}
			} else if (!val.equals(oldVal)) {
				prefs.put(key, val);
				hasChanges = true;
			}
		}
		return hasChanges;
	}


	/**
	 * Update all formatter settings with the settings of the specified profile.
	 * @param profile The profile to write to the preference store
	 */
	private void writeToPreferenceStore(Profile profile, IScopeContext context) {
		final Map<String, String> profileOptions= profile.getSettings();

		for (int i= 0; i < fKeySets.length; i++) {
	        updatePreferences(context.getNode(fKeySets[i].getNodeName()), fKeySets[i].getKeys(), profileOptions);
        }

		final IEclipsePreferences uiPrefs= context.getNode(AtlUIPlugin.getPluginId());
		if (context.getName() == InstanceScope.SCOPE) {
			uiPrefs.put(fProfileKey, profile.getID());
		} else if (context.getName() == ProjectScope.SCOPE && !profile.isSharedProfile()) {
			uiPrefs.put(fProfileKey, profile.getID());
		}
	}


	/**
	 * Get an immutable list as view on all profiles, sorted alphabetically. Unless the set
	 * of profiles has been modified between the two calls, the sequence is guaranteed to
	 * correspond to the one returned by <code>getSortedNames</code>.
	 * @return a list of elements of type <code>Profile</code>
	 *
	 * @see #getSortedDisplayNames()
	 */
	public List<Profile> getSortedProfiles() {
		return Collections.unmodifiableList(fProfilesByName);
	}

	/**
	 * Get the names of all profiles stored in this profile manager, sorted alphabetically. Unless the set of
	 * profiles has been modified between the two calls, the sequence is guaranteed to correspond to the one
	 * returned by <code>getSortedProfiles</code>.
	 * @return All names, sorted alphabetically
	 * @see #getSortedProfiles()
	 */
	public String[] getSortedDisplayNames() {
		final String[] sortedNames = new String[fProfilesByName.size()];
		int i = 0;
		for (final Iterator<Profile> iter = fProfilesByName.iterator(); iter.hasNext();) {
			Profile curr = iter.next();
			sortedNames[i++] = curr.getName();
		}
		return sortedNames;
	}

	/**
	 * Get the profile for this profile id.
	 * @param ID The profile ID
	 * @return The profile with the given ID or <code>null</code>
	 */
	public Profile getProfile(String ID) {
		return fProfiles.get(ID);
	}

	/**
	 * Activate the selected profile, update all necessary options in
	 * preferences and save profiles to disk.
	 */
	public void commitChanges(IScopeContext scopeContext) {
		if (fSelected != null) {
			writeToPreferenceStore(fSelected, scopeContext);
		}
	}

	public void clearAllSettings(IScopeContext context) {
		for (int i = 0; i < fKeySets.length; i++) {
	        updatePreferences(context.getNode(fKeySets[i].getNodeName()), fKeySets[i].getKeys(), new HashMap<String, String>());
        }

		final IEclipsePreferences uiPrefs = context.getNode(AtlUIPlugin.getPluginId());
		uiPrefs.remove(fProfileKey);
	}

	/**
	 * Get the currently selected profile.
	 * @return The currently selected profile.
	 */
	public Profile getSelected() {
		return fSelected;
	}

	/**
	 * Set the selected profile. The profile must already be contained in this profile manager.
	 * @param profile The profile to select
	 */
	public void setSelected(Profile profile) {
		final Profile newSelected = fProfiles.get(profile.getID());
		if (newSelected != null && !newSelected.equals(fSelected)) {
			fSelected = newSelected;
			notifyObservers(SELECTION_CHANGED_EVENT);
		}
	}

	/**
	 * Check whether a user-defined profile in this profile manager
	 * already has this name.
	 * @param name The name to test for
	 * @return Returns <code>true</code> if a profile with the given name exists
	 */
	public boolean containsName(String name) {
		for (Profile curr : fProfilesByName) {
			if (name.equals(curr.getName())) {
				return true;
			}
		}
		return false;
	}

	/**
	 * Add a new custom profile to this profile manager.
	 * @param profile The profile to add
	 */
	public void addProfile(CustomProfile profile) {
		profile.setManager(this);
		final CustomProfile oldProfile = (CustomProfile)fProfiles.get(profile.getID());
		if (oldProfile != null) {
			fProfiles.remove(oldProfile.getID());
			fProfilesByName.remove(oldProfile);
			oldProfile.setManager(null);
		}
		fProfiles.put(profile.getID(), profile);
		fProfilesByName.add(profile);
		Collections.sort(fProfilesByName);
		fSelected = profile;
		notifyObservers(PROFILE_CREATED_EVENT);
	}

	/**
	 * Delete the currently selected profile from this profile manager. The next profile
	 * in the list is selected.
	 * @return true if the profile has been successfully removed, false otherwise.
	 */
	public boolean deleteSelected() {
		if (!(fSelected instanceof CustomProfile))
			return false;

		return deleteProfile((CustomProfile)fSelected);
	}

	public boolean deleteProfile(CustomProfile profile) {
	    int index = fProfilesByName.indexOf(profile);

		fProfiles.remove(profile.getID());
		fProfilesByName.remove(profile);

		profile.setManager(null);

		if (index >= fProfilesByName.size())
			index--;
		fSelected = fProfilesByName.get(index);

		if (!profile.isSharedProfile()) {
			updateProfilesWithName(profile.getID(), null, false);
		}

		notifyObservers(PROFILE_DELETED_EVENT);
		return true;
    }


	public void profileRenamed(CustomProfile profile, String oldID) {
		fProfiles.remove(oldID);
		fProfiles.put(profile.getID(), profile);

		if (!profile.isSharedProfile()) {
			updateProfilesWithName(oldID, profile, false);
		}

		Collections.sort(fProfilesByName);
		notifyObservers(PROFILE_RENAMED_EVENT);
	}

	public void profileReplaced(CustomProfile oldProfile, CustomProfile newProfile) {
		fProfiles.remove(oldProfile.getID());
		fProfiles.put(newProfile.getID(), newProfile);
		fProfilesByName.remove(oldProfile);
		fProfilesByName.add(newProfile);
		Collections.sort(fProfilesByName);

		if (!oldProfile.isSharedProfile()) {
			updateProfilesWithName(oldProfile.getID(), null, false);
		}

		setSelected(newProfile);
		notifyObservers(PROFILE_CREATED_EVENT);
		notifyObservers(SELECTION_CHANGED_EVENT);
	}

	public void profileChanged(CustomProfile profile) {
		if (!profile.isSharedProfile()) {
			updateProfilesWithName(profile.getID(), profile, true);
		}

		notifyObservers(SETTINGS_CHANGED_EVENT);
	}


	protected void updateProfilesWithName(String oldName, Profile newProfile, boolean applySettings) {
		IProject[] projects = ResourcesPlugin.getWorkspace().getRoot().getProjects();
		for (int i = 0; i < projects.length; i++) {
			IScopeContext projectScope = fPreferencesAccess.getProjectScope(projects[i]);
			IEclipsePreferences node = projectScope.getNode(AtlUIPlugin.getPluginId());
			String profileId = node.get(fProfileKey, null);
			if (oldName.equals(profileId)) {
				if (newProfile == null) {
					node.remove(fProfileKey);
				} else {
					if (applySettings) {
						writeToPreferenceStore(newProfile, projectScope);
					} else {
						node.put(fProfileKey, newProfile.getID());
					}
				}
			}
		}

		IScopeContext instanceScope = fPreferencesAccess.getInstanceScope();
		final IEclipsePreferences uiPrefs = instanceScope.getNode(AtlUIPlugin.getPluginId());
		if (newProfile != null && oldName.equals(uiPrefs.get(fProfileKey, null))) {
			writeToPreferenceStore(newProfile, instanceScope);
		}
	}

    public abstract Profile getDefaultProfile();

}