/*
 * Copyright (C) 2003-2012 eXo Platform SAS.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
package org.exoplatform.commons.api.settings;

import org.exoplatform.commons.api.settings.data.Context;
import org.exoplatform.commons.api.settings.data.Scope;

import java.util.List;
import java.util.Map;
import java.util.Set;

/**
 * Stores and removes a value associated with a key.
 * 
 * @LevelAPI Experimental
 */
public interface SettingService {

  /**
   * Sets a value with the key that is composed by context, scope, key. The value
   * will be saved in the database.
   *
   * @param context The context with which the specified value is associated.
   * @param scope The scope with which the specified value is associated.
   * @param key The key with which the specified value is associated.
   * @param value The value associated with the specified key.
   * @LevelAPI Experimental
   */
  public void set(Context context, Scope scope, String key, SettingValue<?> value);

  /**
   * Removes a value associated with a specified composite key.
   *
   * @param context The context with which the specified value is associated.
   * @param scope The scope with which the specified value is associated.
   * @param key The key with which the specified value is associated.
   * @LevelAPI Experimental
   */
  public void remove(Context context, Scope scope, String key);

  /**
   * Removes all values associated with a specified context and scope from the
   * database.
   *
   * @param context The context with which the specified value is associated. The
   *          context type must be USER and context, and Id must not be "null".
   * @param scope The scope with which the specified value is associated. The
   *          scope.id must not be "null".
   * @LevelAPI Experimental
   */
  public void remove(Context context, Scope scope);

  /**
   * Removes all values associated with a specified context from the database.
   * 
   * @param context The context with which the specified value is associated. The
   *          context type must be USER and context, and Id must not be "null".
   * @LevelAPI Experimental
   */
  public void remove(Context context);

  /**
   * Gets values associated with a specified composite key (context, scope, key)
   * in the database.
   *
   * @param context The context with which the specified value is associated. The
   *          context type must be USER and context and Id must not be "null".
   * @param scope The scope with which the specified value is associated. The
   *          scope.id must not be "null".
   * @param key The key with which the specified value is associated.
   * @LevelAPI Experimental
   */
  public SettingValue<?> get(Context context, Scope scope, String key);

  /**
   * Returns the total count of contexts by type
   *
   * @param contextType context type name ('USER' OR 'GLOBAL')
   * @return count of contexts by type
   */
  default long countContextsByType(String contextType) {
    return 0;
  }

  /**
   * Returns context names by type
   *
   * @param contextType context type name ('USER' OR 'GLOBAL')
   * @param offset query offset
   * @param limit query max results
   * @return the list of context names
   */
  default List<String> getContextNamesByType(String contextType, int offset, int limit) {
    return null;
  }

  /**
   * Get settings related to a scope and a context
   *
   * @param context {@link Context} used to search settings
   * @return {@link Map} of settings with key = setting name and as value =
   *         corresponding {@link SettingValue}
   */
  Map<Scope, Map<String, SettingValue<String>>> getSettingsByContext(Context context);

  /**
   * Gets a list of names of contexts of a chosen type that have a setting
   * associated to a dedicated scope
   *
   * @param contextType type of context used in filter
   * @param scopeType type of scope used in filter
   * @param scopeName name of scope used in filter
   * @param settingName name of setting used in filter
   * @param offset search query offset
   * @param limit search query limit
   * @return a {@link List} of {@link String} for filtered context names
   */
  List<Context> getContextsByTypeAndScopeAndSettingName(String contextType,
                                                        String scopeType,
                                                        String scopeName,
                                                        String settingName,
                                                        int offset,
                                                        int limit);

  /**
   * Gets a list of names of contexts of a chosen type that doesn't have settings
   * associated to a dedicated scope
   *
   * @param contextType type of context used in filter
   * @param scopeType type of scope used in filter
   * @param scopeName name of scope used in filter
   * @param settingName
   * @param offset search query offset
   * @param limit search query limit
   * @return a {@link Set} of {@link String} for filtered context names
   */
  public Set<String> getEmptyContextsByTypeAndScopeAndSettingName(String contextType,
                                                                  String scopeType,
                                                                  String scopeName,
                                                                  String settingName,
                                                                  int offset,
                                                                  int limit);

  /**
   * Saves a {@link Context} on database
   *
   * @param context context to save
   */
  public void save(Context context);

  /**
   * Get a list of settings that belongs to the context and scope
   *
   * @param contextType type of ontext
   * @param contextName name of ontext
   * @param scopeType type of scope
   * @param scopeName name of scope
   * @return Map of settings key and value
   */
  public Map<String, SettingValue> getSettingsByContextAndScope(String contextType,
                                                                String contextName,
                                                                String scopeType,
                                                                String scopeName);

}
