/*
 * Copyright 2017 ThoughtWorks, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.thoughtworks.go.config;

import com.google.common.collect.HashMultimap;
import com.google.common.collect.SetMultimap;

import java.util.*;

import static com.google.common.collect.Multimaps.synchronizedSetMultimap;

public class PluginRoleUsersStore {
    private final SetMultimap<PluginRoleConfig, RoleUser> roleToUsersMappings = synchronizedSetMultimap(HashMultimap.create());

    private PluginRoleUsersStore() {

    }

    public static PluginRoleUsersStore instance() {
        return PluginRoleUsersStoreHolder.PLUGIN_ROLE_USERS_STORE;
    }

    public void assignRole(String user, PluginRoleConfig pluginRoleConfig) {
        roleToUsersMappings.put(pluginRoleConfig, new RoleUser(user));
    }

    public List<RoleUser> usersInRole(PluginRoleConfig pluginRoleConfig) {
        return new ArrayList(roleToUsersMappings.get(pluginRoleConfig));
    }

    public void removePluginRolesNotIn(List<PluginRoleConfig> pluginRoles) {
        for (PluginRoleConfig pluginRole : pluginRoles()) {
            if (!pluginRoles.contains(pluginRole)) {
                remove(pluginRole);
            }
        }
    }

    public void remove(PluginRoleConfig pluginRole) {
        roleToUsersMappings.removeAll(pluginRole);
    }

    public void remove(Collection<PluginRoleConfig> pluginRoles) {
        for (PluginRoleConfig role : pluginRoles) {
            remove(role);
        }
    }

    public void revokeAllRolesFor(String username) {
        final RoleUser roleUser = new RoleUser(username);
        synchronized (roleToUsersMappings) {
            Set<PluginRoleConfig> pluginRoles = new HashSet<>(roleToUsersMappings.keySet());
            for (PluginRoleConfig pluginRole : pluginRoles) {
                roleToUsersMappings.get(pluginRole).remove(roleUser);
            }
        }
    }

    protected Set<PluginRoleConfig> pluginRoles() {
        return new HashSet<>(roleToUsersMappings.keySet());
    }

//    Used only in tests
    public void clearAll() {
        roleToUsersMappings.clear();
    }

    private static class PluginRoleUsersStoreHolder {
        static final PluginRoleUsersStore PLUGIN_ROLE_USERS_STORE = new PluginRoleUsersStore();
    }
}