Use context objects and optionals in interfaces.
[Sone.git] / src / main / java / net / pterodactylus / sone / freenet / wot / IdentityLoader.java
1 /*
2  * Sone - IdentityLoader.java - Copyright © 2013 David Roden
3  *
4  * This program is free software: you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation, either version 3 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
16  */
17
18 package net.pterodactylus.sone.freenet.wot;
19
20 import static com.google.common.collect.HashMultimap.create;
21 import static net.pterodactylus.sone.freenet.wot.Context.extractContext;
22
23 import java.util.Collection;
24 import java.util.Set;
25
26 import javax.annotation.Nullable;
27
28 import net.pterodactylus.sone.freenet.plugin.PluginException;
29
30 import com.google.common.base.Function;
31 import com.google.common.base.Optional;
32 import com.google.common.collect.Multimap;
33
34 /**
35  * Loads {@link OwnIdentity}s and the {@link Identity}s they trust.
36  *
37  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
38  */
39 public class IdentityLoader {
40
41         private final WebOfTrustConnector webOfTrustConnector;
42         private final Optional<Context> context;
43
44         public IdentityLoader(WebOfTrustConnector webOfTrustConnector) {
45                 this(webOfTrustConnector, Optional.<Context>absent());
46         }
47
48         public IdentityLoader(WebOfTrustConnector webOfTrustConnector, Optional<Context> context) {
49                 this.webOfTrustConnector = webOfTrustConnector;
50                 this.context = context;
51         }
52
53         public Multimap<OwnIdentity, Identity> loadIdentities() throws WebOfTrustException {
54                 Collection<OwnIdentity> currentOwnIdentities = webOfTrustConnector.loadAllOwnIdentities();
55                 return loadTrustedIdentitiesForOwnIdentities(currentOwnIdentities);
56         }
57
58         private Multimap<OwnIdentity, Identity> loadTrustedIdentitiesForOwnIdentities(Collection<OwnIdentity> ownIdentities) throws PluginException {
59                 Multimap<OwnIdentity, Identity> currentIdentities = create();
60
61                 for (OwnIdentity ownIdentity : ownIdentities) {
62                         if (identityDoesNotHaveTheCorrectContext(ownIdentity)) {
63                                 continue;
64                         }
65
66                         Set<Identity> trustedIdentities = webOfTrustConnector.loadTrustedIdentities(ownIdentity, context.transform(extractContext));
67                         currentIdentities.putAll(ownIdentity, trustedIdentities);
68                 }
69
70                 return currentIdentities;
71         }
72
73         private boolean identityDoesNotHaveTheCorrectContext(OwnIdentity ownIdentity) {
74                 return context.isPresent() && !ownIdentity.hasContext(context.transform(extractContext).get());
75         }
76
77 }