X-Git-Url: https://git.pterodactylus.net/?p=Sone.git;a=blobdiff_plain;f=src%2Fmain%2Fjava%2Fnet%2Fpterodactylus%2Fsone%2Ffreenet%2Fwot%2FIdentityChangeDetector.kt;fp=src%2Fmain%2Fjava%2Fnet%2Fpterodactylus%2Fsone%2Ffreenet%2Fwot%2FIdentityChangeDetector.kt;h=deb35b1a3a14edb81f1dfbe6c5f74f53ae5600eb;hp=0000000000000000000000000000000000000000;hb=d50730f6a330439e0e7ef97ca9329dffe72d5640;hpb=97fe04482ebb8a08e43294acde041c2975cbd8ee

diff --git a/src/main/java/net/pterodactylus/sone/freenet/wot/IdentityChangeDetector.kt b/src/main/java/net/pterodactylus/sone/freenet/wot/IdentityChangeDetector.kt
new file mode 100644
index 0000000..deb35b1
--- /dev/null
+++ b/src/main/java/net/pterodactylus/sone/freenet/wot/IdentityChangeDetector.kt
@@ -0,0 +1,68 @@
+/*
+ * Sone - IdentityChangeDetector.java - Copyright © 2013–2019 David Roden
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package net.pterodactylus.sone.freenet.wot
+
+/**
+ * Detects changes between two lists of [Identity]s. The detector can find
+ * added and removed identities, and for identities that exist in both list
+ * their contexts and properties are checked for added, removed, or (in case of
+ * properties) changed values.
+ */
+class IdentityChangeDetector(oldIdentities: Collection<Identity>) {
+
+	private val oldIdentities: Map<String, Identity> = oldIdentities.associateBy { it.id }
+	var onNewIdentity: IdentityProcessor? = null
+	var onRemovedIdentity: IdentityProcessor? = null
+	var onChangedIdentity: IdentityProcessor? = null
+	var onUnchangedIdentity: IdentityProcessor? = null
+
+	fun detectChanges(newIdentities: Collection<Identity>) {
+		onRemovedIdentity.notify(oldIdentities.values.filter { it !in newIdentities })
+		onNewIdentity.notify(newIdentities.filter { it !in oldIdentities.values })
+		onChangedIdentity.notify(newIdentities.filter { it.id in oldIdentities }.filter { identityHasChanged(oldIdentities[it.id]!!, it) })
+		onUnchangedIdentity.notify(newIdentities.filter { it.id in oldIdentities }.filterNot { identityHasChanged(oldIdentities[it.id]!!, it) })
+	}
+
+	private fun identityHasChanged(oldIdentity: Identity, newIdentity: Identity?) =
+			identityHasNewContexts(oldIdentity, newIdentity!!)
+					|| identityHasRemovedContexts(oldIdentity, newIdentity)
+					|| identityHasNewProperties(oldIdentity, newIdentity)
+					|| identityHasRemovedProperties(oldIdentity, newIdentity)
+					|| identityHasChangedProperties(oldIdentity, newIdentity)
+
+	private fun identityHasNewContexts(oldIdentity: Identity, newIdentity: Identity) =
+			newIdentity.contexts.any { it !in oldIdentity.contexts }
+
+	private fun identityHasRemovedContexts(oldIdentity: Identity, newIdentity: Identity) =
+			oldIdentity.contexts.any { it !in newIdentity.contexts }
+
+	private fun identityHasNewProperties(oldIdentity: Identity, newIdentity: Identity) =
+			newIdentity.properties.keys.any { it !in oldIdentity.properties }
+
+	private fun identityHasRemovedProperties(oldIdentity: Identity, newIdentity: Identity) =
+			oldIdentity.properties.keys.any { it !in newIdentity.properties }
+
+	private fun identityHasChangedProperties(oldIdentity: Identity, newIdentity: Identity) =
+			oldIdentity.properties.entries.any { newIdentity.properties[it.key] != it.value }
+
+}
+
+typealias IdentityProcessor = (Identity) -> Unit
+
+private fun IdentityProcessor?.notify(identities: Iterable<Identity>) =
+		this?.let { identities.forEach(this::invoke) }