Move common Prolog predicates to 'gerrit' package

Because user code will need to import our common rules, move them
to a shorter name "gerrit". This is not likely to collide with any
classes in a running server as we will eventually narrow down the
set of classes available to the PrologEnvironment to a smaller set
than the entire running server, and we aren't likely to ever use a
3rd party library from the gerrit.com domain.

Change-Id: I8f111ea2cb58229159d3a72c081a3808cc6c3438

gerrit-server/src/main/java/gerrit/PRED_$current_user_2.java

@@ -0,0 +1,87 @@
+// Copyright (C) 2011 The Android Open Source Project
+//
+// 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 gerrit;
+
+import com.google.gerrit.reviewdb.Account;
+import com.google.gerrit.reviewdb.ReviewDb;
+import com.google.gerrit.rules.PrologEnvironment;
+import com.google.gerrit.rules.StoredValues;
+import com.google.gerrit.server.CurrentUser;
+import com.google.gerrit.server.IdentifiedUser;
+import com.google.inject.Provider;
+
+import com.googlecode.prolog_cafe.lang.IllegalTypeException;
+import com.googlecode.prolog_cafe.lang.IntegerTerm;
+import com.googlecode.prolog_cafe.lang.JavaObjectTerm;
+import com.googlecode.prolog_cafe.lang.Operation;
+import com.googlecode.prolog_cafe.lang.PInstantiationException;
+import com.googlecode.prolog_cafe.lang.Predicate;
+import com.googlecode.prolog_cafe.lang.Prolog;
+import com.googlecode.prolog_cafe.lang.PrologException;
+import com.googlecode.prolog_cafe.lang.Term;
+
+/**
+ * Loads a CurrentUser object for a user identity.
+ *
+ * <pre>
+ *   '$current_user'(+AccountId, -CurrentUser).
+ * </pre>
+ */
+class PRED_$current_user_2 extends Predicate.P2 {
+  PRED_$current_user_2(Term a1, Term a2, Operation n) {
+    arg1 = a1;
+    arg2 = a2;
+    cont = n;
+  }
+
+  @Override
+  public Operation exec(Prolog engine) throws PrologException {
+    engine.setB0();
+    Term a1 = arg1.dereference();
+    Term a2 = arg2.dereference();
+
+    if (a1.isVariable()) {
+      throw new PInstantiationException(this, 1);
+    }
+    if (!a1.isInteger()) {
+      throw new IllegalTypeException(this, 1, "int", a1);
+    }
+    Account.Id accountId = new Account.Id(((IntegerTerm) a1).intValue());
+
+    final ReviewDb db = StoredValues.REVIEW_DB.getOrNull(engine);
+    IdentifiedUser.GenericFactory userFactory = userFactory(engine);
+    CurrentUser user;
+    if (db != null) {
+      user = userFactory.create(new Provider<ReviewDb>() {
+        public ReviewDb get() {
+          return db;
+        }
+      }, accountId);
+    } else {
+      user = userFactory.create(accountId);
+    }
+
+    if (!a2.unify(new JavaObjectTerm(user), engine.trail)) {
+      return engine.fail();
+    }
+
+    return cont;
+  }
+
+  private IdentifiedUser.GenericFactory userFactory(Prolog engine) {
+    PrologEnvironment env = (PrologEnvironment) engine.control;
+    return env.getInjector().getInstance(IdentifiedUser.GenericFactory.class);
+  }
+}

gerrit-server/src/main/java/gerrit/PRED_$load_commit_labels_1.java

@@ -0,0 +1,80 @@
+// Copyright 2011 Google Inc. All Rights Reserved.
+
+package gerrit;
+
+import com.google.gerrit.common.data.ApprovalType;
+import com.google.gerrit.common.data.ApprovalTypes;
+import com.google.gerrit.reviewdb.PatchSet;
+import com.google.gerrit.reviewdb.PatchSetApproval;
+import com.google.gerrit.reviewdb.ReviewDb;
+import com.google.gerrit.rules.PrologEnvironment;
+import com.google.gerrit.rules.StoredValues;
+import com.google.gwtorm.client.OrmException;
+
+import com.googlecode.prolog_cafe.lang.IntegerTerm;
+import com.googlecode.prolog_cafe.lang.JavaException;
+import com.googlecode.prolog_cafe.lang.ListTerm;
+import com.googlecode.prolog_cafe.lang.Operation;
+import com.googlecode.prolog_cafe.lang.Predicate;
+import com.googlecode.prolog_cafe.lang.Prolog;
+import com.googlecode.prolog_cafe.lang.PrologException;
+import com.googlecode.prolog_cafe.lang.StructureTerm;
+import com.googlecode.prolog_cafe.lang.SymbolTerm;
+import com.googlecode.prolog_cafe.lang.Term;
+
+/** Exports list of {@code commit_label( label('Code-Review', 2), user(12345789) )}. */
+class PRED_$load_commit_labels_1 extends Predicate.P1 {
+  private static final SymbolTerm sym_commit_label = SymbolTerm.makeSymbol("commit_label", 2);
+  private static final SymbolTerm sym_label = SymbolTerm.makeSymbol("label", 2);
+  private static final SymbolTerm sym_user = SymbolTerm.makeSymbol("user", 1);
+
+  PRED_$load_commit_labels_1(Term a1, Operation n) {
+    arg1 = a1;
+    cont = n;
+  }
+
+  @Override
+  public Operation exec(Prolog engine) throws PrologException {
+    engine.setB0();
+    Term a1 = arg1.dereference();
+
+    Term listHead = Prolog.Nil;
+    try {
+      PrologEnvironment env = (PrologEnvironment) engine.control;
+      ReviewDb db = StoredValues.REVIEW_DB.get(engine);
+      PatchSet.Id patchSetId = StoredValues.PATCH_SET_ID.get(engine);
+      ApprovalTypes types = env.getInjector().getInstance(ApprovalTypes.class);
+
+      for (PatchSetApproval a : db.patchSetApprovals().byPatchSet(patchSetId)) {
+        if (a.getValue() == 0) {
+          continue;
+        }
+
+        ApprovalType t = types.byId(a.getCategoryId());
+        if (t == null) {
+          continue;
+        }
+
+        StructureTerm labelTerm = new StructureTerm(
+            sym_label,
+            SymbolTerm.makeSymbol(t.getCategory().getLabelName()),
+            new IntegerTerm(a.getValue()));
+
+        StructureTerm userTerm = new StructureTerm(
+            sym_user,
+            new IntegerTerm(a.getAccountId().get()));
+
+        listHead = new ListTerm(
+            new StructureTerm(sym_commit_label, labelTerm, userTerm),
+            listHead);
+      }
+    } catch (OrmException err) {
+      throw new JavaException(this, 1, err);
+    }
+
+    if (!a1.unify(listHead, engine.trail)) {
+      return engine.fail();
+    }
+    return cont;
+  }
+}

gerrit-server/src/main/java/gerrit/PRED_$user_label_range_4.java

@@ -0,0 +1,92 @@
+// Copyright (C) 2011 The Android Open Source Project
+//
+// 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 gerrit;
+
+import com.google.gerrit.common.data.Permission;
+import com.google.gerrit.common.data.PermissionRange;
+import com.google.gerrit.rules.StoredValues;
+import com.google.gerrit.server.CurrentUser;
+import com.google.gerrit.server.project.ChangeControl;
+
+import com.googlecode.prolog_cafe.lang.IllegalTypeException;
+import com.googlecode.prolog_cafe.lang.IntegerTerm;
+import com.googlecode.prolog_cafe.lang.JavaObjectTerm;
+import com.googlecode.prolog_cafe.lang.Operation;
+import com.googlecode.prolog_cafe.lang.PInstantiationException;
+import com.googlecode.prolog_cafe.lang.Predicate;
+import com.googlecode.prolog_cafe.lang.Prolog;
+import com.googlecode.prolog_cafe.lang.PrologException;
+import com.googlecode.prolog_cafe.lang.Term;
+
+/**
+ * Resolves the valid range for a label on a CurrentUser.
+ *
+ * <pre>
+ *   '$user_label_range'(+Label, +CurrentUser, -Min, -Max)
+ * </pre>
+ */
+class PRED_$user_label_range_4 extends Predicate.P4 {
+  PRED_$user_label_range_4(Term a1, Term a2, Term a3, Term a4, Operation n) {
+    arg1 = a1;
+    arg2 = a2;
+    arg3 = a3;
+    arg4 = a4;
+    cont = n;
+  }
+
+  @Override
+  public Operation exec(Prolog engine) throws PrologException {
+    engine.setB0();
+    Term a1 = arg1.dereference();
+    Term a2 = arg2.dereference();
+    Term a3 = arg3.dereference();
+    Term a4 = arg4.dereference();
+
+    if (a1.isVariable()) {
+      throw new PInstantiationException(this, 1);
+    }
+    if (!a1.isSymbol()) {
+      throw new IllegalTypeException(this, 1, "atom", a1);
+    }
+    String label = a1.name();
+
+    if (a2.isVariable()) {
+      throw new PInstantiationException(this, 2);
+    }
+    if (!a2.isJavaObject() || !a2.convertible(CurrentUser.class)) {
+      throw new IllegalTypeException(this, 2, "CurrentUser)", a2);
+    }
+    CurrentUser user = (CurrentUser) ((JavaObjectTerm) a2).object();
+
+    ChangeControl ctl = StoredValues.CHANGE_CONTROL.get(engine).forUser(user);
+    PermissionRange range = ctl.getRange(Permission.LABEL + label);
+    if (range == null) {
+      return engine.fail();
+    }
+
+    IntegerTerm min = new IntegerTerm(range.getMin());
+    IntegerTerm max = new IntegerTerm(range.getMax());
+
+    if (!a3.unify(min, engine.trail)) {
+      return engine.fail();
+    }
+
+    if (!a4.unify(max, engine.trail)) {
+      return engine.fail();
+    }
+
+    return cont;
+  }
+}

gerrit-server/src/main/java/gerrit/PRED_get_legacy_approval_types_1.java

@@ -0,0 +1,82 @@
+// Copyright (C) 2011 The Android Open Source Project
+//
+// 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 gerrit;
+
+import com.google.gerrit.common.data.ApprovalType;
+import com.google.gerrit.common.data.ApprovalTypes;
+import com.google.gerrit.rules.PrologEnvironment;
+
+import com.googlecode.prolog_cafe.lang.IntegerTerm;
+import com.googlecode.prolog_cafe.lang.ListTerm;
+import com.googlecode.prolog_cafe.lang.Operation;
+import com.googlecode.prolog_cafe.lang.Predicate;
+import com.googlecode.prolog_cafe.lang.Prolog;
+import com.googlecode.prolog_cafe.lang.PrologException;
+import com.googlecode.prolog_cafe.lang.StructureTerm;
+import com.googlecode.prolog_cafe.lang.SymbolTerm;
+import com.googlecode.prolog_cafe.lang.Term;
+
+import java.util.List;
+
+/**
+ * Obtain a list of approval types from the server configuration.
+ * <p>
+ * Unifies to a Prolog list of: {@code approval_type(Label, Id, Fun, Min, Max)}
+ * where:
+ * <ul>
+ * <li>{@code Label} - the newer style label name</li>
+ * <li>{@code Id} - the legacy ApprovalCategory.Id from the database</li>
+ * <li>{@code Fun} - legacy function name</li>
+ * <li>{@code Min, Max} - the smallest and largest configured values.</li>
+ * </ul>
+ */
+class PRED_get_legacy_approval_types_1 extends Predicate.P1 {
+  PRED_get_legacy_approval_types_1(Term a1, Operation n) {
+    arg1 = a1;
+    cont = n;
+  }
+
+  @Override
+  public Operation exec(Prolog engine) throws PrologException {
+    engine.setB0();
+    Term a1 = arg1.dereference();
+
+    PrologEnvironment env = (PrologEnvironment) engine.control;
+    ApprovalTypes types = env.getInjector().getInstance(ApprovalTypes.class);
+
+    List<ApprovalType> list = types.getApprovalTypes();
+    Term head = Prolog.Nil;
+    for (int idx = list.size() - 1; 0 <= idx; idx--) {
+      head = new ListTerm(export(list.get(idx)), head);
+    }
+
+    if (!a1.unify(head, engine.trail)) {
+      return engine.fail();
+    }
+    return cont;
+  }
+
+  static final SymbolTerm symApprovalType = SymbolTerm.makeSymbol(
+      "approval_type", 5);
+
+  static Term export(ApprovalType type) {
+    return new StructureTerm(symApprovalType,
+        SymbolTerm.makeSymbol(type.getCategory().getLabelName()),
+        SymbolTerm.makeSymbol(type.getCategory().getId().get()),
+        SymbolTerm.makeSymbol(type.getCategory().getFunctionName()),
+        new IntegerTerm(type.getMin().getValue()),
+        new IntegerTerm(type.getMax().getValue()));
+  }
+}