feat(rc): Add Remote Config Management API (#502)

- Add Remote Config Management API

Author: lahirumaramba

src/main/java/com/google/firebase/remoteconfig/Condition.java

@@ -0,0 +1,174 @@
+/*
+ * Copyright 2020 Google LLC
+ *
+ * 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.google.firebase.remoteconfig;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import com.google.common.base.Strings;
+import com.google.firebase.internal.NonNull;
+import com.google.firebase.internal.Nullable;
+import com.google.firebase.remoteconfig.internal.TemplateResponse.ConditionResponse;
+
+import java.util.Objects;
+
+/**
+ * Represents a Remote Config condition that can be included in a {@link Template}.
+ * A condition targets a specific group of users. A list of these conditions make up
+ * part of a Remote Config template.
+ */
+public final class Condition {
+
+  private String name;
+  private String expression;
+  private TagColor tagColor;
+
+  /**
+   * Creates a new {@link Condition}.
+   *
+   * @param name A non-null, non-empty, and unique name of this condition.
+   * @param expression A non-null and non-empty expression of this condition.
+   */
+  public Condition(@NonNull String name, @NonNull String expression) {
+    this(name, expression, null);
+  }
+
+  /**
+   * Creates a new {@link Condition}.
+   *
+   * @param name A non-null, non-empty, and unique name of this condition.
+   * @param expression A non-null and non-empty expression of this condition.
+   * @param tagColor A color associated with this condition for display purposes in the
+   *                 Firebase Console. Not specifying this value results in the console picking an
+   *                 arbitrary color to associate with the condition.
+   */
+  public Condition(@NonNull String name, @NonNull String expression, @Nullable TagColor tagColor) {
+    checkArgument(!Strings.isNullOrEmpty(name), "condition name must not be null or empty");
+    checkArgument(!Strings.isNullOrEmpty(expression),
+            "condition expression must not be null or empty");
+    this.name = name;
+    this.expression = expression;
+    this.tagColor = tagColor;
+  }
+
+  Condition(@NonNull ConditionResponse conditionResponse) {
+    checkNotNull(conditionResponse);
+    this.name = conditionResponse.getName();
+    this.expression = conditionResponse.getExpression();
+    if (!Strings.isNullOrEmpty(conditionResponse.getTagColor())) {
+      this.tagColor = TagColor.valueOf(conditionResponse.getTagColor());
+    }
+  }
+
+  /**
+   * Gets the name of the condition.
+   *
+   * @return The name of the condition.
+   */
+  @NonNull
+  public String getName() {
+    return name;
+  }
+
+  /**
+   * Gets the expression of the condition.
+   *
+   * @return The expression of the condition.
+   */
+  @NonNull
+  public String getExpression() {
+    return expression;
+  }
+
+  /**
+   * Gets the tag color of the condition used for display purposes in the Firebase Console.
+   *
+   * @return The tag color of the condition.
+   */
+  @NonNull
+  public TagColor getTagColor() {
+    return tagColor;
+  }
+
+  /**
+   * Sets the name of the condition.
+   *
+   * @param name A non-empty and unique name of this condition.
+   * @return This {@link Condition}.
+   */
+  public Condition setName(@NonNull String name) {
+    checkArgument(!Strings.isNullOrEmpty(name), "condition name must not be null or empty");
+    this.name = name;
+    return this;
+  }
+
+  /**
+   * Sets the expression of the condition.
+   *
+   * <p>See <a href="https://firebase.google.com/docs/remote-config/condition-reference">
+   * condition expressions</a> for the expected syntax of this field.
+   *
+   * @param expression The logic of this condition.
+   * @return This {@link Condition}.
+   */
+  public Condition setExpression(@NonNull String expression) {
+    checkArgument(!Strings.isNullOrEmpty(expression),
+            "condition expression must not be null or empty");
+    this.expression = expression;
+    return this;
+  }
+
+  /**
+   * Sets the tag color of the condition.
+   *
+   * <p>The color associated with this condition for display purposes in the Firebase Console.
+   * Not specifying this value results in the console picking an arbitrary color to associate
+   * with the condition.
+   *
+   * @param tagColor The tag color of this condition.
+   * @return This {@link Condition}.
+   */
+  public Condition setTagColor(@Nullable TagColor tagColor) {
+    this.tagColor = tagColor;
+    return this;
+  }
+
+  ConditionResponse toConditionResponse() {
+    return new ConditionResponse()
+            .setName(this.name)
+            .setExpression(this.expression)
+            .setTagColor(this.tagColor == null ? null : this.tagColor.getColor());
+  }
+
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+    Condition condition = (Condition) o;
+    return Objects.equals(name, condition.name)
+            && Objects.equals(expression, condition.expression) && tagColor == condition.tagColor;
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(name, expression, tagColor);
+  }
+}