/*
 * Copyright 2008 Google 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.google.template.soy.soytree;

import com.google.common.base.Preconditions;
import com.google.template.soy.base.SourceLocation;
import com.google.template.soy.basetree.CopyState;
import com.google.template.soy.soytree.SoyNode.CommandNode;

/**
 * Abstract implementation of a CommandNode.
 *
 */
abstract class AbstractCommandNode extends AbstractSoyNode implements CommandNode {


  /** The name of the Soy command. */
  private final String commandName;

  /** The command text, or empty string if none. */
  private final String commandText;


  /**
   * @param id The id for this node.
   * @param sourceLocation The node's source location.
   * @param commandName The name of the Soy command.
   * @param commandText The command text, or empty string if none.
   */
  public AbstractCommandNode(
      int id, SourceLocation sourceLocation, String commandName, String commandText) {
    super(id, sourceLocation);
    this.commandName = commandName;
    this.commandText = commandText.trim();
  }


  /**
   * Copy constructor.
   * @param orig The node to copy.
   */
  protected AbstractCommandNode(AbstractCommandNode orig, CopyState copyState) {
    super(orig, copyState);
    this.commandName = orig.commandName;
    this.commandText = orig.commandText;
  }


  /**
   * May be overridden by subclasses to keep consistent with tree modifications.
   */
  @Override public String getCommandName() {
    return commandName;
  }

  /**
   * May be overridden by subclasses to keep consistent with tree modifications.
   */
  @Override public String getCommandText() {
    return commandText;
  }


  @Override public String getTagString() {
    return buildTagStringHelper(false);
  }


  /**
   * Helper to build the source tag string (usually for testing/debugging). Handles most cases,
   * including (a) with or without tag text, (b) self-ending tags, or (c) tags whose text contains a
   * brace character.
   *
   * @param isSelfEnding Whether the tag is self-ending, i.e. { ... /}.
   * @return The source tag string, possibly with some differences in spacing.
   */
  protected String buildTagStringHelper(boolean isSelfEnding) {
    return buildTagStringHelper(isSelfEnding, false);
  }


  /**
   * Helper to build the source tag string (usually for testing/debugging). Handles all cases,
   * including (a) with or without tag text, (b) self-ending tags, (c) tags whose text contains a
   * brace character, or (d) implicit 'print' tags.
   *
   * @param isSelfEnding Whether the tag is self-ending, i.e. { ... /}.
   * @param isImplicitCommandName Whether the command name is implicit, e.g. a 'print' tag without
   *     the explicit 'print'.
   * @return The source tag string, possibly with some differences in spacing.
   */
  protected String buildTagStringHelper(boolean isSelfEnding, boolean isImplicitCommandName) {

    String commandName = getCommandName();
    String commandText = getCommandText();

    String maybeSelfEndingStr = isSelfEnding ? " /" : "";

    if (commandText.length() == 0) {
      Preconditions.checkArgument(! isImplicitCommandName);
      return "{" + commandName + maybeSelfEndingStr + "}";

    } else {
      String commandNameStr = isImplicitCommandName ? "" : commandName + " ";

      return "{" + commandNameStr + commandText + maybeSelfEndingStr + "}";
    }
  }


  @Override public String toSourceString() {
    return getTagString();
  }

}