/*
 * Copyright 2011 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.collect.ImmutableMap;
import com.google.template.soy.base.SourceLocation;
import com.google.template.soy.error.ErrorReporter;
import com.google.template.soy.error.SoyErrorKind;

import java.util.Set;

/**
 * Specifies how the outputs of <code>{print}</code> commands that lack escaping directives are
 * encoded.
 *
 */
public enum AutoescapeMode {
  /** Auto-escaping is on for the template so directiveless prints will be HTML escaped. */
  NONCONTEXTUAL("deprecated-noncontextual"),
  /**
   * Contextual auto-escaping is on for the template so directiveless prints will be escaped based
   * on the surrounding context.
   */
  CONTEXTUAL("deprecated-contextual"),
  /**
   * Strict form of contextual autoescaping in which no autoescape-cancelling print directives nor
   * calls to non-strict templates are allowed.
   */
  STRICT("strict"),
  ;

  private static final SoyErrorKind INVALID_AUTOESCAPE_ERROR =
      SoyErrorKind.of("invalid ''autoescape'' value ''{0}'', expected one of {1}");
  private static final ImmutableMap<String, AutoescapeMode> valueToModeMap;

  static {
    ImmutableMap.Builder <String, AutoescapeMode> map = ImmutableMap.builder();
    for (AutoescapeMode value : AutoescapeMode.values()) {
      map.put(value.attributeValue, value);
    }
    valueToModeMap = map.build();
  }


  private final String attributeValue;


  /**
   * Constructs an AutoescapeMode enum.
   *
   * @param attributeValue value of the "autoescape" attribute that specifies this autoescape mode.
   */
  AutoescapeMode(String attributeValue) {
    this.attributeValue = attributeValue;
  }


  /**
   * Returns a form of this attribute's name suitable for use in a template attribute.
   */
  public String getAttributeValue() {
    return attributeValue;
  }


  /**
   * The set created by element-wise application of {@link #getAttributeValue} to all modes.
   */
  public static Set<String> getAttributeValues() {
    return valueToModeMap.keySet();
  }

  static AutoescapeMode parseAutoEscapeMode(String autoescapeModeStr) {
    AutoescapeMode parsed = valueToModeMap.get(autoescapeModeStr);
    if (parsed == null) {
      // failed to parse!
      return AutoescapeMode.STRICT; // default for unparsed
    }
    return parsed;
  }

  /**
   * Returns the parsed value.
   */
  static AutoescapeMode parseAutoEscapeMode(String autoescapeModeStr, SourceLocation loc,
      ErrorReporter reporter) {
    AutoescapeMode parsed = valueToModeMap.get(autoescapeModeStr);
    if (parsed == null) {
      // failed to parse!
      reporter.report(loc, INVALID_AUTOESCAPE_ERROR, autoescapeModeStr,  valueToModeMap.keySet());
      return AutoescapeMode.STRICT;  // default for unparsed
    } else {
      return parsed;
    }
  }
}