content: /*
   * Copyright (C) 2015 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 com.android.ahat;
  
  import java.net.URI;
  import java.util.HashMap;
  import java.util.Map;
  import java.util.TreeMap;
  
  /**
   * A class for getting and modifying query parameters.
   */
  class Query {
    private URI mUri;
  
    // Map from parameter name to value. If the same parameter appears multiple
    // times, only the last value is used.
    private Map<String, String> mParams;
  
    public Query(URI uri) {
      mUri = uri;
      mParams = new HashMap<String, String>();
  
      String query = uri.getQuery();
      if (query != null) {
        for (String param : query.split("&")) {
          int i = param.indexOf('=');
          if (i < 0) {
            mParams.put(param, "");
          } else {
            mParams.put(param.substring(0, i), param.substring(i + 1));
          }
        }
      }
    }
  
    /**
     * Return the value of a query parameter with the given name.
     * If there is no query parameter with that name, returns the default value.
     * If there are multiple query parameters with that name, the value of the
     * last query parameter is returned.
     * If the parameter is defined with an empty value, "" is returned.
     */
    public String get(String name, String defaultValue) {
      String value = mParams.get(name);
      return (value == null) ? defaultValue : value;
    }
  
    /**
     * Return the long value of a query parameter with the given name.
     */
    public long getLong(String name, long defaultValue) {
      String value = get(name, null);
      return value == null ? defaultValue : Long.parseLong(value);
    }
  
    /**
     * Return the int value of a query parameter with the given name.
     */
    public int getInt(String name, int defaultValue) {
      String value = get(name, null);
      return value == null ? defaultValue : Integer.parseInt(value);
    }
  
    /**
     * Return a uri suitable for an href target that links to the current
     * page, except with the named query parameter set to the new value.
     *
     * The generated parameters will be sorted alphabetically so it is easier to
     * test.
     */
    public URI with(String name, String value) {
      StringBuilder newQuery = new StringBuilder();
      newQuery.append(mUri.getRawPath());
      newQuery.append('?');
  
      Map<String, String> params = new TreeMap<String, String>(mParams);
      params.put(name, value);
      String and = "";
      for (Map.Entry<String, String> entry : params.entrySet()) {
        newQuery.append(and);
        newQuery.append(entry.getKey());
        newQuery.append('=');
        newQuery.append(entry.getValue());
        and = "&";
      }
      return DocString.uri(newQuery.toString());
    }
  
    /**
     * Return a uri suitable for an href target that links to the current
     * page, except with the named query parameter set to the new long value.
     */
    public URI with(String name, long value) {
      return with(name, String.valueOf(value));
    }
  }
  