package com.simpligility.maven.plugins.android;
   
   import com.google.common.base.Splitter;
   import com.google.common.collect.Lists;
   
   import java.util.AbstractMap;
   import java.util.Collections;
   import java.util.HashMap;
   import java.util.List;
  import java.util.Map;
  
  /**
   * <p>Parses a list of key/value pairs separated by a space in to a map.</p>
   *
   * <p>Example input:</p>
   * <pre>
   *     list[0] = "firstKey firstValue"
   *     list[1] = "secondKey 'second value with space and single quote escape'
   * </pre>
   *
   * <p>Example output:</p>
   * <pre>
   *     map["firstKey"] = "firstValue"
   *     map["secondKey"] = "'second value with space and single quote escape'"
   * </pre>
   */
  public class InstrumentationArgumentParser
  {
      private static final String SEPARATOR = " ";
  
      /**
       * Parses the given {@code flatArgs} into a map of key/value pairs.
       *
       * @param flatArgs the flat representation of arguments, might be null
       * @return a map representation of the given key/value pair list, might be empty
       * @throws IllegalArgumentException when the given list contains unparseable entries
       */
      public static Map<String, String> parse( final List<String> flatArgs )
      {
          if ( flatArgs == null )
          {
              return Collections.EMPTY_MAP;
          }
  
          final Map<String, String> mappedArgs = new HashMap<String, String>();
  
          for ( final String flatArg : flatArgs )
          {
              final AbstractMap.SimpleEntry<String, String> keyValuePair = parseKeyValuePair( flatArg );
              mappedArgs.put( keyValuePair.getKey(), keyValuePair.getValue() );
          }
  
          return mappedArgs;
      }
  
      private static AbstractMap.SimpleEntry<String, String> parseKeyValuePair( final String arg )
      {
          final List<String> keyValueSplit = Lists.newArrayList( Splitter.on( SEPARATOR ).limit( 2 ).split( arg ) );
  
          if ( keyValueSplit.size() == 1 )
          {
              throw new IllegalArgumentException( "Could not separate \"" + arg + "\" by a whitespace into two parts" );
          }
  
          return new AbstractMap.SimpleEntry<String, String>( keyValueSplit.get( 0 ), keyValueSplit.get( 1 ) );
      }
  }