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1   package edu.iu.ul.maven.plugins.fileweaver;
2   
3   import java.util.ArrayList;
4   import java.util.Iterator;
5   import java.util.List;
6   
7   import org.apache.maven.plugin.AbstractMojo;
8   import org.apache.maven.plugin.MojoExecutionException;
9   
10  /**
11   * Display help information on fileweaver.<br/> Call <pre>  mvn fileweaver:help -Ddetail=true -Dgoal=&lt;goal-name&gt;</pre> to display parameter details.
12   *
13   * @version generated on Mon Apr 02 15:00:23 EDT 2012
14   * @author org.apache.maven.tools.plugin.generator.PluginHelpGenerator (version 2.8)
15   * @goal help
16   * @requiresProject false
17   * @threadSafe
18   */
19  public class HelpMojo
20      extends AbstractMojo
21  {
22      /**
23       * If <code>true</code>, display all settable properties for each goal.
24       * 
25       * @parameter expression="${detail}" default-value="false"
26       */
27      private boolean detail;
28  
29      /**
30       * The name of the goal for which to show help. If unspecified, all goals will be displayed.
31       * 
32       * @parameter expression="${goal}"
33       */
34      private java.lang.String goal;
35  
36      /**
37       * The maximum length of a display line, should be positive.
38       * 
39       * @parameter expression="${lineLength}" default-value="80"
40       */
41      private int lineLength;
42  
43      /**
44       * The number of spaces per indentation level, should be positive.
45       * 
46       * @parameter expression="${indentSize}" default-value="2"
47       */
48      private int indentSize;
49  
50  
51      /** {@inheritDoc} */
52      public void execute()
53          throws MojoExecutionException
54      {
55          if ( lineLength <= 0 )
56          {
57              getLog().warn( "The parameter 'lineLength' should be positive, using '80' as default." );
58              lineLength = 80;
59          }
60          if ( indentSize <= 0 )
61          {
62              getLog().warn( "The parameter 'indentSize' should be positive, using '2' as default." );
63              indentSize = 2;
64          }
65  
66          StringBuffer sb = new StringBuffer();
67  
68          append( sb, "edu.iu.ul.maven.plugins:fileweaver:1.0", 0 );
69          append( sb, "", 0 );
70  
71          append( sb, "FileWeaver", 0 );
72          append( sb, "A Maven plugin to assemble files from literal text and other files, with optional interpolation of token values.", 1 );
73          append( sb, "", 0 );
74  
75          if ( goal == null || goal.length() <= 0 )
76          {
77              append( sb, "This plugin has 2 goals:", 0 );
78              append( sb, "", 0 );
79          }
80  
81          if ( goal == null || goal.length() <= 0 || "help".equals( goal ) )
82          {
83              append( sb, "fileweaver:help", 0 );
84              append( sb, "Display help information on fileweaver.\nCall\n\u00a0\u00a0mvn\u00a0fileweaver:help\u00a0-Ddetail=true\u00a0-Dgoal=<goal-name>\nto display parameter details.", 1 );
85              append( sb, "", 0 );
86              if ( detail )
87              {
88                  append( sb, "Available parameters:", 1 );
89                  append( sb, "", 0 );
90  
91                  append( sb, "detail (Default: false)", 2 );
92                  append( sb, "If true, display all settable properties for each goal.", 3 );
93                  append( sb, "Expression: ${detail}", 3 );
94                  append( sb, "", 0 );
95  
96                  append( sb, "goal", 2 );
97                  append( sb, "The name of the goal for which to show help. If unspecified, all goals will be displayed.", 3 );
98                  append( sb, "Expression: ${goal}", 3 );
99                  append( sb, "", 0 );
100 
101                 append( sb, "indentSize (Default: 2)", 2 );
102                 append( sb, "The number of spaces per indentation level, should be positive.", 3 );
103                 append( sb, "Expression: ${indentSize}", 3 );
104                 append( sb, "", 0 );
105 
106                 append( sb, "lineLength (Default: 80)", 2 );
107                 append( sb, "The maximum length of a display line, should be positive.", 3 );
108                 append( sb, "Expression: ${lineLength}", 3 );
109                 append( sb, "", 0 );
110             }
111         }
112 
113         if ( goal == null || goal.length() <= 0 || "weave".equals( goal ) )
114         {
115             append( sb, "fileweaver:weave", 0 );
116             append( sb, "Build files from external and literal portions, with filtering.\nAny number of output files may be generated.\n", 1 );
117             append( sb, "", 0 );
118             if ( detail )
119             {
120                 append( sb, "Available parameters:", 1 );
121                 append( sb, "", 0 );
122 
123                 append( sb, "outputPath", 2 );
124                 append( sb, "Where to write files, unless a <part> specifies otherwise.", 3 );
125                 append( sb, "Required: Yes", 3 );
126                 append( sb, "Expression: ${project.build.directory}", 3 );
127                 append( sb, "", 0 );
128 
129                 append( sb, "outputs", 2 );
130                 append( sb, "Files to be woven.", 3 );
131                 append( sb, "Required: Yes", 3 );
132                 append( sb, "", 0 );
133 
134                 append( sb, "properties", 2 );
135                 append( sb, "Common properties for filtering all outputs.", 3 );
136                 append( sb, "", 0 );
137             }
138         }
139 
140         if ( getLog().isInfoEnabled() )
141         {
142             getLog().info( sb.toString() );
143         }
144     }
145 
146     /**
147      * <p>Repeat a String <code>n</code> times to form a new string.</p>
148      *
149      * @param str String to repeat
150      * @param repeat number of times to repeat str
151      * @return String with repeated String
152      * @throws NegativeArraySizeException if <code>repeat < 0</code>
153      * @throws NullPointerException if str is <code>null</code>
154      */
155     private static String repeat( String str, int repeat )
156     {
157         StringBuffer buffer = new StringBuffer( repeat * str.length() );
158 
159         for ( int i = 0; i < repeat; i++ )
160         {
161             buffer.append( str );
162         }
163 
164         return buffer.toString();
165     }
166 
167     /** 
168      * Append a description to the buffer by respecting the indentSize and lineLength parameters.
169      * <b>Note</b>: The last character is always a new line.
170      * 
171      * @param sb The buffer to append the description, not <code>null</code>.
172      * @param description The description, not <code>null</code>.
173      * @param indent The base indentation level of each line, must not be negative.
174      */
175     private void append( StringBuffer sb, String description, int indent )
176     {
177         for ( Iterator it = toLines( description, indent, indentSize, lineLength ).iterator(); it.hasNext(); )
178         {
179             sb.append( it.next().toString() ).append( '\n' );
180         }
181     }
182 
183     /** 
184      * Splits the specified text into lines of convenient display length.
185      * 
186      * @param text The text to split into lines, must not be <code>null</code>.
187      * @param indent The base indentation level of each line, must not be negative.
188      * @param indentSize The size of each indentation, must not be negative.
189      * @param lineLength The length of the line, must not be negative.
190      * @return The sequence of display lines, never <code>null</code>.
191      * @throws NegativeArraySizeException if <code>indent < 0</code>
192      */
193     private static List toLines( String text, int indent, int indentSize, int lineLength )
194     {
195         List lines = new ArrayList();
196 
197         String ind = repeat( "\t", indent );
198         String[] plainLines = text.split( "(\r\n)|(\r)|(\n)" );
199         for ( int i = 0; i < plainLines.length; i++ )
200         {
201             toLines( lines, ind + plainLines[i], indentSize, lineLength );
202         }
203 
204         return lines;
205     }
206 
207     /** 
208      * Adds the specified line to the output sequence, performing line wrapping if necessary.
209      * 
210      * @param lines The sequence of display lines, must not be <code>null</code>.
211      * @param line The line to add, must not be <code>null</code>.
212      * @param indentSize The size of each indentation, must not be negative.
213      * @param lineLength The length of the line, must not be negative.
214      */
215     private static void toLines( List lines, String line, int indentSize, int lineLength )
216     {
217         int lineIndent = getIndentLevel( line );
218         StringBuffer buf = new StringBuffer( 256 );
219         String[] tokens = line.split( " +" );
220         for ( int i = 0; i < tokens.length; i++ )
221         {
222             String token = tokens[i];
223             if ( i > 0 )
224             {
225                 if ( buf.length() + token.length() >= lineLength )
226                 {
227                     lines.add( buf.toString() );
228                     buf.setLength( 0 );
229                     buf.append( repeat( " ", lineIndent * indentSize ) );
230                 }
231                 else
232                 {
233                     buf.append( ' ' );
234                 }
235             }
236             for ( int j = 0; j < token.length(); j++ )
237             {
238                 char c = token.charAt( j );
239                 if ( c == '\t' )
240                 {
241                     buf.append( repeat( " ", indentSize - buf.length() % indentSize ) );
242                 }
243                 else if ( c == '\u00A0' )
244                 {
245                     buf.append( ' ' );
246                 }
247                 else
248                 {
249                     buf.append( c );
250                 }
251             }
252         }
253         lines.add( buf.toString() );
254     }
255 
256     /** 
257      * Gets the indentation level of the specified line.
258      * 
259      * @param line The line whose indentation level should be retrieved, must not be <code>null</code>.
260      * @return The indentation level of the line.
261      */
262     private static int getIndentLevel( String line )
263     {
264         int level = 0;
265         for ( int i = 0; i < line.length() && line.charAt( i ) == '\t'; i++ )
266         {
267             level++;
268         }
269         for ( int i = level + 1; i <= level + 4 && i < line.length(); i++ )
270         {
271             if ( line.charAt( i ) == '\t' )
272             {
273                 level++;
274                 break;
275             }
276         }
277         return level;
278     }
279 }