/*
    * #%L
    * Native ARchive plugin for Maven
    * %%
    * Copyright (C) 2002 - 2014 NAR Maven Plugin developers.
    * %%
    * 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.
   * #L%
   */
  package com.github.maven_nar.cpptasks.gcc;
  
  import java.io.BufferedReader;
  import java.io.File;
  import java.io.FileReader;
  import java.io.IOException;
  import java.util.Vector;
  
  import com.github.maven_nar.cpptasks.CUtil;
  import com.github.maven_nar.cpptasks.compiler.CaptureStreamHandler;
  
  /**
   * A add-in class for Gcc processors
   *
   * 
   */
  public class GccProcessor {
    // the results from gcc -dumpmachine
    private static String machine;
    private static String[] specs;
    // the results from gcc -dumpversion
    private static String version;
  
    private static int addLibraryPatterns(final String[] libnames, final StringBuffer buf, final String prefix,
        final String extension, final String[] patterns, final int offset) {
      for (int i = 0; i < libnames.length; i++) {
        buf.setLength(0);
        buf.append(prefix);
        buf.append(libnames[i]);
        buf.append(extension);
        patterns[offset + i] = buf.toString();
      }
      return offset + libnames.length;
    }
  
    /**
     * Converts absolute Cygwin file or directory names to the corresponding
     * Win32 name.
     * 
     * @param names
     *          array of names, some elements may be null, will be changed in
     *          place.
     */
    public static void convertCygwinFilenames(final String[] names) {
      if (names == null) {
        throw new NullPointerException("names");
      }
      final File gccDir = CUtil.getExecutableLocation("gcc.exe");
      if (gccDir != null) {
        final String prefix = gccDir.getAbsolutePath() + "/..";
        final StringBuffer buf = new StringBuffer();
        for (int i = 0; i < names.length; i++) {
          final String name = names[i];
          if (name != null && name.length() > 1 && name.charAt(0) == '/') {
            buf.setLength(0);
            buf.append(prefix);
            buf.append(name);
            names[i] = buf.toString();
          }
        }
      }
    }
  
    public static String[] getLibraryPatterns(final String[] libnames) {
      final StringBuffer buf = new StringBuffer();
      final String[] patterns = new String[libnames.length * 2];
      int offset = addLibraryPatterns(libnames, buf, "lib", ".a", patterns, 0);
      if (isHPUX()) {
        offset = addLibraryPatterns(libnames, buf, "lib", ".sl", patterns, offset);
      } else {
        offset = addLibraryPatterns(libnames, buf, "lib", ".so", patterns, offset);
      }
      return patterns;
    }
  
    public static String getMachine() {
      if (machine == null) {
        final String[] args = new String[] {
            "gcc", "-dumpmachine"
        };
       final String[] cmdout = CaptureStreamHandler.run(args);
       if (cmdout.length == 0) {
         machine = "nomachine";
       } else {
         machine = cmdout[0];
       }
     }
     return machine;
   }
 
   public static String[] getOutputFileSwitch(final String letter, final String outputFile) {
     final StringBuffer buf = new StringBuffer();
     if (outputFile.indexOf(' ') >= 0) {
       buf.append('"');
       buf.append(outputFile.replace('\\', '/'));
       buf.append('"');
     } else {
       buf.append(outputFile.replace('\\', '/'));
     }
     final String[] retval = new String[] {
         letter, buf.toString()
     };
     return retval;
   }
 
   /**
    * Returns the contents of the gcc specs file.
    * 
    * The implementation locates gcc.exe in the executable path and then
    * builds a relative path name from the results of -dumpmachine and
    * -dumpversion. Attempts to use gcc -dumpspecs to provide this information
    * resulted in stalling on the Execute.run
    * 
    * @return contents of the specs file
    */
   public static String[] getSpecs() {
     if (specs == null) {
       final File gccParent = CUtil.getExecutableLocation("gcc.exe");
       if (gccParent != null) {
         //
         // build a relative path like
         // ../lib/gcc-lib/i686-pc-cygwin/2.95.3-5/specs
         //
         //
         // resolve it relative to the location of gcc.exe
         //
         final String relativePath = "../lib/gcc-lib/" + getMachine() +
             '/' +
             getVersion() +
             "/specs";
         final File specsFile = new File(gccParent, relativePath);
         //
         // found the specs file
         //
         try {
           //
           // read the lines in the file
           //
           final BufferedReader reader = new BufferedReader(new FileReader(specsFile));
           final Vector lines = new Vector(100);
           String line = reader.readLine();
           while (line != null) {
             lines.addElement(line);
             line = reader.readLine();
           }
           specs = new String[lines.size()];
           lines.copyInto(specs);
         } catch (final IOException ex) {
         }
       }
     }
     if (specs == null) {
       specs = new String[0];
     }
     return specs;
   }
 
   public static String getVersion() {
     if (version == null) {
       final String[] args = new String[] {
           "gcc", "-dumpversion"
       };
       final String[] cmdout = CaptureStreamHandler.run(args);
       if (cmdout.length == 0) {
         version = "noversion";
       } else {
         version = cmdout[0];
       }
     }
     return version;
   }
 
   public static boolean isCaseSensitive() {
     return true;
   }
 
   /**
    * Determines if task is running with cygwin
    * 
    * @return true if cygwin was detected
    */
   public static boolean isCygwin() {
     return getMachine().indexOf("cygwin") > 0;
   }
 
   private static boolean isHPUX() {
     final String osname = System.getProperty("os.name").toLowerCase();
     if (osname.contains("hp") && osname.contains("ux")) {
       return true;
     }
     return false;
   }
 
   /**
    * 
    * Parses the results of the specs file for a specific processor and
    * options
    * 
    * @param specsContent
    *          Contents of specs file as returned from getSpecs
    * @param specSectionStart
    *          start of spec section, for example "*cpp:"
    * @param options
    *          command line switches such as "-istart"
    */
   public static String[][]
       parseSpecs(final String[] specsContent, final String specSectionStart, final String[] options) {
     if (specsContent == null) {
       throw new NullPointerException("specsContent");
     }
     if (specSectionStart == null) {
       throw new NullPointerException("specSectionStart");
     }
     if (options == null) {
       throw new NullPointerException("option");
     }
     final String[][] optionValues = new String[options.length][];
     final StringBuffer optionValue = new StringBuffer(40);
     for (int i = 0; i < specsContent.length; i++) {
       String specLine = specsContent[i];
       //
       // if start of section then start paying attention
       //
       if (specLine.startsWith(specSectionStart)) {
         final Vector[] optionVectors = new Vector[options.length];
         for (int j = 0; j < options.length; j++) {
           optionVectors[j] = new Vector(10);
         }
         //
         // go to next line and examine contents
         // and repeat until end of file
         //
         for (i++; i < specsContent.length; i++) {
           specLine = specsContent[i];
           for (int j = 0; j < options.length; j++) {
             int optionStart = specLine.indexOf(options[j]);
             while (optionStart >= 0) {
               optionValue.setLength(0);
               //
               // walk rest of line looking for first non
               // whitespace
               // and then next space
               boolean hasNonBlank = false;
               int k = optionStart + options[j].length();
               for (; k < specLine.length(); k++) {
                 //
                 // either a blank or a "}" (close of
                 // conditional)
                 // section will end the path
                 //
                 if (specLine.charAt(k) == ' ' || specLine.charAt(k) == '}') {
                   if (hasNonBlank) {
                     break;
                   }
                 } else {
                   hasNonBlank = true;
                   optionValue.append(specLine.charAt(k));
                 }
               }
               //
               // transition back to whitespace
               // value is over, add it to vector
               if (hasNonBlank) {
                 optionVectors[j].addElement(optionValue.toString());
               }
               //
               // find next occurance on line
               //
               optionStart = specLine.indexOf(options[j], k);
             }
           }
         }
         //
         // copy vectors over to option arrays
         //
         for (int j = 0; j < options.length; j++) {
           optionValues[j] = new String[optionVectors[j].size()];
           optionVectors[j].copyInto(optionValues[j]);
         }
       }
     }
     //
     // fill in any missing option values with
     // a zero-length string array
     for (int i = 0; i < optionValues.length; i++) {
       final String[] zeroLenArray = new String[0];
       if (optionValues[i] == null) {
         optionValues[i] = zeroLenArray;
       }
     }
     return optionValues;
   }
 
   private GccProcessor() {
   }
 }