E4GLPreprocessor.java

/*
** Module   : E4GLPreprocessor.java
** Abstract : driver for E4GL preprocessing
**
** Copyright (c) 2007-2023, Golden Code Development Corporation.
**
** -#- -I- --Date-- --JPRM-- ----------------------------Description-----------------------------
** 001 GES 20070822   @34966 Provides a driver for E4GL preprocessing.
** 002 IAS 20160331          Fixed setOptions() method 
** 003 GBB 20230512          Logging methods replaced by CentralLogger/ConversionStatus.
*/ 
/*
** This program is free software: you can redistribute it and/or modify
** it under the terms of the GNU Affero General Public License as
** published by the Free Software Foundation, either version 3 of the
** License, or (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
** GNU Affero General Public License for more details.
**
** You may find a copy of the GNU Affero GPL version 3 at the following
** location: https://www.gnu.org/licenses/agpl-3.0.en.html
** 
** Additional terms under GNU Affero GPL version 3 section 7:
** 
**   Under Section 7 of the GNU Affero GPL version 3, the following additional
**   terms apply to the works covered under the License.  These additional terms
**   are non-permissive additional terms allowed under Section 7 of the GNU
**   Affero GPL version 3 and may not be removed by you.
** 
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*/

package com.goldencode.p2j.e4gl;

import com.goldencode.p2j.convert.*;

import java.io.*;
import java.util.logging.*;

/**
 * Provides a driver for E4GL preprocessing. This can be used via the
 * command line (see {@link #main} or via a programming API (see
 * {@link #preprocess}).
 */
public class E4GLPreprocessor
implements E4GLConstants
{
   /** Logger */
   private static final ConversionStatus LOG = ConversionStatus.get(E4GLPreprocessor.class);
   
   /** Stores options that control the behavior of the preprocessor. */
   private Options opts = null;
   
   /**
    * Create a preprocess instance that can be used to handle the E4GL
    * preprocessing for a single HTML file and convert that file into a
    * valid 4GL source file. That source file will require normal 4GL
    * preprocessing before it is compilable source code.
    *
    * @param    input
    *           Filename of the input HTML file.
    */
   public E4GLPreprocessor(String input)
   {
      opts = new Options();
      opts.setInput(input);
   }
   
   /**
    * Create a preprocess instance that can be used to handle the E4GL
    * preprocessing for a single HTML file and convert that file into a
    * valid 4GL source file. That source file will require normal 4GL
    * preprocessing before it is compilable source code.
    *
    * @param    input
    *           Filename of the input HTML file.
    * @param    mode
    *           Compatibility mode controlling the code generation (see
    *           {@link E4GLConstants}).
    */
   public E4GLPreprocessor(String input, int mode)
   {
      this(input);
      opts.setMode(mode);
   }
   
   /**
    * Create a preprocess instance that can be used to handle the E4GL
    * preprocessing for a single HTML file and convert that file into a
    * valid 4GL source file. That source file will require normal 4GL
    * preprocessing before it is compilable source code.
    *
    * @param    input
    *           Filename of the input HTML file.
    * @param    mode
    *           Compatibility mode controlling the code generation (see
    *           {@link E4GLConstants}).
    * @param    other
    *           Manually specified options string.
    */
   public E4GLPreprocessor(String input, int mode, String other)
   {
      this(input, mode);
      
      if (other != null)
         opts.processWSOptions(other, false);
   }
   
   /**
    * Decode a compatibility mode name into the corresponding mode constant.
    * The decode is done on a case-insensitive basis.
    * <p>
    * The following mappings are implemented:
    * <p>
    * <pre>
    * Name                     Mode Constant
    * -----------------------  -----------------
    * ws                       WEBSPEED
    * webspeed                 WEBSPEED
    * ws_strict                WEBSPEED_STRICT
    * webspeed_strict          WEBSPEED_STRICT
    * bd                       BLUE_DIAMOND
    * blue_diamond             BLUE_DIAMOND
    * </pre>
    *
    * @param    name
    *           The mode name.
    *
    * @return   The mode constant or <code>UNKNOWN_MODE</code> if there is
    *           any problem.
    */
   public static int decodeMode(String name)
   {
      int mode = UNKNOWN_MODE;
      
      name = name.toLowerCase();
      
      if ("ws".equals(name) || "webspeed".equals(name))
      {
         mode = WEBSPEED;
      }
      else if ("ws_strict".equals(name) || "webspeed_strict".equals(name))
      {
         mode = WEBSPEED_STRICT;
      }
      else if ("bd".equals(name) || "blue_diamond".equals(name))
      {
         mode = BLUE_DIAMOND;
      }
      
      return mode;
   }
   
   /**
    * Read the HTML input file and convert it into 4GL source code.
    *
    * @param    scan
    *           <code>true</code> to scan the input file to resolve all
    *           options before the preprocessing occurs. <code>false</code>
    *           will bypass the scan and use the options that are already
    *           known.
    * @param    out
    *           An explicit stream to use as the destination for the
    *           preprocessed output. <code>null</code> means that the
    *           preprocessor should create its own stream using the current
    *           output filename OR if that filename is <code>null</code>,
    *           then the preprocessor will calculate the output filename
    *           (see {@link #calculateOutputDest}) and then create a
    *           stream to use.
    */
   public void preprocess(boolean scan, PrintStream out)
   {
      E4GLParser parser = null;
      
      if (scan)
      {
         scanForWSOptions();
      }
      
      if (out == null)
      {
         if (opts.getOutput() == null)
         {
            calculateOutputDest();
         }
         
         out = getOutputDest();
      }
      
      try
      {
         parser = getParser();
         parser.preprocess(opts, out);
      }
       
      catch (Exception exc)
      {
         LOG.log(Level.SEVERE, "", exc);
      }
      
      finally
      {
         try
         {
            if (parser != null)
               parser.closeInput();
            
            out.close();
         }
         
         catch (Exception exc)
         {
            // ignore I/O failures
         }
      }
   }
   
   /**
    * Create a new instance of the E4GL parser based on previously set
    * configuration. After the caller is finsihed using the parser, it is
    * important to use {@link E4GLParser#getInput} and to call 
    * <code>close</code> on that stream. Neither the parser nor the lexer
    * (that is being used by the parser) close the input stream when
    * complete.  It is the caller's responsibility to do this!
    *
    * @return   A fully functional parser ready for processing.
    */
   public E4GLParser getParser()
   {
      E4GLParser parser = null;
      
      try
      {
         FileInputStream file  = new FileInputStream(opts.getInput());
         DataInputStream data  = new DataInputStream(file);
         E4GLLexer       lexer = new E4GLLexer(data);
         
         parser = new E4GLParser(lexer);
         parser.setInput(data);
      }
      
      catch(Exception excpt)
      {
         LOG.log(Level.WARNING,"", excpt);
      }
      
      return parser;
   }
   
   /**
    * Scan the input file to parse out any options that are encoded in
    * &lt;META&gt; or &lt;!--WSMETA--&gt; elements. These options will be
    * normalized, cleaned up and merged with any manually specified options.
    * The result can be used to direct the E4GL preprocessing run. Access
    * the options via {@link #getOptions}.
    */
   public void scanForWSOptions()
   {
      E4GLParser parser = null;
      
      try
      {
         parser = getParser();
         parser.scan_options(opts);
      }
       
      catch(Exception excpt)
      {
         LOG.log(Level.WARNING,"", excpt);
      }
      
      finally
      {
         if (parser != null)
            parser.closeInput();         
      }
   }
   
   /**
    * Use the input filename and the known options to calculate the filename
    * for the output destination. It is critical that all options have been
    * determined/resolved before this method is called. To the extent that
    * the options are dependent upon encoded META or WSMETA elements in the
    * HTML input file, it is important to use {@link #scanForWSOptions}
    * before calling this method. The resulting filename will be stored in
    * the current options for downstream usage by the preprocessor.
    *
    * @return   The calculated filename.
    */
   public String calculateOutputDest()
   {
      StringBuilder sb = new StringBuilder();
      
      String input = opts.getInput();
      int    idx   = input.lastIndexOf(".");
      
      // remove the file extension if present
      sb.append((idx != -1) ? input.substring(0, idx) : input);
      
      // add our output extension based on our options
      sb.append(opts.getCompatibilityHelper().suffix());
      
      String dest = sb.toString();
      opts.setOutput(dest);
      
      return dest;
   }
   
   /**
    * Access the specified and/or calculated options for preprocessing the
    * current input file.
    *
    * @return   The options for this preprocessor instance.
    */
   public Options getOptions()
   {
      return opts;
   }
   
   /**
    * Replace the specified and/or calculated options for preprocessing the
    * current input file. WARNING: this will erase any state set by previous
    * calls to {@link #scanForWSOptions} and/or manually set options strings
    * in the preprocessor constructor.
    *
    * @param    options
    *           The options for this preprocessor instance.
    */
   public void setOptions(Options options)
   {
      this.opts = options;
   }
   
   /**
    * Access the specified input filename.
    *
    * @return   A filename.
    */
   public String getInput()
   {
      return opts.getInput();
   }
   
   /**
    * Set the specified input filename.
    *
    * @param    input
    *           A filename.
    */
   public void setInput(String input)
   {
      opts.setInput(input);
   }
   
   /**
    * Access the calculated output filename.
    *
    * @return   A filename.
    */
   public String getOutput()
   {
      return opts.getOutput();
   }
   
   /**
    * Set the specified output filename. WARNING: this will override any
    * previously calculated output filename.
    *
    * @param    output
    *           A filename.
    */
   public void setOutput(String output)
   {
      opts.setOutput(output);
   }
   
   /**
    * Gets the operating system name which must be used to determine how
    * escape characters are treated.
    *
    * @return   The operating system name.
    */
   public String getOpsys()
   {
      return opts.getOpsys();
   }
   
   /**
    * Sets the operating system name which must be used to determine how
    * escape characters are treated.
    *
    * @param    opsys
    *           The new operating system name.
    */
   public void setOpsys(String opsys)
   {
      opts.setOpsys(opsys);
   }
   
   /**
    * Get a stream that outputs to the file specified by the current output
    * filename (see {@link #getOutput}). The target file will be removed if
    * it exists.
    *
    * @return   A stream or <code>null</code> if any failure occurs.
    */
   public PrintStream getOutputDest()
   {
      PrintStream out = null;
      
      File dest = new File(opts.getOutput());
      
      try
      {
         // if this filename exists as a directory, we can't save results
         if (!dest.isDirectory())
         {   
            // remove the target file if it exists.
            if (dest.exists())
            {
               dest.delete();
            }
            
            out = new PrintStream(new FileOutputStream(dest));
         }
      }
      
      catch (Exception excpt)
      {
         LOG.log(Level.WARNING,"", excpt);
      }
      
      return out;
   }
   
   /**
    * Emit a syntax statement and optional error message to
    * <code>stderr</code>, then exit the process with the specified return
    * code. This method is called from {@link #main} when the user passes
    * command line parameters which are not viable.
    *
    * @param    msg
    *           Optional error message; may be <code>null</code>.
    * @param    rc
    *           Process return code used with <code>System.exit()</code>.
    */
   private static void syntax(String msg, int rc)
   {
      if (msg != null)
      {
         LOG.log(Level.SEVERE, msg);
      }
      
      String[] staticText =
      {
         "",
         "---------------------E4GL Preprocessor Driver---------------------",
         "",
         "Reads HTML files (with Embedded 4GL) and converts them into 4GL",
         "source code (procedure or include files).",
         "",
         "Syntax:",
         "",
         "   java E4GLPreprocessor [-options] <file>",
         "",
         "Where",
         "",
         "   options",
         "",
         "      C<mode>   = specify the compatibility mode where <mode>:",
         "                  - WS or WEBSPEED",
         "                  - WS_STRICT or WEBSPEED_STRICT",
         "                  - BD or BLUE_DIAMOND",
         "      O<wsopts> = manually add an options string to augment",
         "                  that found by scanning for 'wsoptions' in",
         "                  <META> or <!--WSMETA--> HTML elements",
         "      S         = scan for wsoptions and content-type meta-data,",
         "                  dump the results to STDOUT and then exit without",
         "                  any further processing",
         "",
         "   file    = absolute and/or relative filename of the file", 
         "             to process",
         ""
      };
      
      for (int i = 0; i < staticText.length; i++)
      {
         LOG.log(Level.CONFIG, staticText[i]);
      }
      
      System.exit(rc);
   }
   
   /**
    * Command line driver for E4GL preprocessing. Reads HTML files
    * (containing Embedded 4GL) and converts them into 4GL source code
    * (procedure or include files).
    * <p>
    * Syntax:
    * <pre>
    * java E4GLPreprocessor [-options] &lt;file&gt;
    * </pre>
    * Where:
    * <ul>
    *   <li> Options
    *   <ul>
    *      <li> C&lt;mode&gt; to specify the compatibility mode where
    *           &lt;mode&gt;
    *      <ul>
    *         <li> WS or WEBSPEED
    *         <li> WS_STRICT or WEBSPEED_STRICT",
    *         <li> BD or BLUE_DIAMOND",
    *      </ul>
    *      <li> O&lt;wsopts&gt; = manually add an options string to augment
    *           that found by scanning for 'wsoptions' in &lt;META&gt; or
    *           &lt;!--WSMETA--&gt; HTML elements
    *      <li> S = scan for wsoptions and content-type meta-data,
    *           dump the results to STDOUT and then exit without any
    *           further processing
    *   </ul>
    *   <li> file = absolute and/or relative filename of the file to process
    * </ul>
    *
    * @param    args
    *           Command line parameters. Use matching double quotes to
    *           pass any argument that requires special characters or
    *           whitespace.
    */
   public static void main(String[] args) 
   {
      // option defaults
      boolean scanonly  = false;
      String  wsoptions = null;
      int     mode      = DEFAULT_MODE;
      int     idx       = 0;
      
      if (args.length < 1)
      {
         syntax("Missing <file> parameter.", -1);
      }
      
      // process options
      while (idx < args.length && args[idx].startsWith("-"))
      {
         String  parm  = null;
         boolean known = false;
         
         char opt = args[idx].charAt(1);
         
         if (opt == 's' || opt == 'S')
         {
            scanonly = true;
            known = true;
         }
         
         // all other options need more than 2 chars
         if (!known)
         {
            if (args[idx].length() < 3)
               syntax(String.format("Invalid option '%s'.", args[idx]), -2);
            else
               parm = args[idx].substring(2);
         }
         
         if (opt == 'c' || opt == 'C')
         {
            known = true;
            mode = E4GLPreprocessor.decodeMode(parm);
            
            if (mode == UNKNOWN_MODE)
            {
               syntax("Unknown compatibility mode.", -3);
            }
         }
         
         if (opt == 'o' || opt == 'O')
         {
            known = true;
            char first = parm.charAt(0);
            char last  = parm.charAt(parm.length() - 1);
            
            // strip off any surrounding quotes
            if (first == '\"' || first == '\'')
               parm = parm.substring(1);
            if (last == '\"' || last == '\'')
               parm = parm.substring(0,parm.length() - 1);
            
            wsoptions = parm;
         }
         
         if (!known)
            syntax(String.format("Unknown option '%s'.", args[idx]), -4);
         
         idx++;
      }
      
      // there must be at least 1 arg left
      if (idx >= args.length)
      {
         syntax("Missing <file> parameter.", -5);
      }
      
      // drive processing
      try
      {
         E4GLPreprocessor preproc = new E4GLPreprocessor(args[idx],
                                                         mode,
                                                         wsoptions);
         
         if (scanonly)
         {
            preproc.scanForWSOptions();
            System.out.println(preproc.getOptions().toString());
         }
         else
         {
            preproc.preprocess(true, null);
         }
      }
       
      catch(Exception excpt)
      {
         LOG.log(Level.SEVERE, "", excpt);
      }
   }   
}