package com.github.mikkoi.maven.plugins.enforcer.rule.propertyusage;
   
   import org.apache.maven.plugin.logging.Log;
   
   import javax.annotation.Nonnull;
   import java.io.IOException;
   import java.nio.charset.Charset;
   import java.nio.file.Files;
   import java.nio.file.Paths;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.Map;
  import java.util.Set;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  /**
   * Handle issues with .properties files.
   */
  class UsageFiles {
  
      private final Log log;
  
      UsageFiles(final Log log) {
          this.log = log;
      }
  
      /**
       * Read usages by matching the property name in template.
       * this is substituted with the property name.
       *
       * @param filenames  Collection of file names to search for property usage.
       * @param templatesAndProperties  Collection of templates (regexp) to use for matching, and their equivalent property.
       * @return Map of usages not found and their location (file,row), though location does not matter here.
       */
      @Nonnull
      Set<String> readDefinedUsagesFromFiles(
              @Nonnull final Collection<String> filenames,
              @Nonnull final Map<String,String> templatesAndProperties,
              @Nonnull final Charset charset)
              throws IOException {
          final Set<String> results = new HashSet<>();
          final Map<Pattern,String> tplPatterns = new HashMap<>();
          templatesAndProperties.forEach((tpl,property) -> tplPatterns.put(Pattern.compile(tpl, Pattern.COMMENTS | Pattern.UNICODE_CHARACTER_CLASS),property));
          for (final String filename : filenames) {
              log.debug("Reading file '" + filename + "'.");
              final String allFile = String.join("", Files.readAllLines(Paths.get(filename), charset));
              tplPatterns.forEach((tplP, property) -> {
                  log.debug("    Matching pattern '" + tplP.pattern() + "'.");
                  log.debug("        Matching with allFile '" + allFile + "'.");
                  final Matcher matcher = tplP.matcher(allFile);
                  if (matcher.find()) {
                      log.debug("        Pattern match found (" + filename + ")" + ", pattern '" + tplP.pattern() + "'.");
                      results.add(property);
                  }
              });
          }
          return results;
      }
  
      /**
       * @param filenames Collection of file names to search for property usage.
       * @param templates Map of templates (regexp) to use for matching,
       *                  can be used to separate proper usage patterns for properties.
       * @return Map of usages not found and their location (file, row).
       */
      @Nonnull
      Set<UsageLocation> readAllUsagesFromFiles(
              @Nonnull final Collection<String> filenames,
              @Nonnull final Set<String> templates,
              @Nonnull final Charset charset)
              throws IOException {
          final Set<UsageLocation> foundProperties = new HashSet<>();
          final ArrayList<Pattern> tplPatterns = new ArrayList<>();
          templates.forEach(tpl -> tplPatterns.add(Pattern.compile(tpl, Pattern.COMMENTS | Pattern.UNICODE_CHARACTER_CLASS)));
          for (final String filename : filenames) {
              log.debug("Reading file '" + filename + "'.");
              final Collection<String> lines = Files.readAllLines(Paths.get(filename), charset);
              tplPatterns.forEach(tplP -> {
                  log.debug("    Matching pattern '" + tplP.pattern() + "'.");
                  int rowNr = 1;
                  for (final String row : lines) {
                      log.debug("        Matching with row '" + row + "'.");
                      final Matcher matcher = tplP.matcher(row);
                      if (matcher.find()) {
                          log.debug("            Pattern match found (" + filename + ":" + rowNr + ")" + ", pattern '" + tplP.pattern() + "'.");
                          final String propname = matcher.group(1);
                          log.debug("            Extracted property '" + propname + "'.");
                          foundProperties.add(new UsageLocation(propname, rowNr, filename));
                      }
                      rowNr += 1;
                  }
              });
          }
          return foundProperties;
      }
  
     static class UsageLocation {
 
         @Nonnull
         private String property;
 
         private int row;
 
         @Nonnull
         private String filename;
 
         /**
          * @param propertyVal Property name
          * @param rowVal      number
          * @param filenameVal Name of file
          */
         UsageLocation(@Nonnull final String propertyVal, final int rowVal, @Nonnull final String filenameVal) {
             property = propertyVal;
             row = rowVal;
             filename = filenameVal;
         }
 
         @Nonnull
         public String getProperty() {
             return property;
         }
 
         int getRow() {
             return row;
         }
 
         @Nonnull
         String getFilename() {
             return filename;
         }
     }
 }