#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include <libxml/xmlmemory.h>
#include <libxml/parser.h>
#include <libxml/parserInternals.h>
#include <libxml/HTMLparser.h>
#include <libxml/HTMLtree.h>
#include <libxml/tree.h>
#include <libxml/xpath.h>
#include <libxml/debugXML.h>
#include <libxml/xmlerror.h>
#include <libxml/globals.h>
#include <libxml/xmlreader.h>
#include <libxml/pattern.h>

#define BUFFER_SIZE  128

int main(int argc, char **argv)
{
   FILE *xmlFile;
   char *filename = NULL;
   const char *pattern = NULL;
   xmlPatternPtr patternc = NULL;
   xmlTextReaderPtr reader;
   int options = 0;
   
   int readlen;
   char buffer[BUFFER_SIZE];

   if (argc != 3)
   {
      printf("Usage : %s <XML file> <XPath pattern>\n", argv[0]);
      return -1;
   }

   LIBXML_TEST_VERSION;

   pattern = argv[2];

   if (pattern != NULL) 
   {
      patternc = xmlPatterncompile(
                    (const xmlChar *) pattern, 
                    NULL, 
                    1,
                    NULL
      );

      if (patternc == NULL) 
      {
         xmlGenericError(
            xmlGenericErrorContext,
            "Pattern %s failed to compile\n", 
            pattern
         );
         pattern = NULL;

         printf("Pattern %s failed to compile\n", pattern);

         return -5;
      }
   }

   filename = argv[1];

   if ((xmlFile = fopen(filename , "r")) == NULL)
   {
      printf("Not able to open file %s\n", filename);
      return -2;
   }

   options |= XML_PARSE_NOERROR;
   options |= XML_PARSE_NOWARNING;

   do
   {
      int ret;

      readlen = fread(buffer, 1, BUFFER_SIZE, xmlFile);

      reader = xmlReaderForMemory(
               buffer,
               readlen,
               filename,
               NULL,
               options
      );

      if (reader == NULL)
      {
         printf("Reader is NULL\n");
         return -3;
      }

      ret = xmlTextReaderRead(reader);

      //printf("==============\n");
      //printf("Buffer is %s\n", buffer);
      //printf("==============\n");

      while (ret == 1) 
      {
          const xmlChar *name, *value;
          
          name = xmlTextReaderConstName(reader);

          if (name == NULL)
          {
             name = BAD_CAST "--";
          }

          value = xmlTextReaderConstValue(reader);

          printf("%d %d %s %d %d",
                  xmlTextReaderDepth(reader),
                  xmlTextReaderNodeType(reader),
                  name,
                  xmlTextReaderIsEmptyElement(reader),
                  xmlTextReaderHasValue(reader)
          );

          if (value == NULL)
          {
             printf("\n");
          }
          else 
          {
             printf(" %s\n", value);
          }

          if (xmlPatternMatch(patternc, xmlTextReaderCurrentNode(reader)) == 1) 
          {
             printf("Node matches pattern %s\n", pattern);
          }

          ret = xmlTextReaderRead(reader);
      }

      xmlFreeTextReader(reader);
   } while (readlen == BUFFER_SIZE);

   xmlFreePattern(patternc);

   xmlCleanupParser();

   xmlMemoryDump();

   fclose(xmlFile);

   return 0;
}