#ifndef _LOG_H_
#define _LOG_H_

#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <assert.h>

#include <libxml/parser.h>
#include <libxml/tree.h>
#include <libxml/xmlmemory.h>
#include <libxml/xpath.h>

#define CONF_FILE_NAME     "/opt/can_book.xml"
#define DEBUG_SON "debug"  /* 除錯資訊的兒子節點 */
#define DEBUG_GRAND_SON_ATTR "debug_level_attr"   /* 日誌資訊孫子節點 */

xmlChar *DebugLevelRead(void); // 獲取除錯資訊等級，預設除錯等級是4

#endif /* _LOG_H_ */
 

/***************************************************************
  <?xml version="1.0" encoding="UTF-8" ?>
<can_books>
 <debug>
 <debug_level debug_level_attr="4" />
 </debug>
 <can0>
 <tag id="1">
  <attr>ESL</attr>
  <goods>1</goods>
  </tag>
 </can0>
</can_books>
***************************************************************/
#include "log.h"

xmlChar *DebugLevelRead(void)
{
  assert(CONF_FILE_NAME);
  
  xmlDocPtr doc = NULL;    // 文件物件指標
  xmlNodePtr root = NULL;  // 根節點物件指標

  // 讀入一個帶有"UTF-8"的xml文件，並返回一個文件指標
  if((doc = xmlReadFile(CONF_FILE_NAME, "UTF-8", 256)) == NULL)
  {
    fprintf(stderr, "Failed to parse xml file:%s\n", CONF_FILE_NAME);
    return NULL;
  }

  // 獲得文件的根節點
  if((root = xmlDocGetRootElement(doc)) == NULL)
  {
    fprintf(stderr, "Failed to get root node.\n");
    goto FAILED;
  }

  xmlNodePtr cur = NULL;   // 當前節點 -- 根節點的子節點
  xmlNodePtr cur_grandson = NULL;  // 當前節點的子節點
  xmlChar *debug_level = NULL;  // 除錯等級字串
  
  cur = root->xmlChildrenNode;
  while(cur != NULL)
  {
    if(!xmlStrcmp(cur->name, (const xmlChar *)DEBUG_SON))
    {
      cur_grandson = cur->xmlChildrenNode;
      debug_level = xmlGetProp(cur_grandson, (const xmlChar*)DEBUG_GRAND_SON_ATTR); // 讀取節點屬性
      printf("debug_level = %s\r\n", debug_level);
    }
    cur = cur->next;
  }

  xmlSaveFormatFileEnc(CONF_FILE_NAME, doc, "UTF-8", 1); // 將文件以"UTF-8"格式進行儲存
  xmlFreeDoc(doc); // 釋放文件指標

  return debug_level;
FAILED:
  if(doc)
  {
    xmlFreeDoc(doc);
  }
  return NULL;
}