/*This is a modified version of tagtostruct.h created by Nick Szmyd that was reused
with his permission*/ 

#ifndef __TAGTOSTRUCT_H
#define __TAGTOSTRUCT_H

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

#define SIZE 150

//contains the information for one media object
typedef struct node {
   char name[SIZE];
   char keywords[SIZE];
   char subsection[SIZE];
   char url[SIZE];
   char level[SIZE];
   struct node *next;
} node;


//pointers to nodes of different types 
typedef struct tagstructure {
   struct node *ts;
   struct node *as;
   struct node *vs;
   struct node *is;
} tagstructure;


//reads the tag structure and creates the appropriate nodes  
tagstructure *conversion(char *filename) 
{
tagstructure *tags; 	//pointer to all nodes
node *active, 		//pointer to current node
     *head;		//pointer to head of list
char temp[80];		//temporarily holds tag type, level, and param types
int ch,			//holds current character
    flag, 		//flag of when to create a new node 
    flag2, 		//flag of when a tag is closed 
    cat,		//tells which param we are working with 
    i;			//lcv
FILE *file1;		//file pointer of file to read from 

   flag2 = 1;

   if ((file1 = fopen(filename, "r")) == NULL) {
      printf("Error opening file for input!\n");
      exit(0);
   }

   tags = malloc(sizeof(tagstructure));   
   tags->ts = NULL;
   tags->as = NULL;
   tags->vs = NULL;
   tags->is = NULL;
   for (;;) {
      ch = fgetc(file1);
      if(ch == EOF)
      if (ch == EOF) break;
      if (ch == '>') ch = fgetc(file1);
      if (!isspace(ch)) {
         if (ch == '<') {
            ch = fgetc(file1);
            if(ch == '/')
            {
              temp[0] = fgetc(file1);
              temp[1] = fgetc(file1); 
              temp[2] = '\0';
              ch = fgetc(file1);

              if(flag2 == 0)		//found a closing tag, make sure it matches 
              {
                if((head == tags->ts)&&(!(strcmp(temp, "ts") == 0)))
                {
                  printf("Invalid closing tag on ts\n");
                  exit(0);
                }
                if((head == tags->as)&&(!(strcmp(temp, "as") == 0)))
                {
                  printf("Invalid closing tag on as\n");
                  exit(0);
                }
                if((head == tags->is)&&(!(strcmp(temp, "is") == 0)))
                {
                  printf("Invalid closing tag on is\n");
                  exit(0);
                }
                if((head == tags->vs)&&(!(strcmp(temp, "vs") == 0)))
                {
                  printf("Invalid closing tag on vs\n");
                  exit(0);
                }
                i = 0;
                while(ch != '>')
                {
                  temp[i++] = ch;
                  ch = fgetc(file1);
                }
                temp[i] = '\0';
                if(strcmp(temp,active->level) != 0)
                {
                  printf("Invalid closing tag with level %s for opening tag with level %d\n", temp, active->level); 
                  exit(0);
                }
                flag2 = 1;
              }
              else
              {
                while (ch != '>') ch = fgetc(file1);
              }
            }
            else
            {
              for (i = 0; i < 2; i++) {
                 temp[i] = ch;
                 ch = fgetc(file1);
              }
              temp[i] = '\0';
              if (ch == '>') {		//found an opening tag
                 if (strcmp(temp, "ts") == 0) {
                    tags->ts = malloc(sizeof(node));
                    active = tags->ts;
                    head = tags->ts;
                 }
                 else if (strcmp(temp, "as") == 0) {
                    tags->as = malloc(sizeof(node));
                    head = tags->as;
                    active = tags->as;
                 }
                 else if (strcmp(temp, "vs") == 0) {
                    tags->vs = malloc(sizeof(node));
                    active = tags->vs;
                    head = tags->vs;
                 }
                 else if (strcmp(temp, "is") == 0) {
                    tags->is = malloc(sizeof(node));
                    active = tags->is;
                    head = tags->is;
                 }
                 else
                 {
                   printf("Invalid tag type %s\n", temp);
                   exit(0);
                 }
                 active->next = NULL;
                 flag = 1;
                 flag2 = 1;
              }
              else if (isdigit(ch) || (ch >= 'A' && ch <= 'Z') || (ch >= 'a' && ch <= 'z'))
              {
                 flag2 = 0;
                 if((strcmp(temp, "as") != 0)&&(strcmp(temp, "is") != 0)&&(strcmp(temp, "vs") != 0)&&(strcmp(temp, "ts") != 0))
                 {
                   printf("Invalid tag type %s\n", temp);
                   exit(0);
                 }
                 i = 0;
                 while (isdigit(ch) || (ch >= 'A' && ch <= 'Z') || (ch >= 'a' && ch <= 'z'))
                 {
                    temp[i++] = ch;
                    ch = fgetc(file1);
                 }
                 temp[i] = '\0';
                 if(flag == 1)
                 {
                   flag = 0;
                 }
                 else {
                    active->next = malloc(sizeof(node));
                    active = active->next;
                    active->next = NULL;
                 }
                 strcpy(active->level,temp);
              }
              else {
                 printf("in here\n");
                 while (ch != '>') ch = fgetc(file1);
              } 
            }
         }
         else {		//found a parameter
            i = 0;
            while (ch != '=') {
               temp[i++] = ch;
               ch = fgetc(file1);
            }
            temp[i] = '\0';
            if (strcmp(temp, "name") == 0) cat = 1;
            else if (strcmp(temp, "keywords") == 0) cat = 2;
            else if (strcmp(temp, "subsection") == 0) cat = 3;
            else if (strcmp(temp, "url") == 0) cat = 4;
            else 
            {
              printf("Invalid parameter type %s\n", temp);
              exit(0);
            }
            ch = fgetc(file1);
            ch = fgetc(file1);
            i = 0;
            while (ch != '"') {
               if (ch != '\n') 
                  temp[i++] = ch;
               else
                  temp[i++] = ' ';
               ch = fgetc(file1);
            }
            temp[i] = '\0';
            switch (cat) {
               case 1: strcpy(active->name, temp); break;
               case 2: strcpy(active->keywords, temp); break;
               case 3: strcpy(active->subsection, temp); break;
               case 4: strcpy(active->url, temp);
            }
         }
      }
   } 
   close(file1);
   return tags;
}

#endif