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

//3 Function prototypes
void parse_input(unsigned char ch);
//Input: one byte/char extracted from file
//Output: fields stored in memory for output
//Passes input along to subfunctions to parse data into fields
void parse_output();
//Input: fields stored in memory
//Output: fields combined into one long char. string for output to screen & file
void outscr();
//Input: Record char string
//Output: Outputs 1 data record per line with RRN & "|" delimiter per field to screen
//Assumes user's screen width set to accept 120 characters wide
void outstor();
//Input: Record char string
//Output: Outputs 1 data record per line in output file, "data.txt"
void ini_rec();
//Initializes/resets the data extraction record structure for next record/set of fields
long FileSize (FILE *stream);
//Input: input file stream
//Output: returns input file size

//Subfunctions of parse_input() -> Individual field parsing functions
//Takes input from parent & parses it to appropriate field to store in memory
void parse_f1(unsigned char ch);
void parse_f2(unsigned char ch);
void parse_f3(unsigned char ch);
void parse_f4(unsigned char ch);
void parse_f5(unsigned char ch);
void parse_f6(unsigned char ch);
void parse_f7(unsigned char ch);
void parse_f8(unsigned char ch);
void parse_f9(unsigned char ch);


//Declare global variables
//Global variables used to avoid passing variables into functions
FILE *infile; //file handle for input file
FILE *outfile; //file handle for output file
long flength; //var used to calculate filesize of input file
//var "byte" indicates byte offset for comparison with filesize
int byte = 0, rrn = 0; //var "rrn" self explanatory
//positioning variables
//var "k" for array position to hold field char
// var "fnum" indicates field number to parse, default is 1
//var "atrec" indicates when one set of fields or a record has been reached for output
int k = 0, fnum = 1, atrec = 0; 

//Data extraction record structure
typedef struct record{ // 1 record contains these 9 fields
     char status[6];
     char date[9];
     char location[13];
     char state_country[13];
     char make_model[13];
     char arn[7];
     char severity[9];
     char op_type[13];
     char car_name[13];
}Record;

Record the_record; //initialize a record struct for use

//Data output record structure
//One long char string, each, to hold 1 record
char outdata[97]; //for output to file
char scrdata[97]; //for output to screen

int main(int argc,char *argv[])
{
     //initialize certain variables when 1st run program.
     unsigned char ch;

     if (argc<2)
     {
          puts("No input file specified. Please type command again with input filename.\n");
          return 0;//Self explanatory
     }
     
     //Open file handle to input file
     infile = fopen(argv[1],"rb");
     
     //Abort program & display error if file open fails
     if(infile==NULL)
     {
          printf("Error opening %s\n",argv[1]);
          return 1;
     }

     //Create file handle to output file
     outfile = fopen("datafile.txt", "wb");
     
     //Abort program & display error if file open fails
     if(outfile==NULL)
     {
          printf("Error creating datafile.txt\n");
          return 1;
     }
     
     //Calculate filesize
     flength = FileSize(infile);

     //Initialize record struct for input
     ini_rec();

     //Extract data until EOF reached
     while((ch=fgetc(infile))!= EOF){
          if(atrec){ //output when 1 record reached
               parse_output();
               outscr();
               outstor();
               ini_rec();
               atrec = 0;
          }
          byte++; //increment byte offset indicator
          parse_input(ch);
     }
     //output last record
     parse_output();
     outscr();
     outstor();

     //close file handles when done reading & writing file
     fclose(infile);
     fclose(outfile);
     
     return 0;
}

void parse_input(unsigned char ch){
     switch(fnum){ //Route to subfunction based on fnum
     case 1:
          parse_f1(ch);
          break;
     case 2:
          parse_f2(ch);
          break;
     case 3:
          parse_f3(ch);
          break;
     case 4:
          parse_f4(ch);
          break;
     case 5:
          parse_f5(ch);
          break;
     case 6:
          parse_f6(ch);
          break;
     case 7:
          parse_f7(ch);
          break;
     case 8:
          parse_f8(ch);
          break;
     case 9:
          parse_f9(ch);
          break;
     default: 
          parse_f1(ch); //default is route to parse field 1
          break;
     }
     return;
}

void parse_f1(unsigned char ch){
     if(byte == flength) return; //discard last byte due to use of unsigned char
     if(ch == 13) return;
     if(ch == 10){
          fnum = 2;
          k = 0;
          return;}
     if(k < 5) the_record.status[k++] = ch;
     return;
}

void parse_f2(unsigned char ch){
     if(ch == 13) return;
     if(ch == 10){
          fnum = 3;
          k = 0;
          return;}
     if(k < 8) the_record.date[k++] = ch;
     return;
}

void parse_f3(unsigned char ch){
     if(ch == 44){
          fnum = 4;
          k = 0;
          return;}
     if(k < 12) the_record.location[k++] = ch;
     return;
}

void parse_f4(unsigned char ch){
     if(!k){
          if(ch == ' ') return;}
     if(ch == 13) return;
     if(ch == 10){
          fnum = 5;
          k = 0;
          return;}
     if(k < 12) the_record.state_country[k++] = ch;
     return;
}

void parse_f5(unsigned char ch){
     if(ch == 13) return;
     if(ch == 10){
          fnum = 6;
          k = 0;
          return;}
     if(k < 12) the_record.make_model[k++] = ch;
     return;
}

void parse_f6(unsigned char ch){
     if(ch == 13) return;
     if(ch == 10){
          fnum = 7;
          k = 0;
          return;}
     if(k < 6) the_record.arn[k++] = ch;
     return;
}

void parse_f7(unsigned char ch){
     if(ch == 13) return;
     if(ch == 10){
          fnum = 8;
          k = 0;
          return;}
     if(k < 8) the_record.severity[k++] = ch;
     return;
}

void parse_f8(unsigned char ch){
     if(ch == 13) return;
     if((ch == 44) || (ch == 58) || (ch == 10)){
          fnum = 9;
          k = 0;
          return;}
     if(k < 12) the_record.op_type[k++] = ch;
     return;
}

void parse_f9(unsigned char ch){
     if(!k){
          if(ch == ' ') return;}
     if(ch == 13) return;
     if(ch == 10){
          fnum = 1;
          k = 0;
          atrec = 1;
          rrn++;
          return;}
     if(k < 12) the_record.car_name[k++] = ch;
     return;
}

void parse_output(){
     strcat(scrdata, the_record.arn);
     strcat(scrdata, "|");
     strcat(scrdata, the_record.status);
     strcat(scrdata, "|");
     strcat(scrdata, the_record.date);
     strcat(scrdata, "|");
     strcat(scrdata, the_record.location);
     strcat(scrdata, "|");
     strcat(scrdata, the_record.state_country);
     strcat(scrdata, "|");
     strcat(scrdata, the_record.make_model);
     strcat(scrdata, "|");
     strcat(scrdata, the_record.severity);
     strcat(scrdata, "|");
     strcat(scrdata, the_record.op_type);
     strcat(scrdata, "|");
     strcat(scrdata, the_record.car_name);
     strcat(scrdata, "\n");
     for(int i = 0; i < 96; i++){
          if(scrdata[i] == '|') outdata[i] = ' ';
          else outdata[i] = scrdata[i];
     }
     outdata[96] = '\0';
     return;
}

/* old output parsing method
void parse_output(){
     int i;
     for(i = 0; i < 6; i++) scrdata[i] = the_record.arn[i];
     scrdata[6] = '|';
     for(i = 7; i < 12; i++) scrdata[i] = the_record.status[i];
     scrdata[12] = '|';
     for(i = 13; i < 21; i++) scrdata[i] = the_record.date[i];
     scrdata[21] = '|';
     for(i = 22; i < 34; i++) scrdata[i] = the_record.location[i];
     scrdata[34] = '|';
     for(i = 35; i < 47; i++) scrdata[i] = the_record.state_country[i];
     scrdata[47] = '|';
     for(i = 48; i < 60; i++) scrdata[i] = the_record.make_model[i];
     scrdata[60] = '|';
     for(i = 61; i < 69; i++) scrdata[i] = the_record.severity[i];
     scrdata[69] = '|';
     for(i = 70; i < 82; i++) scrdata[i] = the_record.op_type[i];
     scrdata[82] = '|';
     for(i = 83; i < 95; i++) scrdata[i] = the_record.car_name[i];
     scrdata[95] = 10;
     scrdata[96] = '\0';
     for(i = 0; i < 96; i++){
          if(scrdata[i] == 124) outdata[i] = ' ';
          else outdata[i] = scrdata[i];
     }
     outdata[96] = '\0';
     return;
}
*/

void outscr(){
     printf("%d: ",rrn);
     puts(scrdata);
     return;
}

void outstor(){
     fputs(outdata,outfile);
     return;
}

void ini_rec(){
     int i;
     for(i = 0; i < 5; i++) the_record.status[i] = ' ';
     the_record.status[5] = '\0';
     for(i = 0; i < 8; i++) the_record.date[i] = ' ';
     the_record.date[8] = '\0';
     for(i = 0; i < 12; i++) the_record.location[i] = ' ';
     the_record.location[12] = '\0';
     for(i = 0; i < 12; i++) the_record.state_country[i] = ' ';
     the_record.state_country[12] = '\0';
     for(i = 0; i < 12; i++) the_record.make_model[i] = ' ';
     the_record.make_model[12] = '\0';
     for(i = 0; i < 6; i++) the_record.arn[i] = ' ';
     the_record.arn[6] = '\0';
     for(i = 0; i < 8; i++) the_record.severity[i] = ' ';
     the_record.severity[8] = '\0';
     for(i = 0; i < 12; i++) the_record.op_type[i] = ' ';
     the_record.op_type[12] = '\0';
     for(i = 0; i < 12; i++) the_record.car_name[i] = ' ';
     the_record.car_name[12] = '\0';
     return;
}

long FileSize (FILE *stream)
{
     long length;//temp variable
     fseek (stream, 0L, SEEK_END);//seek to EOF
     length = ftell(stream);//store EOF byte position which is filesize
     //reset file for future reading by seeking to origin
     fseek (stream, 0L, SEEK_SET);
     return length;//return filesize
}

     for(int i = 0; i < 96; i++){

fflush( outfile );

void parse_output(){
    scrdata[0] = 0;
    strcat(scrdata, the_record.arn);
    ...
    ...
    ...
}

int i;
for(i = 0; i < 96; i++){...}

while((ch=fgetc(infile))!= EOF){...}

unsigned char ch;
while(!feof(infile)){
     ch = fgetc(infile);
     ...
}