#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include "cgi.h"

#define MAX_ENTRIES 10000

void log_error(char *str) {
  FILE *logFile;
  time_t now;

  time(&now);
  logFile = fopen("errors.txt", "a");
  if(logFile != NULL) {
    fprintf(logFile, "%s\t%s\n", ctime(&now), str);
    fclose(logFile);
  }
  printf("An error occured in processing.\n");
  printf("Our apologies. Please try again later, or email <a href=\"mailto:wsnz@ihug.co.nz\">wsnz@ihug.co.nz</a> with your request.\n");
  exit(0);
}

typedef struct {
    char *name;
    char *val;
} entry;

char *makeword(char *line, char stop);
char *fmakeword(FILE *f, char stop, int *len);
char x2c(char *what);
void unescape_url(char *url);
void plustospace(char *str);
void missing_entry(char * entry);

main(int argc, char *argv[]) {
    entry entries[MAX_ENTRIES];
    register int x,m=0;
    int cl, count, alreadyIn = 0;
    FILE *my_f;
    char *my_b, file_name[80], email_address[80], line[1024];

    printf("Content-type: text/html%c%c",10,10);

    if(strcmp(getenv("REQUEST_METHOD"),"POST")) {
        printf("This script should be referenced with a METHOD of POST.\n");
        exit(1);
    }
    if(strcmp(getenv("CONTENT_TYPE"),
                  "application/x-www-form-urlencoded")) {
        printf("This script can only be used to decode form results. \n");
        exit(1);
    }
    cl = atoi(getenv("CONTENT_LENGTH"));

    for(x=0;cl && (!feof(stdin));x++) {
        m=x;
        entries[x].val = fmakeword(stdin,'&',&cl);
        plustospace(entries[x].val);
        unescape_url(entries[x].val);
        entries[x].name = makeword(entries[x].val,'=');
    }

/* make sure that they've entered all the things that they need to enter */

   if(entries[0].val[0] == '\0')
      missing_entry("file name");
   if(entries[1].val[0] == '\0')
      missing_entry("email address");

/* convert everything to useful values */

   strcpy(file_name, "lists/");
   strcat(file_name, entries[0].val);

    /* don't want people sending anything other than lower case letters for the file name - no .. or any other commands */

    count = 6;
    while(count < strlen(file_name)) {
      if((file_name[count] < 'a') || (file_name[count] > 'z'))
	log_error(file_name);
      count++;
    }
    strcat(file_name, ".txt");
    strcpy(email_address, entries[1].val);

    /* first check and see if the email address is already in the file */

    my_f = fopen(file_name, "r");
    if(my_f == NULL)
      log_error("Unable to open email file for reading.");
    my_b = fgets(line, 101, my_f);
    while((!alreadyIn) && (my_b != NULL)) {
      line[strlen(line)-1] = '\0';
      if(!strcmp(line, email_address))
	alreadyIn = 1;
      my_b = fgets(line, 101, my_f);
    }
    close(my_f);
    
    /* write the email address to the file if it's not already there */

    if(!alreadyIn) {
      my_f = fopen(file_name, "a");
      if(my_f == NULL)
	log_error("Unable to open email file for appending.");
      fprintf(my_f, "%s\n", email_address);
      fclose(my_f);
    }

    /* print out the page to show the user */

    my_f = fopen("./header.txt", "r");
    if(my_f == NULL)
      log_error("Unable to open header file.");
    my_b = fgets(line, 1024, my_f);
    while(my_b != NULL) {
      printf("%s\n", line);
      my_b = fgets(line, 1024, my_f);
    }
    fclose(my_f);

    printf("<p>The email address %s has been added to the database. You will receive occasional mailings from OUSA. To change this, please email <a href=\"mailto:wsnz@ihug.co.nz\" onMouseOver=\"show('Send email to wsnz@ihug.co.nz'); return true\" onMouseOut=\"noshow(); return true\">wsnz@ihug.co.nz</a></p>\n", email_address);

    my_f = fopen("./footer.txt", "r");
    if(my_f == NULL)
      log_error("Unable to open footer file.");
    my_b = fgets(line, 1024, my_f);
    while(my_b != NULL) {
      printf("%s\n", line);
      my_b = fgets(line, 1024, my_f);
    }
    fclose(my_f);
}