#include "functions.h"

// Get stdin line with buffer overrun protection
int getstdin(char *prompt, char *buff, size_t sz) {
  int ch, extra;

  // Print optional prompt
  if (prompt != NULL) {
    printf ("%s", prompt);
    fflush (stdout);
  }

  // Get the intput from stdin
  if (fgets (buff, sz, stdin) == NULL) {
    return NO_INPUT;
  }

  // If it was too long, there'll be no newline. In that case, we flush
  // to end of line so that excess doesn't affect the next call.
  if (buff[strlen(buff) - 1] != '\n') { // strlen of the actually entered line, not the original array size
    extra = 0;
    while (((ch = getchar()) != '\n') && (ch != EOF)) {
      extra = 1;
    }
    return (extra == 1) ? TOO_LONG : OK;
  }

  // Otherwise remove newline and give string back to caller.
  buff[strlen(buff) - 1] = '\0';
  return OK;
}

// Append CR-LF to the end of a string (after cleaning up any existing trailing CR or LF)
void appendcrlf(char *string) {
  // Make sure it doesn't already end with CR or LF
  while (string[strlen(string) - 1] == '\r' || string[strlen(string) - 1] == '\n') {
    string[strlen(string) - 1] = '\0';
  }

  int startlen = strlen(string);
  string[startlen] = '\r'; // Add CR
  string[startlen + 1] = '\n'; // Add LF
  string[startlen + 2] = '\0'; // Finish with null terminator
}

// Remove leading colon ':' which is the starting character of a prefix in an IRC message
void stripprefix(char *string) {
  // Make a copy to work with
  char string2[strlen(string)];

  printf("stripprefix(): starting with '%s', strlen: %zd.\n", string, strlen(string));

  // Don't bother if this isn't a prefix with a leading ':'
  if (string[0] != ':') {
    printf("stripprefix(): no leading ':', returning.\n");
    return;
  }

  // Copy the old string into a new one, but...
  for (size_t i = 1; i < strlen(string); i++) {
    string2[i - 1] = string[i];
  }

  // Copy result back to original string
  strncpy(string, string2, strlen(string) - 1);

  // Finish with null terminator
  string[strlen(string) - 1] = '\0';

  printf("stripprefix(): finishing with '%s', strlen: %zd.\n", string, strlen(string));
}

// Extract final parameter from IRC message, removing the leading colon ':'
// e.g. given this string:
// ":irc.tghost.co.uk 332 blabounce #test :This is a test topic!"
// We want to end up with:
// "This is a test topic!"
void extractfinalparameter(char *string) {
  // Make a copy to work with
  char string2[strlen(string)];

  // Position of colon
  int colonpos = -1;

  printf("extractfinalparameter(): starting with '%s', strlen: %zd.\n", string, strlen(string));

  // Strip the colon at position 0 if there is one
  stripprefix(string);

  // Find the colon
  for (size_t i = 0; i < strlen(string); i++) {
    if (string[i] == ':') {
      printf("Found colon at position %zd!\n", i);
      colonpos = i;
      break;
    }
  }

  if (colonpos == -1) {
    printf("no colon found, returning\n");
    return;
  }

  // Build a new string starting from the next position after the colon
  int counter = 0;
  for (size_t i = colonpos + 1; i < strlen(string); i++) {
    string2[counter] = string[i];
    counter++;
  }

  // Copy result back to original string
  strncpy(string, string2, counter);

  // Finish with null terminator
  string[counter] = '\0';

  printf("extractfinalparameter(): finishing with '%s', strlen: %zd.\n", string, strlen(string));
}

// Extract the IRC nick from a prefix
// e.g. given this string:
// ":foo!bar@baz"
// We want to end up with:
// "foo"
void extractnickfromprefix(char *string) {
  // Position of bang
  int bangpos = -1;

  printf("extractnickfromprefix(): starting with '%s', strlen: %zd.\n", string, strlen(string));

  // Strip the colon at position 0 if there is one
  stripprefix(string);

  // Find the bang
  for (size_t i = 0; i < strlen(string); i++) {
    if (string[i] == '!') {
      printf("Found bang at position %zd!\n", i);
      bangpos = i;
      break;
    }
  }

  if (bangpos == -1) {
    printf("no bang found, returning\n");
    return;
  }

  // Terminate the string at whatever position we found the bang
  string[bangpos] = '\0';

  printf("extractnickfromprefix(): finishing with '%s', strlen: %zd.\n", string, strlen(string));
}