horrible-harry/wordplay.cpp

#include "images.h"
#include "lastseen.h"
#include "render.h"
#include "terminal.h"
#include "utils.h"
#include <regex.h>
#include <string.h>
#include <string>

#include "zf_log.h"

#include <unistd.h> // write

extern struct console_details console;

#define BSIZE 512

/*
 * harry_idle_event(fd)
 *
 * User is idle, let's let them know we're here.  HAHAHA!
 *
 */
void harry_idle_event(int fd) {
  // Make something happen
  char buffer[100];
  int slen;
  int r;
  // This is no where near finished, BUT!
  const char *phrases[] = {"Hahaha",    "Snicker, snicker", "Boo!",
                           "MeOW",      "I see U",          "Arrooo!",
                           "Ahh-wooo!", "Aaaooo!"};
  const char *cp;
  static LastSeen last_seen_harry_event(2);

  do {
    r = randint((sizeof(phrases) / sizeof(char *)));
  } while (last_seen_harry_event.seen_before(r));

  cp = phrases[r];
  int color = random() % 15 + 1;

  slen = snprintf(buffer, sizeof(buffer), "^S2^C%02d%s^P2^CR^D%02d", color, cp,
                  (int)strlen(cp));
  if (slen >= sizeof(buffer)) {
    ZF_LOGE("snprintf %d > size %d", slen, (int)sizeof(buffer));
    buffer[0] = 0;
  }
  ZF_LOGD("harry_event: render(%d, \"%s\")", fd, buffer);
  std::string str(buffer);
  // render(fd, buffer, strlen(buffer));
  render(fd, str);
}

void init_harry() {
  // init_have_seen(last_seen_harry_event, MAX_HARRY_EVENT_DUPS);
  // ZF_LOGD("init => %d %d", last_seen_harry_event[0],
  // last_seen_harry_event[1]);
  console_init(&console);
}

regex_t ANSI;
regex_t WORDS;
regex_t WORD;

int init_regex(void) {
  int ret;
  char ansi[] = "\x1b\[[0-9]+(;[0-9]+)*?[a-zA-Z]";
  char words[] = "[a-zA-Z]+( [a-zA-Z]+)+";
  char word[] = "[a-zA-Z]+";
  char errorbuf[100];

  if (ret = regcomp(&ANSI, ansi, REG_EXTENDED | REG_NEWLINE)) {
    regerror(ret, &ANSI, errorbuf, sizeof(errorbuf));
    ZF_LOGW("Regex %s failed to compile: %s", ansi, errorbuf);
    return 0;
  };

  if (ret = regcomp(&WORDS, words, REG_EXTENDED | REG_NEWLINE)) {
    regerror(ret, &WORDS, errorbuf, sizeof(errorbuf));
    ZF_LOGW("Regex %s failed to compile: %s", words, errorbuf);
    return 0;
  };

  if (ret = regcomp(&WORD, word, REG_EXTENDED | REG_NEWLINE)) {
    regerror(ret, &WORD, errorbuf, sizeof(errorbuf));
    ZF_LOGW("Regex %s failed to compile: %s", word, errorbuf);
    return 0;
  };

  return 1;
}

int regmatch(regex_t *preg, const char *string, size_t nmatch,
             regmatch_t pmatch[], int eflags) {
  // returns number of matches found.  (Max nmatch)
  int matches = 0;
  int offset = 0;

  while (matches < nmatch) {
    int ret = regexec(preg, string + offset, nmatch - matches, pmatch + matches,
                      eflags);
    if (!ret) {
      int current = offset;
      offset += pmatch[matches].rm_eo;
      pmatch[matches].rm_so += current;
      pmatch[matches].rm_eo += current;
      matches++;
    } else if (ret == REG_NOMATCH) {
      break;
    } else {
      break;
    }
  }
  return matches;
}

#define MAX_MATCH 32
regmatch_t rxmatch[MAX_MATCH];

int rx_match(regex_t *regex, const char *buffer) {
  int ret;

  ret = regmatch(regex, buffer, MAX_MATCH, rxmatch, 0);
  if (0) {
    for (int i = 0; i < ret; i++) {
      ZF_LOGI("%d : (%d-%d)", i, rxmatch[i].rm_so, rxmatch[i].rm_eo);
    }
  }
  return ret;
}

/**
 * random_activate()
 *
 * Is a weight (1-10),
 * tests if random number is < weight * 10.
 *
 * So random_activate(9) happens more frequently
 * then random_activate(8) or lower.
 *
 * This probably needs to be fixed.
 * We need a better randint(RANGE) code.
 */
int random_activate(int w) {
  int r = randint(100);
  if (r <= (w * 10)) {
    return 1;
  };
  return 0;
}

/*
  word_state():    // deprecated

  -1 only lower
  +1 only upper
   0 mixed
*/
int word_state(const char *buffer, int len) {
  int p;
  int upper = 0;
  int lower = 0;
  int ret;
  float pct;

  for (p = 0; p < len; p++) {
    char c = buffer[p];
    if (isalpha(c)) {
      if (isupper(c)) {
        upper++;
      };
      if (islower(c)) {
        lower++;
      };
    }
  }

  if (upper == lower) {
    return 0;
  }

  if (upper > lower) {
    ret = 1;
    pct = ((float)lower / (float)upper) * 100.0;
  } else {
    ret = -1;
    pct = ((float)upper / (float)lower) * 100.0;
  }

  // ZF_LOGD("So far %d with %f %%", ret, pct);

  if (pct < 40.0) {
    return ret;
  }
  return 0;
}

/*
Given a buffer and length, mangle away.

toupper, tolower, flipper
 */
int word_mangler(char *buffer, int len) {
  int p;
  int count = 0;
  int state;

  // state = word_state(buffer, len);
  // ZF_LOGD("word_state(%.*s) %d", len, buffer, state);
  state = randrange(-1, 1);

  // TODO:  Transposer

  for (p = 0; p < len; p++) {
    char c = buffer[p];

    if (randint(len) == p) {
      break;
    }
    switch (state) {
    case -1:
      // upper
      if (islower(c)) {
        count++;
        buffer[p] = toupper(c);
      }
      break;
    case 1:
      // lower
      if (isupper(c)) {
        count++;
        buffer[p] = tolower(c);
      }
      break;
    case 0:
      // flipper
      if (islower(c)) {
        count++;
        buffer[p] = toupper(c);
      } else {
        if (isupper(c)) {
          count++;
          buffer[p] = tolower(c);
        }
      }
      break;
    }
  }
  return count;
}

int word_wrangler(char *buffer, int len) {
  int p;
  int count;
  int state;

  // state = word_state(buffer, len);
  // ZF_LOGD("word_state(%.*s) %d", len, buffer, state);
  if (len < 5) {
    return 0;
  }

  p = randint(len - 4) + 2;

  for (count = 0; count < 4; count++) {
    if (!isalpha(buffer[p + count]))
      break;
  }

  ZF_LOGV_MEM(buffer, len, "wrangler %d len %d:", p, count);

  if (count >= 2) {
    for (int x = 0; x < count / 2; x++) {
      char ch = buffer[p + x];
      buffer[p + x] = buffer[p + count - 1 - x];
      buffer[p + count - 1 - x] = ch;
    }
    ZF_LOGV_MEM(buffer, len, "word now:");
    return 1;
  } else
    return 0;
}

int buffer_insert(char *buffer, int len, int max_length, int pos,
                  const char *insert) {
  if (len + strlen(insert) > max_length) {
    ZF_LOGD("buffer_insert failed [%s]", repr(insert));
    return 0;
  }
  memmove(buffer + pos + strlen(insert), buffer + pos, len - pos);
  strncpy(buffer + pos, insert, strlen(insert));
  return 1;
}

/*
 * The buffer that we've been given is much larger now.
 *
 * We can no longer mangle or insert into the given buffer.
 * Why?  Because we don't know what is behind it now!
 */
int mangle(int fd, const char *buffer, int len) {
  int x, i;
  int need_render = 0; // changing word case around doesn't need the render
  int mangled = 0;
  int mangled_chars = 0;
  char play[BSIZE * 2]; // The main buffer to send.
  const char *cp;

  // Make a copy of buffer, since it can no longer be changed
  // inserted into.

  memcpy(play, buffer, len);

  // NEVER reference buffer from this point on!

  char work[BSIZE * 2]; // The mess with buffer.

  /*
   We use the work buffer to blank out the ANSI
   before trying to locate words.  (So we don't
   grab part of the ANSI codes and mangle those!)
  */

  // Use terminal - clean out ANSI

  // ZF_LOGI("mangle:");
  ZF_LOGI_MEM(play, len, "Mangle (%u bytes):", len);

  // strcpy(work, buffer);

  /*
  NOTE:  We copy the buffer, so we can clear out ANSI codes, etc.
  Otherwise we might mess some ANSI up in the manglying
  process.
  */

  /*
  Is there a way to track -- what I've inserted, and make it exempt from
  other modifications / mangler, wrangler?
   */

  /*
   (random) Look for ANSI CLS and:

      display random spooky texts around, with delays ... then CLS.

      display ANSI graphic file, with delays ... then CLS
   */
  const char *ANSI_CLS = "\x1b[2J";
  cp = strnstr(play, len, ANSI_CLS); // strstr(buffer, ANSI_CLS);

  if (cp != NULL) {
    static int ANSI_CLS_count = 0; // count the number we've seen
    ZF_LOGI("seen: ANSI_CLS");
    ANSI_CLS_count++;

    // Don't activate on the very first CLS.  Too soon, don't screw up the ANSI
    // detection.
    if (ANSI_CLS_count > 1) {
      // Ok, figure out the restore color, just in case
      struct console_details temp_console;
      // Make exact copy of our current console state.
      memcpy(&temp_console, &console, sizeof(console));
      // Play the buffer into the console
      console_receive(&temp_console, play, cp - play);
      char restore_color[30]; // ansi color
      strcpy(restore_color, color_restore(&temp_console));

      if (random_activate(3)) {
        char display[100] = "";
        int slen;
        int needs_cls = 0;

        struct image {
          const char **lines;
          int size;
          int cls;
          int width; // height = size
        } images[] = {{ghost, sizeof(ghost) / sizeof(char *), 1, 0},
                      {ghead, sizeof(ghead) / sizeof(char *), 1, 0},
                      {wolf, sizeof(wolf) / sizeof(char *), 1, 0},
                      {panther, sizeof(panther) / sizeof(char *), 1, 0},
                      {bat, sizeof(bat) / sizeof(char *), 1, 0},
                      {icu, sizeof(icu) / sizeof(char *), 0, 20},
                      {skull, sizeof(skull) / sizeof(char *), 0, 19},
                      {skullblink, sizeof(skullblink) / sizeof(char *), 0, 19}};

        static LastSeen last_files(2);
        int r;

        do {
          r = randint((sizeof(images) / sizeof(image)));
        } while (last_files.seen_before(r));

        char fgoto[32];

        if (!images[r].cls) {
          int x = 0, y = 0;

          x = randint(79 - images[r].width) + 1;
          y = randint(24 - images[r].size) + 1;

          int slen;
          // render image, home cursor
          slen = snprintf(fgoto, sizeof(fgoto), "^f%02d%02d\x1b[1;1H", x, y);
          if (slen >= sizeof(fgoto)) {
            ZF_LOGE("snprintf %d > size %d", slen, (int)sizeof(fgoto));
            fgoto[0] = 0;
          }
        } else {
          strcpy(fgoto, "^F");
        }

        // (2); // (sizeof(possibles) / sizeof(file_need)) - 1);
        needs_cls = images[r].cls;

        // I get what's happening.  Mystic moves cursor to home, CLS, cursor
        // home. When we get here, we're ALWAYS at the top of the screen...
        // Hence our bat isn't displayed at the end of the screen.

        // This is before the actual CLS, so we CLS before displaying our files.
        // I tried a ^P2 before doing this .. but I'd rather have the picture up
        // right away I think.

        // Ok, yes, there's no filename being sent.  :P
        render_image(images[r].lines, images[r].size);

        slen = snprintf(display, sizeof(display), "%s%s%s^P3",
                        needs_cls ? "\x1b[2J" : "", fgoto, restore_color);
        if (slen >= sizeof(display)) {
          ZF_LOGE("snprintf %d > size %d", slen, (int)sizeof(display));
          display[0] = 0;
        }
        ZF_LOGI("mangle(ANSI_CLS): %d file inserted %s", r, repr(display));

        // Move the buffer so there's room for the display string.
        if (buffer_insert(play, len, sizeof(play), cp - play, display)) {
          len += strlen(display);
          // if (string_insert(buffer, 1024, cp - buffer, display)) {

          ZF_LOGI_MEM(play, len, "mangle(ANSI_CLS) (%u bytes):", len);
          // ZF_LOGI("mangle(ANSI_CLS):");
          // ZF_LOGI_REPR(buffer);
          // ZF_LOGI("mangle(ANSI_CLS): [%s]", repr(buffer));
          need_render = 1;

          /*
          Copy the new buffer over, but hide our "render" code
          from the remaining mangler steps.
          */
          memcpy(work, play, len);
          // strcpy(work, buffer);
          i = cp - play;
          // find offset into "buffer"
          // apply to work.
          memset(work + i, ' ', strlen(display));

        } else {
          ZF_LOGD("insert failed [%s].", repr(display));
        }
      } else {
        if (random_activate(4)) {
          int r;
          char display[100] = "";
          int slen;

          /*
          Interesting note here:
          "Anyone there" qualifies as a valid WORDS regex match.
          It is possible that it can get mangled/wrangled!
          */
          const char *phrasing[] = {
              "^R1Haha^P1ha^P1ha", "Poof!", "Got U", "Anyone there?",
              "^R1Knock, ^P1Knock",
              /*
              This picks random color and position -- then
              homes cursor and changes to another color.  (This can be seen.)
               */
              "^G0101^C07^S9Segmentation fault (core dumped)^P2"};
          static LastSeen last_phrasing(2);

          ZF_LOGI("mangle(ANSI_CLS)");
          // sprintf( display, "^P2...");
          // This string actually screws up ANSI detection (takes too long)
          // strcpy(display, "^P2^S501234567890^P1abcdef^P2g^P3h^P4i^S0^P2");

          // strcpy(display, "^P2^S301234^P15^S0^P2");

          // Add in random text, plus color!
          do {
            r = randint(sizeof(phrasing) / sizeof(char *));
          } while (last_phrasing.seen_before(r));

          int color = random() % 15 + 1;
          int x = random() % 30 + 1;
          int y = random() % 15 + 1;

          /*
          Don't have it pause there before moving the cursor.

          Move the cursor, get the color changed, THEN pause.
          Then act all crazy.

          NOTE:  Make sure if you use any ^R Render effects, turn them off
          before trying to display the restore_color.  :P   ^R0 Also, make
          sure you re-home the cursor ^G0101 because that's where they are
          expecting the cursor to be!  (At least it's how Mystic does it.)

          HOME, CLS, HOME, ...  Not sure what others do there.  We'll see.
          */

          slen = snprintf(display, sizeof(display),
                          "^G%02d%02d^S3^C%02d^P1%s^S0^R0%s^P1^G0101", x, y,
                          color, phrasing[r], restore_color);
          if (slen >= sizeof(display)) {
            ZF_LOGE("snprintf %d > size %d (Phrase: %d, %s)", slen,
                    (int)sizeof(display), r, phrasing[r]);
            display[0] = 0;
          }

          // sprintf(display, "^P1^S3^C%02d%s^S0^R0%s^P1", color, phrasing[r],
          // restore_color);
          // Added debug statement so we can identify what was sent... color,
          // number picked and what that is
          ZF_LOGD("mangle(ANSI_CLS): Inserted color=%02d r=%d phrase='%s'",
                  color, r, phrasing[r]);
          ZF_LOGI_MEM(play, len, "mangle(ANSI_CLS) :");

          // Move the buffer so there's room for the display string.
          if (buffer_insert(play, len, sizeof(play), cp - play, display)) {
            len += strlen(display);

            // if (string_insert(buffer, BSIZE * 4, cp - buffer, display)) {
            ZF_LOGI_MEM(play, len, "mangle(ANSI_CLS) + :");
            // ZF_LOGI("mangle(ANSI_CLS):");
            // ZF_LOGI_REPR(buffer);
            need_render = 1;

            /*
            Copy the new buffer over, but hide our "render" code
            from the remaining mangler steps.
            */
            memcpy(work, play, len);
            // strcpy(work, buffer);
            i = cp - play;
            // find offset into "buffer"
            // apply to work.
            memset(work + i, ' ', strlen(display));

          } else {
            ZF_LOGD("insert failed [%s].", repr(display));
          }
        }
      }
    }
  }

  memcpy(work, play, len);

  // strcpy(work, buffer); // sure.

  // NOTE: This is NOT aware of my ^TRIGGERS, so they will show up
  // as valid things to mangle in work.  (Keep this in mind).

  const char replace_with = ' ';
  for (x = 0; x < len; x++) {
    termchar tc = console_char(&console, play[x]);
    int ansi = tc.in_ansi;

    if (ansi) {
      work[x] = replace_with;
      if (tc.ansi != START) {
        ZF_LOGD("ANSI type %d at %d", tc.ansi, x);
      }
    }
    // fixup "work" so it's a valid C string
    if (buffer[x] == 0) {
      work[x] = replace_with;
    }
  }
  // fixup "work" buffer so it's a valid c string
  // (required for regex to work.)
  work[len] = 0;

  ZF_LOGV_MEM(work, len, "Work now:");

  /*
   (random) Locate words (in work), and possibly flip them around.
   Transpose words.  Transpose case.  Transpose letters.

   Ok, what would be interesting, is if we could find
   W\x1[0;34mORDS with color changes in them, and work with them.
   without screwing up the color changes, of course.  :P

  Example:

   Y\x1b[0;1mes \x1b[0;1;34m\x1b[0;1;34;44m N\x1b[0;1;44mo
   Yes No
   ^ This would be a job for a crazy regex.

   I'd have to map the characters to positions in the buffer.  :S
   I'd want mangle and wrangle to work.

   The Message menu -- doesn't hardly get mangled at all (at least on
   my test site).  Because all of the color changes break up the
   words in the menu.
   */
  x = rx_match(&WORDS, work);
  ZF_LOGD("found %d word groups", x);

  if (x > 0) {
    for (i = 0; i < x; i++) {

      // Yes!  Be random!
      if (random_activate(8)) {
        int c = word_mangler(play + rxmatch[i].rm_so,
                             rxmatch[i].rm_eo - rxmatch[i].rm_so);
        if (c) {
          mangled++;
          mangled_chars += c;
        }
      }

      if (random_activate(4)) {
        word_wrangler(play + rxmatch[i].rm_so,
                      rxmatch[i].rm_eo - rxmatch[i].rm_so);
      }
    }
  }

  /*
   (random) Locate single words, and transpose words.
   Transpose letters.
   */

  /*
   (random) Display up to certain point.  Delay.
   Print some characters slowly.  Delay.
   */

  if (mangled)
    ZF_LOGI("Mangled %d word, %d chars (render %d)", mangled, mangled_chars,
            need_render);

  if (need_render) {
    ZF_LOGD_MEM(play, len, "Ready to render:");
    // ZF_LOGD("HH %d : (%d) %s", need_render, (int)strlen(buffer),
    // repr(buffer));
  }

  if (need_render) {
    render(fd, play, len);
  } else {
    write(fd, play, len);
  };
  return need_render && mangled;
}

int harry_happens(time_t *last_event, int wakeup) {
  time_t now = time(NULL);
  int elapsed = now - *last_event;

  if (elapsed > wakeup) {
    // Ok!  It's been too long since we've done something.
    *last_event = now;
    return 1;
  }
  return 0;
}

int mangle_clrscr(std::string &buffer, std::string &work, size_t pos) {
  static int ANSI_CLS_count = 0;
  ZF_LOGI("seen: ANSI_CLS");
  ANSI_CLS_count++;

  if (ANSI_CLS_count > 1) {
    // get the restore color value
    struct console_details temp_console;
    memcpy(&temp_console, &console, sizeof(console));
    console_receive(&temp_console, buffer.substr(0, pos));
    char restore_color[30];
    strncpy(restore_color, color_restore(&temp_console), sizeof(restore_color));

    if (random_activate(3)) {
      char display[100] = "";
      int slen;
      int needs_cls = 0;

      struct image {
        const char **lines;
        int size;
        int cls;
        int width; // height = size
      } images[] = {{ghost, sizeof(ghost) / sizeof(char *), 1, 0},
                    {ghead, sizeof(ghead) / sizeof(char *), 1, 0},
                    {wolf, sizeof(wolf) / sizeof(char *), 1, 0},
                    {panther, sizeof(panther) / sizeof(char *), 1, 0},
                    {bat, sizeof(bat) / sizeof(char *), 1, 0},
                    {icu, sizeof(icu) / sizeof(char *), 0, 20},
                    {skull, sizeof(skull) / sizeof(char *), 0, 19},
                    {skullblink, sizeof(skullblink) / sizeof(char *), 0, 19}};

      static LastSeen last_files(2);
      int r;

      do {
        r = randint((sizeof(images) / sizeof(image)));
      } while (last_files.seen_before(r));

      char fgoto[32];

      if (!images[r].cls) {
        int x = 0, y = 0;

        x = randint(79 - images[r].width) + 1;
        y = randint(24 - images[r].size) + 1;

        int slen;
        // render image, home cursor
        slen = snprintf(fgoto, sizeof(fgoto), "^f%02d%02d\x1b[1;1H", x, y);
        if (slen >= sizeof(fgoto)) {
          ZF_LOGE("snprintf %d > size %d", slen, (int)sizeof(fgoto));
          fgoto[0] = 0;
        }
      } else {
        strcpy(fgoto, "^F");
      }

      needs_cls = images[r].cls;

      // I get what's happening.  Mystic moves cursor to home, CLS, cursor
      // home. When we get here, we're ALWAYS at the top of the screen...
      // Hence our bat isn't displayed at the end of the screen.

      // This is before the actual CLS, so we CLS before displaying our files.
      // I tried a ^P2 before doing this .. but I'd rather have the picture up
      // right away I think.

      // Ok, yes, there's no filename being sent.  :P
      render_image(images[r].lines, images[r].size);

      slen = snprintf(display, sizeof(display), "%s%s%s^P3",
                      needs_cls ? "\x1b[2J" : "", fgoto, restore_color);
      if (slen >= sizeof(display)) {
        ZF_LOGE("snprintf %d > size %d", slen, (int)sizeof(display));
        display[0] = 0;
      }
      ZF_LOGI("mangle(ANSI_CLS): %d file inserted %s", r, repr(display));

      // Move the buffer so there's room for the display string.
      buffer.insert(pos, display);
      work.insert(pos, std::string(strlen(display), ' '));
      return 1; // need_render = 1;
    } else {
      if (random_activate(4)) {
        int r;
        char display[100] = "";
        int slen;

        const char *phrasing[] = {
            "^R1Haha^P1ha^P1ha", "Poof!", "Got U", "Anyone there?",
            "^R1Knock, ^P1Knock",
            /*
            This picks random color and position -- then
            homes cursor and changes to another color.  (This can be seen.)
             */
            "^G0101^C07^S9Segmentation fault (core dumped)^P2"};
        static LastSeen last_phrasing(2);

        ZF_LOGI("mangle(ANSI_CLS)");

        do {
          r = randint(sizeof(phrasing) / sizeof(char *));
        } while (last_phrasing.seen_before(r));

        int color = randint(14) + 1;
        int x = randint(30) + 1;
        int y = randint(15) + 1;

        /*
        Don't have it pause there before moving the cursor.

        Move the cursor, get the color changed, THEN pause.
        Then act all crazy.

        NOTE:  Make sure if you use any ^R Render effects, turn them off
        before trying to display the restore_color.  :P   ^R0 Also, make
        sure you re-home the cursor ^G0101 because that's where they are
        expecting the cursor to be!  (At least it's how Mystic does it.)

        HOME, CLS, HOME, ...  Not sure what others do there.  We'll see.
        */

        if (strncmp(phrasing[r], "^G", 2) == 0) {
          // This starts with a GOTO, so don't use our random position
          slen = snprintf(display, sizeof(display), "^S3^P1%s^S0^R0%s^P1^G0101",
                          phrasing[r], restore_color);
        } else {
          slen = snprintf(display, sizeof(display),
                          "^G%02d%02d^S3^C%02d^P1%s^S0^R0%s^P1^G0101", x, y,
                          color, phrasing[r], restore_color);
        };
        if (slen >= sizeof(display)) {
          ZF_LOGE("snprintf %d > size %d (Phrase: %d, %s)", slen,
                  (int)sizeof(display), r, phrasing[r]);
          display[0] = 0;
        }

        // sprintf(display, "^P1^S3^C%02d%s^S0^R0%s^P1", color, phrasing[r],
        // restore_color);
        // Added debug statement so we can identify what was sent... color,
        // number picked and what that is
        ZF_LOGD("mangle(ANSI_CLS): Inserted color=%02d r=%d phrase='%s'", color,
                r, phrasing[r]);
        ZF_LOGI("mangle(ANSI_CLS): %d %s", r, repr(display));

        // Move the buffer so there's room for the display string.
        buffer.insert(pos, display);
        work.insert(pos, std::string(strlen(display), ' '));
        return 1; // need_render = 1;
      }
    }
  }
}

int mangle(int fd, std::string buffer) {
  // a simple default for now.
  ZF_LOGI_MEM(buffer.data(), buffer.size(), "mangle(%d): %lu bytes", fd,
              buffer.size());

  int need_render = 0;
  int mangled = 0;
  int mangled_chars = 0;
  static std::string work;

  work.assign(buffer);

  const char *ANSI_CLS = "\x1b[2J";
  size_t pos = buffer.find(ANSI_CLS);

  if (pos != std::string::npos) {
    if (mangle_clrscr(buffer, work, pos)) {
      need_render = 1;
    }
  }

  if (need_render) {
    render(fd, buffer);
  } else {
    write(fd, buffer.data(), buffer.size());
  }
  return need_render;
}