horrible-harry/terminal.cpp

/*
Terminal tracking

Actually, I believe I only really need to track the color information.
Everything else, I'm not sure I really care about.

 */

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

#include "terminal.h"
#include "zf_log.h"

extern const char *repr(const char *data);

void console_init(struct console_details *cdp) {
  cdp->posx = 0;
  cdp->posy = 0;
  cdp->savedx = 0;
  cdp->savedy = 0;
  cdp->in_ansi = 0;
  cdp->fgcolor = 7;
  cdp->bgcolor = 0;
  cdp->status = 0;
}

void ansi_color(struct console_details *cdp, int color) {
  // ZF_LOGV("ansi_color(%d)", color);
  if (color == 0) {
    cdp->status = 0;
    cdp->fgcolor = 7;
    cdp->bgcolor = 0;
    return;
  }
  if (color == 1) {
    cdp->status = 1;
    return;
  }
  if (color == 5) {
    cdp->status = 5;
    return;
  }
  if ((color >= 30) && (color <= 37)) {
    cdp->fgcolor = color - 30;
    return;
  }
  if ((color >= 40) && (color <= 47)) {
    cdp->bgcolor = color - 40;
    return;
  }
  ZF_LOGD("ansi_color( %d ) is unknown to me.", color);
}

const char *color_restore(struct console_details *cdp) {
  static char buffer[30];
  if (cdp->status == 0) {
    sprintf(buffer, "\x1b[0;3%d;4%dm", cdp->fgcolor, cdp->bgcolor);
  } else {
    sprintf(buffer, "\x1b[0;%d;3%d;4%dm", cdp->status, cdp->fgcolor,
            cdp->bgcolor);
  };
  return buffer;
}

void console_ansi(struct console_details *cdp, const char *ansi) {
  int understood = 0;
  const char *cp = ansi;
  const char *last = ansi + strlen(ansi) - 1;
  int number, number2;

  if (*cp == '\x1b') {
    cp++;
    // Ok, that's expected.
    if (*cp == '[') {
      cp++;

      // https://en.wikipedia.org/wiki/ANSI_escape_code#CSI_sequences

      switch (*last) {
      case 'A':
        // cursor up
        if (cp == last) {
          number = 1;
        } else {
          number = atoi(cp);
          if (number < 1) {
            ZF_LOGD("console_ansi( %s ): number error (%d)", repr(ansi),
                    number);
            number = 1;
          }
        };
        cdp->posy -= number;
        if (cdp->posy < 0) {
          cdp->posy = 0;
          ZF_LOGD(
              "console_ansi( %s ): attempt to move above top of screen (%d)",
              repr(ansi), number);
        }
        understood = 1;
        return;
      case 'B':
        // cursor down
        if (cp == last) {
          number = 1;
        } else {
          number = atoi(cp);
          if (number < 1) {
            ZF_LOGD("console_ansi( %s ): number error (%d)", repr(ansi),
                    number);
            number = 1;
          }
        };
        cdp->posy += number;
        // check range/"scroll"
        understood = 1;
        return;

      case 'C':
        // cursor forward
        if (cp == last) {
          number = 1;
        } else {
          number = atoi(cp);
          if (number < 1) {
            ZF_LOGD("console_ansi( %s ): number error (%d)", repr(ansi),
                    number);
            number = 1;
          }
        };
        cdp->posx += number;

        // Well.  According to the "spec", the screen limits are hard
        // If the cursor is already at the edge of the screen, this has no
        // effect. ^ This is *NOT* how any ANSI BBS terminal program acts!

        while (cdp->posx > 79) {
          cdp->posy++;
          // check range/"scroll"
          cdp->posx -= 79;
        }
        understood = 1;
        return;

      case 'D':
        // cursor backwards
        if (cp == last) {
          number = 1;
        } else {
          number = atoi(cp);
          if (number < 1) {
            ZF_LOGD("console_ansi( %s ): number error (%d)", repr(ansi),
                    number);
            number = 0;
          }
        };
        cdp->posx -= number;

        // Well.  According to the "spec", the screen limits are hard
        // If the cursor is already at the edge of the screen, this has no
        // effect. ^ This is *NOT* how any ANSI BBS terminal program acts!

        while (cdp->posx < 0) {
          cdp->posy--;
          if (cdp->posy < 0) {
            cdp->posy = 0;
          }
          cdp->posx += 79;
        }
        understood = 1;
        return;

      case 'H':
        // cursor position

        if (*cp == ';') {
          // Missing first number
          number = 1;
          cp++;
          if (cp == last) {
            // missing 2nd number as well?
            number2 = 1;
          } else {
            number2 = atoi(cp);
          }
        } else {
          // Ok, find the first number
          number = atoi(cp);

          cp = strchr(cp, ';');
          if (cp == NULL) {
            // Missing 2nd number
            number2 = 1;
          } else {
            // 2nd number found, maybe.
            cp++;
            if (cp == last) {
              number2 = 1;
            } else {
              number2 = atoi(cp);
            }
          }
        }

        // Our positions start at zero, not one.
        cdp->posx = number - 1;
        cdp->posy = number2 - 1;

        understood = 1;
        break;

      case 'J':
        // clear
        if (cp == last) {
          number = 0;
        } else {
          number = atoi(cp);
        };

        // clears ... part of the screen.
        if (number == 2) {
          cdp->posx = 0;
          cdp->posy = 0;
        };
        understood = 1;
        break;

      case 'm':
        // color
        if (cp == last) {
          // nothing given, default to 0.
          number = 0;
          ansi_color(cdp, number);
        } else {
          while (cp != last) {
            number = atoi(cp);
            ansi_color(cdp, number);
            cp++;

            while ((cp != last) && (isdigit(*cp))) {
              cp++;
            };

            if (cp != last) {
              if (*cp == ';') {
                cp++;
              }
            }
          }
        }
        understood = 1;
        break;

      case 't':
      case 'r':
      case 'h':
      case '!':
        // These are ones that I don't care about.
      case 'n': // This is terminal detect -- give me cursor position
        understood = 1;
        break;

      default:
        // unsure -- possibly not important
        ZF_LOGD("console_ansi( %s ): ???", repr(ansi));
        understood = 0;
      }
    }
  };

  if (!understood) {
    ZF_LOGD("console_ansi( %s ): was not understood.", repr(ansi));
  }
}

/*
 * console_char()
 *  return whether or not we are still in_ansi
 */
int console_char(struct console_details *cdp, char ch) {
  char *cp;

  if (cdp->in_ansi) {
    // Ok, append this char
    cp = cdp->ansi + strlen(cdp->ansi);
    *cp = ch;
    cp++;
    *cp = 0;
    if (isalpha(ch)) {
      // Ok!
      console_ansi(cdp, cdp->ansi);
      cdp->in_ansi = 0;
      cdp->ansi[0] = 0;
      return 1;
    }
    return 1;
  } else {
    if (ch == '\x1b') {
      cp = cdp->ansi;
      *cp = ch;
      cp++;
      *cp = 0;
      cdp->in_ansi = 1;
      return 1;
    }
    if (ch == '\r') {
      // Carriage return
      cdp->posx = 0;
      return 0;
    }
    if (ch == '\n') {
      cdp->posy++;
      // check range/"scroll"
      return 0;
    }
    if (ch == '\b') {
      // Backspace.
      if (cdp->posx > 0) {
        cdp->posx--;
      }
      return 0;
    }
    if (ch == '\f') {
      // form feed
      // treat as clear screen
      cdp->posx = 0;
      cdp->posy = 0;
      return 0;
    }

    /*
      I don't believe that anything else can possibly be here, other then an
      actual printable character.  So!
    */

    cdp->posx++;

    if (cdp->posx > 79) {
      cdp->posx = 0;
      cdp->posy++;
      // check range/"scroll"
    }
    return 0;
  }
}

void console_string(struct console_details *cdp, const char *chars) {
  int x;
  for (x = 0; x < strlen(chars); x++) {
    console_char(cdp, chars[x]);
  }
}

void console_receive(struct console_details *cdp, const char *chars, int len) {
  int x;

  for (x = 0; x < len; x++) {
    console_char(cdp, chars[x]);
  }
}