twproxy2/ansicolor.h

#ifndef ANSICOLOR_H
#define ANSICOLOR_H

#include <cstdint>
#include <string>
#include <stdexcept>

#define CSI "\x1b["

/**
 * ANSI Color codes
 */

/**
 * @brief The colors available under ANSI-BBS
 */
enum class COLOR : std::int8_t {
  /// BLACK (0)
  BLACK,
  /// RED (1)
  RED,
  /// GREEN (2)
  GREEN,
  /// BROWN (3)
  BROWN,
  /// YELLOW (3)
  YELLOW = 3,
  /// BLUE (4)
  BLUE,
  /// MAGENTA (5)
  MAGENTA,
  /// CYAN (6)
  CYAN,
  /// WHITE (7)
  WHITE
};

/**
 * @brief ANSI-BBS text attributes
 */
enum class ATTR : std::int8_t {
  /// RESET forces all attributes (and Colors) to be sent.
  RESET,
  /// BOLD is the same as BRIGHT.
  BOLD,
  /// BRIGHT is the same as BOLD.
  BRIGHT = 1,
  /// SLOW BLINK
  BLINK = 5,
  /// INVERSE is Background on Foreground.
  INVERSE = 7
};

// std::int32_t

constexpr long strhash(const char *txt) {
  long result = 0;

  for (int x = 0; x < 3; ++x) {
    if (txt[x] == 0) break;
    char c = txt[x];
    // toupper
    if ((c >= 'a') && (c <= 'z')) c &= ~0x20;
    result = (result << 8) | c;
  }

  return result;
};

#define A_BOLD 0x01
#define A_BLINK 0x02
#define A_INVERSE 0x04
#define A_RESET 0x10

/**
 * @class ANSIColor
 * This holds foreground, background and ANSI-BBS attribute
 * information.
 * The special attribute RESET forces attribute and color
 * output always.
 *
 * @brief Foreground, Background and Attributes
 *
 */
class ANSIColor {
  /** Foreground color */
  COLOR fg;
  /** Background color */
  COLOR bg;
  int attr;

 public:
  ANSIColor();
  ANSIColor(ATTR a);
  ANSIColor(COLOR f);
  ANSIColor(COLOR f, ATTR a);
  ANSIColor(COLOR f, ATTR a1, ATTR a2);
  ANSIColor(COLOR f, COLOR b);
  ANSIColor(COLOR f, COLOR b, ATTR a);
  ANSIColor(COLOR f, COLOR b, ATTR a1, ATTR a2);
  ANSIColor(std::initializer_list<int> il);

  constexpr ANSIColor(const char *text)
      : fg(COLOR::WHITE), bg(COLOR::BLACK), attr(0) {
    const char *cp = text;
    bool use_on = false;

    while (*cp != 0) {
      long key = strhash(cp);

      switch (key) {
        case strhash("BRI"):
          attr |= A_BOLD;
          break;
        case strhash("BOL"):
          attr |= A_BOLD;
          break;
        case strhash("BLI"):
          attr |= A_BLINK;
          break;
        case strhash("INV"):
          attr |= A_INVERSE;
          break;
        case strhash("RES"):
          attr |= A_RESET;
          break;
        case strhash("ON "):
          use_on = true;
          break;

        case strhash("BLA"):
          if (use_on)
            bg = COLOR::BLACK;
          else
            fg = COLOR::BLACK;
          break;
        case strhash("RED"):
          if (use_on)
            bg = COLOR::RED;
          else
            fg = COLOR::RED;
          break;
        case strhash("GRE"):
          if (use_on)
            bg = COLOR::GREEN;
          else
            fg = COLOR::GREEN;
          break;
        case strhash("BRO"):
          if (use_on)
            bg = COLOR::BROWN;
          else
            fg = COLOR::BROWN;
          break;
        case strhash("YEL"):
          if (use_on)
            bg = COLOR::YELLOW;
          else {
            fg = COLOR::YELLOW;
            attr |= A_BOLD;
          }
          // if (use_on) throw error!
          break;
        case strhash("BLU"):
          if (use_on)
            bg = COLOR::BLUE;
          else
            fg = COLOR::BLUE;
          break;
        case strhash("MAG"):
          if (use_on)
            bg = COLOR::MAGENTA;
          else
            fg = COLOR::MAGENTA;
          break;
        case strhash("CYA"):
          if (use_on)
            bg = COLOR::CYAN;
          else
            fg = COLOR::CYAN;
          break;
        case strhash("WHI"):
          if (use_on)
            bg = COLOR::WHITE;
          else
            fg = COLOR::WHITE;
          break;
        default:
          throw std::range_error("Invalid/unknown color or attribute");
      }

      // skip to the space character
      while ((*cp != ' ') && (*cp != 0)) ++cp;
      // skip past the space character
      while (*cp == ' ') ++cp;
    }
  };

  /*
  ANSIColor(int c1);
  ANSIColor(int c1, int c2);
  */

  ANSIColor &Attr(ATTR a);
  bool operator==(const ANSIColor &c) const;
  bool operator!=(const ANSIColor &c) const;
  void setFg(COLOR f);
  void setFg(COLOR f, ATTR a);
  void setBg(COLOR b);

  /**
   * Get the foreground color
   * @return COLOR
   */
  COLOR getFg() { return fg; };
  /**
   * Get the background color
   * @return COLOR
   */
  COLOR getBg() { return bg; };
  void setAttr(ATTR a);

  std::string output(void) const;
  std::string operator()(void) const;
};

#ifdef NON_WORKING
#include <vector>

constexpr std::vector<int> from_text(const char *text) {
  std::vector<int> vi;

  const char *cp = text;
  bool use_on = false;

  while (*cp != 0) {
    int key = strhash(cp);

    switch (key) {
      case strhash("BRI"):
        vi.push_back(1);
        break;
      case strhash("BOL"):
        vi.push_back(1);
        break;
      case strhash("BLI"):
        vi.push_back(5);
        break;
      case strhash("INV"):
        vi.push_back(7);
        break;

      case strhash("ON "):
        use_on = true;
        break;

      case strhash("BLU"):
        if (use_on)
          ac.setBg(COLOR::BLUE);
        else
          ac.setFg(COLOR::BLUE);

        break;
      case strhash("RED"):
        if (use_on)
          ac.setBg(COLOR::RED);
        else
          ac.setFg(COLOR::RED);
        break;
      case strhash("GRE"):
        if (use_on)
          ac.setBg(COLOR::GREEN);
        else
          ac.setFg(COLOR::GREEN);
        break;
      case strhash("YEL"):
        // if (use_on) throw error!
        ac.setFg(COLOR::YELLOW);
        ac.Attr(ATTR::BOLD);
        break;
      case strhash("BRO"):
        if (use_on)
          ac.setBg(COLOR::BROWN);
        else
          ac.setFg(COLOR::BROWN);
        break;
      case strhash("CYA"):
        if (use_on)
          ac.setBg(COLOR::CYAN);
        else
          ac.setFg(COLOR::CYAN);
        break;
      case strhash("MAG"):
        if (use_on)
          ac.setBg(COLOR::MAGENTA);
        else
          ac.setFg(COLOR::MAGENTA);
        break;
      case strhash("BLA"):
        if (use_on)
          ac.setBg(COLOR::BLACK);
        else
          ac.setFg(COLOR::BLACK);
        break;
      case strhash("WHI"):
        if (use_on)
          ac.setBg(COLOR::WHITE);
        else
          ac.setFg(COLOR::WHITE);
        break;
    }

    // skip to the space character
    while ((*cp != ' ') && (*cp != 0)) ++cp;
    // skip past the space character
    while (*cp == ' ') ++cp;
  }
  return vi;
}
#endif

/*
Maybe make char, char, char (fg, bg, attr) and store those from
the constexpr.

This "works", in that it does construct an ANSIColor from text.

However, it isn't stored as an ANSIColor, but calls the function
at run-time.  (I was hoping for an efficient way to construct
ANSIColor from a string.)

Maybe a template that constructs it from a initializer_list?
 */

constexpr ANSIColor ac_from_text(const char *text) {
  ANSIColor ac(nullptr);

  const char *cp = text;
  bool use_on = false;

  while (*cp != 0) {
    int key = strhash(cp);

    switch (key) {
      case strhash("BRI"):
        ac.Attr(ATTR::BRIGHT);
        break;
      case strhash("BOL"):
        ac.Attr(ATTR::BOLD);
        break;
      case strhash("BLI"):
        ac.Attr(ATTR::BLINK);
        break;
      case strhash("INV"):
        ac.Attr(ATTR::INVERSE);
        break;

      case strhash("ON "):
        use_on = true;
        break;

      case strhash("BLU"):
        if (use_on)
          ac.setBg(COLOR::BLUE);
        else
          ac.setFg(COLOR::BLUE);

        break;
      case strhash("RED"):
        if (use_on)
          ac.setBg(COLOR::RED);
        else
          ac.setFg(COLOR::RED);
        break;
      case strhash("GRE"):
        if (use_on)
          ac.setBg(COLOR::GREEN);
        else
          ac.setFg(COLOR::GREEN);
        break;
      case strhash("YEL"):
        // if (use_on) throw error!
        ac.setFg(COLOR::YELLOW);
        ac.Attr(ATTR::BOLD);
        break;
      case strhash("BRO"):
        if (use_on)
          ac.setBg(COLOR::BROWN);
        else
          ac.setFg(COLOR::BROWN);
        break;
      case strhash("CYA"):
        if (use_on)
          ac.setBg(COLOR::CYAN);
        else
          ac.setFg(COLOR::CYAN);
        break;
      case strhash("MAG"):
        if (use_on)
          ac.setBg(COLOR::MAGENTA);
        else
          ac.setFg(COLOR::MAGENTA);
        break;
      case strhash("BLA"):
        if (use_on)
          ac.setBg(COLOR::BLACK);
        else
          ac.setFg(COLOR::BLACK);
        break;
      case strhash("WHI"):
        if (use_on)
          ac.setBg(COLOR::WHITE);
        else
          ac.setFg(COLOR::WHITE);
        break;
    }

    // skip to the space character
    while ((*cp != ' ') && (*cp != 0)) ++cp;
    // skip past the space character
    while (*cp == ' ') ++cp;
  }
  return ac;
};

extern ANSIColor reset;

#endif