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  // (c) Dean McNamee <dean@gmail.com>, 2012.
  // C++ port by Mapbox, Konstantin Käfer <mail@kkaefer.com>, 2014-2017.
  //
  // https://github.com/deanm/css-color-parser-js
  // https://github.com/kkaefer/css-color-parser-cpp
  //
  // Permission is hereby granted, free of charge, to any person obtaining a copy
  // of this software and associated documentation files (the "Software"), to
  // deal in the Software without restriction, including without limitation the
  // rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
  // sell copies of the Software, and to permit persons to whom the Software is
  // furnished to do so, subject to the following conditions:
  //
  // The above copyright notice and this permission notice shall be included in
  // all copies or substantial portions of the Software.
  //
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  // FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  // IN THE SOFTWARE.
  
  #include "csscolorparser.h"
  
  #include <algorithm>
  #include <cmath>
  #include <cstdint>
  #include <sstream>
  #include "base/std/container/vector.h"
  
  namespace CSSColorParser {
  
  // http://www.w3.org/TR/css3-color/
  struct NamedColor {
      const char *name;
      Color       color;
  };
  
  const ccstd::vector<NamedColor> NAMED_COLORS = {
      {"transparent", {0, 0, 0, 0}},
      {"aliceblue", {240, 248, 255, 1}},
      {"antiquewhite", {250, 235, 215, 1}},
      {"aqua", {0, 255, 255, 1}},
      {"aquamarine", {127, 255, 212, 1}},
      {"azure", {240, 255, 255, 1}},
      {"beige", {245, 245, 220, 1}},
      {"bisque", {255, 228, 196, 1}},
      {"black", {0, 0, 0, 1}},
      {"blanchedalmond", {255, 235, 205, 1}},
      {"blue", {0, 0, 255, 1}},
      {"blueviolet", {138, 43, 226, 1}},
      {"brown", {165, 42, 42, 1}},
      {"burlywood", {222, 184, 135, 1}},
      {"cadetblue", {95, 158, 160, 1}},
      {"chartreuse", {127, 255, 0, 1}},
      {"chocolate", {210, 105, 30, 1}},
      {"coral", {255, 127, 80, 1}},
      {"cornflowerblue", {100, 149, 237, 1}},
      {"cornsilk", {255, 248, 220, 1}},
      {"crimson", {220, 20, 60, 1}},
      {"cyan", {0, 255, 255, 1}},
      {"darkblue", {0, 0, 139, 1}},
      {"darkcyan", {0, 139, 139, 1}},
      {"darkgoldenrod", {184, 134, 11, 1}},
      {"darkgray", {169, 169, 169, 1}},
      {"darkgreen", {0, 100, 0, 1}},
      {"darkgrey", {169, 169, 169, 1}},
      {"darkkhaki", {189, 183, 107, 1}},
      {"darkmagenta", {139, 0, 139, 1}},
      {"darkolivegreen", {85, 107, 47, 1}},
      {"darkorange", {255, 140, 0, 1}},
      {"darkorchid", {153, 50, 204, 1}},
      {"darkred", {139, 0, 0, 1}},
      {"darksalmon", {233, 150, 122, 1}},
      {"darkseagreen", {143, 188, 143, 1}},
      {"darkslateblue", {72, 61, 139, 1}},
      {"darkslategray", {47, 79, 79, 1}},
      {"darkslategrey", {47, 79, 79, 1}},
      {"darkturquoise", {0, 206, 209, 1}},
      {"darkviolet", {148, 0, 211, 1}},
      {"deeppink", {255, 20, 147, 1}},
      {"deepskyblue", {0, 191, 255, 1}},
      {"dimgray", {105, 105, 105, 1}},
      {"dimgrey", {105, 105, 105, 1}},
      {"dodgerblue", {30, 144, 255, 1}},
      {"firebrick", {178, 34, 34, 1}},
      {"floralwhite", {255, 250, 240, 1}},
      {"forestgreen", {34, 139, 34, 1}},
      {"fuchsia", {255, 0, 255, 1}},
      {"gainsboro", {220, 220, 220, 1}},
      {"ghostwhite", {248, 248, 255, 1}},
      {"gold", {255, 215, 0, 1}},
      {"goldenrod", {218, 165, 32, 1}},
      {"gray", {128, 128, 128, 1}},
      {"green", {0, 128, 0, 1}},
      {"greenyellow", {173, 255, 47, 1}},
      {"grey", {128, 128, 128, 1}},
      {"honeydew", {240, 255, 240, 1}},
      {"hotpink", {255, 105, 180, 1}},
      {"indianred", {205, 92, 92, 1}},
      {"indigo", {75, 0, 130, 1}},
      {"ivory", {255, 255, 240, 1}},
      {"khaki", {240, 230, 140, 1}},
      {"lavender", {230, 230, 250, 1}},
      {"lavenderblush", {255, 240, 245, 1}},
      {"lawngreen", {124, 252, 0, 1}},
      {"lemonchiffon", {255, 250, 205, 1}},
      {"lightblue", {173, 216, 230, 1}},
      {"lightcoral", {240, 128, 128, 1}},
      {"lightcyan", {224, 255, 255, 1}},
      {"lightgoldenrodyellow", {250, 250, 210, 1}},
      {"lightgray", {211, 211, 211, 1}},
      {"lightgreen", {144, 238, 144, 1}},
      {"lightgrey", {211, 211, 211, 1}},
      {"lightpink", {255, 182, 193, 1}},
      {"lightsalmon", {255, 160, 122, 1}},
      {"lightseagreen", {32, 178, 170, 1}},
      {"lightskyblue", {135, 206, 250, 1}},
      {"lightslategray", {119, 136, 153, 1}},
      {"lightslategrey", {119, 136, 153, 1}},
      {"lightsteelblue", {176, 196, 222, 1}},
      {"lightyellow", {255, 255, 224, 1}},
      {"lime", {0, 255, 0, 1}},
      {"limegreen", {50, 205, 50, 1}},
      {"linen", {250, 240, 230, 1}},
      {"magenta", {255, 0, 255, 1}},
      {"maroon", {128, 0, 0, 1}},
      {"mediumaquamarine", {102, 205, 170, 1}},
      {"mediumblue", {0, 0, 205, 1}},
      {"mediumorchid", {186, 85, 211, 1}},
      {"mediumpurple", {147, 112, 219, 1}},
      {"mediumseagreen", {60, 179, 113, 1}},
      {"mediumslateblue", {123, 104, 238, 1}},
      {"mediumspringgreen", {0, 250, 154, 1}},
      {"mediumturquoise", {72, 209, 204, 1}},
      {"mediumvioletred", {199, 21, 133, 1}},
      {"midnightblue", {25, 25, 112, 1}},
      {"mintcream", {245, 255, 250, 1}},
      {"mistyrose", {255, 228, 225, 1}},
      {"moccasin", {255, 228, 181, 1}},
      {"navajowhite", {255, 222, 173, 1}},
      {"navy", {0, 0, 128, 1}},
      {"oldlace", {253, 245, 230, 1}},
      {"olive", {128, 128, 0, 1}},
      {"olivedrab", {107, 142, 35, 1}},
      {"orange", {255, 165, 0, 1}},
      {"orangered", {255, 69, 0, 1}},
      {"orchid", {218, 112, 214, 1}},
      {"palegoldenrod", {238, 232, 170, 1}},
      {"palegreen", {152, 251, 152, 1}},
      {"paleturquoise", {175, 238, 238, 1}},
      {"palevioletred", {219, 112, 147, 1}},
      {"papayawhip", {255, 239, 213, 1}},
      {"peachpuff", {255, 218, 185, 1}},
      {"peru", {205, 133, 63, 1}},
      {"pink", {255, 192, 203, 1}},
      {"plum", {221, 160, 221, 1}},
      {"powderblue", {176, 224, 230, 1}},
      {"purple", {128, 0, 128, 1}},
      {"red", {255, 0, 0, 1}},
      {"rosybrown", {188, 143, 143, 1}},
      {"royalblue", {65, 105, 225, 1}},
      {"saddlebrown", {139, 69, 19, 1}},
      {"salmon", {250, 128, 114, 1}},
      {"sandybrown", {244, 164, 96, 1}},
      {"seagreen", {46, 139, 87, 1}},
      {"seashell", {255, 245, 238, 1}},
      {"sienna", {160, 82, 45, 1}},
      {"silver", {192, 192, 192, 1}},
      {"skyblue", {135, 206, 235, 1}},
      {"slateblue", {106, 90, 205, 1}},
      {"slategray", {112, 128, 144, 1}},
      {"slategrey", {112, 128, 144, 1}},
      {"snow", {255, 250, 250, 1}},
      {"springgreen", {0, 255, 127, 1}},
      {"steelblue", {70, 130, 180, 1}},
      {"tan", {210, 180, 140, 1}},
      {"teal", {0, 128, 128, 1}},
      {"thistle", {216, 191, 216, 1}},
      {"tomato", {255, 99, 71, 1}},
      {"turquoise", {64, 224, 208, 1}},
      {"violet", {238, 130, 238, 1}},
      {"wheat", {245, 222, 179, 1}},
      {"white", {255, 255, 255, 1}},
      {"whitesmoke", {245, 245, 245, 1}},
      {"yellow", {255, 255, 0, 1}},
      {"yellowgreen", {154, 205, 50, 1}}};
  
  template <typename T>
  uint8_t clampCssByte(T i) {         // Clamp to integer 0 .. 255.
      i = static_cast<T>(::round(i)); // Seems to be what Chrome does (vs truncation).
      return static_cast<uint8_t>(i < 0 ? 0 : i > 255 ? 255
                                                      : i);
  }
  
  template <typename T>
  float clampCssFloat(T f) { // Clamp to float 0.0 .. 1.0.
      return f < 0 ? 0 : f > 1 ? 1
                               : float(f);
  }
  
  float parseFloat(const ccstd::string &str) {
      return strtof(str.c_str(), nullptr);
  }
  
  int64_t parseInt(const ccstd::string &str, uint8_t base = 10) {
      return strtoll(str.c_str(), nullptr, base);
  }
  
  uint8_t parseCssInt(const ccstd::string &str) { // int or percentage.
      if (str.length() && str.back() == '%') {
          return clampCssByte(parseFloat(str) / 100.0f * 255.0f);
      }
      return clampCssByte(parseInt(str));
  }
  
  float parseCssFloat(const ccstd::string &str) { // float or percentage.
      if (str.length() && str.back() == '%') {
          return clampCssFloat(parseFloat(str) / 100.0f);
      }
      return clampCssFloat(parseFloat(str));
  }
  
  float cssHueToRgb(float m1, float m2, float h) {
      if (h < 0.0f) {
          h += 1.0f;
      } else if (h > 1.0f) {
          h -= 1.0f;
      }
  
      if (h * 6.0f < 1.0f) {
          return m1 + (m2 - m1) * h * 6.0f;
      }
      if (h * 2.0f < 1.0f) {
          return m2;
      }
      if (h * 3.0f < 2.0f) {
          return m1 + (m2 - m1) * (2.0f / 3.0f - h) * 6.0f;
      }
      return m1;
  }
  
  ccstd::vector<ccstd::string> split(const ccstd::string &s, char delim) {
      ccstd::vector<ccstd::string> elems;
      std::stringstream            ss(s);
      ccstd::string                item;
      while (std::getline(ss, item, delim)) {
          elems.push_back(item);
      }
      return elems;
  }
  
  Color parse(const ccstd::string &cssStr) {
      ccstd::string str = cssStr;
  
      // Remove all whitespace, not compliant, but should just be more accepting.
      str.erase(std::remove(str.begin(), str.end(), ' '), str.end());
  
      // Convert to lowercase.
      std::transform(str.begin(), str.end(), str.begin(), ::tolower);
  
      for (const auto &namedColor : NAMED_COLORS) {
          if (str == namedColor.name) {
              return namedColor.color;
          }
      }
  
      // #abc and #abc123 syntax.
      if (str.length() && str.front() == '#') {
          if (str.length() == 4) {
              int64_t iv =
                  parseInt(str.substr(1), 16); // REFINE(deanm): Stricter parsing.
              if (!(iv >= 0 && iv <= 0xfff)) {
                  return {};
              }
  
              return Color(
                  static_cast<uint8_t>(((iv & 0xf00) >> 4) | ((iv & 0xf00) >> 8)),
                  static_cast<uint8_t>((iv & 0xf0) | ((iv & 0xf0) >> 4)),
                  static_cast<uint8_t>((iv & 0xf) | ((iv & 0xf) << 4)), 1);
          }
  
          if (str.length() == 7) {
              int64_t iv = parseInt(str.substr(1), 16); // REFINE(deanm): Stricter parsing.
              if (!(iv >= 0 && iv <= 0xffffff)) {
                  return {}; // Covers NaN.
              }
  
              return Color(static_cast<uint8_t>((iv & 0xff0000) >> 16),
                           static_cast<uint8_t>((iv & 0xff00) >> 8),
                           static_cast<uint8_t>(iv & 0xff), 1);
          }
  
          return Color();
      }
  
      size_t op = str.find_first_of('(');
      size_t ep = str.find_first_of(')');
      if (op != ccstd::string::npos && ep + 1 == str.length()) {
          const ccstd::string                fname = str.substr(0, op);
          const ccstd::vector<ccstd::string> params =
              split(str.substr(op + 1, ep - (op + 1)), ',');
  
          float alpha = 1.0f;
  
          if (fname == "rgba" || fname == "rgb") {
              if (fname == "rgba") {
                  if (params.size() != 4) {
                      return {};
                  }
                  alpha = parseCssFloat(params.back());
              } else {
                  if (params.size() != 3) {
                      return {};
                  }
              }
  
              return Color(parseCssInt(params[0]), parseCssInt(params[1]),
                           parseCssInt(params[2]), alpha);
          }
  
          if (fname == "hsla" || fname == "hsl") {
              if (fname == "hsla") {
                  if (params.size() != 4) {
                      return {};
                  }
                  alpha = parseCssFloat(params.back());
              } else {
                  if (params.size() != 3) {
                      return {};
                  }
              }
  
              float h = parseFloat(params[0]) / 360.0f;
              while (h < 0.0f) {
                  ++h;
              }
              while (h > 1.0f) {
                  --h;
              }
  
              // NOTE(deanm): According to the CSS spec s/l should only be
              // percentages, but we don't bother and let float or percentage.
              float s = parseCssFloat(params[1]);
              float l = parseCssFloat(params[2]);
  
              float m2 = l <= 0.5f ? l * (s + 1.0f) : l + s - l * s;
              float m1 = l * 2.0f - m2;
  
              return Color(
                  clampCssByte(cssHueToRgb(m1, m2, h + 1.0f / 3.0f) * 255.0f),
                  clampCssByte(cssHueToRgb(m1, m2, h) * 255.0f),
                  clampCssByte(cssHueToRgb(m1, m2, h - 1.0f / 3.0f) * 255.0f),
                  alpha);
          }
      }
  
      return {};
  }
  
  } // namespace CSSColorParser
  