package funkin.util;

/**
 * Enum abstract representing ANSI codes for text colors, background colors, and text styles.
 */
// TODO: Add more colors maybe?
// TODO: Make this work WITH AnsiTrace.

enum abstract AnsiCode(String) from String to String
{
  var RESET = '\x1b[0m';
  var BOLD = '\x1b[1m';
  var DIM = '\x1b[2m';
  var UNDERLINE = '\x1b[4m';
  var BLINK = '\x1b[5m';
  var INVERSE = '\x1b[7m';
  var HIDDEN = '\x1b[8m';
  var STRIKETHROUGH = '\x1b[9m';

  var BLACK = '\x1b[30m';
  var RED = '\x1b[31m';
  var GREEN = '\x1b[32m';
  var YELLOW = '\x1b[33m';
  var BLUE = '\x1b[34m';
  var MAGENTA = '\x1b[35m';
  var CYAN = '\x1b[36m';
  var WHITE = '\x1b[37m';

  var BG_BLACK = '\x1b[40m';
  var BG_RED = '\x1b[41m';
  var BG_GREEN = '\x1b[42m';
  var BG_YELLOW = '\x1b[43m';
  var BG_BLUE = '\x1b[44m';
  var BG_MAGENTA = '\x1b[45m';
  var BG_CYAN = '\x1b[46m';
  var BG_WHITE = '\x1b[47m';

  var BRIGHT_BLACK = '\x1b[90m';
  var BRIGHT_RED = '\x1b[91m';
  var BRIGHT_GREEN = '\x1b[92m';
  var BRIGHT_YELLOW = '\x1b[93m';
  var BRIGHT_BLUE = '\x1b[94m';
  var BRIGHT_MAGENTA = '\x1b[95m';
  var BRIGHT_CYAN = '\x1b[96m';
  var BRIGHT_WHITE = '\x1b[97m';

  var BG_BRIGHT_BLACK = '\x1b[100m';
  var BG_BRIGHT_RED = '\x1b[101m';
  var BG_BRIGHT_GREEN = '\x1b[102m';
  var BG_BRIGHT_YELLOW = '\x1b[103m';
  var BG_BRIGHT_BLUE = '\x1b[104m';
  var BG_BRIGHT_MAGENTA = '\x1b[105m';
  var BG_BRIGHT_CYAN = '\x1b[106m';
  var BG_BRIGHT_WHITE = '\x1b[107m';
}

/**
 * This class provides functionality for applying ANSI codes to strings for terminal output.
 */
@:nullSafety
class AnsiUtil
{
  #if sys
  @:noCompletion
  private static final REGEX_TEAMCITY_VERSION:EReg = ~/^9\.(0*[1-9]\d*)\.|\d{2,}\./;

  @:noCompletion
  private static final REGEX_TERM_256:EReg = ~/(?i)-256(color)?$/;

  @:noCompletion
  private static final REGEX_TERM_TYPES:EReg = ~/(?i)^screen|^xterm|^vt100|^vt220|^rxvt|color|ansi|cygwin|linux/;
  #end

  @:noCompletion
  private static final REGEX_ANSI_CODES:EReg = ~/\x1b\[[0-9;]*m/g;

  @:noCompletion
  private static var codesSupported:Null<Bool> = null;

  /**
   * Safe wrapper for Sys.getEnv (returns null on non-sys targets).
   */
  private static function getEnvSafe(name:String):Null<String>
  {
    #if sys
    return Sys.getEnv(name);
    #else
    return null;
    #end
  }

  /**
   * Applies the specified ANSI codes to the input string.
   *
   * You can pass one or multiple ANSI codes for combining styles.
   *
   * @param input The input.
   * @param codes The ANSI codes to apply.
   *
   * @return The styled string.
   */
  public static function apply(input:Dynamic, codes:Array<AnsiCode>):String
  {
    return stripCodes(codes.join('') + input + AnsiCode.RESET);
  }

  @:noCompletion
  private static function stripCodes(output:String):String
  {
    #if sys
    if (codesSupported == null)
    {
      final term:Null<String> = getEnvSafe('TERM');

      if (term == 'dumb') codesSupported = false;
      else
      {
        if (codesSupported != true && term != null) codesSupported = REGEX_TERM_256.match(term) || REGEX_TERM_TYPES.match(term);

        if (getEnvSafe('CI') != null)
        {
          final ciEnvNames:Array<String> = [
            "GITHUB_ACTIONS", "GITEA_ACTIONS",    "TRAVIS", "CIRCLECI",
                  "APPVEYOR",     "GITLAB_CI", "BUILDKITE",    "DRONE"
          ];

          for (ci in ciEnvNames)
          {
            if (getEnvSafe(ci) != null)
            {
              codesSupported = true;
              break;
            }
          }

          if (codesSupported != true && getEnvSafe("CI_NAME") == "codeship") codesSupported = true;
        }

        final teamCity:Null<String> = getEnvSafe("TEAMCITY_VERSION");
        if (codesSupported != true && teamCity != null) codesSupported = REGEX_TEAMCITY_VERSION.match(teamCity);

        if (codesSupported != true)
        {
          codesSupported = getEnvSafe('TERM_PROGRAM') == 'iTerm.app'
            || getEnvSafe('TERM_PROGRAM') == 'Apple_Terminal'
            || getEnvSafe('COLORTERM') != null
            || getEnvSafe('ANSICON') != null
            || getEnvSafe('ConEmuANSI') != null
            || getEnvSafe('WT_SESSION') != null;
        }
      }
    }
    #else
    codesSupported = false;
    #end
    return codesSupported == true ? output : REGEX_ANSI_CODES.replace(output, '');
  }
}