(function (Prism) {
  Prism.languages.velocity = Prism.languages.extend('markup', {});

  var velocity = {
    variable: {
      pattern:
        /(^|[^\\](?:\\\\)*)\$!?(?:[a-z][\w-]*(?:\([^)]*\))?(?:\.[a-z][\w-]*(?:\([^)]*\))?|\[[^\]]+\])*|\{[^}]+\})/i,
      lookbehind: true,
      inside: {}, // See below
    },
    string: {
      pattern: /"[^"]*"|'[^']*'/,
      greedy: true,
    },
    number: /\b\d+\b/,
    boolean: /\b(?:false|true)\b/,
    operator: /[=!<>]=?|[+*/%-]|&&|\|\||\.\.|\b(?:eq|g[et]|l[et]|n(?:e|ot))\b/,
    punctuation: /[(){}[\]:,.]/,
  };

  velocity.variable.inside = {
    string: velocity['string'],
    function: {
      pattern: /([^\w-])[a-z][\w-]*(?=\()/,
      lookbehind: true,
    },
    number: velocity['number'],
    boolean: velocity['boolean'],
    punctuation: velocity['punctuation'],
  };

  Prism.languages.insertBefore('velocity', 'comment', {
    unparsed: {
      pattern: /(^|[^\\])#\[\[[\s\S]*?\]\]#/,
      lookbehind: true,
      greedy: true,
      inside: {
        punctuation: /^#\[\[|\]\]#$/,
      },
    },
    'velocity-comment': [
      {
        pattern: /(^|[^\\])#\*[\s\S]*?\*#/,
        lookbehind: true,
        greedy: true,
        alias: 'comment',
      },
      {
        pattern: /(^|[^\\])##.*/,
        lookbehind: true,
        greedy: true,
        alias: 'comment',
      },
    ],
    directive: {
      pattern:
        /(^|[^\\](?:\\\\)*)#@?(?:[a-z][\w-]*|\{[a-z][\w-]*\})(?:\s*\((?:[^()]|\([^()]*\))*\))?/i,
      lookbehind: true,
      inside: {
        keyword: {
          pattern: /^#@?(?:[a-z][\w-]*|\{[a-z][\w-]*\})|\bin\b/,
          inside: {
            punctuation: /[{}]/,
          },
        },
        rest: velocity,
      },
    },
    variable: velocity['variable'],
  });

  Prism.languages.velocity['tag'].inside['attr-value'].inside.rest =
    Prism.languages.velocity;
})(Prism);