Prism.languages.wiki = Prism.languages.extend('markup', {
  'block-comment': {
    pattern: /(^|[^\\])\/\*[\s\S]*?\*\//,
    lookbehind: true,
    alias: 'comment',
  },
  heading: {
    pattern: /^(=+)[^=\r\n].*?\1/m,
    inside: {
      punctuation: /^=+|=+$/,
      important: /.+/,
    },
  },
  emphasis: {
    // TODO Multi-line
    pattern: /('{2,5}).+?\1/,
    inside: {
      'bold-italic': {
        pattern: /(''''').+?(?=\1)/,
        lookbehind: true,
        alias: ['bold', 'italic'],
      },
      bold: {
        pattern: /(''')[^'](?:.*?[^'])?(?=\1)/,
        lookbehind: true,
      },
      italic: {
        pattern: /('')[^'](?:.*?[^'])?(?=\1)/,
        lookbehind: true,
      },
      punctuation: /^''+|''+$/,
    },
  },
  hr: {
    pattern: /^-{4,}/m,
    alias: 'punctuation',
  },
  url: [
    /ISBN +(?:97[89][ -]?)?(?:\d[ -]?){9}[\dx]\b|(?:PMID|RFC) +\d+/i,
    /\[\[.+?\]\]|\[.+?\]/,
  ],
  variable: [
    /__[A-Z]+__/,
    // FIXME Nested structures should be handled
    // {{formatnum:{{#expr:{{{3}}}}}}}
    /\{{3}.+?\}{3}/,
    /\{\{.+?\}\}/,
  ],
  symbol: [/^#redirect/im, /~{3,5}/],
  // Handle table attrs:
  // {|
  // ! style="text-align:left;"| Item
  // |}
  'table-tag': {
    pattern: /((?:^|[|!])[|!])[^|\r\n]+\|(?!\|)/m,
    lookbehind: true,
    inside: {
      'table-bar': {
        pattern: /\|$/,
        alias: 'punctuation',
      },
      rest: Prism.languages.markup['tag'].inside,
    },
  },
  punctuation: /^(?:\{\||\|\}|\|-|[*#:;!|])|\|\||!!/m,
});

Prism.languages.insertBefore('wiki', 'tag', {
  // Prevent highlighting inside <nowiki>, <source> and <pre> tags
  nowiki: {
    pattern: /<(nowiki|pre|source)\b[^>]*>[\s\S]*?<\/\1>/i,
    inside: {
      tag: {
        pattern: /<(?:nowiki|pre|source)\b[^>]*>|<\/(?:nowiki|pre|source)>/i,
        inside: Prism.languages.markup['tag'].inside,
      },
    },
  },
});