Mailspring/src/regexp-utils.coffee

_ = require('underscore')
RegExpUtils =

  # It's important that the regex be wrapped in parens, otherwise
  # javascript's RegExp::exec method won't find anything even when the
  # regex matches!
  #
  # It's also imporant we return a fresh copy of the RegExp every time. A
  # javascript regex is stateful and multiple functions using this method
  # will cause unexpected behavior!
  #
  # See http://tools.ietf.org/html/rfc5322#section-3.4 and
  # https://tools.ietf.org/html/rfc6531 and
  # https://en.wikipedia.org/wiki/Email_address#Local_part
  emailRegex: -> new RegExp(/([a-z.A-Z0-9!#$%&'*+\-/=?^_`{|}~;:]+@[A-Za-z0-9.-]+\.[A-Za-z]{2,63})/g)

  # http://stackoverflow.com/questions/16631571/javascript-regular-expression-detect-all-the-phone-number-from-the-page-source
  phoneRegex: -> new RegExp(/(?:\+?(\d{1,3}))?[- (]*(\d{3})[- )]*(\d{3})[- ]*(\d{4})(?: *x(\d+))?\b/g)

  # http://stackoverflow.com/a/16463966
  # http://www.regexpal.com/?fam=93928
  # NOTE: This does not match full urls with `http` protocol components.
  domainRegex: -> new RegExp(/^(?!:\/\/)([a-zA-Z0-9-_]+\.)*[a-zA-Z0-9][a-zA-Z0-9-_]+\.[a-zA-Z]{2,11}?/i)

  # https://www.safaribooksonline.com/library/view/regular-expressions-cookbook/9780596802837/ch07s16.html
  ipAddressRegex: -> new RegExp(/^(?:[0-9]{1,3}\.){3}[0-9]{1,3}$/i)

  # Test cases: https://regex101.com/r/pD7iS5/3
  urlRegex: ({matchEntireString} = {}) ->
    parts = [
      '('
        # one of:
        '('
          # optional scheme, ala https://
          '([A-Za-z]{3,9}:(?:\\/\\/))?'

          # optional username:password
          '(?:[\\-;:&=\\+\\$,\\w]+@)?'

          # one of:
          '('
            # domain
            '([a-zA-Z0-9-_]+\\.)*[a-zA-Z0-9][a-zA-Z0-9-_]+\\.[a-zA-Z]{2,11}'

            '|'

            # ip address
            '(?:[0-9]{1,3}\.){3}[0-9]{1,3}'
          ')'

          '|'

          # mailto:username@password.com
          'mailto:\\/*(?:\\w+\\.|[\\-;:&=\\+\\$.,\\w]+@)[A-Za-z0-9\\.\\-]+'
        ')'

        # optionally followed by:
        '('
          # URL components
          '(?:\\/[\\+~%\\/\\.\\w\\-_]*)?'
          # optionally followed by a ?
          '\\??'
          # optionally followed by a query string
          '(?:[\\-\\+=&;%@\\.\\w_]*)#?(?:[\\.\\!\\/\\\\\\w]*)'
        ')?'
      ')'
    ]
    if matchEntireString
      parts.unshift('^')

    return new RegExp(parts.join(''), 'g')

  # Test cases: https://regex101.com/r/jD5zC7/2
  # Returns the following capturing groups:
  # 1. start of the opening a tag to href="
  # 2. The contents of the href without quotes
  # 3. the rest of the opening a tag
  # 4. the contents of the a tag
  # 5. the closing tag
  linkTagRegex: -> new RegExp(/(<a.*?href\s*?=\s*?['"])(.*?)(['"].*?>)([\s\S]*?)(<\/a>)/gim)

  # Test cases: https://regex101.com/r/cK0zD8/4
  # Catches link tags containing which are:
  # - Non empty
  # - Not a mailto: link
  # Returns the following capturing groups:
  # 1. start of the opening a tag to href="
  # 2. The contents of the href without quotes
  # 3. the rest of the opening a tag
  # 4. the contents of the a tag
  # 5. the closing tag
  urlLinkTagRegex: -> new RegExp(/(<a.*?href\s*?=\s*?['"])((?!mailto).+?)(['"].*?>)([\s\S]*?)(<\/a>)/gim)

  # https://regex101.com/r/zG7aW4/3
  imageTagRegex: -> /<img\s+[^>]*src="([^"]*)"[^>]*>/g

  punctuation: ({exclude}={}) ->
    exclude ?= []
    punctuation = [ '.', ',', '\\/', '#', '!', '$', '%', '^', '&', '*',
      ';', ':', '{', '}', '=', '\\-', '_', '`', '~', '(', ')', '@', '+',
      '?', '>', '<', '\\[', '\\]', '+' ]
    punctuation = _.difference(punctuation, exclude).join('')
    return new RegExp("[#{punctuation}]", 'g')

  # This tests for valid schemes as per RFC 3986
  # We need both http: https: and mailto: and a variety of other schemes.
  # This does not check for invalid usage of the http: scheme. For
  # example, http:bad.com would pass. We do not check for
  # protocol-relative uri's.
  #
  # Regex explanation here: https://regex101.com/r/nR2yL6/2
  # See RFC here: https://tools.ietf.org/html/rfc3986#section-3.1
  # SO discussion: http://stackoverflow.com/questions/10687099/how-to-test-if-a-url-string-is-absolute-or-relative/31991870#31991870
  hasValidSchemeRegex: -> new RegExp('^[a-z][a-z0-9+.-]*:', 'i')

  looseStyleTag: -> /<style/gim

  # Regular expression matching javasript function arguments:
  # https://regex101.com/r/pZ6zF0/1
  functionArgs: -> /\(\s*([^)]+?)\s*\)/

  illegalPathCharactersRegexp: ->
    #https://msdn.microsoft.com/en-us/library/windows/desktop/aa365247(v=vs.85).aspx
    /[\\\/:|?*><"]/g

module.exports = RegExpUtils