discourse/lib/user_name_suggester.rb
Sam adf8539f64
FIX: allow for final sigma in suggested usernames ()
Final sigma is not lower cased correctly in Ruby causing issues with routing.

This works around the issue by downcasing all usernames containing a sigma using JS.
2020-12-23 08:51:36 +11:00

165 lines
4.7 KiB
Ruby

# frozen_string_literal: true
module UserNameSuggester
GENERIC_NAMES = ['i', 'me', 'info', 'support', 'admin', 'webmaster', 'hello', 'mail', 'office', 'contact', 'team']
def self.suggest(name_or_email, allowed_username = nil)
return unless name_or_email.present?
name = parse_name_from_email(name_or_email)
find_available_username_based_on(name, allowed_username)
end
def self.parse_name_from_email(name_or_email)
return name_or_email if name_or_email.to_s !~ User::EMAIL
# When 'walter@white.com' take 'walter'
name = Regexp.last_match[1]
# When 'me@eviltrout.com' take 'eviltrout'
name = Regexp.last_match[2] if GENERIC_NAMES.include?(name)
name
end
def self.find_available_username_based_on(name, allowed_username = nil)
name = fix_username(name)
offset = nil
i = 1
attempt = name
normalized_attempt = User.normalize_username(attempt)
original_allowed_username = allowed_username
allowed_username = User.normalize_username(allowed_username) if allowed_username
until (
normalized_attempt == allowed_username ||
User.username_available?(attempt) ||
i > 100
)
if offset.nil?
normalized = User.normalize_username(name)
similar = "#{normalized}(0|1|2|3|4|5|6|7|8|9)+"
count = DB.query_single(<<~SQL, like: "#{normalized}%", similar: similar).first
SELECT count(*) FROM users
WHERE username_lower LIKE :like AND
username_lower SIMILAR TO :similar
SQL
if count > 0
params = {
count: count + 10,
name: normalized,
allowed_normalized: allowed_username || ''
}
# increasing the search space a bit to allow for some extra noise
available = DB.query_single(<<~SQL, params).first
WITH numbers AS (SELECT generate_series(1, :count) AS n)
SELECT n FROM numbers
LEFT JOIN users ON (
username_lower = :name || n::varchar
) AND (
username_lower <> :allowed_normalized
)
WHERE users.id IS NULL
ORDER by n ASC
LIMIT 1
SQL
# we start at 1
offset = available.to_i - 1
offset = 0 if offset < 0
else
offset = 0
end
end
suffix = (i + offset).to_s
max_length = User.username_length.end - suffix.length
attempt = "#{truncate(name, max_length)}#{suffix}"
normalized_attempt = User.normalize_username(attempt)
i += 1
end
until normalized_attempt == allowed_username || User.username_available?(attempt) || i > 200
attempt = SecureRandom.hex[1..SiteSetting.max_username_length]
normalized_attempt = User.normalize_username(attempt)
i += 1
end
if allowed_username == normalized_attempt
original_allowed_username
else
attempt
end
end
def self.fix_username(name)
rightsize_username(sanitize_username(name))
end
def self.sanitize_username(name)
name = name.to_s.dup
if SiteSetting.unicode_usernames
name.unicode_normalize!
# TODO: Jan 2022, review if still needed
# see: https://meta.discourse.org/t/unicode-username-with-as-the-final-char-leads-to-an-error-loading-profile-page/173182
if name.include?('Σ')
ctx = MiniRacer::Context.new
name = ctx.eval("#{name.to_s.to_json}.toLowerCase()")
ctx.dispose
end
else
name = ActiveSupport::Inflector.transliterate(name)
end
name.gsub!(UsernameValidator.invalid_char_pattern, '_')
name = apply_allowlist(name) if UsernameValidator.char_allowlist_exists?
name.gsub!(UsernameValidator::INVALID_LEADING_CHAR_PATTERN, '')
name.gsub!(UsernameValidator::CONFUSING_EXTENSIONS, "_")
name.gsub!(UsernameValidator::INVALID_TRAILING_CHAR_PATTERN, '')
name.gsub!(UsernameValidator::REPEATED_SPECIAL_CHAR_PATTERN, '_')
name
end
def self.apply_allowlist(name)
name.grapheme_clusters
.map { |c| UsernameValidator.allowed_char?(c) ? c : '_' }
.join
end
def self.rightsize_username(name)
name = truncate(name, User.username_length.end)
name.gsub!(UsernameValidator::INVALID_TRAILING_CHAR_PATTERN, '')
missing_char_count = User.username_length.begin - name.grapheme_clusters.size
name << '1' * missing_char_count if missing_char_count > 0
name
end
def self.truncate(name, max_grapheme_clusters)
clusters = name.grapheme_clusters
if clusters.size > max_grapheme_clusters
clusters = clusters[0..max_grapheme_clusters - 1]
name = clusters.join
end
while name.length > UsernameValidator::MAX_CHARS
clusters.pop
name = clusters.join
end
name
end
end