vervis/src/Field.hs

{- This file is part of Vervis.
 -
 - Written in 2016 by fr33domlover <fr33domlover@riseup.net>.
 -
 - ♡ Copying is an act of love. Please copy, reuse and share.
 -
 - The author(s) have dedicated all copyright and related and neighboring
 - rights to this software to the public domain worldwide. This software is
 - distributed without any warranty.
 -
 - You should have received a copy of the CC0 Public Domain Dedication along
 - with this software. If not, see
 - <http://creativecommons.org/publicdomain/zero/1.0/>.
 -}

module Field
    ( loginField
    , passField
    )
where

import Import

import Data.Char (isDigit)
import Data.Char.Local (isAsciiLetter)

checkLoginTemplate :: Field Handler Text -> Field Handler Text
checkLoginTemplate =
    let first = isAsciiLetter
        rest c = isAsciiLetter c || isDigit c || c `elem` ("-._" :: String)
        ok t =
            case uncons t of
                Just (c, r) -> first c && all rest r
                Nothing     -> False
    in  checkBool
            ok
            ( "The first character must be a letter, and every other \
            \ character must be a letter, a digit, ‘.’ (period) , ‘-’ (dash) \
            \or ‘_’ (underscore)." :: Text)

checkLoginUnique :: Field Handler Text -> Field Handler Text
checkLoginUnique = checkM $ \ login -> runDB $ do
    let sharer = Sharer
            { sharerIdent = login
            , sharerName  = Nothing
            }
    mus <- checkUnique sharer
    return $ if isNothing mus
        then Right login
        else Left ("This username is already in use" :: Text)

loginField :: Field Handler Text
loginField = checkLoginUnique . checkLoginTemplate $ textField

checkPassLength :: Field Handler Text -> Field Handler Text
checkPassLength =
    let msg :: Text
        msg =
            "The password must be at least 8 characters long. Yes, I know, \
            \having so many different passwords for many different sites is \
            \annoying and cumbersome. I'm trying to figure out an \
            \alternative, such as a client TLS certificate, that can work \
            \somewhat like SSH and GPG keys."
        minlen = 8
    in  checkBool  ((>= minlen) . length) msg

passConfirmField :: Field Handler Text
passConfirmField = Field
    { fieldParse = \ vals _files ->
        return $ case vals of
            [a, b] ->
                if a == b
                    then Right $ Just a
                    else Left "Passwords don’t match"
            [] -> Right Nothing
            _ -> Left "You must enter the password twice"
    , fieldView = \ idAttr nameAttr otherAttrs _eResult _isReq ->
        $(widgetFile "password-field")
    , fieldEnctype = UrlEncoded
    }

passField :: Field Handler Text
passField = checkPassLength passConfirmField