module Main exposing (Issue, Model, Msg(..), PasswdFeedback, init, inp, main, update, validate, view)

import Browser
import Html exposing (Html, div, input, pre, text)
import Html.Attributes exposing (disabled, placeholder, style, type_, value)
import Html.Events exposing (onInput)
import Set


main =
    Browser.sandbox { init = init, update = update, view = view }


type alias Model =
    { name : String
    , pass : String
    , pass2 : String
    , fdbk : PasswdFeedback
    }


type alias PasswdFeedback =
    { locked : Bool
    , narration : List String
    }


type alias Issue =
    { hide : Bool
    , explaination : String
    }


init : Model
init =
    Model "" "" "" (PasswdFeedback True [])


type Msg
    = DelName String
    | DelPass String
    | DelPass2 String


view model =
    div []
        [ inp "text" "Name" model.name DelName False
        , inp "password" "Password" model.pass DelPass False
        , inp "password" "Password2" model.pass2 DelPass2 model.fdbk.locked
        , pre [ style "color" "red" ] [ text (String.join "\n" model.fdbk.narration) ]
        ]


update msg model =
    case msg of
        DelName x ->
            { model | name = x }

        DelPass x ->
            { model | pass = x, fdbk = validate x }

        DelPass2 x ->
            { model | pass2 = x }


inp : String -> String -> String -> (String -> msg) -> Bool -> Html msg
inp t ph val signal q =
    input [ type_ t, placeholder ph, value val, onInput signal, disabled q ] []


validate : String -> PasswdFeedback
validate passwd =
    let
        isCaps c =
            String.contains (String.fromChar c) "ABCDEFGHIJKLMNOPQRSTUVWXYZ"

        isLower c =
            String.contains (String.fromChar c) "abcdefghijklmnopqrstuvwxyz"

        isPunct c =
            String.contains (String.fromChar c) "~!@#$%^&*()-_=+[]{}'\\;:,./<>?|"

        isDigit c =
            Maybe.withDefault -1 (String.toInt (String.fromChar c)) >= 0

        -- isDigit : Char -> Bool
        nonZero =
            String.length passwd > 0

        lenOk =
            Issue (String.length passwd > 7) "Password too small."

        hasDigit =
            Issue (String.any isDigit passwd) "No digits."

        hasCapital =
            Issue (String.any isCaps passwd) "No capitals."

        hasLower =
            Issue (String.any isLower passwd) "No lower case."

        hasPunct =
            Issue (String.any isPunct passwd) "No punctuation."

        worthShowing issue =
            if issue.hide == False then
                Just issue.explaination

            else
                Nothing

        goodPass =
            List.all .hide [ lenOk, hasDigit, hasCapital, hasLower, hasPunct ]
    in
    if nonZero && goodPass then
        PasswdFeedback False []
        -- else if ...the 32 cases

    else
        PasswdFeedback True
            (List.filterMap worthShowing [ lenOk, hasDigit, hasCapital, hasLower, hasPunct ])