SimpleTimeTracker.elm

import Html exposing (Html, Attribute, text, toElement, div, textarea, ul, li)
import Html.Attributes exposing (..)
import Html.Events exposing (on, targetValue)
import Signal exposing (Address)
import StartApp.Simple as StartApp
import String
import Regex
import Dict

type alias Model = { text:String, times:List String }

main =
  StartApp.start { model = initial_model, view = view, update = update }


initial_model = 
  { text="", times=[] }


update : String -> Model -> Model
update newStr oldModel =
  let
    lines = String.split "\n" newStr
    valid_times = List.filterMap maybe_valid_time lines
    converted_times = to_thing valid_times
  in
    {text=newStr, times=converted_times}

maybe_valid_time line =
  let
    splitResult = Regex.split (Regex.AtMost 1) (Regex.regex " ") line
  in
    maybe_two splitResult
     `Maybe.andThen` valid_time_length
     `Maybe.andThen` numeric_min_hours
     `Maybe.andThen` valid_time_values

maybe_two : List a -> Maybe (a, a)
maybe_two n =
  case n of
    [] ->
      Nothing
    time :: name :: [] ->
      Just (time, name)
    time :: other ->
      Nothing

valid_time_length (time, name) =
  if String.length time == 4
  then Just (time, name)
  else Nothing

numeric_min_hours x =
  let
    (time, name) = x
    hours = String.left 2 time
    mins = String.right 2 time
    num_hours_result = String.toInt hours
    num_mins_result = String.toInt mins
  in
    case (num_hours_result, num_mins_result) of
      (Ok num_hours, Ok num_mins) ->
        Just (num_hours, num_mins, name)
      _ ->
        Nothing

valid_time_values x =
  let
    (hr, min, name) = x
  in
    if(hr >= 0 && hr < 24 && min >= 0 && min < 60)
    then Just(hr, min, name)
    else Nothing

to_thing x =
  x
    |> zip_self
    |> List.map to_minutes
    |> List.foldl time_collect Dict.empty
    |> Dict.toList
    |> List.map format_time

zip_self list =
  case list of
    hl::tl ->
      List.map2 (\a b -> (a, b)) list tl
    [] ->
      []

to_minutes x =
  let
    (before, after) = x
    (b_hr, b_min, b_name) = before
    (a_hr, a_min, _) = after
    mins = (a_hr - b_hr) * 60 + a_min - b_min
  in
    (b_name, mins)

time_collect x dict =
  let
    (name, mins) = x
  in
    case Dict.get name dict of
      Just total ->
        Dict.insert name (total+mins) dict
      Nothing ->
        Dict.insert name mins dict

format_time x =
  let
    (name, total_mins) = x
    hrs = total_mins // 60
    mins = total_mins % 60
    string_hrs = toString hrs
    string_mins = toString mins
  in
    string_hrs ++ "h " ++ string_mins ++ "m - " ++ name


view : Address String -> Model -> Html
view address model =
  div [ container_style ]
    [ div [ item_style ] [ make_input address model.text ]
    , div [ item_style ] [ list model.times ]
    ]
     
list n =
  ul [] (List.map (\x -> li [] [text x]) n)

make_input address text =
  textarea
    [ placeholder "0900 Example task"
    , value text
    , on "input" targetValue (Signal.message address)
    , textarea_style
    ]
    []

container_style =
  style
    [ ("display", "flex")
    , ("height","100vh")
    ]

item_style : Attribute
item_style =
  style
    [ ("flex-grow", "1")
    , ("flex-shrink", "1")
    , ("flex-basis", "150px")
    , ("height","100%")
    ]

textarea_style : Attribute
textarea_style =
  style
    [ ("resize", "none")
    , ("height","100%")
    , ("width", "100%")
    ]