module Decisions.BulkDecisionsView exposing (view)

import Decisions.Model exposing (..)
import Decisions.Messages exposing (..)
import Html exposing (..)
import Html.Attributes exposing (..)
import Html.Events exposing (onClick, onInput, onMouseEnter, onWithOptions, on)
import Json.Decode as Json
import Set
import Dict


view : Model -> Html Msg
view model =
    if model.hasBulkDecisions then
        let
            bulkDecisionToggle =
                div
                    [ class "button table__button-bulk-decisions"
                    , onClick ToggleShowBulkDecisions
                    ]
                    [ text "bulk decisions" ]
        in
            span [ class "table__bulk-decisions-container" ]
                (if model.showBulkDecisions then
                    [ bulkDecisionToggle
                    , div [ class "table__bulk-decisions-menu" ]
                        [ span []
                            [ textarea
                                [ rows 10
                                , cols 15
                                , class "form__input form__input--textarea-bulk-decisions"
                                , placeholder "Eg.\n10\n11\n12"
                                , onInput SetBulkDecisionsText
                                , value model.bulkDecisionsText
                                ]
                                [ text model.bulkDecisionsText ]
                            , bulkDecisionDropdownSelect model
                            ]
                        ]
                    ]
                 else
                    [ bulkDecisionToggle ]
                )
    else
        text ""


bulkDecisionDropdownSelect model =
    let
        bulkDecisionsOptions =
            model.bulkDecisionsOptions

        optionList =
            (List.map viewOption bulkDecisionsOptions)

        viewOption { parent, isSelectable, childHeader, children } =
            if List.isEmpty children then
                li
                    [ class "table-cell__menu-item"
                    , onClick (SelectBulkDecision parent Nothing)
                    ]
                    [ text parent ]
            else
                (li
                    (if isSelectable then
                        [ class "table-cell__menu-item table-cell__menu-item--with-children"
                        , onMouseEnter (ViewBulkDecisionDropdownChildren parent)
                        , onClick (SelectBulkDecision parent Nothing)
                        ]
                     else
                        [ class "table-cell__menu-item table-cell__menu-item--disabled-with-children"
                        , onMouseEnter (ViewBulkDecisionDropdownChildren parent)
                        ]
                    )
                    [ text parent
                    , (case model.focussedBulkDecisionOption of
                        Nothing ->
                            text ""

                        Just option ->
                            if option == parent then
                                let
                                    childHeaderLi =
                                        case childHeader of
                                            Just headerString ->
                                                li [ class "table-cell__menu-item table-cell__menu-item--header" ] [ text headerString ]

                                            Nothing ->
                                                text ""
                                in
                                    ul
                                        [ class "table-cell__menu table-cell__menu--sub"
                                        ]
                                        (childHeaderLi :: List.map (viewSubChoice parent) children)
                            else
                                text ""
                      )
                    ]
                )

        viewSubChoice parent child =
            li
                [ class "table-cell__menu-item"
                , onClickNoPropagate (SelectBulkDecision parent (Just child))
                ]
                [ text child ]

        rowIds =
            model.tableState.rows
                |> List.map getSerialNumber
                |> Set.fromList

        getSerialNumber row =
            Dict.get "0" row.data.stringDictData
                |> Maybe.map .value
                |> Maybe.withDefault ""

        invalidBulkDecisionIds =
            model.bulkDecisionsText
                |> String.split "\n"
                |> List.map String.trim
                |> List.filter (String.isEmpty >> not)
                |> List.filter (\i -> not (Set.member i rowIds))
                |> String.join ", "

        userPrompt =
            div [ class "bulk-decisions__prompt" ]
                (if String.isEmpty invalidBulkDecisionIds then
                    [ p [ class "hint" ] [ text "Select rows or enter ids in the text input, one per new line." ]
                    , p [ class "hint" ] [ text "Then choose a decision to apply it to all of them." ]
                    ]
                 else
                    [ p [ class "hint" ] [ text "The following lines are not valid ids in the decisions table and will not be updated: " ]
                    , p [ class "hint" ] [ text invalidBulkDecisionIds ]
                    ]
                )
    in
        span []
            [ span [ class "bulk-decisions-dropdown--control" ]
                [ a
                    [ class "table-cell__control"
                    , onClickNoPropagate ToggleBulkDecisionsDropdown
                    ]
                    [ text "Choose decision", span [ class "caret" ] [] ]
                , (if model.showBulkDecisionsDropdown then
                    ul [ class "bulk-decisions__decision-menu" ] optionList
                   else
                    text ""
                  )
                ]
            , userPrompt
            ]


onClickNoPropagate : msg -> Attribute msg
onClickNoPropagate msg =
    onWithOptions "click"
        { stopPropagation = True, preventDefault = False }
        (Json.succeed msg)


onChange : (String -> msg) -> Attribute msg
onChange handler =
    on "change" <| Json.map handler <| Json.at [ "target", "value" ] Json.string