{-# LANGUAGE DataKinds       #-}
{-# LANGUAGE LambdaCase      #-}
{-# LANGUAGE QuasiQuotes     #-}
{-# LANGUAGE RecordWildCards #-}

module Server.Frontend.Tickets
  ( getTicketsR
  , postGtfsTicketImportR
  , getTicketViewR
  , getTicketMapViewR
  , getDelAnnounceR
  , postAnnounceR
  , getTokenBlock
  ) where

import           Server.Frontend.Routes

import           Config                    (ServerConfig (..), UffdConfig (..))
import           Control.Monad             (forM, forM_, join)
import           Control.Monad.Extra       (maybeM)
import           Control.Monad.IO.Class    (MonadIO (liftIO))
import           Data.Coerce               (coerce)
import           Data.Function             (on, (&))
import           Data.Functor              ((<&>))
import           Data.List                 (lookup, nubBy)
import           Data.List.NonEmpty        (nonEmpty)
import           Data.Map                  (Map)
import qualified Data.Map                  as M
import           Data.Maybe                (catMaybes, fromJust, isJust)
import           Data.Text                 (Text)
import qualified Data.Text                 as T
import           Data.Time                 (UTCTime (..), addDays,
                                            getCurrentTime, utctDay)
import           Data.Time.Calendar        (Day)
import           Data.Time.Format.ISO8601  (iso8601Show)
import           Data.UUID                 (UUID)
import qualified Data.UUID                 as UUID
import qualified Data.Vector               as V
import           Extrapolation             (Extrapolator (..),
                                            LinearExtrapolator (..))
import           Fmt                       ((+|), (|+))
import           GHC.Float                 (int2Double)
import qualified GTFS
import           Numeric                   (showFFloat)
import           Persist
import           Server.Frontend.SpaceTime (mkSpaceTimeDiagram,
                                            mkSpaceTimeDiagramHandler)
import           Server.Util               (Service, secondsNow)
import           Text.Read                 (readMaybe)
import           Yesod
import           Yesod.Auth
import           Yesod.Auth.Uffd           (UffdUser (..), uffdClient)


getTicketsR :: Handler Html
getTicketsR = do
  req <- getRequest
  let maybeDay = lookup "day" (reqGetParams req) >>= (readMaybe . T.unpack)
  mdisplayname <- maybeAuthId <&> fmap uffdDisplayName

  (day, isToday) <- liftIO $ getCurrentTime <&> utctDay <&> \today ->
    case maybeDay of
      Just day -> (day, day == today)
      Nothing  -> (today, True)

  maybeSpaceTime <- mkSpaceTimeDiagramHandler day

  let prevday = (T.pack . iso8601Show . addDays (-1))  day
  let nextday = (T.pack . iso8601Show . addDays 1) day
  gtfs <- getYesod <&> getGtfs

  -- TODO: tickets should have all trip information saved
  tickets <- runDB $ selectList [ TicketDay ==. day ] [ Asc TicketTripName ] >>= mapM (\ticket -> do
    stops <- selectList [ StopTicket ==. entityKey ticket ] []
    startStation <- getJust (stopStation $ entityVal $ head stops)
    pure (ticket, startStation, fmap entityVal stops))

  let trips = GTFS.tripsOnDay gtfs day

  (widget, enctype) <- generateFormPost (tripImportForm (fmap (,day) (M.elems trips)))
  defaultLayout $ do
    [whamlet|
<h1> _{MsgTrainsOnDay (iso8601Show day)}
$maybe name <- mdisplayname
  <p>_{MsgLoggedInAs name} - <a href="@{AuthR LogoutR}">_{MsgLogout}</a>
<nav>
  <a class="nav-left" href="@?{(TicketsR, [("day", prevday)])}">← #{prevday}
  $if isToday
    _{Msgtoday}
  $else
    <a href="@{TicketsR}">_{Msgtoday}
  <a class="nav-right" href="@?{(TicketsR, [("day", nextday)])}">#{nextday} →
<section>
  <h2>_{MsgTickets}
  <ol>
   $forall (Entity (TicketKey ticketId) Ticket{..}, startStation, stops) <- tickets
    <li><a href="@{TicketViewR ticketId}">_{MsgTrip} #{ticketTripName}</a>
         : _{Msgdep} #{stopDeparture (head stops)} #{stationName startStation} → #{ticketHeadsign}
   $if null tickets
     <li style="text-align: center"><em>(_{MsgNone})</em>
$maybe spaceTime <- maybeSpaceTime
  <section>
    ^{spaceTime}
<section>
  <h2>_{MsgAccordingToGtfs}
  <form method=post action="@{GtfsTicketImportR day}" enctype=#{enctype}>
    ^{widget}
    <button>_{MsgImportTrips}
   $if null trips
     <li style="text-align: center"><em>(_{MsgNone})
|]


-- TODO: this function should probably look for duplicate imports
postGtfsTicketImportR :: Day -> Handler Html
postGtfsTicketImportR day = do
  gtfs <- getYesod <&> getGtfs
  let trips = GTFS.tripsOnDay gtfs day
  ((result, widget), enctype) <- runFormPost (tripImportForm (fmap (,day) (M.elems trips)))
  case result of
    FormSuccess selected -> do
      now <- liftIO getCurrentTime

      shapeMap <- selected
        <&> (\(trip@GTFS.Trip{..}, _) -> (GTFS.shapeId tripShape, tripShape))
        & nubBy ((==) `on` fst)
        & mapM (\(shapeId, shape) -> runDB $ do
           key <- insert Shape
           insertMany
             $ shape
             & GTFS.shapePoints
             & V.indexed
             & V.toList
             <&> \(idx, pos) -> ShapePoint (Geopos pos) idx key
           pure (shapeId, key))
        <&> M.fromList

      stationMap <- selected
        <&> (\(trip@GTFS.Trip{..}, _) -> V.toList (tripStops <&> GTFS.stopStation))
        & concat
        & nubBy ((==) `on` GTFS.stationId)
        & mapM (\GTFS.Station{..} -> runDB $ do
            maybeExists <- selectFirst [ StationShortName ==. stationId ] []
            case maybeExists of
              Nothing -> do
                key <- insert Station
                  { stationGeopos = Geopos (stationLat, stationLon)
                  , stationShortName = stationId , stationName }
                pure (stationId, key)
              Just (Entity key _) -> pure (stationId, key))
        <&> M.fromList

      selected
        <&> (\(trip@GTFS.Trip{..}, day) ->
            let
              ticket = Ticket
                   { ticketTripName = tripTripId, ticketDay = day, ticketImported = now
                   , ticketSchedule_version = Nothing, ticketVehicle = Nothing
                   , ticketCompleted = False, ticketHeadsign = gtfsHeadsign trip
                   , ticketShape = fromJust (M.lookup (GTFS.shapeId tripShape) shapeMap)}
              stops = V.toList tripStops <&> \GTFS.Stop{..} ticketId -> Stop
                   { stopTicket = ticketId
                   , stopStation = fromJust (M.lookup (GTFS.stationId stopStation) stationMap)
                   , stopArrival, stopDeparture, stopSequence}
            in (ticket, stops))
        & unzip
        & \(tickets, stops) -> runDB $ do
            ticketIds <- insertMany tickets
            forM (zip ticketIds stops) $ \(ticketId, unfinishedStops) ->
              insertMany (fmap (\s -> s ticketId) unfinishedStops)

      redirect (TicketsR, [("day", T.pack (iso8601Show day))])

    FormFailure _ -> defaultLayout [whamlet|
<section>
  <h2>_{MsgAccordingToGtfs}
  <form method=post action="@{GtfsTicketImportR day}" enctype=#{enctype}>
    ^{widget}
    <button>_{MsgImportTrips}
|]

getTicketViewR :: UUID -> Handler Html
getTicketViewR ticketId = do
  let ticketKey = TicketKey ticketId
  Ticket{..} <- runDB $ get ticketKey
     >>= \case {Nothing -> notFound; Just a -> pure a}

  stops <- runDB $ selectList [StopTicket ==. ticketKey] [] >>= mapM (\stop -> do
    station <- getJust (stopStation (entityVal stop))
    pure (entityVal stop, station))

  anns <- runDB $ selectList [ AnnouncementTicket ==. ticketKey ] []
  joins <- runDB $ selectList [ TrackerTicketTicket ==. ticketKey ] []
    <&> fmap (trackerTicketTracker . entityVal)
  trackers <- runDB $ selectList
    ([ TrackerId <-. joins ] ||. [ TrackerCurrentTicket ==. Just ticketKey ])
    [Asc TrackerExpires]
  lastPing <- runDB $ selectFirst [ TrainPingToken <-. fmap entityKey trackers ] [Desc TrainPingTimestamp]
  anchors <- runDB $ selectList [ TrainAnchorTicket ==. ticketKey ] []
    <&> nonEmpty . fmap entityVal

  (widget, enctype) <- generateFormPost (announceForm ticketId)

  nowSeconds <- secondsNow ticketDay
  defaultLayout $ do
    mr <- getMessageRender
    setTitle (toHtml (""+|mr MsgTrip|+" "+|ticketTripName|+" "+|mr Msgon|+" "+|ticketDay|+"" :: Text))
    [whamlet|
<h1>_{MsgTrip} #
  <a href="@{GtfsTripViewR ticketTripName}">#{ticketTripName}
  _{Msgon}
  <a href="@?{(TicketsR, [("day", T.pack (iso8601Show ticketDay))])}">#{ticketDay}
<section>
  <h2>_{MsgLive}
  <p><strong>_{MsgLastPing}: </strong>
    $maybe Entity _ TrainPing{..} <- lastPing
      _{MsgTrainPing (latitude trainPingGeopos) (longitude trainPingGeopos) trainPingTimestamp}
      (<a href="/api/debug/pings/#{UUID.toString ticketId}/#{ticketDay}">_{Msgraw}</a>)
    $nothing
      <em>(_{MsgNoTrainPing})
  <p><strong>_{MsgEstimatedDelay}</strong>:
    $maybe history <- anchors
      $maybe TrainAnchor{..} <- guessAtSeconds history nowSeconds
        \ #{trainAnchorDelay} (_{MsgOnStationSequence (showFFloat (Just 3) trainAnchorSequence "")})
    $nothing
      <em> (_{MsgNone})
  <p><a href="@{TicketMapViewR ticketId}">_{MsgMap}</a>
<section>
  <h2>_{MsgStops}
  <ol>
    $forall (Stop{..}, Station{..}) <- stops
      <li value="#{stopSequence}"> #{stopArrival} #{stationName}
        $maybe history <- anchors
          $maybe delay <- guessDelay history (int2Double stopSequence)
            \ (#{delay})
<section>
  <h2>_{MsgAnnouncements}
  <ul>
    $forall Entity (AnnouncementKey uuid) Announcement{..} <- anns
      <li><em>#{announcementHeader}: #{announcementMessage}</em> <a href="@{DelAnnounceR uuid}">_{Msgdelete}</a>
    $if null anns
      <li><em>(_{MsgNone})</em>
  <h3>_{MsgNewAnnouncement}
  <form method=post action=@{AnnounceR ticketId} enctype=#{enctype}>
    ^{widget}
    <button>_{MsgSubmit}
<section>
  <h2>_{MsgTokens}
  <table>
    <tr><th style="width: 20%">_{MsgAgent}</th><th style="width: 50%">_{MsgToken}</th><th>_{MsgExpires}</th><th>_{MsgStatus}</th>
    $if null trackers
      <tr><td></td><td style="text-align:center"><em>(_{MsgNone})
    $forall Entity (TrackerKey key) Tracker{..} <- trackers
      <tr :trackerBlocked:.blocked>
        <td title="#{trackerAgent}">#{trackerAgent}
        <td title="#{key}">#{key}
        <td title="#{trackerExpires}">#{trackerExpires}
        $if trackerBlocked
          <td title="_{MsgUnblockToken}"><a href="@?{(TokenBlock key, [("unblock", "true")])}">_{MsgUnblockToken}</a>
        $else
          <td title="_{MsgBlockToken}"><a href="@{TokenBlock key}">_{MsgBlockToken}</a>
|]
          where guessDelay history = fmap trainAnchorDelay . extrapolateAtPosition LinearExtrapolator history
                guessAtSeconds = extrapolateAtSeconds LinearExtrapolator


getTicketMapViewR :: UUID -> Handler Html
getTicketMapViewR ticketId = do
  Ticket{..} <- runDB $ get (TicketKey ticketId)
    >>= \case { Nothing -> notFound ; Just ticket -> pure ticket }

  stops <- runDB $ selectList [StopTicket ==. TicketKey ticketId] [] >>= mapM (\stop -> do
    station <- getJust (stopStation (entityVal stop))
    pure (entityVal stop, station))

  (widget, enctype) <- generateFormPost (announceForm ticketId)

  defaultLayout [whamlet|
<h1>_{MsgTrip} <a href="@{TicketViewR ticketId}">#{ticketTripName} _{Msgon} #{ticketDay}</a>
<link rel="stylesheet" href="https://unpkg.com/leaflet@1.9.3/dist/leaflet.css"
     integrity="sha256-kLaT2GOSpHechhsozzB+flnD+zUyjE2LlfWPgU04xyI="
     crossorigin=""/>
<script src="https://unpkg.com/leaflet@1.9.3/dist/leaflet.js"
     integrity="sha256-WBkoXOwTeyKclOHuWtc+i2uENFpDZ9YPdf5Hf+D7ewM="
     crossorigin=""></script>
<div id="map">
<p id="status">
<script>
  let map = L.map('map');

  L.tileLayer('https://tile.openstreetmap.org/{z}/{x}/{y}.png', {
      attribution: '&copy; <a href="https://www.openstreetmap.org/copyright">OpenStreetMap</a> contributors'
  }).addTo(map);

  ws = new WebSocket((location.protocol == "http:" ? "ws" : "wss") + "://" + location.host + "/api/train/subscribe/#{UUID.toText ticketId}");

  var marker = null;

  ws.onmessage = (msg) => {
    let json = JSON.parse(msg.data);
    if (marker === null) {
      marker = L.marker([json.lat, json.long]);
      marker.addTo(map);
    } else {
      marker.setLatLng([json.lat, json.long]);
    }
    map.setView([json.lat, json.long], 13);
    document.getElementById("status").innerText = "_{MsgLastPing}: "+json.lat+","+json.long+" ("+json.timestamp+")";
  }
|]

tripImportForm
  :: [(GTFS.Trip GTFS.Deep GTFS.Deep, Day)]
  -> Html
  -> MForm Handler (FormResult [(GTFS.Trip GTFS.Deep GTFS.Deep, Day)], Widget)
tripImportForm trips extra = do
  forms <- forM trips $ \(trip, day) -> do
    (aRes, aView) <- mreq checkBoxField "import" Nothing
    let dings = fmap (\res -> if res then Just (trip, day) else Nothing) aRes
    pure (trip, day, dings, aView)

  let widget = toWidget [whamlet|
     #{extra}
     <ol>
       $forall (trip@GTFS.Trip{..}, day, res, view) <- forms
         <li>
           ^{fvInput view}
           <label for="^{fvId view}">
             _{MsgTrip} #{GTFS.tripName trip}
               : _{Msgdep} #{GTFS.stopDeparture (V.head tripStops)} #{GTFS.stationName (GTFS.stopStation (V.head tripStops))} → #{gtfsHeadsign trip}
  |]

  let (a :: FormResult [Maybe (GTFS.Trip GTFS.Deep GTFS.Deep, Day)]) =
        sequenceA (fmap (\(_,_,res,_) -> res) forms)

  pure (fmap catMaybes a, widget)

gtfsHeadsign :: GTFS.Trip GTFS.Deep GTFS.Deep -> Text
gtfsHeadsign GTFS.Trip{..} =
  case tripHeadsign of
    Just headsign -> headsign
    Nothing       -> GTFS.stationName (GTFS.stopStation (V.last tripStops))


announceForm :: UUID -> Html -> MForm Handler (FormResult Announcement, Widget)
announceForm ticketId = renderDivs $ Announcement
  <$> pure (TicketKey ticketId)
  <*> areq textField (fieldSettingsLabel MsgHeader) Nothing
  <*> areq textField (fieldSettingsLabel MsgText) Nothing
  <*> aopt urlField (fieldSettingsLabel MsgMaybeWeblink) Nothing
  <*> lift (liftIO getCurrentTime <&> Just)

postAnnounceR :: UUID -> Handler Html
postAnnounceR ticketId = do
    ((result, widget), enctype) <- runFormPost (announceForm ticketId)
    case result of
        FormSuccess ann -> do
          runDB $ insert ann
          redirect RootR -- (TicketViewR trip day)
        _ -> defaultLayout
            [whamlet|
                <p>_{MsgInvalidInput}.
                <form method=post action=@{AnnounceR ticketId} enctype=#{enctype}>
                    ^{widget}
                    <button>_{MsgSubmit}
            |]

getDelAnnounceR :: UUID -> Handler Html
getDelAnnounceR uuid = do
  ann <- runDB $ do
    a <- get (AnnouncementKey uuid)
    delete (AnnouncementKey uuid)
    pure a
  case ann of
    Nothing -> notFound
    Just Announcement{..} ->
      let (TicketKey ticketId) = announcementTicket
      in redirect (TicketViewR ticketId)

getTokenBlock :: Token -> Handler Html
getTokenBlock token = do
  YesodRequest{..} <- getRequest
  let blocked = lookup "unblock" reqGetParams /= Just "true"
  maybe <- runDB $ do
    update (TrackerKey token) [ TrackerBlocked =. blocked ]
    get (TrackerKey token)
  case maybe of
    Just r@Tracker{..} -> do
      liftIO $ print r
      redirect $ case trackerCurrentTicket of
        Just ticket -> TicketViewR (coerce ticket)
        Nothing     -> RootR
    Nothing -> notFound