{-# LANGUAGE DeriveAnyClass #-}
{-# LANGUAGE UndecidableInstances #-}

{- | Demonstration of merging multiple sites

  For an alternative (easier) approach, see `Ex05_MultiRoute.hs`.
-}
module Ema.Example.Ex04_Multi where

import Data.Generics.Sum.Any (AsAny (_As))
import Ema
import Ema.Example.Common (tailwindLayout)
import Ema.Example.Ex00_Hello qualified as Ex00
import Ema.Example.Ex01_Basic qualified as Ex01
import Ema.Example.Ex02_Clock qualified as Ex02
import Ema.Example.Ex03_Store qualified as Ex03
import Ema.Route.Generic
import GHC.Generics qualified as GHC
import Generics.SOP (Generic, HasDatatypeInfo, I (I), NP (Nil, (:*)))
import Optics.Core (Prism', (%))
import Text.Blaze.Html5 ((!))
import Text.Blaze.Html5 qualified as H
import Text.Blaze.Html5.Attributes qualified as A
import Prelude hiding (Generic)

data M = M
  { mClock :: Ex02.Model
  , mClockFast :: Ex02.Model
  , mStore :: Ex03.Model
  }
  deriving stock (GHC.Generic)

data R
  = R_Index
  | R_Hello Ex00.Route
  | R_Basic Ex01.Route
  | R_Clock Ex02.Route
  | R_ClockFast Ex02.Route
  | R_Store Ex03.Route
  deriving stock (Show, Ord, Eq, GHC.Generic)
  deriving anyclass (Generic, HasDatatypeInfo)
  deriving
    (HasSubRoutes, HasSubModels, IsRoute)
    via ( GenericRoute
            R
            '[ WithModel M
             , WithSubModels
                [ ()
                , ()
                , ()
                , -- You can refer to a record field by the field name
                  -- (We use `Proxy` only because heteregenous type
                  -- lists must be uni-kind).
                  Proxy "mClock"
                , Proxy "mClockFast"
                , -- Or by the field type.
                  -- Thanks to Data.Generics.Product.Any
                  Ex03.Model
                ]
             ]
        )

main :: IO ()
main = do
  void $ Ema.runSite @R ()

instance EmaSite R where
  siteInput cliAct () = do
    x1 :: Dynamic m Ex02.Model <- siteInput @Ex02.Route cliAct Ex02.delayNormal
    x2 :: Dynamic m Ex02.Model <- siteInput @Ex02.Route cliAct Ex02.delayFast
    x3 :: Dynamic m Ex03.Model <- siteInput @Ex03.Route cliAct ()
    pure $ liftA3 M x1 x2 x3
  siteOutput rp m = \case
    R_Index ->
      pure $ Ema.AssetGenerated Ema.Html $ renderIndex rp m
    R_Hello r ->
      siteOutput (rp % (_As @"R_Hello")) m2 r
    R_Basic r ->
      siteOutput (rp % (_As @"R_Basic")) m3 r
    R_Clock r ->
      siteOutput (rp % (_As @"R_Clock")) m4 r
    R_ClockFast r ->
      siteOutput (rp % (_As @"R_Clock")) m5 r
    R_Store r ->
      siteOutput (rp % (_As @"R_Store")) m6 r
    where
      I () :* I m2 :* I m3 :* I m4 :* I m5 :* I m6 :* Nil = subModels @R m

renderIndex :: Prism' FilePath R -> M -> LByteString
renderIndex rp m =
  tailwindLayout (H.title "Ex04_Multi" >> H.base ! A.href "/") $
    H.div ! A.class_ "container mx-auto text-center mt-8 p-2" $ do
      H.p "You can compose Ema sites. Here are three sites composed to produce one:"
      H.ul ! A.class_ "flex flex-col justify-center .items-center mt-4 space-y-4" $ do
        H.li $ routeElem (R_Hello $ Ex00.Route ()) "Ex00_Hello"
        H.li $ routeElem (R_Basic Ex01.Route_Index) "Ex01_Basic"
        H.li $ routeElem (R_Clock Ex02.Route_Index) "Ex02_Clock"
        H.li $ routeElem (R_ClockFast Ex02.Route_Index) "Ex02_ClockFast"
        H.li $ routeElem (R_Store Ex03.Route_Index) "Ex03_Store"
      H.p $ do
        "The current time is: "
        H.small $ show $ mClock m
  where
    routeElem r w = do
      H.a ! A.class_ "text-xl text-purple-500 hover:underline" ! A.href (H.toValue $ routeUrl rp r) $ w