{-# LANGUAGE QuasiQuotes                #-}
{-# LANGUAGE FlexibleContexts           #-}
{-# LANGUAGE OverloadedStrings          #-}
{-# LANGUAGE TypeApplications           #-}
{-# LANGUAGE GADTs                      #-}
{-# LANGUAGE GeneralizedNewtypeDeriving #-}
module Main where

import qualified Knit.Report               as K
import qualified Knit.Effect.RandomFu      as KR
import qualified Colonnade                 as C

import           Control.Monad.IO.Class     (MonadIO)
import qualified Data.Map                  as M
import qualified Data.Random               as R
import qualified Data.Text.IO              as T
import qualified Data.Text.Lazy            as TL
import qualified Data.Text                 as T
import           Data.String.Here           (here)
import qualified Graphics.Vega.VegaLite    as V

import           Control.Monad.Reader       (ReaderT
                                            , ask
                                            , runReaderT
                                            )

templateVars :: M.Map String String
templateVars = M.fromList
  [ ("lang"     , "English")
  , ("author"   , "Adam Conner-Sax")
  , ("pagetitle", "knit-haskell mtl example with random effect")
--  , ("tufte","True")
  ]

-- A demo application stack 
newtype MyApp env a = MyStack { unMyApp :: ReaderT env IO a } deriving (Functor, Applicative, Monad, MonadIO)

type ExampleApp = MyApp T.Text

runExampleApp :: T.Text -> ExampleApp a -> IO a
runExampleApp t = flip runReaderT t . unMyApp

getEnv :: MyApp env env
getEnv = MyStack $ ask

main :: IO ()
main = do
  let pandocWriterConfig =
        K.PandocWriterConfig (Just "pandoc-templates/minWithVega-pandoc.html")  templateVars K.mindocOptionsF
  resE <- runExampleApp "This is from the MyApp environment."
          $ K.knitHtml (Just "RandomExample.Main") K.logAll pandocWriterConfig
          $ KR.runRandomIOSimple $ makeDoc
  case resE of
    Right htmlAsText ->
      T.writeFile "examples/html/random_example.html"
        $ TL.toStrict
        $ htmlAsText
    Left err -> putStrLn $ "Pandoc error: " ++ show err

md1 :: T.Text
md1 = [here|
## Some example markdown
* [Markdown][MarkdownLink] is a nice way to write formatted notes with a minimum of code.
* It supports links and tables and some *styling* information.

[MarkDownLink]:<https://pandoc.org/MANUAL.html#pandocs-markdown>
|]

makeDoc :: (K.Member K.ToPandoc effs
           , K.PandocEffects effs
           , K.Member KR.Random effs -- this one needs to be handled before knitting
           , K.KnitBase ExampleApp effs) => K.Semantic effs ()
makeDoc = K.wrapPrefix "makeDoc" $ do
  K.logLE K.Info "adding some markdown..."
  K.addMarkDown md1

  K.logLE K.Info "adding some latex..."
  K.addMarkDown "## Some example latex"
  K.addLatex "Overused favorite equation: $e^{i\\pi} + 1 = 0$"

  K.logLE K.Info "adding a visualization..."
  K.addMarkDown "## An example hvega visualization"
  K.addHvega "someID" exampleVis

  K.logLE K.Info "Retrieving some text from the base monad and current date-time."
  envText <- K.liftKnit @ExampleApp getEnv
  curTime <- K.getCurrentTime 
  K.addMarkDown "## An example of getting env from a base monad, and time from the Pandoc Effects."  
  K.addMarkDown $ envText <> "\n\n" <> (T.pack $ show curTime)

  K.logLE K.Info "Using another polysemy effect, here RandomFu"
  let draws = [1..20 :: Int]
  someNormalDoubles <- KR.sampleRVar $ mapM (const $ R.stdNormal @Double) draws
  K.addMarkDown "## An example of using the RandomFu effect to get random numbers and using Colonnade to make tables."
  K.addMarkDown $ "some std normal draws: "
  K.addColonnadeTextTable (C.headed "#" (T.pack . show . fst) <> C.headed "Draw" (T.pack . show . snd)) $ zip draws someNormalDoubles
  
exampleVis :: V.VegaLite
exampleVis =
  let cars =  V.dataFromUrl "https://vega.github.io/vega-datasets/data/cars.json" []
      enc = V.encoding
        . V.position V.X [ V.PName "Horsepower", V.PmType V.Quantitative ]
        . V.position V.Y [ V.PName "Miles_per_Gallon", V.PmType V.Quantitative ]
        . V.color [ V.MName "Origin", V.MmType V.Nominal ]
      bkg = V.background "rgba(0, 0, 0, 0.05)"
  in V.toVegaLite [ bkg, cars, V.mark V.Circle [], enc [] ]