{-# LANGUAGE ImportQualifiedPost #-}
{-# LANGUAGE BlockArguments, LambdaCase, TupleSections, OverloadedStrings #-}
{-# LANGUAGE TypeApplications #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE ViewPatterns #-}
{-# OPTIONS_GHC -Wall -fno-warn-tabs #-}

module Control.Moffy.Samples.FollowboxOrigin (
	-- * followbox
	followbox ) where

import Prelude hiding (break, repeat, scanl)
import Control.Arrow ((>>>))
import Control.Monad (void, forever, (<=<))
import Control.Moffy
import Control.Moffy.Event.Lock
import Control.Moffy.Samples.Event.Random
import Control.Moffy.Samples.Event.Delete
import Control.Moffy.Samples.Event.Mouse qualified as Mouse
import Control.Moffy.Samples.Event.Area
import Control.Moffy.Samples.Viewable.Basic
import Control.Moffy.Samples.Followbox.Event
import Control.Moffy.Samples.Followbox.Clickable
import Control.Moffy.Samples.Followbox.ViewType
import Control.Moffy.Samples.Followbox.TypeSynonym (ErrorMessage)
import Data.Type.Set
import Data.Type.Flip ((<$%>), (<*%>))
import Data.OneOfThem
import Data.Hashable
import Data.HashMap.Strict qualified as HM
import Data.Bool
import Data.ByteString.Lazy qualified as LBS
import Data.ByteString.Char8 qualified as BSC
import Data.Text qualified as T
import Data.Time (utcToLocalTime, UTCTime)
import Data.Time.Clock.POSIX (posixSecondsToUTCTime)
import Data.Aeson (Object, Value(..), eitherDecode)
import Data.Aeson.KeyMap (toHashMap)
import Text.Read (readMaybe)
import Codec.Picture qualified as P

---------------------------------------------------------------------------

-- * PARAMETER LIST
-- 	+ MAX NUMBER OF GITHUB USER
-- 	+ BACKGROUND
-- 	+ FONT
-- 	+ AVATAR, NAME AND CROSS
-- 	+ COLORS
-- * SIG AND REACT
--	+ FOLLOWBOX
--	+ USER VIEW
--	+ GET USERS
--	+ GET OBJECT
-- * MOUSE EVENTS
-- * VIEWS
-- * ERRORS

---------------------------------------------------------------------------
-- PARAMETER LIST
---------------------------------------------------------------------------

-- MAX NUMBER OF GITHUB USER

userPageMax :: Int
userPageMax = 2 ^ (27 :: Int)

-- BACKGROUND

titlePos, refreshPos, resetTimePos :: Position
titlePos = (50, 44); refreshPos = (600, 65)
resetTimePos = (100, 470)

-- FONT

defaultFont :: FontName
defaultFont = "sans"

middleSize, largeSize :: FontSize
middleSize = 30; largeSize = 40

-- AVATAR, NAME AND CROSS

avatarSizeX, avatarSizeY :: Double
(avatarSizeX, avatarSizeY) = (80, 80)

avatarPos, namePos :: Int -> Position
avatarPos n = (100, 120 + 120 * fromIntegral n)
namePos n = (210, 150 + 120 * fromIntegral n)

crossSize :: Double
crossSize = largeSize / 2

crossPos :: Int -> Position
crossPos n = (500, 162 + 120 * fromIntegral n)

crossMergin :: Double
crossMergin = 5

-- COLORS

barColor :: Color
barColor = Color 0x32 0xcd 0x32

nameColor :: Color
nameColor = Color 0x00 0xcd 0x00

---------------------------------------------------------------------------
-- SIG AND REACT
---------------------------------------------------------------------------

-- FOLLOWBOX

followbox :: SigF s View ()
followbox = void $ fieldWithResetTime `break` deleteEvent `break` checkTerminate

fieldWithResetTime :: SigF s View ()
fieldWithResetTime = (<>) <$%> field <*%> resetTime

field :: SigF s View ()
field = do
	rfs <- waitFor $ link refreshPos "Refresh"
	lck <- waitFor $ adjust newLockId
	let	frame = title <> view rfs
	emit frame
	(frame <>) <$%> ((\a b c -> a <> b <> c)
		<$%> (chooseUser 0 <$%> refresh rfs <*%> close lck 0)
		<*%> (chooseUser 1 <$%> refresh rfs <*%> close lck 1)
		<*%> (chooseUser 2 <$%> refresh rfs <*%> close lck 2))
	where
	title = text white largeSize titlePos "Who to follow"
	link p t = clickableText p
		<$> adjust (withTextExtents defaultFont middleSize t)

chooseUser :: Int -> Maybe (Either Int [(Png, T.Text)]) -> Int -> View
chooseUser _ (Just (Left i)) _ = bar $ fromIntegral i
chooseUser n (Just (Right us)) i = userView n (us !! (i `mod` length us))
chooseUser _ Nothing _ = View []

refresh :: Clickable s -> SigF s (Maybe (Either Int [(Png, T.Text)])) ()
refresh rfs = forever do
	emit Nothing
	us <- Just . Left <$%> users
	emit . Just $ Right us
	waitFor . adjust $ click rfs

close :: LockId -> Int -> SigF s Int ()
close lck i = forever do
	emit =<< waitFor
		(withLock lck (adjust $ getRandomR (0, 29) :: ReactF s Int))
	waitFor . clickArea $ crossArea i

resetTime :: SigF s View ()
resetTime = forever do
	emit $ View []
	emit =<< waitFor do
		(t, tz) <- (,) <$> adjust checkBeginSleep <*> adjust getTimeZone
		pure . text white middleSize resetTimePos . T.pack
			$ "Wait until " <> show (utcToLocalTime tz t)
	waitFor $ adjust endSleep

-- USER VIEW

userView :: Int -> (Png, T.Text) -> View
userView n (avt, nm) = image (avatarPos n) avt <> name n nm <> cross n

name :: Int -> T.Text -> View
name n nm = text nameColor largeSize (namePos n) nm

cross :: Int -> View
cross (crossPos -> (l, t)) = line white 4 lt rb <> line white 4 lb rt
	where
	(lt, lb, rt, rb) = ((l, t), (l, b), (r, t), (r, b))
	(r, b) = (l + crossSize, t + crossSize)

crossArea :: Int -> (Position, Position)
crossArea (crossPos -> (l, t)) = ((l', t'), (r', b'))
	where
	(r, b) = (l + crossSize, t + crossSize)
	(l', t') = (l - crossMergin, t - crossMergin)
	(r', b') = (r + crossMergin, b + crossMergin)

-- GET USERS

users :: SigF s Int [(Png, T.Text)]
users = waitFor (mapM ex2 <$> getObjs') >>= err \(unzip -> (avs, nms)) ->
	sequence <$> ssum (avatar `mapM` avs) >>= err (pure . flip zip nms)
	where
	ex2 (toHashMap -> o) = (,)
		<$> extract "avatar_url" o noAvatarAddress
		<*> extract "login" o noLoginName
	ssum = scanl (+) 0
	err = either \e -> waitFor (adjust (uncurry raiseError e)) >> users

extract :: Hashable k => k -> HM.HashMap k Value -> e -> Either e T.Text
extract k o e = case HM.lookup k o of Just (String v) -> Right v; _ -> Left e

avatar :: T.Text -> SigF s Int (Either (Error, ErrorMessage) Png)
avatar url = emit 1 >> waitFor (png . snd <$> adjust (httpGet url))

png :: LBS.ByteString -> Either (Error, String) Png
png = LBS.toStrict >>> convert >>>
	either (Left . (NoAvatar ,)) (Right . Png avatarSizeX avatarSizeY)
	where convert img =
		LBS.toStrict . P.encodePng . P.convertRGB8 <$> P.decodeImage img

bar :: Double -> View
bar p = line barColor 50 (80, 300) (80 + p * 25, 300)

-- GET OBJECT

getObjs' :: ReactF s [Object]
getObjs' = getObjs >>= \case
	Left em -> adjust (raiseError NotJson em) >> getObjs'
	Right [] -> adjust (raiseError EmptyJson "Empty JSON") >> getObjs'
	Right os -> pure os

getObjs :: ReactF s (Either String [Object])
getObjs = do
	n <- adjust $ getRandomR (0, userPageMax)
	(hdr, bdy) <- adjust . httpGet $ api n
	case (rmng hdr, rst hdr) of
		(Just rmn, _) | rmn > (0 :: Int) -> pure $ eitherDecode bdy
		(Just _, Just t) -> sleep t >> getObjs
		(Just _, Nothing) -> err noRateLimitReset >> getObjs
		(Nothing, _) -> err noRateLimitRemaining >> getObjs
	where
	api = ("https://api.github.com/users?since=" <>) . T.pack . show @Int
	rmng = (read . BSC.unpack <$>) . lookup "X-RateLimit-Remaining"
	rst = ut <=< lookup "X-RateLimit-Reset"
	ut = (posixSecondsToUTCTime . fromInteger <$>) . readMaybe . BSC.unpack
	err :: (Error, String) -> ReactF s ()
	err = adjust . uncurry raiseError

sleep :: UTCTime -> ReactF s ()
sleep t = adjust (beginSleep t) >> adjust endSleep

---------------------------------------------------------------------------
-- MOUSE EVENTS
---------------------------------------------------------------------------

clickArea :: (Point, Point) -> ReactF s ()
clickArea ((l, u), (r, d)) = void . adjust
	. find inside $ fst <$%> repeat Mouse.move `indexBy` repeat leftClick
	where inside (x, y) = l <= x && x <= r && u <= y && y <= d

leftClick :: React s (Singleton Mouse.Down) ()
leftClick = clickOn Mouse.ButtonPrimary

clickOn :: Mouse.Button -> React s (Singleton Mouse.Down) ()
clickOn b0 = bool (clickOn b0) (pure ()) . (== b0) =<< Mouse.down

---------------------------------------------------------------------------
-- VIEWS
---------------------------------------------------------------------------

text :: Color -> FontSize -> Position -> T.Text -> View
text c fs p = View . (: []) . expand . Singleton . Text' c defaultFont fs p

line :: Color -> LineWidth -> Position -> Position -> View
line c w p q = View . (: []) . expand . Singleton $ Line' c w p q

image :: Position -> Png -> View
image p = View . (: []) . expand . Singleton . Image' p

---------------------------------------------------------------------------
-- ERRORS
---------------------------------------------------------------------------

noRateLimitRemaining,
	noRateLimitReset, noAvatarAddress, noLoginName :: (Error, String)
noRateLimitRemaining = (NoRateLimitRemaining, "No X-RateLimit-Remaining header")
noRateLimitReset = (NoRateLimitReset, "No X-RateLimit-Reset header")
noAvatarAddress = (NoAvatarAddress, "No Avatar Address")
noLoginName = (NoLoginName, "No Login Name")