module Display.Curses
  (displayId, startup, shutdown, display, nextEvent, Session) where

import UI.HSCurses.Curses as C
import qualified UI.HSCurses.CursesHelper as C
import Data.List as L
import Data.Map as M
import Data.Char
import qualified Data.ByteString.Char8 as BS
import Control.Monad

import Geometry
import qualified Keys as K (Key(..))
import qualified Color

displayId = "curses"

data Session =
  Session
    { win :: Window,
      styles :: Map (Color.Color, Color.Color) C.CursesStyle }

startup :: (Session -> IO ()) -> IO ()
startup k =
  do
    C.start
    cursSet CursorInvisible
    let s = [ ((f, b), C.Style (toFColor f) (toBColor b))
            | f <- [minBound..maxBound],
              -- No more color combinations possible: 16*4, 64 is max.
              b <- Color.legalBG ]
    nr <- colorPairs
    when (nr < L.length s) $
      C.end >>
      error ("Terminal has too few color pairs (" ++ show nr ++ "). Giving up.")
    let (ks, vs) = unzip s
    ws <- C.convertStyles vs
    let styleMap = M.fromList (zip ks ws)
    k (Session C.stdScr styleMap)

shutdown :: Session -> IO ()
shutdown w = C.end

display :: Area -> Session -> (Loc -> (Color.Attr, Char)) -> String -> String
           -> IO ()
display ((y0,x0),(y1,x1)) (Session { win = w, styles = s }) f msg status =
  do
    -- let defaultStyle = C.defaultCursesStyle
    -- Terminals with white background require this:
    let defaultStyle = s ! Color.defaultAttr
    C.erase
    C.setStyle defaultStyle
    mvWAddStr w 0 0 (toWidth (x1 - x0 + 1) msg)  -- TODO: BS as in vty
    mvWAddStr w (y1+2) 0 (toWidth (x1 - x0 + 1) status)
    sequence_ [ C.setStyle (findWithDefault defaultStyle a s)
                >> mvWAddStr w (y+1) x [c]
              | x <- [x0..x1], y <- [y0..y1], let (a, c) = f (y, x) ]
    refresh

toWidth :: Int -> String -> String
toWidth n x = take n (x ++ repeat ' ')

keyTranslate :: C.Key -> K.Key
keyTranslate e =
  case e of
    C.KeyChar '\ESC' -> K.Esc
    C.KeyExit        -> K.Esc
    C.KeyChar '\n'   -> K.Return
    C.KeyChar '\r'   -> K.Return
    C.KeyEnter       -> K.Return
    C.KeyChar '\t'   -> K.Tab
    C.KeyUp          -> K.Up
    C.KeyDown        -> K.Down
    C.KeyLeft        -> K.Left
    C.KeyRight       -> K.Right
    C.KeyHome        -> K.Home
    C.KeyPPage       -> K.PgUp
    C.KeyEnd         -> K.End
    C.KeyNPage       -> K.PgDn
    C.KeyBeg         -> K.Begin
    C.KeyB2          -> K.Begin
    C.KeyClear       -> K.Begin
    -- No KP_ keys; see https://github.com/skogsbaer/hscurses/issues/10
    -- For now, movement keys are more important than hero selection:
    C.KeyChar c
      | c `elem` ['1'..'9'] -> K.KP c
      | otherwise           -> K.Char c
    _                       -> K.Unknown (show e)

nextEvent :: Session -> IO K.Key
nextEvent session =
  do
    e <- C.getKey refresh
    return (keyTranslate e)
--    case keyTranslate e of
--      Unknown _ -> nextEvent session
--      k -> return k

toFColor :: Color.Color -> C.ForegroundColor
toFColor Color.Black     = C.BlackF
toFColor Color.Red       = C.DarkRedF
toFColor Color.Green     = C.DarkGreenF
toFColor Color.Yellow    = C.BrownF
toFColor Color.Blue      = C.DarkBlueF
toFColor Color.Magenta   = C.PurpleF
toFColor Color.Cyan      = C.DarkCyanF
toFColor Color.White     = C.WhiteF
toFColor Color.BrBlack   = C.GreyF
toFColor Color.BrRed     = C.RedF
toFColor Color.BrGreen   = C.GreenF
toFColor Color.BrYellow  = C.YellowF
toFColor Color.BrBlue    = C.BlueF
toFColor Color.BrMagenta = C.MagentaF
toFColor Color.BrCyan    = C.CyanF
toFColor Color.BrWhite   = C.BrightWhiteF

toBColor :: Color.Color -> C.BackgroundColor
toBColor Color.Black     = C.BlackB
toBColor Color.Red       = C.DarkRedB
toBColor Color.Green     = C.DarkGreenB
toBColor Color.Yellow    = C.BrownB
toBColor Color.Blue      = C.DarkBlueB
toBColor Color.Magenta   = C.PurpleB
toBColor Color.Cyan      = C.DarkCyanB
toBColor Color.White     = C.WhiteB
toBColor _               = C.BlackB  -- a limitation of curses