module Main where

import Prelude hiding (lookup)
import Control.Monad.State
import Data.Char
import qualified Data.Map as M (lookup)
import Data.Ix
import Data.List
import System.Random
import System.Environment

import Util.Grid
import Color
import LanguageSelect
import Curses
import World
import Keymap
import Vision
import Window

start :: IO ()
start = do
  init_curses
  raw_mode

finish :: IO ()
finish = do
  cooked_mode
  exit_curses

-- These are odd numbers, so that the view extends the same distance
-- from the midpoint on all sides.
view_hsize :: Int
view_hsize = 39

view_vsize :: Int
view_vsize = 19

draw_map :: (GlyphWindow w) => w -> Position -> World -> IO ()
draw_map w center world = do
  sequence_ (map draw_glyph locs)
  if inRange (window_bounds w) you_loc
    then move_cursor w you_loc
    else return ()
  where
    (hsize, vsize) = window_size w
    wcenter = (hsize `div` 2, vsize `div` 2)
    ulcorner = center `subpos` wcenter
    land = landscape world
    mons = monsters world
    locs = range (window_bounds w)
    you_loc = (you_pos world) `subpos` ulcorner
    draw_glyph (h, v) =
      write_glyph w (h, v) (glyph_at land mons (ulcorner `addpos` (h, v)))

draw_game_map :: (GlyphWindow w) => w -> World -> IO ()
draw_game_map w world =
  draw_map w (you_pos world) world

draw_bigmap :: (GlyphWindow w) => w -> Position -> World -> IO ()
draw_bigmap w center world = do
  draw_map w center world

main_loop :: World -> IO World
main_loop world | game_over world = return world
main_loop world = do
  let mode = user_mode world
  case mode of
    Mode_game -> do
      let mapw = mapwin world
      draw_game_map mapw world
      refresh_window mapw
      key <- get_key
      evalStateT clear_messages world
      case (flip M.lookup) (keymap world) key of
        Nothing -> do flash
                      main_loop world
        Just action -> do world' <- execStateT action world
                          main_loop world'
    Mode_bigmap center -> do
      let bigw = bigwin world
      draw_bigmap bigw center world
      refresh_window bigw
      key <- get_key
      case (flip M.lookup) (dir_keymap world) key of
        Nothing -> do
          -- Make sure the areas not covered by other windows are blanked
          clear_window bigw
          refresh_window bigw
          -- Do this by clearing the screen
          clear_screen
          refresh_window (mapwin world)
          refresh_window (msgwin world)
          main_loop world { user_mode = Mode_game }
        Just (dx, dy) -> do
          main_loop world {
            user_mode = Mode_bigmap (center `addpos` (10 * dx, 10 * dy))
          }



get_seed :: IO StdGen
get_seed = do
  args <- getArgs
  case args of
    ((a : _) : _) -> return $ mkStdGen $ digitToInt a
    _ -> getStdGen

main :: IO ()
main = do
  start
  msgw <- new_window (0, 0) (79, 0)
  mapw <- new_window (0, 1) (view_hsize-1, view_vsize)
  (hsize, vsize) <- screen_size
  bigw <- new_window (0, 0) (hsize-1, vsize-1)
  seed <- get_seed
  write_string mapw Text "Generating world..."
  refresh_window mapw
  update_screen
  let world = set_language English $
              new_world seed default_keymap default_dir_keymap msgw mapw bigw
  main_loop world
  destroy_window bigw
  destroy_window mapw
  destroy_window msgw
  finish