Merlin.elm

module Merlin where

import Text exposing (..)
import Graphics.Input exposing (..)
import Graphics.Element exposing (..)
import Graphics.Collage exposing (..)
import Color exposing (..)

import List
import Mouse
import Window
import Signal
import Signal.Extra

import Debug

-- Model

size = 5

start u =
    case u of
        Viewport (w,h) -> {
            view={w=w,h=h},
            states=List.map (always True) [1..size^2]
        }

gridSize (w,h) = (min w h)*2/3
divide n side =
    let n' = toFloat n
    in (side-4-((n'-1)*2))/n'

-- Update

type Update = Viewport (Int, Int) | Click (Float,Float)

update u world =
    case u of
        Viewport vp -> updateViewport vp world
        Click square -> updateClick square world

updateClick (row,col) world =
    let which (row,col) = ((row-1)*size)+col-1
        ok n = n >= 1 && n <= size
        allOffsets = List.map (\(x,y) -> (row+x,col+y)) [(0,1),(-1,0),(0,0),(0,-1),(1,0)]
        coordOffsets = List.filter (\ (x,y) -> ok x && ok y) allOffsets
        offsets = List.map which coordOffsets
        toggle which states =
            let before = List.take which states
                (first :: rest) = List.drop which states
            in before ++ (not first :: rest)
    in {world | states <- List.foldl toggle world.states offsets}

updateViewport (w,h) world =
    let view = world.view
        view' = {view | w<-w,h<-h}
    in {world | view <- view'}

-- Display

displaySquare row col world =
    let side = gridSize (toFloat world.view.w,toFloat world.view.h)
        small = divide size side
        frnd = toFloat << round
        (state :: rest) = List.drop ((((floor row)-1)*size)+(floor col)-1) world.states
        style = if state then filled green else outlined (solid white)
        disp = collage (floor small) (floor small) <| [style (rect small small)]
    in clickable (Signal.message clicks.address (row,col)) disp

rowOfSquares world row =
    let squares = List.map (\col -> displaySquare row col world) [1..size]
        between = spacer 2 2
    in flow right (List.intersperse between squares)

makeSquares world =
    let rows = List.map (rowOfSquares world) [1..size]
        between = spacer 2 2
    in flow down (List.intersperse between rows)

winStyle = { typeface = [], height = Just 24, color = white, bold = True, italic = False, line = Nothing}

win world =
    if List.all (not) world.states then [container world.view.w world.view.h middle <| centered <| style winStyle <| fromString "You Win!"]
    else []

display world =
    let backdrop = filled black <| rect (toFloat world.view.w) (toFloat world.view.h)
        side = gridSize (toFloat world.view.w,toFloat world.view.h)
        grid = outlined (solid white) (rect side side)
        table = collage world.view.w world.view.h [backdrop,grid]
        squares = List.concatMap (\row -> List.map (\col -> displaySquare row col world) [1..size]) [1..size]
    in layers <| [table, container world.view.w world.view.h middle (makeSquares world)] ++ win world

-- Signals

clicks = Signal.mailbox (0.0,0.0)
squareClicks = Signal.map Click clicks.signal
dimensions = Signal.map Viewport (Window.dimensions)
inputs = Signal.mergeMany [dimensions,squareClicks]

main =
    let states = Signal.Extra.foldp' update start inputs
    in Signal.map display states