about summary refs log tree commit diff
path: root/users/grfn/xanthous/src/Xanthous/Data.hs
blob: 9b3c35c5457c283b5c794488b3992bc7dd376782 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
{-# LANGUAGE PartialTypeSignatures  #-}
{-# LANGUAGE StandaloneDeriving     #-}
{-# LANGUAGE RoleAnnotations        #-}
{-# LANGUAGE RecordWildCards        #-}
{-# LANGUAGE DeriveTraversable      #-}
{-# LANGUAGE TemplateHaskell        #-}
{-# LANGUAGE NoTypeSynonymInstances #-}
{-# LANGUAGE DuplicateRecordFields  #-}
{-# LANGUAGE QuantifiedConstraints  #-}
{-# LANGUAGE UndecidableInstances   #-}
--------------------------------------------------------------------------------
-- | Common data types for Xanthous
--------------------------------------------------------------------------------
{-# LANGUAGE AllowAmbiguousTypes #-}
module Xanthous.Data
  ( Opposite(..)

    -- *
  , Position'(..)
  , Position
  , x
  , y

    -- **
  , Positioned(..)
  , _Positioned
  , position
  , positioned
  , loc
  , _Position
  , positionFromPair
  , positionFromV2
  , addPositions
  , diffPositions
  , stepTowards
  , isUnit

    -- * Boxes
  , Box(..)
  , topLeftCorner
  , bottomRightCorner
  , setBottomRightCorner
  , dimensions
  , inBox
  , boxIntersects
  , boxCenter
  , boxEdge
  , module Linear.V2

    -- *
  , Per(..)
  , invertRate
  , invertedRate
  , (|*|)
  , Ticks(..)
  , Tiles(..)
  , TicksPerTile
  , TilesPerTick
  , timesTiles
  , Square(..)
  , Cubic(..)
  , Grams
  , Meters
  , Unit(..)
  , UnitSymbol(..)

    -- *
  , Dimensions'(..)
  , Dimensions
  , HasWidth(..)
  , HasHeight(..)

    -- *
  , Direction(..)
  , move
  , asPosition
  , directionOf
  , Cardinal(..)

    -- *
  , Corner(..)
  , Edge(..)
  , cornerEdges

    -- *
  , Neighbors(..)
  , edges
  , neighborDirections
  , neighborPositions
  , neighborCells
  , arrayNeighbors
  , rotations
  , HasTopLeft(..)
  , HasTop(..)
  , HasTopRight(..)
  , HasLeft(..)
  , HasRight(..)
  , HasBottomLeft(..)
  , HasBottom(..)
  , HasBottomRight(..)

    -- *
  , Hitpoints(..)
  ) where
--------------------------------------------------------------------------------
import           Xanthous.Prelude hiding (Left, Down, Right, (.=), elements)
--------------------------------------------------------------------------------
import           Linear.V2 hiding (_x, _y)
import qualified Linear.V2 as L
import           Linear.V4 hiding (_x, _y)
import           Test.QuickCheck (CoArbitrary, Function, elements)
import           Test.QuickCheck.Arbitrary.Generic
import           Data.Group
import           Brick (Location(Location), Edges(..))
import           Data.Monoid (Product(..), Sum(..))
import           Data.Array.IArray
import           Data.Aeson.Generic.DerivingVia
import           Data.Aeson
                 ( ToJSON(..), FromJSON(..), object, (.=), (.:), withObject)
import           Data.Random (Distribution)
import           Data.Coerce
import           Data.Proxy (Proxy(Proxy))
--------------------------------------------------------------------------------
import           Xanthous.Util (EqEqProp(..), EqProp, between)
import           Xanthous.Util.QuickCheck (GenericArbitrary(..))
import           Xanthous.Orphans ()
import           Xanthous.Util.Graphics
--------------------------------------------------------------------------------

-- | opposite ∘ opposite ≡ id
class Opposite x where
  opposite :: x -> x

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

-- fromScalar ∘ scalar ≡ id
class Scalar a where
  scalar :: a -> Double
  fromScalar :: Double -> a

instance Scalar Double where
  scalar = id
  fromScalar = id

newtype ScalarIntegral a = ScalarIntegral a
  deriving newtype (Eq, Ord, Num, Enum, Real, Integral)
instance Integral a => Scalar (ScalarIntegral a) where
  scalar = fromIntegral
  fromScalar = floor

deriving via (ScalarIntegral Integer) instance Scalar Integer
deriving via (ScalarIntegral Word) instance Scalar Word

-- | Units of measure
class Unit a where
  unitSuffix :: Text
type UnitSymbol :: Symbol -> Type -> Type
newtype UnitSymbol suffix a = UnitSymbol a
instance KnownSymbol suffix => Unit (UnitSymbol suffix a) where
  unitSuffix = pack $ symbolVal @suffix Proxy

newtype ShowUnitSuffix a b = ShowUnitSuffix a
instance (Show b, Unit a, Coercible a b) => Show (ShowUnitSuffix a b) where
  show a = show (coerce @_ @b a) <> " " <> unpack (unitSuffix @a)

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

data Position' a where
  Position :: { _x :: a
             , _y :: a
             } -> (Position' a)
  deriving stock (Show, Eq, Generic, Ord, Functor, Foldable, Traversable)
  deriving anyclass (NFData, Hashable, CoArbitrary, Function)
  deriving EqProp via EqEqProp (Position' a)
  deriving (ToJSON, FromJSON)
       via WithOptions '[ FieldLabelModifier '[Drop 1] ]
                       (Position' a)

x, y :: Lens' (Position' a) a
x = lens (\(Position xx _) -> xx) (\(Position _ yy) xx -> Position xx yy)
y = lens (\(Position _ yy) -> yy) (\(Position xx _) yy -> Position xx yy)

type Position = Position' Int

instance Arbitrary a => Arbitrary (Position' a) where
  arbitrary = genericArbitrary
  shrink (Position px py) = Position <$> shrink px <*> shrink py


instance Num a => Semigroup (Position' a) where
  (Position x₁ y₁) <> (Position x₂ y₂) = Position (x₁ + x₂) (y₁ + y₂)

instance Num a => Monoid (Position' a) where
  mempty = Position 0 0

instance Num a => Group (Position' a) where
  invert (Position px py) = Position (negate px) (negate py)

-- | Positions convert to scalars by discarding their orientation and just
-- measuring the length from the origin
instance (Ord a, Num a, Scalar a) => Scalar (Position' a) where
  scalar = fromIntegral . length . line 0 . view _Position
  fromScalar n = Position (fromScalar n) (fromScalar n)

data Positioned a where
  Positioned :: Position -> a -> Positioned a
  deriving stock (Show, Eq, Ord, Functor, Foldable, Traversable, Generic)
  deriving anyclass (NFData, CoArbitrary, Function)
type role Positioned representational

_Positioned :: Iso (Position, a) (Position, b) (Positioned a) (Positioned b)
_Positioned = iso hither yon
  where
    hither (pos, a) = Positioned pos a
    yon (Positioned pos b) = (pos, b)

instance Arbitrary a => Arbitrary (Positioned a) where
  arbitrary = Positioned <$> arbitrary <*> arbitrary

instance ToJSON a => ToJSON (Positioned a) where
  toJSON (Positioned pos val) = object
    [ "position" .= pos
    , "data" .= val
    ]

instance FromJSON a => FromJSON (Positioned a) where
  parseJSON = withObject "Positioned" $ \obj ->
    Positioned <$> obj .: "position" <*> obj .: "data"

position :: Lens' (Positioned a) Position
position = lens
  (\(Positioned pos _) -> pos)
  (\(Positioned _ a) pos -> Positioned pos a)

positioned :: Lens (Positioned a) (Positioned b) a b
positioned = lens
  (\(Positioned _ x') -> x')
  (\(Positioned pos _) x' -> Positioned pos x')

loc :: Iso' Position Location
loc = iso hither yon
  where
    hither (Position px py) = Location (px, py)
    yon (Location (lx, ly)) = Position lx ly

_Position :: Iso' (Position' a) (V2 a)
_Position = iso hither yon
  where
    hither (Position px py) = (V2 px py)
    yon (V2 lx ly) = Position lx ly

positionFromPair :: (Num a, Integral i, Integral j) => (i, j) -> Position' a
positionFromPair (i, j) = Position (fromIntegral i) (fromIntegral j)

positionFromV2 :: (Num a, Integral i) => V2 i -> Position' a
positionFromV2 (V2 xx yy) = Position (fromIntegral xx) (fromIntegral yy)

-- | Add two positions
--
-- Operation for the additive group on positions
addPositions :: Num a => Position' a -> Position' a -> Position' a
addPositions = (<>)

-- | Subtract two positions.
--
-- diffPositions pos₁ pos₂ = pos₁ `addPositions` (invert pos₂)
diffPositions :: Num a => Position' a -> Position' a -> Position' a
diffPositions (Position x₁ y₁) (Position x₂ y₂) = Position (x₁ - x₂) (y₁ - y₂)

-- | Is this position a unit position? or: When taken as a difference, does this
-- position represent a step of one tile?
--
-- ∀ dir :: Direction. isUnit ('asPosition' dir)
isUnit :: (Eq a, Num a) => Position' a -> Bool
isUnit (Position px py) =
  abs px `elem` [0,1] && abs py `elem` [0, 1] && (px, py) /= (0, 0)

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

data Dimensions' a = Dimensions
  { _width :: a
  , _height :: a
  }
  deriving stock (Show, Eq, Functor, Generic)
  deriving anyclass (CoArbitrary, Function)
makeFieldsNoPrefix ''Dimensions'

instance Arbitrary a => Arbitrary (Dimensions' a) where
  arbitrary = Dimensions <$> arbitrary <*> arbitrary

type Dimensions = Dimensions' Word

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

data Direction where
  Up        :: Direction
  Down      :: Direction
  Left      :: Direction
  Right     :: Direction
  UpLeft    :: Direction
  UpRight   :: Direction
  DownLeft  :: Direction
  DownRight :: Direction
  Here      :: Direction
  deriving stock (Show, Eq, Ord, Generic)
  deriving anyclass (CoArbitrary, Function, NFData, ToJSON, FromJSON, Hashable)
  deriving Arbitrary via GenericArbitrary Direction

instance Opposite Direction where
  opposite Up        = Down
  opposite Down      = Up
  opposite Left      = Right
  opposite Right     = Left
  opposite UpLeft    = DownRight
  opposite UpRight   = DownLeft
  opposite DownLeft  = UpRight
  opposite DownRight = UpLeft
  opposite Here      = Here

move :: Num a => Direction -> Position' a -> Position' a
move Up        = y -~ 1
move Down      = y +~ 1
move Left      = x -~ 1
move Right     = x +~ 1
move UpLeft    = move Up . move Left
move UpRight   = move Up . move Right
move DownLeft  = move Down . move Left
move DownRight = move Down . move Right
move Here      = id

asPosition :: Direction -> Position
asPosition dir = move dir mempty

-- | Returns the direction that a given position is from a given source position
directionOf
  :: Position -- ^ Source
  -> Position -- ^ Target
  -> Direction
directionOf (Position x₁ y₁) (Position x₂ y₂) =
  case (x₁ `compare` x₂, y₁ `compare` y₂) of
    (EQ, EQ) -> Here
    (EQ, LT) -> Down
    (EQ, GT) -> Up
    (LT, EQ) -> Right
    (GT, EQ) -> Left

    (LT, LT) -> DownRight
    (GT, LT) -> DownLeft

    (LT, GT) -> UpRight
    (GT, GT) -> UpLeft

-- | Take one (potentially diagonal) step towards the given position
--
-- ∀ src tgt. isUnit (src `diffPositions` (src `stepTowards tgt`))
stepTowards
  :: Position -- ^ Source
  -> Position -- ^ Target
  -> Position
stepTowards (view _Position -> p₁) (view _Position -> p₂)
  | p₁ == p₂ = _Position # p₁
  | otherwise =
    let (_:p:_) = line p₁ p₂
    in _Position # p

-- | Newtype controlling arbitrary generation to only include cardinal
-- directions ('Up', 'Down', 'Left', 'Right')
newtype Cardinal = Cardinal { getCardinal :: Direction }
  deriving stock (Eq, Show, Ord, Generic)
  deriving anyclass (NFData, Function, CoArbitrary)
  deriving newtype (Opposite)

instance Arbitrary Cardinal where
  arbitrary = Cardinal <$> elements [Up, Down, Left, Right]

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

data Corner
  = TopLeft
  | TopRight
  | BottomLeft
  | BottomRight
  deriving stock (Show, Eq, Ord, Enum, Bounded, Generic)
  deriving Arbitrary via GenericArbitrary Corner

instance Opposite Corner where
  opposite TopLeft = BottomRight
  opposite TopRight = BottomLeft
  opposite BottomLeft = TopRight
  opposite BottomRight = TopLeft

data Edge
  = TopEdge
  | LeftEdge
  | RightEdge
  | BottomEdge
  deriving stock (Show, Eq, Ord, Enum, Bounded, Generic)
  deriving Arbitrary via GenericArbitrary Edge

instance Opposite Edge where
  opposite TopEdge = BottomEdge
  opposite BottomEdge = TopEdge
  opposite LeftEdge = RightEdge
  opposite RightEdge = LeftEdge

cornerEdges :: Corner -> (Edge, Edge)
cornerEdges TopLeft = (TopEdge, LeftEdge)
cornerEdges TopRight = (TopEdge, RightEdge)
cornerEdges BottomLeft = (BottomEdge, LeftEdge)
cornerEdges BottomRight = (BottomEdge, RightEdge)

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

data Neighbors a = Neighbors
  { _topLeft
  , _top
  , _topRight
  , _left
  , _right
  , _bottomLeft
  , _bottom
  , _bottomRight :: a
  }
  deriving stock (Show, Eq, Ord, Functor, Foldable, Traversable, Generic)
  deriving anyclass (NFData, CoArbitrary, Function, MonoFoldable)
  deriving Arbitrary via GenericArbitrary (Neighbors a)

type instance Element (Neighbors a) = a

makeFieldsNoPrefix ''Neighbors

instance Applicative Neighbors where
  pure α = Neighbors
    { _topLeft     = α
    , _top         = α
    , _topRight    = α
    , _left        = α
    , _right       = α
    , _bottomLeft  = α
    , _bottom      = α
    , _bottomRight = α
    }
  nf <*> nx = Neighbors
    { _topLeft     = nf ^. topLeft     $ nx ^. topLeft
    , _top         = nf ^. top         $ nx ^. top
    , _topRight    = nf ^. topRight    $ nx ^. topRight
    , _left        = nf ^. left        $ nx ^. left
    , _right       = nf ^. right       $ nx ^. right
    , _bottomLeft  = nf ^. bottomLeft  $ nx ^. bottomLeft
    , _bottom      = nf ^. bottom      $ nx ^. bottom
    , _bottomRight = nf ^. bottomRight $ nx ^. bottomRight
    }

edges :: Neighbors a -> Edges a
edges neighs = Edges
  { eTop = neighs ^. top
  , eBottom = neighs ^. bottom
  , eLeft = neighs ^. left
  , eRight = neighs ^. right
  }

neighborDirections :: Neighbors Direction
neighborDirections = Neighbors
  { _topLeft     = UpLeft
  , _top         = Up
  , _topRight    = UpRight
  , _left        = Left
  , _right       = Right
  , _bottomLeft  = DownLeft
  , _bottom      = Down
  , _bottomRight = DownRight
  }

neighborPositions :: Num a => Position' a -> Neighbors (Position' a)
neighborPositions pos = (`move` pos) <$> neighborDirections

neighborCells :: Num a => V2 a -> Neighbors (V2 a)
neighborCells = map (view _Position) . neighborPositions . review _Position

arrayNeighbors
  :: (IArray a e, Ix i, Num i)
  => a (V2 i) e
  -> V2 i
  -> Neighbors (Maybe e)
arrayNeighbors arr center = arrLookup <$> neighborPositions (_Position # center)
  where
    arrLookup (view _Position -> pos)
      | inRange (bounds arr) pos = Just $ arr ! pos
      | otherwise                = Nothing

-- | Returns a list of all 4 90-degree rotations of the given neighbors
rotations :: Neighbors a -> V4 (Neighbors a)
rotations orig@(Neighbors tl t tr l r bl b br) = V4
   orig                            -- tl t  tr
                                   -- l     r
                                   -- bl b  br

   (Neighbors bl l tl b t br r tr) -- bl l tl
                                   -- b    t
                                   -- br r tr

   (Neighbors br b bl r l tr t tl) -- br b bl
                                   -- r    l
                                   -- tr t tl

   (Neighbors tr r br t b tl l bl) -- tr r br
                                   -- t    b
                                   -- tl l bl

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

newtype Per a b = Rate Double
  deriving stock (Eq, Generic)
  deriving anyclass (NFData, CoArbitrary, Function)
  deriving (Arbitrary, Num, Ord, Enum, Real, Fractional, ToJSON, FromJSON)
       via Double
  deriving (Semigroup, Monoid) via Product Double
  deriving Show via ShowUnitSuffix (Per a b) Double
deriving via Double
  instance ( Distribution d Double
           , forall xx yy. Coercible xx yy => Coercible (d xx) (d yy)
           )
  => Distribution d (Per a b)

instance (Unit a, Unit b) => Unit (a `Per` b) where
  unitSuffix = unitSuffix @a <> "/" <> unitSuffix @b

invertRate :: a `Per` b -> b `Per` a
invertRate (Rate p) = Rate $ 1 / p

invertedRate :: Iso (a `Per` b) (b' `Per` a') (b `Per` a) (a' `Per` b')
invertedRate = iso invertRate invertRate

type (:*:) :: Type -> Type -> Type
type family (:*:) a b where
  (a `Per` b) :*: b = a
  (Square a) :*: a = Cubic a
  a :*: a = Square a

infixl 7 |*|
class MulUnit a b where
  (|*|) :: a -> b -> a :*: b

instance (Scalar a, Scalar b) => MulUnit (a `Per` b) b where
  (Rate rate) |*| b = fromScalar $ rate * scalar b

instance forall a. (Scalar a, a :*: a ~ Square a) => MulUnit a a where
  x' |*| y' = Square @a . fromScalar $ scalar x' * scalar y'

instance forall a. (Scalar a) => MulUnit (Square a) a where
  x' |*| y' = Cubic @a . fromScalar $ scalar x' * scalar y'

newtype Square a = Square a
  deriving stock (Eq, Generic)
  deriving anyclass (NFData, CoArbitrary, Function)
  deriving ( Arbitrary, Num, Ord, Enum, Real, Fractional, ToJSON, FromJSON
           , Scalar
           )
       via a
deriving via (a :: Type)
  instance ( Distribution d a
           , forall xx yy. Coercible xx yy => Coercible (d xx) (d yy)
           )
  => Distribution d (Square a)

instance Unit a => Unit (Square a) where
  unitSuffix = unitSuffix @a <> "²"

instance Show a => Show (Square a) where
  show (Square n) = show n <> "²"

newtype Cubic a = Cubic a
  deriving stock (Eq, Generic)
  deriving anyclass (NFData, CoArbitrary, Function)
  deriving ( Arbitrary, Num, Ord, Enum, Real, Fractional, ToJSON, FromJSON
           , Scalar
           )
       via a
deriving via (a :: Type)
  instance ( Distribution d a
           , forall xx yy. Coercible xx yy => Coercible (d xx) (d yy)
           )
  => Distribution d (Cubic a)

instance Unit a => Unit (Cubic a) where
  unitSuffix = unitSuffix @a <> "³"

instance Show a => Show (Cubic a) where
  show (Cubic n) = show n <> "³"


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

newtype Ticks = Ticks Word
  deriving stock (Eq, Generic)
  deriving anyclass (NFData, CoArbitrary, Function)
  deriving (Num, Ord, Bounded, Enum, Integral, Real, ToJSON, FromJSON) via Word
  deriving (Semigroup, Monoid) via (Sum Word)
  deriving Scalar via ScalarIntegral Ticks
  deriving Arbitrary via GenericArbitrary Ticks
  deriving Unit via UnitSymbol "ticks" Ticks
  deriving Show via ShowUnitSuffix Ticks Word
deriving via Word
  instance ( Distribution d Word
           , forall xx yy. Coercible xx yy => Coercible (d xx) (d yy)
           )
  => Distribution d Ticks

newtype Tiles = Tiles Double
  deriving stock (Eq, Generic)
  deriving anyclass (NFData, CoArbitrary, Function)
  deriving (Num, Ord, Enum, Real, ToJSON, FromJSON, Scalar) via Double
  deriving (Semigroup, Monoid) via (Sum Double)
  deriving Arbitrary via GenericArbitrary Tiles
  deriving Unit via UnitSymbol "m" Tiles
  deriving Show via ShowUnitSuffix Tiles Double
deriving via Double
  instance ( Distribution d Double
           , forall xx yy. Coercible xx yy => Coercible (d xx) (d yy)
           )
  => Distribution d Tiles

type TicksPerTile = Ticks `Per` Tiles
type TilesPerTick = Tiles `Per` Ticks

timesTiles :: TicksPerTile -> Tiles -> Ticks
timesTiles = (|*|)

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

newtype Hitpoints = Hitpoints Word
  deriving stock (Eq, Generic)
  deriving anyclass (NFData, CoArbitrary, Function)
  deriving (Arbitrary, Num, Ord, Bounded, Enum, Integral, Real, ToJSON, FromJSON)
       via Word
  deriving (Semigroup, Monoid) via Sum Word
  deriving Unit via UnitSymbol "hp" Hitpoints
  deriving Show via ShowUnitSuffix Hitpoints Word

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

-- | Grams, the fundamental measure of weight in Xanthous.
newtype Grams = Grams Double
  deriving stock (Eq, Generic)
  deriving anyclass (NFData, CoArbitrary, Function)
  deriving ( Arbitrary, Num, Ord, Enum, Real, Floating, Fractional, RealFloat
           , RealFrac, Scalar, ToJSON, FromJSON
           )
       via Double
  deriving (Semigroup, Monoid) via Sum Double
  deriving Unit via UnitSymbol "g" Grams
  deriving Show via ShowUnitSuffix Grams Double

-- | Every tile is 1 meter
type Meters = Tiles

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

data Box a = Box
  { _topLeftCorner :: V2 a
  , _dimensions    :: V2 a
  }
  deriving stock (Show, Eq, Ord, Functor, Generic)
  deriving Arbitrary via GenericArbitrary (Box a)
makeFieldsNoPrefix ''Box

bottomRightCorner :: Num a => Box a -> V2 a
bottomRightCorner box =
  V2 (box ^. topLeftCorner . L._x + box ^. dimensions . L._x)
     (box ^. topLeftCorner . L._y + box ^. dimensions . L._y)

setBottomRightCorner :: (Num a, Ord a) => Box a -> V2 a -> Box a
setBottomRightCorner box br@(V2 brx bry)
  | brx < box ^. topLeftCorner . L._x || bry < box ^. topLeftCorner . L._y
  = box & topLeftCorner .~ br
        & dimensions . L._x .~ ((box ^. topLeftCorner . L._x) - brx)
        & dimensions . L._y .~ ((box ^. topLeftCorner . L._y) - bry)
  | otherwise
  = box & dimensions . L._x .~ (brx - (box ^. topLeftCorner . L._x))
        & dimensions . L._y .~ (bry - (box ^. topLeftCorner . L._y))

inBox :: (Ord a, Num a) => Box a -> V2 a -> Bool
inBox box pt = flip all [L._x, L._y] $ \component ->
  between (box ^. topLeftCorner . component)
          (box ^. to bottomRightCorner . component)
          (pt ^. component)

boxIntersects :: (Ord a, Num a) => Box a -> Box a -> Bool
boxIntersects box₁ box₂
  = any (inBox box₁) [box₂ ^. topLeftCorner, bottomRightCorner box₂]

boxCenter :: (Fractional a) => Box a -> V2 a
boxCenter box = V2 cx cy
 where
   cx = box ^. topLeftCorner . L._x + (box ^. dimensions . L._x / 2)
   cy = box ^. topLeftCorner . L._y + (box ^. dimensions . L._y / 2)

boxEdge :: (Enum a, Num a) => Box a -> Edge -> [V2 a]
boxEdge box LeftEdge =
  V2 (box ^. topLeftCorner . L._x)
  <$> [box ^. topLeftCorner . L._y .. box ^. to bottomRightCorner . L._y]
boxEdge box RightEdge =
  V2 (box ^. to bottomRightCorner . L._x)
  <$> [box ^. to bottomRightCorner . L._y .. box ^. to bottomRightCorner . L._y]
boxEdge box TopEdge =
  flip V2 (box ^. topLeftCorner . L._y)
  <$> [box ^. topLeftCorner . L._x .. box ^. to bottomRightCorner . L._x]
boxEdge box BottomEdge =
  flip V2 (box ^. to bottomRightCorner . L._y)
  <$> [box ^. topLeftCorner . L._x .. box ^. to bottomRightCorner . L._x]