{-
	Copyright (C) 2018 Dr. Alistair Ward

	This file is part of BishBosh.

	BishBosh is free software: you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.

	BishBosh is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with BishBosh.  If not, see <https://www.gnu.org/licenses/>.
-}
{- |
 [@AUTHOR@]	Dr. Alistair Ward

 [@DESCRIPTION@]

	* Static tests.
-}

module BishBosh.Test.HUnit.Model.GameTree(
-- * Constants
	testCases
) where

import qualified	BishBosh.Attribute.CaptureMoveSortAlgorithm	as Attribute.CaptureMoveSortAlgorithm
import qualified	BishBosh.Component.Turn				as Component.Turn
import qualified	BishBosh.Input.RankValues			as Input.RankValues
import qualified	BishBosh.Model.Game				as Model.Game
import qualified	BishBosh.Model.GameTree				as Model.GameTree
import qualified	BishBosh.Notation.MoveNotation			as Notation.MoveNotation
import qualified	BishBosh.Property.Empty				as Property.Empty
import qualified	BishBosh.Property.FixedMembership		as Property.FixedMembership
import qualified	BishBosh.Property.ForsythEdwards		as Property.ForsythEdwards
import qualified	Data.Default
import qualified	Data.Maybe
import qualified	Data.Tree
import qualified	Test.HUnit
import			Test.HUnit((~:), (~?=))

-- | Check the sanity of the implementation, by validating a list of static test-cases.
testCases :: Test.HUnit.Test
testCases	= Test.HUnit.test [
	let
		maxDepth	= 4
	in "'BishBosh.Model.GameTree.countGames' failed" ~: map Model.GameTree.countGames [0 .. maxDepth] ~?= take (succ maxDepth) [1, 20, 400, 8902, 197281, 4865609],	-- <https://oeis.org/A048987>
	"'BishBosh.Model.GameTree.countPositions' failed" ~: map (
		\searchDepth -> fromIntegral (Model.GameTree.countPositions searchDepth) ~?= foldr (
			(+) . Model.GameTree.countGames
		) 0 [1 .. searchDepth]
	) [1 .. 4],
	"'BishBosh.Model.GameTree.sortGameTree/MVVLVA' failed" ~: map (
		\turn -> Notation.MoveNotation.showNotation Data.Default.def (turn :: Component.Turn.Turn)
	) (
		take 4 $ sortAvailableMoves (Just Attribute.CaptureMoveSortAlgorithm.MVVLVA) testString
	) ~?= ["c4d5p","e4d5p","c3d5p","d1d5p"],
	"'BishBosh.Model.GameTree.sortGameTree/SEE' failed" ~: map (
		\turn -> Notation.MoveNotation.showNotation Data.Default.def (turn :: Component.Turn.Turn)
	) (
		take 3 $ sortAvailableMoves (Just Attribute.CaptureMoveSortAlgorithm.SEE) testString
	) ~?= ["c4d5p","e4d5p","a1b1"]
 ] where
	sortAvailableMoves :: Maybe Attribute.CaptureMoveSortAlgorithm.CaptureMoveSortAlgorithm -> String -> [Component.Turn.Turn]
	sortAvailableMoves maybeSortAlgorithm	= Data.Maybe.mapMaybe (
		Model.Game.maybeLastTurn . Data.Tree.rootLabel
	 ) . Data.Tree.subForest . Model.GameTree.deconstruct . Model.GameTree.sortGameTree maybeSortAlgorithm (
		Input.RankValues.findRankValue $ Input.RankValues.fromAssocs (
			zip Property.FixedMembership.members $ map (
				fromRational . (/ 10)	-- Map into the closed unit-interval.
			) [
				1,	-- P
				5,	-- R
				3,	-- N
				7 / 2,	-- B
				9,	-- Q
				0	-- K
			]
		)
	 ) Property.Empty.empty {-MoveFrequency-} . Model.GameTree.fromGame . Property.ForsythEdwards.readFEN

	testString	= "rn1qkb1r/pp2pppp/2p1bn2/3p4/2P1P3/1PN2B2/P1P2PPP/R1BQK1NR w KQkq - 0 5"