(define "NextCanNotMove"
    (not (can Move (do (forEach Piece Next) ifAfterwards:(not ("KingCheck" Next)))))
)

//**** Defines used to model the castling Moves. ****
(define "KingCheck"
    (is Threatened (id "King" #1) at:(where "King" #1)) 
)

(define "KingInTheInitialPlace"
    (= (what at:(mapEntry "King" (mover))) (id "King" Mover))
)

(define "HasNeverMoved"
    (= (state at:(mapEntry #1 (mover))) 1) 
)

(define "ThatPieceNeverMoved"
    (= (state at:(mapEntry #1 (mover))) 1) 
)

(define "PieceHasMoved"
    (set State at:(last To) 0) 
)

(define "RememberPieceHasMoved"
    (then 
        (if 
            (= (state at:(last To)) 1) 
            "PieceHasMoved"
        ) 
    ) 
)

(define "KingNotCheckedAndToEmpty"
    (and 
        (is Empty (to)) 
        (not (is Threatened (id "King" Mover) at:(to)))
    ) 
)

(define "DoCastle"
    (move Slide 
        (from (mapEntry #1 (mover))) 
        #2 
        (between 
            (exact #3) 
            if:#4
        ) 
        #5
    )
)

(define "SmallCastling"
    ("DoCastle" "King" E 2 "KingNotCheckedAndToEmpty" (then (and ("PieceHasMoved") ("DoCastle" "RookRight" W 2 True))))
)

(define "BigCastling"
    ("DoCastle" "King" W 2 "KingNotCheckedAndToEmpty" (then (and ("PieceHasMoved") ("DoCastle" "RookLeft" E 3 True))))
)

(define "Castling"
    (if (and {
            "KingInTheInitialPlace" 
            ("HasNeverMoved" "King")
            (not ("KingCheck" Mover)) 
        })
        (or
            (if (and 
                    ("HasNeverMoved" "RookLeft")
                    (can Move ("DoCastle" "RookLeft" E 3 (is Empty (to))))
                )
                "BigCastling"
            )
            (if (and 
                    ("HasNeverMoved" "RookRight")
                    (can Move ("DoCastle" "RookRight" W 2 (is Empty (to))))
                )
                "SmallCastling"
            )
        )
    )		
)

//**** Defines used to model the extra Pawn moves. ****
(define "SetEnPassantLocation"
    (then 
        (set Pending (ahead (last To) Backward))
    )
)

(define "InLocationEnPassant"
    (and 
        (is Pending) 
        (= (to) (value Pending)) 
    )
)

(define "EnPassant"
    (move Step
        (directions {FR FL}) 
        (to if:"InLocationEnPassant") 
        (then 
            (remove 
                (ahead (last To) Backward)
            )
        )
    )
)

(define "InitialPawnMove"
    (if (is In (from) (sites Start (piece (what at:(from)))))
        ("DoubleStepForwardToEmpty" "SetEnPassantLocation")
    )
)

//------------------------------------------------------------------------------

(game "Chess Puzzle" 
    ("TwoPlayersNorthSouth") 
    (equipment { 
        (board (square 8))
        
        ("ChessPawn" "Pawn"
            (or 
                "InitialPawnMove"
                "EnPassant"
            )
            (then 
                (and
                    ("ReplayInMovingOn" (sites Mover "Promotion"))
                    (set Counter)
                )
            )
        )
        ("ChessRook" "Rook" (then (set Counter)) ("RememberPieceHasMoved"))
        ("ChessKing" "King" (then (set Counter)) ("RememberPieceHasMoved"))
        ("ChessBishop" "Bishop" (then (set Counter)))
        ("ChessKnight" "Knight" (then (set Counter)))
        ("ChessQueen" "Queen" (then (set Counter)))
        
        (map "King" {(pair 1 "E1") (pair 2 "E8")})
        (map "RookLeft" {(pair 1 "A1") (pair 2 "A8")})
        (map "RookRight" {(pair 1 "H1") (pair 2 "H8")})
        (regions "Promotion" P1 (sites Top))
        (regions "Promotion" P2 (sites Bottom))
    }) 
    (rules 
        (start { 
            <challenge:start>
        })
        
        (play 
            (if "SameTurn"
                (move Promote (last To) (piece {"Queen" "Knight" "Bishop" "Rook"}) Mover)
                (do 
                    (or 
                        (forEach Piece)
                        ("Castling")
                    )
                    ifAfterwards:(not ("KingCheck" Mover))
                )
            )
        )
        
        (end {
            (if (and {
                    ("KingCheck" Next)
                    "NextCanNotMove"
                    (<= (count Turns) <challenge:limit>)
                }) 
                (result P1 Win)
            ) 
            (if (or (no Moves Next) (and (= <challenge:limit> (count Turns)) (not (is Mover Next)))) (result P1 Loss))
        }) 
    )
)

//------------------------------------------------------------------------------

(option "Challenge" <challenge> args:{ <start> <limit> }
    {
    (item "1 (1 Move)" 
        <(place "King1" 42) (place "Rook1" 12) (place "King2" 58)> 
        <1> 
        ""
    )
    
    (item "2 (2 Moves)" 
        <(place "King1" 6) (place "Queen1" 35) (place "Knight1" 47) (place "Rook1" {0 5}) (place "Pawn1" {9 10 13 14 15 16 26 28}) 
        (place "Bishop2" {49 38}) (place "Pawn2" {48 41 50 51 54 55}) (place "Queen2" 59) (place "Rook2" 60) (place "King2" 63)> 
        <3>
        ""
    )
    
    (item "3 (2 Moves)" 
        <(place "King1" 4) (place "Queen1" 47) (place "Bishop1" 26) (place "Knight1" {46 35}) (place "Rook1" {0 7}) (place "Pawn1" {8 9 10 19 28 13 14 15}) 
        (place "Bishop2" {34 58}) (place "Pawn2" {48 49 50 43 36 37 45 55}) (place "Queen2" 59) (place "Rook2" {56 53}) (place "Knight2" 42) (place "King2" 62)>
        <3> 
        ""
    )
    
    (item "4 (2 Moves)" 
        <(place "King1" 6) (place "Queen1" 18) (place "Bishop1" {24 9}) (place "Knight1" {1 21}) (place "Rook1" {0 5}) (place "Pawn1" {8 35 28 13 14 15}) 
        (place "Bishop2" {41 58}) (place "Pawn2" {40 49 50 43 53 54 55}) (place "Queen2" 30) (place "Rook2" {56 63}) (place "Knight2" {32 45}) (place "King2" 59)>
        <3> 
        ""
    )
    
    (item "5 (2 Moves)" 
        <(place "King1" 6) (place "Queen1" 3) (place "Bishop1" {44 47}) (place "Knight1" {54}) (place "Rook1" {0 5}) (place "Pawn1" {8 25 18 13 30 23}) 
        (place "Bishop2" {41 28}) (place "Pawn2" {48 49 50 43 27 55}) (place "Queen2" 59) (place "Rook2" {56 63}) (place "Knight2" {52 42}) (place "King2" 61)>
        <3> 
        ""
    )
    
    (item "6 (2 Moves)" 
        <(place "King1" 6) (place "Queen1" 39) (place "Bishop1" {26 45}) (place "Rook1" {0 4}) (place "Pawn1" {8 9 18 13 14 15}) 
        (place "Bishop2" {41 58}) (place "Pawn2" {48 49 50 43 27 53 55}) (place "Queen2" 37) (place "Rook2" {56 61}) (place "King2" 62)>
        <3>
        ""
    )
    
    (item "7 (2 Moves)" 
        <(place "King1" 58) (place "Rook1" {0}) (place "Pawn1" {41}) 
        (place "Bishop2" {57}) (place "Pawn2" {48 49}) (place "King2" 56)>
        <3>
        ""
    )
    
    (item "8 (3 Moves)" 
        <(place "King1" 31) (place "Bishop1" {22}) (place "Knight1" {14}) (place "Rook1" {4}) (place "Pawn1" {48 49}) 
        (place "Bishop2" {56 6}) (place "King2" 7)>
        <5> 
        ""
    )
    
    (item "9 (3 Moves)" 
        <(place "King1" 4) (place "Bishop1" {2 5}) (place "Knight1" {1 6}) (place "Rook1" {0 7}) (place "Pawn1" (sites Row 1)) (place "Queen1" 3)
        (place "King2" 31)>
        <5> 
        ""
    )
    
    (item "10 (10 Moves)" 
        < (place "Pawn1" {13 22}) (place "Pawn2" {48 49 30 21})
        (place "Rook1" {4}) (place "Knight1" {33}) (place "Queen1" 29) (place "King1" 6) 
        (place "Rook2" {51}) (place "Knight2" {41}) (place "Bishop2" {45}) (place "Queen2" 31) (place "King2" 56) >
        <11>
        ""
    )
})

//------------------------------------------------------------------------------

(metadata 
    
    (info
        {
        (description "In this Chess Puzzle, you must checkmate the black king with the smallest number of moves possible with the white pieces.")
        (rules "Play using the standard rules of chess.")
        (source "<a href=\"https://www.chess.com\" target=\"_blank\" class=\"style1\" style=\"color: #0000EE\" />www.chess.com</a>")
        (id "455")
        (version "1.3.12")
        (classification "puzzle/planning")
        (credit "Eric Piette")
        }
    )
    
    (graphics {
        (show Check "King")
        (piece Scale "Pawn" 0.825)
        (piece Families {"Defined" "Microsoft" "Pragmata" "Symbola"})
        (board Style Chess)
        (adversarialPuzzle)
    })
    
    (ai 
        "Chess Puzzle_ai"
    )
    
)