import XCTest
@testable import Model

final class FourInARowRulesTests: XCTestCase {
    private var rules: FourInARowRules!
    private var board: Board!
    
    override func setUpWithError() throws {
        try super.setUpWithError()
        
        guard let rules = FourInARowRules(columns: 3, rows: 3, minAligned: 3) else {
            XCTFail()
            return
        }
        
        self.rules = rules
        self.board = self.rules.createBoard()
    }
    
    func testEmptyHistory() {
        XCTAssertTrue(self.rules.history.isEmpty)
    }
    
    func testBoardIsValid() {
        XCTAssertTrue(self.rules.isValid(board: self.board))
    }
    
    func testState() {
        XCTAssertEqual(self.rules.state, GameState.Playing(turn: .A))
    }
    
    func testMovesAreValid() {
        for move in self.rules.validMoves(board: self.board) {
            rules.state = .Playing(turn: move.player)
            XCTAssertTrue(self.rules.isValid(board: board, move: move), "\(move)")
        }
    }
    
    func testMovesOfPlayerAreValid() throws {
        for player in PieceType.allCases {
            try self.setUpWithError()
            
            try self._testMovesOfPlayerAreValid(player: player)
            
            try self.tearDownWithError()
        }
    }
    
    private func _testMovesOfPlayerAreValid(player: PieceType) throws {
        for action in self.rules.validMoves(board: self.board, for_player: player) {
            rules.state = .Playing(turn: player)
            XCTAssertTrue(self.rules.isValid(board: board, move: Move(player: player, action: action)), "\(action)")
        }
    }
    
    func testOnMoveDone() {
        let coord = Coords(1, board.rows - 1)
        board[coord] = Piece(type: .A)
        let move = Move(player: .A, action: .InsertOnSide(side: .Top, offset: 1))
        self.rules.onMoveDone(move: move, board: self.board)
        
        XCTAssertEqual(self.rules.state, GameState.Playing(turn: .B))
        XCTAssertEqual(self.rules.history.last, move)
    }
    
    func testOnMoveDoneDraw() {
        board[0, 0] = Piece(type: .A)
        board[1, 0] = Piece(type: .A)
        board[2, 0] = Piece(type: .B)
        board[0, 1] = Piece(type: .B)
        board[1, 1] = Piece(type: .B)
        board[2, 1] = Piece(type: .A)
        board[0, 2] = Piece(type: .A)
        board[1, 2] = Piece(type: .A)
        
        board[2, 2] = Piece(type: .B)
        
        XCTAssertTrue(rules.isValid(board: board))
        
        let move = Move(player: .B, action: .InsertOnSide(side: .Top, offset: 2))
        
        self.rules.onMoveDone(move: move, board: board)
        
        XCTAssertEqual(rules.state, GameState.Finished(winner: nil))
    }
    
    func testOnMoveDoneWin() {
        board[0, 0] = Piece(type: .A)
        board[1, 0] = Piece(type: .A)
        board[2, 0] = Piece(type: .A) //
        board[0, 1] = Piece(type: .B)
        board[1, 1] = Piece(type: .B)
        board[2, 1] = Piece(type: .A)
        board[0, 2] = Piece(type: .A)
        board[1, 2] = Piece(type: .A)
        board[2, 2] = Piece(type: .B)
        
        XCTAssertTrue(rules.isValid(board: board))
        
        let move = Move(player: .A, action: .InsertOnSide(side: .Top, offset: 2))
        
        self.rules.onMoveDone(move: move, board: board)
        
        XCTAssertEqual(rules.state, GameState.Finished(winner: .A))
    }
    
    func testCountMaxRow() throws {
        for (coords, expected) in [
            (Coords(1, 0), 3),
            (Coords(0, 1), 2),
            (Coords(0, 2), 2),
            (Coords(1, 1), 3),
            (Coords(2, 2), 3),
            (Coords(2, 1), 2),
        ] {
            try self.setUpWithError()
            
            // AAA
            // BAB
            // BBA
            board[0, 0] = Piece(type: .A)
            board[1, 0] = Piece(type: .A)
            board[2, 0] = Piece(type: .A)
            board[0, 1] = Piece(type: .B)
            board[1, 1] = Piece(type: .A)
            board[2, 1] = Piece(type: .B)
            board[0, 2] = Piece(type: .B)
            board[1, 2] = Piece(type: .B)
            board[2, 2] = Piece(type: .A)
            
            self._testCountMaxRow(coords: coords, expected: expected)
            
            try self.tearDownWithError()
        }
    }
    
    private func _testCountMaxRow(coords: Coords, expected: Int) {
        XCTAssertEqual(FourInARowRules.countMaxRow(center: coords, board: board), expected, "\(coords)")
    }
}