import { describe, it, expect } from 'vitest';
import {
    getLineCandidates,
    isInBounds,
    isCellOccupied,
    getNeighborPositions,
    findPartInRegion,
    findPartAtPosition
} from '@/samples/boop/utils';
import { createInitialState, BOARD_SIZE, WIN_LENGTH } from '@/samples/boop';
import { createGameContext } from '@/core/game';
import { registry } from '@/samples/boop';

describe('Boop Utils', () => {
    describe('isInBounds', () => {
        it('should return true for valid board positions', () => {
            expect(isInBounds(0, 0)).toBe(true);
            expect(isInBounds(3, 3)).toBe(true);
            expect(isInBounds(5, 5)).toBe(true);
        });

        it('should return false for positions outside board', () => {
            expect(isInBounds(-1, 0)).toBe(false);
            expect(isInBounds(0, -1)).toBe(false);
            expect(isInBounds(BOARD_SIZE, 0)).toBe(false);
            expect(isInBounds(0, BOARD_SIZE)).toBe(false);
            expect(isInBounds(6, 6)).toBe(false);
        });
    });

    describe('getLineCandidates', () => {
        it('should generate all possible winning lines', () => {
            const lines = Array.from(getLineCandidates());
            // For 8x8 board with WIN_LENGTH=3:
            // 4 directions × various starting positions
            expect(lines.length).toBeGreaterThan(0);
        });

        it('should generate lines with correct length', () => {
            const lines = Array.from(getLineCandidates());
            for (const line of lines) {
                expect(line.length).toBe(WIN_LENGTH);
            }
        });

        it('should generate horizontal lines', () => {
            const lines = Array.from(getLineCandidates());
            const horizontalLines = lines.filter(line => 
                line.every(([_, y]) => y === line[0][1])
            );
            expect(horizontalLines.length).toBeGreaterThan(0);
            // First horizontal line should start at [0,0], [1,0], [2,0] (direction [0,1] means varying x)
            const firstHorizontal = horizontalLines[0];
            expect(firstHorizontal).toEqual([[0, 0], [1, 0], [2, 0]]);
        });

        it('should generate vertical lines', () => {
            const lines = Array.from(getLineCandidates());
            const verticalLines = lines.filter(line => 
                line.every(([x, _]) => x === line[0][0])
            );
            expect(verticalLines.length).toBeGreaterThan(0);
        });

        it('should generate diagonal lines', () => {
            const lines = Array.from(getLineCandidates());
            const diagonalLines = lines.filter(line => {
                const [[x1, y1], [x2, y2]] = line;
                return x1 !== x2 && y1 !== y2;
            });
            expect(diagonalLines.length).toBeGreaterThan(0);
        });

        it('should only include lines that fit within board bounds', () => {
            const lines = Array.from(getLineCandidates());
            for (const line of lines) {
                for (const [x, y] of line) {
                    expect(isInBounds(x, y)).toBe(true);
                }
            }
        });
    });

    describe('isCellOccupied', () => {
        it('should return false for empty cell in initial state', () => {
            const state = createInitialState();
            expect(isCellOccupied(state, 0, 0)).toBe(false);
            expect(isCellOccupied(state, 3, 3)).toBe(false);
        });

        it('should return true for occupied cell', async () => {
            const ctx = createGameContext(registry, createInitialState());
            
            // Place a piece via command (need to await)
            await ctx._commands.run('place 2 2 white kitten');
            
            expect(isCellOccupied(ctx, 2, 2)).toBe(true);
        });
    });

    describe('getNeighborPositions', () => {
        it('should return 8 neighbor positions for center position', () => {
            const neighbors = Array.from(getNeighborPositions(2, 2));
            expect(neighbors.length).toBe(8);
            
            const expected = [
                [1, 1], [1, 2], [1, 3],
                [2, 1],          [2, 3],
                [3, 1], [3, 2], [3, 3]
            ];
            expect(neighbors).toEqual(expect.arrayContaining(expected));
        });

        it('should include diagonal neighbors', () => {
            const neighbors = Array.from(getNeighborPositions(0, 0));
            expect(neighbors).toContainEqual([1, 1]);
            expect(neighbors).toContainEqual([-1, -1]);
        });

        it('should not include the center position itself', () => {
            const neighbors = Array.from(getNeighborPositions(5, 5));
            expect(neighbors).not.toContainEqual([5, 5]);
        });
    });

    describe('findPartInRegion', () => {
        it('should find a piece in the specified region', () => {
            const state = createInitialState();
            
            // Find a white kitten in white's supply
            const piece = findPartInRegion(state, 'white', 'kitten');
            expect(piece).not.toBeNull();
            expect(piece?.player).toBe('white');
            expect(piece?.type).toBe('kitten');
            expect(piece?.regionId).toBe('white');
        });

        it('should return null if no matching piece in region', () => {
            const state = createInitialState();
            
            // No kittens on board initially
            const piece = findPartInRegion(state, 'board', 'kitten');
            expect(piece).toBeNull();
        });

        it('should filter by player when specified', () => {
            const state = createInitialState();
            
            const whitePiece = findPartInRegion(state, 'white', 'kitten', 'white');
            expect(whitePiece).not.toBeNull();
            expect(whitePiece?.player).toBe('white');

            const blackPiece = findPartInRegion(state, 'white', 'kitten', 'black');
            expect(blackPiece).toBeNull();
        });

        it('should search all regions when regionId is empty string', () => {
            const state = createInitialState();
            
            // Find any cat piece
            const piece = findPartInRegion(state, '', 'cat');
            expect(piece).not.toBeNull();
            expect(piece?.type).toBe('cat');
        });
    });

    describe('findPartAtPosition', () => {
        it('should return null for empty position', () => {
            const state = createInitialState();
            expect(findPartAtPosition(state, 0, 0)).toBeNull();
        });

        it('should find piece at specified position', async () => {
            const ctx = createGameContext(registry, createInitialState());
            
            // Place a piece
            await ctx._commands.run('place 3 3 white kitten');
            
            const piece = findPartAtPosition(ctx, 3, 3);
            expect(piece).not.toBeNull();
            expect(piece?.player).toBe('white');
            expect(piece?.type).toBe('kitten');
        });

        it('should work with game context', () => {
            const ctx = createGameContext(registry, createInitialState());
            const piece = findPartAtPosition(ctx, 5, 5);
            expect(piece).toBeNull();
        });
    });
});