import { describe, it, expect } from 'vitest';
import {
    registry,
    checkWinner,
    isCellOccupied,
    getPartAt,
    placeKitten,
    applyBoops,
    checkGraduation,
    processGraduation,
    hasWinningLine,
    removePieceFromBoard,
    createInitialState,
    BoopState,
    WinnerType,
    PlayerType,
    getBoardRegion,
} from '@/samples/boop';
import {Entity} from "@/utils/entity";
import {createGameContext} from "@/";
import type { PromptEvent } from '@/utils/command';

function createTestContext() {
    const ctx = createGameContext(registry, createInitialState);
    return { registry, ctx };
}

function getState(ctx: ReturnType<typeof createTestContext>['ctx']): Entity<BoopState> {
    return ctx.state;
}

function waitForPrompt(ctx: ReturnType<typeof createTestContext>['ctx']): Promise<PromptEvent> {
    return new Promise(resolve => {
        ctx.commands.on('prompt', resolve);
    });
}

describe('Boop - helper functions', () => {
    describe('isCellOccupied', () => {
        it('should return false for empty cell', () => {
            const { ctx } = createTestContext();
            const state = getState(ctx);

            expect(isCellOccupied(state, 3, 3)).toBe(false);
        });

        it('should return true for occupied cell', () => {
            const { ctx } = createTestContext();
            const state = getState(ctx);
            placeKitten(state, 3, 3, 'white');

            expect(isCellOccupied(state, 3, 3)).toBe(true);
        });

        it('should return false for different cell', () => {
            const { ctx } = createTestContext();
            const state = getState(ctx);
            placeKitten(state, 0, 0, 'white');

            expect(isCellOccupied(state, 1, 1)).toBe(false);
        });
    });

    describe('getPartAt', () => {
        it('should return null for empty cell', () => {
            const { ctx } = createTestContext();
            const state = getState(ctx);

            expect(getPartAt(state, 2, 2)).toBeNull();
        });

        it('should return the part at occupied cell', () => {
            const { ctx } = createTestContext();
            const state = getState(ctx);
            placeKitten(state, 2, 2, 'black');

            const part = getPartAt(state, 2, 2);
            expect(part).not.toBeNull();
            if (part) {
                expect(part.value.player).toBe('black');
                expect(part.value.pieceType).toBe('kitten');
            }
        });
    });

    describe('placeKitten', () => {
        it('should add a kitten to the board', () => {
            const { ctx } = createTestContext();
            const state = getState(ctx);
            placeKitten(state, 2, 3, 'white');

            expect(state.value.parts.length).toBe(1);
            expect(state.value.parts[0].value.position).toEqual([2, 3]);
            expect(state.value.parts[0].value.player).toBe('white');
            expect(state.value.parts[0].value.pieceType).toBe('kitten');
        });

        it('should decrement the correct player kitten supply', () => {
            const { ctx } = createTestContext();
            const state = getState(ctx);

            placeKitten(state, 0, 0, 'white');
            expect(state.value.whiteKittensInSupply).toBe(7);
            expect(state.value.blackKittensInSupply).toBe(8);

            placeKitten(state, 0, 1, 'black');
            expect(state.value.whiteKittensInSupply).toBe(7);
            expect(state.value.blackKittensInSupply).toBe(7);
        });

        it('should add piece to board region children', () => {
            const { ctx } = createTestContext();
            const state = getState(ctx);
            placeKitten(state, 1, 1, 'white');

            const board = getBoardRegion(state);
            expect(board.value.children.length).toBe(1);
        });

        it('should generate unique IDs for pieces', () => {
            const { ctx } = createTestContext();
            const state = getState(ctx);
            placeKitten(state, 0, 0, 'white');
            placeKitten(state, 0, 1, 'black');

            const ids = state.value.parts.map(p => p.id);
            expect(new Set(ids).size).toBe(2);
        });
    });

    describe('applyBoops', () => {
        it('should boop adjacent kitten away from placed kitten', () => {
            const { ctx } = createTestContext();
            const state = getState(ctx);

            placeKitten(state, 3, 3, 'black');
            placeKitten(state, 2, 2, 'white');

            expect(state.value.parts[1].value.position).toEqual([2, 2]);

            applyBoops(state, 3, 3, 'kitten');

            expect(state.value.parts[1].value.position).toEqual([1, 1]);
        });

        it('should not boop a cat when a kitten is placed', () => {
            const { ctx } = createTestContext();
            const state = getState(ctx);

            placeKitten(state, 3, 3, 'black');
            const whitePart = state.value.parts[0];
            whitePart.produce(p => {
                p.pieceType = 'cat';
            });

            applyBoops(state, 3, 3, 'kitten');

            expect(whitePart.value.position).toEqual([3, 3]);
        });

        it('should remove piece that is booped off the board', () => {
            const { ctx } = createTestContext();
            const state = getState(ctx);

            placeKitten(state, 0, 0, 'white');
            placeKitten(state, 1, 1, 'black');

            applyBoops(state, 1, 1, 'kitten');

            expect(state.value.parts.length).toBe(1);
            expect(state.value.parts[0].value.player).toBe('black');
            expect(state.value.whiteKittensInSupply).toBe(8);
        });

        it('should not boop piece if target cell is occupied', () => {
            const { ctx } = createTestContext();
            const state = getState(ctx);

            placeKitten(state, 1, 1, 'white');
            placeKitten(state, 2, 1, 'black');
            placeKitten(state, 0, 1, 'black');

            applyBoops(state, 0, 1, 'kitten');

            const whitePart = state.value.parts.find(p => p.value.player === 'white');
            expect(whitePart).toBeDefined();
            if (whitePart) {
                expect(whitePart.value.position).toEqual([1, 1]);
            }
        });

        it('should boop multiple adjacent pieces', () => {
            const { ctx } = createTestContext();
            const state = getState(ctx);

            placeKitten(state, 3, 3, 'white');
            placeKitten(state, 2, 2, 'black');
            placeKitten(state, 2, 3, 'black');

            applyBoops(state, 3, 3, 'kitten');

            expect(state.value.parts[1].value.position).toEqual([1, 1]);
            expect(state.value.parts[2].value.position).toEqual([1, 3]);
        });

        it('should not boop the placed piece itself', () => {
            const { ctx } = createTestContext();
            const state = getState(ctx);

            placeKitten(state, 3, 3, 'white');

            applyBoops(state, 3, 3, 'kitten');

            expect(state.value.parts[0].value.position).toEqual([3, 3]);
        });
    });

    describe('removePieceFromBoard', () => {
        it('should remove piece from parts and board children', () => {
            const { ctx } = createTestContext();
            const state = getState(ctx);
            placeKitten(state, 2, 2, 'white');
            const part = state.value.parts[0];

            removePieceFromBoard(state, part);

            expect(state.value.parts.length).toBe(0);
            const board = getBoardRegion(state);
            expect(board.value.children.length).toBe(0);
        });
    });

    describe('checkGraduation', () => {
        it('should return empty array when no kittens in a row', () => {
            const { ctx } = createTestContext();
            const state = getState(ctx);

            placeKitten(state, 0, 0, 'white');
            placeKitten(state, 2, 2, 'white');

            const lines = checkGraduation(state, 'white');
            expect(lines.length).toBe(0);
        });

        it('should detect horizontal line of 3 kittens', () => {
            const { ctx } = createTestContext();
            const state = getState(ctx);

            placeKitten(state, 1, 0, 'white');
            placeKitten(state, 1, 1, 'white');
            placeKitten(state, 1, 2, 'white');

            const lines = checkGraduation(state, 'white');
            expect(lines.length).toBe(1);
            expect(lines[0]).toEqual([[1, 0], [1, 1], [1, 2]]);
        });

        it('should detect vertical line of 3 kittens', () => {
            const { ctx } = createTestContext();
            const state = getState(ctx);

            placeKitten(state, 0, 2, 'white');
            placeKitten(state, 1, 2, 'white');
            placeKitten(state, 2, 2, 'white');

            const lines = checkGraduation(state, 'white');
            expect(lines.length).toBe(1);
            expect(lines[0]).toEqual([[0, 2], [1, 2], [2, 2]]);
        });

        it('should detect diagonal line of 3 kittens', () => {
            const { ctx } = createTestContext();
            const state = getState(ctx);

            placeKitten(state, 0, 0, 'white');
            placeKitten(state, 1, 1, 'white');
            placeKitten(state, 2, 2, 'white');

            const lines = checkGraduation(state, 'white');
            expect(lines.length).toBe(1);
            expect(lines[0]).toEqual([[0, 0], [1, 1], [2, 2]]);
        });

        it('should detect anti-diagonal line of 3 kittens', () => {
            const { ctx } = createTestContext();
            const state = getState(ctx);

            placeKitten(state, 2, 0, 'white');
            placeKitten(state, 1, 1, 'white');
            placeKitten(state, 0, 2, 'white');

            const lines = checkGraduation(state, 'white');
            expect(lines.length).toBe(1);
            expect(lines[0]).toEqual([[2, 0], [1, 1], [0, 2]]);
        });

        it('should not detect line with mixed piece types', () => {
            const { ctx } = createTestContext();
            const state = getState(ctx);

            placeKitten(state, 0, 0, 'white');
            placeKitten(state, 0, 1, 'white');
            placeKitten(state, 0, 2, 'white');

            state.value.parts[1].produce(p => {
                p.pieceType = 'cat';
            });

            const lines = checkGraduation(state, 'white');
            expect(lines.length).toBe(0);
        });
    });

    describe('processGraduation', () => {
        it('should convert kittens to cats and update supply', () => {
            const { ctx } = createTestContext();
            const state = getState(ctx);

            placeKitten(state, 0, 0, 'white');
            placeKitten(state, 0, 1, 'white');
            placeKitten(state, 0, 2, 'white');

            const lines = checkGraduation(state, 'white');
            expect(lines.length).toBe(1);

            processGraduation(state, 'white', lines);

            expect(state.value.parts.length).toBe(0);
            expect(state.value.whiteCatsInSupply).toBe(3);
        });

        it('should only graduate pieces on the winning lines', () => {
            const { ctx } = createTestContext();
            const state = getState(ctx);

            placeKitten(state, 0, 0, 'white');
            placeKitten(state, 0, 1, 'white');
            placeKitten(state, 0, 2, 'white');
            placeKitten(state, 3, 3, 'white');

            const lines = checkGraduation(state, 'white');
            processGraduation(state, 'white', lines);

            expect(state.value.parts.length).toBe(1);
            expect(state.value.parts[0].value.position).toEqual([3, 3]);
            expect(state.value.whiteCatsInSupply).toBe(3);
        });
    });

    describe('hasWinningLine', () => {
        it('should return false for no line', () => {
            expect(hasWinningLine([[0, 0], [1, 1], [3, 3]])).toBe(false);
        });

        it('should return true for horizontal line', () => {
            expect(hasWinningLine([[0, 0], [0, 1], [0, 2]])).toBe(true);
        });

        it('should return true for vertical line', () => {
            expect(hasWinningLine([[0, 0], [1, 0], [2, 0]])).toBe(true);
        });

        it('should return true for diagonal line', () => {
            expect(hasWinningLine([[0, 0], [1, 1], [2, 2]])).toBe(true);
        });

        it('should return true for anti-diagonal line', () => {
            expect(hasWinningLine([[2, 0], [1, 1], [0, 2]])).toBe(true);
        });
    });

    describe('checkWinner', () => {
        it('should return null for empty board', () => {
            const { ctx } = createTestContext();
            const state = getState(ctx);

            expect(checkWinner(state)).toBeNull();
        });

        it('should return winner when player has 3 cats in a row', () => {
            const { ctx } = createTestContext();
            const state = getState(ctx);

            placeKitten(state, 0, 0, 'white');
            placeKitten(state, 0, 1, 'white');
            placeKitten(state, 0, 2, 'white');

            state.value.parts.forEach(p => {
                p.produce(part => {
                    part.pieceType = 'cat';
                });
            });

            expect(checkWinner(state)).toBe('white');
        });

        it('should return draw when both players use all pieces', () => {
            const { ctx } = createTestContext();
            const state = getState(ctx);

            for (let i = 0; i < 8; i++) {
                placeKitten(state, i % 6, Math.floor(i / 6) + (i % 2), 'white');
            }
            for (let i = 0; i < 8; i++) {
                placeKitten(state, i % 6, Math.floor(i / 6) + 3 + (i % 2), 'black');
            }

            const result = checkWinner(state);
            expect(result === 'draw' || result === null).toBe(true);
        });
    });
});

describe('Boop - game flow', () => {
    it('should have setup and turn commands registered', () => {
        const { registry: reg } = createTestContext();

        expect(reg.has('setup')).toBe(true);
        expect(reg.has('turn')).toBe(true);
    });

    it('should setup board when setup command runs', async () => {
        const { ctx } = createTestContext();

        const promptPromise = waitForPrompt(ctx);
        const runPromise = ctx.commands.run('setup');

        const promptEvent = await promptPromise;
        expect(promptEvent).not.toBeNull();
        expect(promptEvent.schema.name).toBe('play');

        promptEvent.reject(new Error('test end'));

        const result = await runPromise;
        expect(result.success).toBe(false);
    });

    it('should accept valid move via turn command', async () => {
        const { ctx } = createTestContext();

        const promptPromise = waitForPrompt(ctx);
        const runPromise = ctx.commands.run<{winner: WinnerType}>('turn white');

        const promptEvent = await promptPromise;
        expect(promptEvent).not.toBeNull();
        expect(promptEvent.schema.name).toBe('play');

        promptEvent.resolve({ name: 'play', params: ['white', 2, 2], options: {}, flags: {} });

        const result = await runPromise;
        expect(result.success).toBe(true);
        if (result.success) expect(result.result.winner).toBeNull();
        expect(ctx.state.value.parts.length).toBe(1);
        expect(ctx.state.value.parts[0].value.position).toEqual([2, 2]);
    });

    it('should reject move for wrong player and re-prompt', async () => {
        const { ctx } = createTestContext();

        const promptPromise = waitForPrompt(ctx);
        const runPromise = ctx.commands.run<{winner: WinnerType}>('turn white');

        const promptEvent1 = await promptPromise;
        promptEvent1.resolve({ name: 'play', params: ['black', 2, 2], options: {}, flags: {} });

        const promptEvent2 = await waitForPrompt(ctx);
        expect(promptEvent2).not.toBeNull();

        promptEvent2.resolve({ name: 'play', params: ['white', 2, 2], options: {}, flags: {} });

        const result = await runPromise;
        expect(result.success).toBe(true);
        if (result.success) expect(result.result.winner).toBeNull();
    });

    it('should reject move to occupied cell and re-prompt', async () => {
        const { ctx } = createTestContext();
        const state = getState(ctx);

        placeKitten(state, 2, 2, 'black');

        const promptPromise = waitForPrompt(ctx);
        const runPromise = ctx.commands.run<{winner: WinnerType}>('turn white');

        const promptEvent1 = await promptPromise;
        promptEvent1.resolve({ name: 'play', params: ['white', 2, 2], options: {}, flags: {} });

        const promptEvent2 = await waitForPrompt(ctx);
        expect(promptEvent2).not.toBeNull();

        promptEvent2.resolve({ name: 'play', params: ['white', 0, 0], options: {}, flags: {} });

        const result = await runPromise;
        expect(result.success).toBe(true);
        if (result.success) expect(result.result.winner).toBeNull();
    });

    it('should reject move when kitten supply is empty', async () => {
        const { ctx } = createTestContext();
        const state = getState(ctx);

        state.produce(s => {
            s.whiteKittensInSupply = 0;
        });

        const promptPromise = waitForPrompt(ctx);
        const runPromise = ctx.commands.run<{winner: WinnerType}>('turn white');

        const promptEvent1 = await promptPromise;
        promptEvent1.resolve({ name: 'play', params: ['white', 0, 0], options: {}, flags: {} });

        const promptEvent2 = await waitForPrompt(ctx);
        expect(promptEvent2).not.toBeNull();

        promptEvent2.reject(new Error('test end'));

        const result = await runPromise;
        expect(result.success).toBe(false);
    });

    it('should boop adjacent pieces after placement', async () => {
        const { ctx } = createTestContext();
        const state = getState(ctx);

        let promptPromise = waitForPrompt(ctx);
        let runPromise = ctx.commands.run<{winner: WinnerType}>('turn white');
        let prompt = await promptPromise;
        prompt.resolve({ name: 'play', params: ['white', 3, 3], options: {}, flags: {} });
        let result = await runPromise;
        expect(result.success).toBe(true);
        expect(state.value.parts.length).toBe(1);

        promptPromise = waitForPrompt(ctx);
        runPromise = ctx.commands.run<{winner: WinnerType}>('turn black');
        prompt = await promptPromise;
        prompt.resolve({ name: 'play', params: ['black', 2, 2], options: {}, flags: {} });
        result = await runPromise;
        expect(result.success).toBe(true);
        expect(state.value.parts.length).toBe(2);

        const whitePart = state.value.parts.find(p => p.value.player === 'white');
        expect(whitePart).toBeDefined();
        if (whitePart) {
            expect(whitePart.value.position).not.toEqual([3, 3]);
        }
    });

    it('should graduate kittens to cats and check for cat win', async () => {
        const { ctx } = createTestContext();
        const state = getState(ctx);

        placeKitten(state, 1, 0, 'white');
        placeKitten(state, 1, 1, 'white');
        placeKitten(state, 1, 2, 'white');

        const lines = checkGraduation(state, 'white');
        expect(lines.length).toBeGreaterThanOrEqual(1);

        processGraduation(state, 'white', lines);

        expect(state.value.parts.length).toBe(0);
        expect(state.value.whiteCatsInSupply).toBe(3);
    });
});