import { describe, expect, test } from "@suaveplan/testing/runner";
import {
    calculateVelocity,
    dequantizeVector,
    GameInterpolator,
    GameStateManager,
    PositionPredictor,
    PredictionAlgorithm,
    quantizeVector,
    RotationPredictor,
    StateReconciliation,
} from "./index.js";

describe("GameStateManager", () => {
    test("pushes and retrieves states", () => {
        const manager = new GameStateManager();
        manager.pushState({ version: 1, entities: {} });
        expect(manager.getStateCount()).toBe(1);
        expect(manager.getLatestState()?.version).toBe(1);
        expect(manager.getStateAt(0)?.version).toBe(1);
    });

    test("getStateAt returns undefined for out of bounds", () => {
        const manager = new GameStateManager();
        expect(manager.getStateAt(0)).toBeUndefined();
    });

    test("getLatestState returns undefined when empty", () => {
        const manager = new GameStateManager();
        expect(manager.getLatestState()).toBeUndefined();
    });
});

describe("quantize/dequantize", () => {
    test("roundtrips a vector", () => {
        const v = { x: 0.5, y: -0.25, z: 0.75 };
        const q = quantizeVector(v, 16);
        const d = dequantizeVector(q, 16);
        expect(d.x).toBeCloseTo(v.x, 1);
        expect(d.y).toBeCloseTo(v.y, 1);
        expect(d.z).toBeCloseTo(v.z, 1);
    });

    test("handles vector without z component", () => {
        const v = { x: 0.5, y: -0.25 };
        const q = quantizeVector(v, 8);
        expect(q.z).toBeUndefined();
        const d = dequantizeVector(q, 8);
        expect(d.x).toBeCloseTo(v.x, 1);
        expect(d.y).toBeCloseTo(v.y, 1);
        expect(d.z).toBeUndefined();
    });
});

describe("PositionPredictor", () => {
    test("needs at least 2 points to predict", () => {
        const predictor = new PositionPredictor();
        predictor.addPosition({ x: 0, y: 0, z: 0 }, 0);
        expect(predictor.predictPosition(100)).toBeNull();
    });
    test("linear prediction works", () => {
        const predictor = new PositionPredictor({
            algorithm: PredictionAlgorithm.LINEAR,
        });
        predictor.addPosition({ x: 0, y: 0, z: 0 }, 0);
        predictor.addPosition({ x: 10, y: 0, z: 0 }, 1000);
        const pred = predictor.predictPosition(100);
        expect(pred).not.toBeNull();
        expect(pred!.x).toBeGreaterThan(10);
    });
    test("clear history resets predictor", () => {
        const predictor = new PositionPredictor();
        predictor.addPosition({ x: 0, y: 0, z: 0 }, 0);
        predictor.addPosition({ x: 10, y: 0, z: 0 }, 1000);
        predictor.clearHistory();
        expect(predictor.predictPosition(100)).toBeNull();
    });
});

describe("RotationPredictor", () => {
    test("predicts rotation", () => {
        const predictor = new RotationPredictor();
        predictor.addRotation({ yaw: 0, pitch: 0 }, 0);
        predictor.addRotation({ yaw: 10, pitch: 5 }, 1000);
        const pred = predictor.predictRotation(100);
        expect(pred).not.toBeNull();
        expect(pred!.yaw).toBeGreaterThan(0);
    });
});

describe("GameInterpolator", () => {
    test("linear position interpolation", () => {
        const interp = new GameInterpolator();
        const result = interp.interpolatePosition(
            { x: 0, y: 0, z: 0 },
            { x: 10, y: 20, z: 30 },
            0.5
        );
        expect(result.x).toBe(5);
        expect(result.y).toBe(10);
        expect(result.z).toBe(15);
    });
    test("rotation interpolation handles angle wrapping", () => {
        const interp = new GameInterpolator();
        const result = interp.interpolateRotation(
            { yaw: 170, pitch: 0 },
            { yaw: -170, pitch: 0 },
            0.5
        );
        expect(Math.abs(result.yaw)).toBeLessThanOrEqual(180);
    });
    test("player state interpolation", () => {
        const interp = new GameInterpolator();
        const start = {
            position: { x: 0, y: 0, z: 0 },
            rotation: { yaw: 0, pitch: 0 },
            stats: {
                health: 100,
                shield: 50,
                speed: 5,
                isMoving: false,
                isSprinting: false,
            },
        };
        const end = {
            position: { x: 10, y: 0, z: 0 },
            rotation: { yaw: 90, pitch: 0 },
            stats: {
                health: 80,
                shield: 40,
                speed: 10,
                isMoving: true,
                isSprinting: true,
            },
        };
        const result = interp.interpolatePlayerState(start, end, 0.5);
        expect(result.position.x).toBe(5);
        expect(result.stats.health).toBe(90);
    });
});

describe("StateReconciliation", () => {
    test("processes inputs", () => {
        const sr = new StateReconciliation();
        const seq = sr.processInput(
            { moveX: 1, moveY: 0, rotateYaw: 0, rotatePitch: 0, actions: [] },
            0
        );
        expect(seq).toBe(0);
        expect(sr.getClientSequence()).toBe(0);
    });
    test("ping/pong tracking", () => {
        const sr = new StateReconciliation();
        sr.sendPing();
        sr.receivePong();
        expect(sr.getAveragePing()).toBeGreaterThanOrEqual(0);
    });
    test("reset clears state", () => {
        const sr = new StateReconciliation();
        sr.processInput(
            { moveX: 1, moveY: 0, rotateYaw: 0, rotatePitch: 0, actions: [] },
            0
        );
        sr.reset();
        expect(sr.getClientSequence()).toBe(-1);
    });
});

describe("calculateVelocity", () => {
    test("calculates velocity from history", () => {
        const history = [
            { value: { x: 0, y: 0, z: 0 }, timestamp: 0 },
            { value: { x: 10, y: 0, z: 0 }, timestamp: 1000 },
        ];
        const vel = calculateVelocity(history);
        expect(vel.x).toBe(10);
        expect(vel.y).toBe(0);
    });
    test("returns zero for single point", () => {
        const history = [{ value: { x: 5, y: 0, z: 0 }, timestamp: 0 }];
        const vel = calculateVelocity(history);
        expect(vel.x).toBe(0);
    });
});