// static/script.js
let scene, camera, renderer, controls;
let spheres = [];
let fluidParticles = [];
let simulationRunning = false;

const PARTICLE_COUNT = 5000;
const SPACE_SIZE = 20;
const FLUID_SPEED = 0.1;
const FRICTION_FACTOR = 0.9;
const GRAVITY_CONSTANT = 0.1;

init();
animate();

function init() {
    // Scene setup
    scene = new THREE.Scene();
    camera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight, 0.1, 1000);
    camera.position.set(0, 10, 20);

    renderer = new THREE.WebGLRenderer({ antialias: true });
    renderer.setSize(window.innerWidth - 300, window.innerHeight);
    document.getElementById('scene-container').appendChild(renderer.domElement);

    controls = new THREE.OrbitControls(camera, renderer.domElement);
    controls.enableDamping = true;
    controls.dampingFactor = 0.05;

    // Add spheres
    const brownGeometry = new THREE.SphereGeometry(0.5, 32, 32);
    const brownMaterial = new THREE.MeshBasicMaterial({ color: 0x8B4513 });
    const brownSphere = new THREE.Mesh(brownGeometry, brownMaterial);
    brownSphere.position.set(0, 0, 0);
    brownSphere.userData = { mass: 92 };
    scene.add(brownSphere);
    spheres.push(brownSphere);

    const greenGeometry = new THREE.SphereGeometry(0.4, 32, 32);
    const greenMaterial = new THREE.MeshBasicMaterial({ color: 0x00FF00 });
    const greenSphere = new THREE.Mesh(greenGeometry, greenMaterial);
    greenSphere.position.set(5, 0, 5);
    greenSphere.userData = { mass: 29 };
    scene.add(greenSphere);
    spheres.push(greenSphere);

    const redGeometry = new THREE.SphereGeometry(0.3, 32, 32);
    const redMaterial = new THREE.MeshBasicMaterial({ color: 0xFF0000 });
    const redSphere = new THREE.Mesh(redGeometry, redMaterial);
    redSphere.position.set(-5, 0, -5);
    redSphere.userData = { mass: 10 };
    scene.add(redSphere);
    spheres.push(redSphere);

    // Add fluid particles
    const particleGeometry = new THREE.SphereGeometry(0.05, 8, 8);
    const particleMaterial = new THREE.MeshBasicMaterial({ color: 0x00BFFF, transparent: true, opacity: 0.5 });
    for (let i = 0; i < PARTICLE_COUNT; i++) {
        const particle = new THREE.Mesh(particleGeometry, particleMaterial);
        particle.position.set(
            (Math.random() - 0.5) * SPACE_SIZE,
            (Math.random() - 0.5) * SPACE_SIZE,
            (Math.random() - 0.5) * SPACE_SIZE
        );
        particle.userData = {
            velocity: new THREE.Vector3(
                (Math.random() - 0.5) * FLUID_SPEED,
                (Math.random() - 0.5) * FLUID_SPEED,
                (Math.random() - 0.5) * FLUID_SPEED
            )
        };
        scene.add(particle);
        fluidParticles.push(particle);
    }

    // Add grid helper for reference
    const gridHelper = new THREE.GridHelper(SPACE_SIZE, 20);
    gridHelper.position.y = -SPACE_SIZE / 2;
    scene.add(gridHelper);

    // Event listeners for controls
    document.getElementById('start-btn').addEventListener('click', () => {
        simulationRunning = true;
        updateParams();
    });

    document.getElementById('reset-btn').addEventListener('click', () => {
        simulationRunning = false;
        resetSimulation();
    });

    // Update sphere positions and masses from sliders
    ['brown', 'green', 'red'].forEach(color => {
        document.getElementById(`${color}-mass`).addEventListener('input', updateParams);
        document.getElementById(`${color}-x`).addEventListener('input', updateParams);
        document.getElementById(`${color}-y`).addEventListener('input', updateParams);
        document.getElementById(`${color}-z`).addEventListener('input', updateParams);
    });

    // Handle window resize
    window.addEventListener('resize', () => {
        camera.aspect = (window.innerWidth - 300) / window.innerHeight;
        camera.updateProjectionMatrix();
        renderer.setSize(window.innerWidth - 300, window.innerHeight);
    });
}

function updateParams() {
    spheres[0].userData.mass = parseFloat(document.getElementById('brown-mass').value);
    spheres[0].position.set(
        parseFloat(document.getElementById('brown-x').value),
        parseFloat(document.getElementById('brown-y').value),
        parseFloat(document.getElementById('brown-z').value)
    );

    spheres[1].userData.mass = parseFloat(document.getElementById('green-mass').value);
    spheres[1].position.set(
        parseFloat(document.getElementById('green-x').value),
        parseFloat(document.getElementById('green-y').value),
        parseFloat(document.getElementById('green-z').value)
    );

    spheres[2].userData.mass = parseFloat(document.getElementById('red-mass').value);
    spheres[2].position.set(
        parseFloat(document.getElementById('red-x').value),
        parseFloat(document.getElementById('red-y').value),
        parseFloat(document.getElementById('red-z').value)
    );
}

function resetSimulation() {
    fluidParticles.forEach(particle => {
        particle.position.set(
            (Math.random() - 0.5) * SPACE_SIZE,
            (Math.random() - 0.5) * SPACE_SIZE,
            (Math.random() - 0.5) * SPACE_SIZE
        );
        particle.userData.velocity.set(
            (Math.random() - 0.5) * FLUID_SPEED,
            (Math.random() - 0.5) * FLUID_SPEED,
            (Math.random() - 0.5) * FLUID_SPEED
        );
    });
}

function animate() {
    requestAnimationFrame(animate);

    if (simulationRunning) {
        // Update fluid particles
        fluidParticles.forEach(particle => {
            let position = particle.position;
            let velocity = particle.userData.velocity;

            // Check for interactions with spheres
            spheres.forEach(sphere => {
                let distance = position.distanceTo(sphere.position);
                let sphereRadius = sphere.geometry.parameters.radius + 0.5; // Interaction radius

                if (distance < sphereRadius) {
                    // Apply friction
                    velocity.multiplyScalar(FRICTION_FACTOR);

                    // Apply gravitational deflection
                    let direction = sphere.position.clone().sub(position).normalize();
                    let forceMagnitude = (GRAVITY_CONSTANT * sphere.userData.mass) / (distance * distance);
                    let force = direction.multiplyScalar(forceMagnitude);
                    velocity.add(force);
                }
            });

            // Update position
            position.add(velocity);

            // Boundary conditions (wrap around)
            if (Math.abs(position.x) > SPACE_SIZE / 2) position.x = -Math.sign(position.x) * SPACE_SIZE / 2;
            if (Math.abs(position.y) > SPACE_SIZE / 2) position.y = -Math.sign(position.y) * SPACE_SIZE / 2;
            if (Math.abs(position.z) > SPACE_SIZE / 2) position.z = -Math.sign(position.z) * SPACE_SIZE / 2;
        });

        // Update sphere positions (gravitational interaction between spheres)
        spheres.forEach((sphere, i) => {
            let acceleration = new THREE.Vector3();
            spheres.forEach((otherSphere, j) => {
                if (i !== j) {
                    let distance = sphere.position.distanceTo(otherSphere.position);
                    if (distance > 0.1) { // Avoid division by zero
                        let direction = otherSphere.position.clone().sub(sphere.position).normalize();
                        let force = (GRAVITY_CONSTANT * otherSphere.userData.mass) / (distance * distance);
                        acceleration.add(direction.multiplyScalar(force));
                    }
                }
            });
            sphere.position.add(acceleration);
        });
    }

    controls.update();
    renderer.render(scene, camera);
}