const workspace = document.getElementById('workspace');
const spawnBtns = document.querySelectorAll('.spawn-btn');

let elementsOnDesk = [];
let draggingElement = null;
let offsetX = 0;
let offsetY = 0;

// Rezepturenbuch (die Formeln müssen genau den Kombinationen der Symbole entsprechen)
const recipes = [
    {
        ingredients: ['H', 'H', 'O'], // 2x Wasserstoff, 1x Sauerstoff
        result: 'H₂O (Wasser)',
        color: '#3498db'
    },
    {
        ingredients: ['Cl', 'Na'], // 1x Natrium, 1x Chlor
        result: 'NaCl (Kochsalz)',
        color: '#ecf0f1'
    },
    {
        ingredients: ['O', 'O'], // 2x Sauerstoff
        result: 'O₂ (Sauerstoff-Molekül)',
        color: '#bdc3c7'
    },
    {
        ingredients: ['C', 'O', 'O'], // 1x Kohlenstoff, 2x Sauerstoff
        result: 'CO₂ (Kohlendioxid)',
        color: '#7f8c8d'
    },
    {
        ingredients: ['C', 'H', 'H', 'H', 'H'], // 1x Kohlenstoff, 4x Wasserstoff
        result: 'CH₄ (Methan)',
        color: '#f39c12'
    },
    {
        ingredients: ['N', 'H', 'H', 'H'], // 1x Stickstoff, 3x Wasserstoff
        result: 'NH₃ (Ammoniak)',
        color: '#9b59b6'
    }
];

// Button-Klicks registrieren
spawnBtns.forEach(btn => {
    btn.addEventListener('click', () => {
        spawnAtom(btn.dataset.element, btn.dataset.color);
    });
});

function spawnAtom(symbol, color) {
    const el = document.createElement('div');
    el.classList.add('atom');
    el.innerText = symbol;
    el.dataset.symbol = symbol;
    el.style.backgroundColor = color;
    
    // Zufällige Position auf dem Tisch
    const x = Math.random() * (workspace.clientWidth - 50);
    const y = Math.random() * (workspace.clientHeight - 50);
    
    el.style.left = x + 'px';
    el.style.top = y + 'px';
    
    makeDraggable(el);
    workspace.appendChild(el);
    elementsOnDesk.push(el);
}

function makeDraggable(el) {
    el.addEventListener('mousedown', (e) => {
        draggingElement = el;
        const rect = el.getBoundingClientRect();
        
        offsetX = e.clientX - rect.left;
        offsetY = e.clientY - rect.top;
        el.style.zIndex = 1000;
    });
}

document.addEventListener('mousemove', (e) => {
    if (draggingElement) {
        const workspaceRect = workspace.getBoundingClientRect();
        
        let newX = e.clientX - workspaceRect.left - offsetX;
        let newY = e.clientY - workspaceRect.top - offsetY;
        
        // Grenzen beachten
        newX = Math.max(0, Math.min(newX, workspaceRect.width - draggingElement.offsetWidth));
        newY = Math.max(0, Math.min(newY, workspaceRect.height - draggingElement.offsetHeight));
        
        draggingElement.style.left = newX + 'px';
        draggingElement.style.top = newY + 'px';
    }
});

document.addEventListener('mouseup', () => {
    if (draggingElement) {
        draggingElement.style.zIndex = '';
        checkForReactions();
        draggingElement = null;
    }
});

function checkForReactions() {
    if (!draggingElement) return;

    const rect1 = draggingElement.getBoundingClientRect();
    
    // Finde alle Elemente, die sich berühren (inklusive des gezogenen Elements)
    // Einfache Kollisionserkennung: Wir gruppieren alle Elemente, die nahe beieinander liegen.
    let cluster = [draggingElement];
    let added = true;
    
    // Erweitere den Cluster iterativ, bis keine berührenden Elemente mehr gefunden werden
    while(added) {
        added = false;
        for (let el of elementsOnDesk) {
            if (cluster.includes(el)) continue;
            
            // Prüfe Kollision mit irgendeinem Element im Cluster
            let touches = cluster.some(cEl => {
                const r1 = cEl.getBoundingClientRect();
                const r2 = el.getBoundingClientRect();
                return !(r1.right < r2.left || 
                         r1.left > r2.right || 
                         r1.bottom < r2.top || 
                         r1.top > r2.bottom);
            });
            
            if (touches) {
                cluster.push(el);
                added = true;
            }
        }
    }

    if (cluster.length > 1) {
        const symbols = cluster.map(el => el.dataset.symbol).sort();
        
        // Prüfe gegen alle Rezepte
        for (const recipe of recipes) {
            const recipeSymbols = [...recipe.ingredients].sort();
            
            if (JSON.stringify(symbols) === JSON.stringify(recipeSymbols)) {
                // REAKTION!
                const midX = draggingElement.style.left;
                const midY = draggingElement.style.top;
                
                // Lösche alte Atome
                cluster.forEach(el => {
                    if (workspace.contains(el)) {
                        workspace.removeChild(el);
                    }
                    elementsOnDesk = elementsOnDesk.filter(e => e !== el);
                });
                
                // Neues Molekül erstellen
                createMolecule(recipe.result, recipe.color, midX, midY);
                break;
            }
        }
    }
}

function createMolecule(name, color, x, y) {
    const el = document.createElement('div');
    el.classList.add('molecule');
    el.innerText = name;
    el.dataset.symbol = name; // Für diesen Prototyp können Moleküle noch nicht weiterreagieren
    el.style.backgroundColor = color;
    el.style.left = x;
    el.style.top = y;
    
    makeDraggable(el);
    workspace.appendChild(el);
    elementsOnDesk.push(el);
    
    // Animation
    el.animate([
        { transform: 'scale(0.5)' },
        { transform: 'scale(1.2)' },
        { transform: 'scale(1)' }
    ], { duration: 300 });
}