Crafting

const recipes = [
  {
    id: 'iron_sword',
    inputs: [
      { contract: MATERIALS, trait: { type: 'Iron Ore' }, count: 2 },
      { contract: MATERIALS, trait: { type: 'Wood' }, count: 1 },
    ],
    output: {
      name: 'Iron Sword',
      attributes: [{ trait_type: 'Damage', value: 10 }],
    },
  },
  {
    id: 'steel_sword',
    inputs: [
      { contract: WEAPONS, trait: { type: 'Iron Sword' }, count: 1 },
      { contract: MATERIALS, trait: { type: 'Steel Ingot' }, count: 2 },
    ],
    output: {
      name: 'Steel Sword',
      attributes: [{ trait_type: 'Damage', value: 25 }],
    },
  },
];

const BURN_ADDRESS = '0x000000000000000000000000000000000000dEaD';

app.post('/craft', async (req, res) => {
  const { recipeId, inputTokenIds, playerAddress } = req.body;
  const recipe = recipes.find(r => r.id === recipeId);
  
  if (!recipe) {
    return res.status(400).json({ error: 'Invalid recipe' });
  }
  
  // Verify ownership of all inputs
  for (const tokenId of inputTokenIds) {
    const owner = await nftContract.ownerOf(tokenId);
    if (owner.toLowerCase() !== playerAddress.toLowerCase()) {
      return res.status(403).json({ error: 'Not owner of input' });
    }
  }
  
  // Verify inputs match recipe requirements
  // ... validation logic
  
  // Burn inputs
  for (const tokenId of inputTokenIds) {
    await nftContract.transferFrom(playerAddress, BURN_ADDRESS, tokenId);
  }
  
  // Mint output via Minting API
  const outputId = generateTokenId();
  await mintNFT(playerAddress, outputId, recipe.output);
  
  res.json({ success: true, outputId });
});

async function upgradeItem(tokenId: string, materialsUsed: string[]) {
  const nft = await getNFT(tokenId);
  const level = nft.attributes.find(a => a.trait_type === 'Level')?.value || 1;
  
  // Burn material NFTs
  for (const materialId of materialsUsed) {
    await burnNFT(materialId);
  }
  
  // Update metadata via Minting API refresh
  await refreshMetadata(tokenId, {
    ...nft.metadata,
    attributes: nft.attributes.map(a => 
      a.trait_type === 'Level' ? { ...a, value: level + 1 } : a
    ),
  });
}