Merge pull request #50 from lukso-network/add-base-uri-script

Add base URI metadata fetches

digital-assets/base-uri-metadata.ts

@@ -0,0 +1,156 @@
+import { ethers } from 'ethers';
+import { ERC725 } from '@erc725/erc725.js';
+
+import lsp8Artifact from '@lukso/lsp-smart-contracts/artifacts/LSP8IdentifiableDigitalAsset.json';
+import lsp8Schema from '@erc725/erc725.js/schemas/LSP8IdentifiableDigitalAsset.json';
+import { INTERFACE_IDS, ERC725YDataKeys } from '@lukso/lsp-smart-contracts';
+
+const provider = new ethers.JsonRpcProvider(
+  'https://rpc.testnet.lukso.gateway.fm',
+);
+
+const SAMPLE_LSP8_ASSET = '0x8734600968c7e7193bb9b1b005677b4edbadcd18';
+
+// Create contract instance
+const myAssetContract = new ethers.Contract(
+  SAMPLE_LSP8_ASSET,
+  lsp8Artifact.abi,
+  provider,
+);
+
+const erc725js = new ERC725(lsp8Schema);
+
+// Token ID as Bytes32 value (1)
+// https://github.com/lukso-network/LIPs/blob/main/LSPs/LSP-8-IdentifiableDigitalAsset.md#lsp8tokenidformat
+const byte32TokenId =
+  '0x0000000000000000000000000000000000000000000000000000000000000001';
+
+async function getTokenIdFormat() {
+  try {
+    const tokenIdFormat = parseInt(
+      // https://docs.lukso.tech/tools/erc725js/classes/ERC725#getdata
+      await myAssetContract.getData(ERC725YDataKeys.LSP8['LSP8TokenIdFormat']),
+      16,
+    );
+    return tokenIdFormat;
+  } catch (err) {
+    console.error(
+      'Could not retrieve LSP8TokenIdFormat. Please provide an LSP8 asset address.',
+    );
+    return null;
+  }
+}
+
+// https://github.com/lukso-network/LIPs/blob/main/LSPs/LSP-8-IdentifiableDigitalAsset.md#lsp8tokenmetadatabaseuri
+function decodeTokenId(encodedTokenId: string, tokenIdFormat: number) {
+  switch (tokenIdFormat) {
+    // Number
+    case 0:
+    case 100:
+      return BigInt(encodedTokenId).toString();
+    // String
+    case 1:
+    case 101:
+      return ethers.toUtf8String(encodedTokenId).replace(/\0+$/, '');
+    // Address
+    case 2:
+    case 102:
+      return '0x' + encodedTokenId.slice(encodedTokenId.length - 40);
+    // Byte Value
+    case 3:
+    case 103:
+      // Extracts the non-zero portion (right padded)
+      return encodedTokenId.replace(/0+$/, '');
+    // Hash Digest
+    case 4:
+    case 104:
+      // Hash digests are not modified during encoding, so return as is
+      return encodedTokenId;
+  }
+}
+
+async function fetchMetadataFromBaseURI(
+  tokenID: string,
+  tokenIdFormat: number,
+) {
+  let isLSP8 = false;
+  try {
+    // https://docs.lukso.tech/contracts/contracts/ERC725/#supportsinterface
+    isLSP8 = await myAssetContract.supportsInterface(
+      INTERFACE_IDS.LSP8IdentifiableDigitalAsset,
+    );
+  } catch (err) {
+    console.error(
+      `Could not check if address ${SAMPLE_LSP8_ASSET} supports interface ${INTERFACE_IDS.LSP8IdentifiableDigitalAsset}, is it a smart contract address?`,
+    );
+    return;
+  }
+
+  if (!isLSP8) {
+    console.log(
+      `Contract: ${SAMPLE_LSP8_ASSET} does not support the LSP8 interface ID: ${INTERFACE_IDS.LSP8IdentifiableDigitalAsset}.`,
+    );
+    return;
+  }
+
+  /**
+   * Retrieve and decode the Base URI
+   * https://docs.lukso.tech/tools/erc725js/classes/ERC725#getdata
+   *
+   * Note: assets created with LSP versions below @lukso/[email protected]
+   * lack support for retrieving token ID metadata with BaseURI.
+   * https://github.com/lukso-network/LIPs/blob/main/LSPs/LSP-8-IdentifiableDigitalAsset.md#lsp8tokenmetadatabaseuri
+   */
+  let tokenBaseURI = await myAssetContract.getData(
+    ERC725YDataKeys.LSP8['LSP8TokenMetadataBaseURI'],
+  );
+
+  if (tokenBaseURI === '0x') {
+    console.log('BaseURI is not set.');
+    return;
+  }
+
+  // If token ID format is mixed
+  if (tokenIdFormat >= 100) {
+    // Retrieve token ID format for the individual token ID
+    // https://docs.lukso.tech/contracts/contracts/LSP8IdentifiableDigitalAsset/#getdatafortokenid
+    tokenBaseURI = await myAssetContract.getDataForTokenId(
+      tokenID,
+      ERC725YDataKeys.LSP8['LSP8TokenIdFormat'],
+    );
+  }
+
+  // Decode the baseURI
+  // https://docs.lukso.tech/tools/erc725js/classes/ERC725#decodedata
+  const decodedBaseURI = erc725js.decodeData([
+    { keyName: 'LSP8TokenMetadataBaseURI', value: tokenBaseURI },
+  ]);
+
+  // Build valid link to JSON metadata
+  let baseURLlink = decodedBaseURI[0].value.url;
+  if (!baseURLlink.endsWith('/')) {
+    baseURLlink += '/';
+  }
+
+  const decodedTokenID = decodeTokenId(tokenID, tokenIdFormat);
+  const metadataJsonLink = `${baseURLlink}${decodedTokenID}`;
+
+  // Fetch the URL
+  const response = await fetch(metadataJsonLink);
+  if (!response.ok) {
+    throw new Error(`HTTP Response Error: ${response.status}`);
+  }
+  if (!response.json) {
+    throw new Error('Metadata is not a JSON object');
+  }
+  const jsonMetadata = await response.json();
+  console.log('Metadata Contents: ', jsonMetadata);
+}
+
+// Get the  global token ID format of the asset
+const tokenIdFormat = await getTokenIdFormat();
+console.log('Token ID Format: ', tokenIdFormat);
+
+if (tokenIdFormat !== null) {
+  fetchMetadataFromBaseURI(byte32TokenId, tokenIdFormat);
+}