feat: indexer (decentraland#19)

* feat: indexer

* chore: README

.gitignore

@@ -0,0 +1,65 @@
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+
+# Runtime data
+pids
+*.pid
+*.seed
+*.pid.lock
+
+# Directory for instrumented libs generated by jscoverage/JSCover
+lib-cov
+
+# Coverage directory used by tools like istanbul
+coverage
+
+# nyc test coverage
+.nyc_output
+
+# Grunt intermediate storage (http://gruntjs.com/creating-plugins#storing-task-files)
+.grunt
+
+# Bower dependency directory (https://bower.io/)
+bower_components
+
+# node-waf configuration
+.lock-wscript
+
+# Compiled binary addons (https://nodejs.org/api/addons.html)
+build/Release
+
+# Dependency directories
+node_modules/
+jspm_packages/
+
+# TypeScript v1 declaration files
+typings/
+
+# Optional npm cache directory
+.npm
+
+# Optional eslint cache
+.eslintcache
+
+# Optional REPL history
+.node_repl_history
+
+# Output of 'npm pack'
+*.tgz
+
+# Yarn Integrity file
+.yarn-integrity
+
+# dotenv environment variables file
+.env
+
+# next.js build output
+.next
+
+dist
+build
+*DS_Store

LICENSE

@@ -0,0 +1,14 @@
+Copyright 2020 Metaverse Holdings Ltd.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use files included in this repository except in compliance
+with the License. You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+

indexer/README.md

@@ -0,0 +1,14 @@
+# Blockchain indexer
+
+It uses [thegraph](https://thegraph.com)
+
+**Run**
+
+```bash
+npm run codegen
+npm run build
+
+npm run deploy
+```
+
+checkout the docs https://thegraph.com/docs/quick-start

indexer/abis/ERC721.json

@@ -0,0 +1,154 @@
+{
+  "contractName": "ERC721",
+  "abi": [
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "_tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "ownerOf",
+      "outputs": [
+        {
+          "name": "owner",
+          "type": "address"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "internalType": "uint256",
+          "name": "_tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "tokenURI",
+      "outputs": [
+        {
+          "internalType": "string",
+          "name": "",
+          "type": "string"
+        }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "constant": true,
+      "inputs": [
+        {
+          "name": "_owner",
+          "type": "address"
+        }
+      ],
+      "name": "balanceOf",
+      "outputs": [
+        {
+          "name": "balance",
+          "type": "uint256"
+        }
+      ],
+      "payable": false,
+      "type": "function"
+    },
+    {
+      "anonymous": false,
+      "inputs": [
+        {
+          "indexed": true,
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "tokenId",
+          "type": "uint256"
+        },
+        {
+          "indexed": false,
+          "name": "operator",
+          "type": "address"
+        },
+        {
+          "indexed": false,
+          "name": "userData",
+          "type": "bytes"
+        },
+        {
+          "indexed": false,
+          "name": "operatorData",
+          "type": "bytes"
+        }
+      ],
+      "name": "Transfer",
+      "type": "event"
+    },
+    {
+      "anonymous": false,
+      "inputs": [
+        {
+          "indexed": true,
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "tokenId",
+          "type": "uint256"
+        },
+        {
+          "indexed": false,
+          "name": "operator",
+          "type": "address"
+        },
+        {
+          "indexed": false,
+          "name": "userData",
+          "type": "bytes"
+        }
+      ],
+      "name": "Transfer",
+      "type": "event"
+    },
+    {
+      "anonymous": false,
+      "inputs": [
+        {
+          "indexed": true,
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "Transfer",
+      "type": "event"
+    }
+  ]
+}