add cli. add rewind cmd

src/cli.js

@@ -0,0 +1,23 @@
+const fs = require('fs');
+
+const ALL_CONTRACTS = require('../data/contracts');
+const BLOCKS_PER_HOUR = 300;
+const ARGS = process.argv.slice(2);
+
+switch (ARGS[0]) {
+    case 'rewind':
+        if (isNaN(ARGS[1])) {
+          console.log('Invalid argument passed. Provide the number of hours you would like to rewind syncing to.');
+          break;
+        }
+        const rewindBlocks = BLOCKS_PER_HOUR * Number(ARGS[1]);
+        for(const key in ALL_CONTRACTS) {
+            if (process.env.ONLY && process.env.ONLY != key) continue
+            const lastFile = `./storage/lastBlock.${key}.txt`;
+            const currentBlock = fs.readFileSync(lastFile);
+            const newBlock = Number(currentBlock) - rewindBlocks;
+            console.log(`Rewinding ${lastFile} ${rewindBlocks} blocks (${newBlock})`);
+            fs.writeFileSync(lastFile, newBlock.toString());
+        }
+        break;
+}