fix: decrement total tokens by one for each burn, fix the collection id, remove tokens field of git repo in the mapping file. (#249)

subgraph/src/contract.ts

@@ -1,4 +1,4 @@
-import { log, ethereum, BigInt } from '@graphprotocol/graph-ts';
+import { log, ethereum, BigInt, Address } from '@graphprotocol/graph-ts';
 
 // Event Imports [based on the yaml config]
 import { Initialized as InitializedEvent } from '../generated/FleekNFA/FleekNFA';
@@ -15,7 +15,7 @@ export function handleInitialized(event: InitializedEvent): void {
     ]);
 
     // start collection entity
-    const collection = new Collection(event.address.toHexString());
+    const collection = new Collection(event.address);
     collection.totalTokens = BigInt.fromU32(0);
     collection.save();
 

subgraph/src/mint.ts

@@ -92,16 +92,8 @@ export function handleNewMint(event: NewMintEvent): void {
     repository = new GitRepository(gitRepository);
   }
 
-  let repositoryTokens = repository.tokens;
-  if (repositoryTokens === null) {
-    repositoryTokens = [token.id];
-  } else {
-    repositoryTokens.push(token.id);
-  }
-  repository.tokens = repositoryTokens;
-
   // Increase total tokens counter
-  const collection = Collection.load(event.address.toHexString());
+  const collection = Collection.load(event.address);
   if (collection) {
     collection.totalTokens = collection.totalTokens.plus(BigInt.fromU32(1));
     collection.save();

subgraph/src/transfer.ts

@@ -1,10 +1,10 @@
-import { Bytes, log, store } from '@graphprotocol/graph-ts';
+import { BigInt, Bytes, log, store } from '@graphprotocol/graph-ts';
 
 // Event Imports [based on the yaml config]
 import { Transfer as TransferEvent } from '../generated/FleekNFA/FleekNFA';
 
 // Entity Imports [based on the schema]
-import { Owner, Token, Transfer } from '../generated/schema';
+import { Collection, Owner, Token, Transfer } from '../generated/schema';
 
 export function handleTransfer(event: TransferEvent): void {
   const transfer = new Transfer(
@@ -39,6 +39,14 @@ export function handleTransfer(event: TransferEvent): void {
       // Remove the entity from storage
       // Its controllers and owner will be affected.
       store.remove('Token', TokenId.toString());
+      // decrement the collection entity's token count
+      const collection = Collection.load(event.address);
+      if (collection) {
+        collection.totalTokens = collection.totalTokens.minus(
+          BigInt.fromU32(1)
+        );
+        collection.save();
+      }
     } else {
       // Transfer
       // Load the Token by using its TokenId