Improves modularity of the code

Adds cleaner and block processor to increase the modularity and reuse of the code

pisa/block_processor.py

@@ -0,0 +1,57 @@
+import binascii
+from hashlib import sha256
+
+from pisa import logging, bitcoin_cli
+from pisa.utils.auth_proxy import JSONRPCException
+
+
+class BlockProcessor:
+    @staticmethod
+    def getblock(block_hash):
+        block = None
+
+        try:
+            block = bitcoin_cli.getblock(block_hash)
+
+        except JSONRPCException as e:
+            logging.error("[BlockProcessor] couldn't get block from bitcoind. Error code {}".format(e))
+
+        return block
+
+    @staticmethod
+    def get_potential_matches(txids, locator_uuid_map):
+        potential_locators = {sha256(binascii.unhexlify(txid)).hexdigest(): txid for txid in txids}
+
+        # Check is any of the tx_ids in the received block is an actual match
+        intersection = set(locator_uuid_map.keys()).intersection(potential_locators.keys())
+        potential_matches = {locator: potential_locators[locator] for locator in intersection}
+
+        if len(potential_matches) > 0:
+            logging.info("[BlockProcessor] list of potential matches: {}".format(potential_matches))
+
+        else:
+            logging.info("[BlockProcessor] no potential matches found")
+
+    @staticmethod
+    def get_matches(potential_matches, locator_uuid_map, appointments):
+        matches = []
+
+        for locator, dispute_txid in potential_matches.items():
+            for uuid in locator_uuid_map[locator]:
+                try:
+                    # ToDo: #20-test-tx-decrypting-edge-cases
+                    justice_rawtx = appointments[uuid].encrypted_blob.decrypt(binascii.unhexlify(dispute_txid))
+                    justice_rawtx = binascii.hexlify(justice_rawtx).decode()
+                    justice_txid = bitcoin_cli.decoderawtransaction(justice_rawtx).get('txid')
+                    matches.append((locator, uuid, dispute_txid, justice_txid, justice_rawtx))
+
+                    logging.info("[BlockProcessor] match found for locator {} (uuid: {}): {}".format(
+                        locator, uuid, justice_txid))
+
+                except JSONRPCException as e:
+                    # Tx decode failed returns error code -22, maybe we should be more strict here. Leaving it simple
+                    # for the POC
+                    logging.error("[BlockProcessor] can't build transaction from decoded data. Error code {}".format(e))
+
+        return matches
+