Add cli for importcontract as hex string, save to leveldb in /tmp with initiating txid as key

cli.py

@@ -0,0 +1,18 @@
+import argparse, textwrap
+from utils import *
+import database as db
+
+if __name__ == '__main__':
+    parser = argparse.ArgumentParser(formatter_class=argparse.RawTextHelpFormatter,
+        description=textwrap.dedent('''\
+                == Contracts ==
+                importcontract "hexstr" - import an existing trade from a hex string
+                exportcontract - (not implemented) export the data of an existing xcat trade as a hex string
+
+                '''))
+    parser.add_argument("-importcontract", type=str, action="store", help="import an existing trade from a hex string.")
+    args = parser.parse_args()
+
+    if args.importcontract:
+        hexstr = args.importcontract
+        db.create(hexstr)

database.py

@@ -0,0 +1,26 @@
+import plyvel
+from utils import *
+import binascii
+import sys
+
+db = plyvel.DB('/tmp/testdb', create_if_missing=True)
+
+trade = get_trade()
+## txid we retrieve by
+txid = trade['sell']['fund_tx']
+
+def hex2dict(hexstr):
+    jsonstr = x2s(hexstr)
+    return json.loads(jsonstr)
+
+def create(hexstr):
+    trade = hex2dict(hexstr)
+    txid = trade['sell']['fund_tx']
+    # Save trade by initiating txid
+    db.put(b(txid), b(hexstr))
+
+def get(txid):
+    return db.get(b(txid))
+
+hexstr = get(txid)
+print(x2s(hexstr))

utils.py

@@ -3,9 +3,30 @@ import json
 import random
 import binascii
 
-def hex2str(hexstring):
+def b(string):
+    """Convert a string to bytes"""
+    return str.encode(string)
+
+def x(h):
+    """Convert a hex string to bytes"""
+    return binascii.unhexlify(h.encode('utf8'))
+
+def b2x(b):
+    """Convert bytes to a hex string"""
+    return binascii.hexlify(b).decode('utf8')
+
+def x2s(hexstring):
+    """Convert hex to a utf-8 string"""
     return binascii.unhexlify(hexstring).decode('utf-8')
 
+def s2x(string):
+    """Convert a utf-8 string to hex"""
+    return b2x(b(string))
+
+
+######################
+
+
 def sha256(secret):
     preimage = secret.encode('utf8')
     h = hashlib.sha256(preimage).digest()

zXcat.py

@@ -117,7 +117,7 @@ def parse_secret(txid):
     print("Decoded", scriptSig)
     asm = scriptSig['asm'].split(" ")
     pubkey = asm[1]
-    secret = hex2str(asm[2])
+    secret = x2s(asm[2])
     redeemPubkey = P2PKHBitcoinAddress.from_pubkey(x(pubkey))
     print('redeemPubkey', redeemPubkey)
     print(secret)