contrib: Rewrite contrib/lightning-pay in Python, support bolt11

fixes #718

Makefile

@@ -248,10 +248,12 @@ check-markdown:
 check-spelling:
 	@tools/check-spelling.sh
 
+PYSRC=$(shell git ls-files "*.py") contrib/pylightning/lightning-pay
+
 check-python:
 	@# E501 line too long (N > 79 characters)
 	@# E731 do not assign a lambda expression, use a def
-	@git ls-files "*.py" | xargs flake8 --ignore=E501,E731 --exclude=contrib/pylightning/lightning/__init__.py
+	@flake8 --ignore=E501,E731 --exclude=contrib/pylightning/lightning/__init__.py ${PYSRC}
 
 check-source: check-makefile check-source-bolt check-whitespace check-markdown check-spelling check-python
 

contrib/lightning-pay

@@ -1,32 +0,0 @@
-#! /bin/sh -e
-# A terrible script to make a payment.
-
-if [ $# -ne 3 ]; then
-    echo "Usage: <destination-id> <amount-in-milli-satoshi> <payment-hash>" >&2
-    exit 1
-fi
-DEST="$1"
-AMOUNT="$2"
-PHASH="$3"
-
-if ROUTE=`cli/lightning-cli getroute $DEST $AMOUNT 1`; then
-    # Strip down to raw array.
-    ROUTE=`echo $ROUTE | sed 's/^{ "route" : \(.*\) }$/\1/'`
-    # Get first amount.
-    PAID=`echo $ROUTE | tr , '\012' | sed -n 's/.*msatoshi[^0-9]*\([0-9]*\).*/\1/p' | head -n1`
-    echo -n "Paying fee $(($PAID - $AMOUNT)) on $AMOUNT ("`echo "scale=3; ($PAID - $AMOUNT) * 100 / $AMOUNT" | bc`"%).  Send [Y/n]? "
-    read REPLY
-    case $REPLY in
-	""|y*|Y)
-	    cli/lightning-cli sendpay "$ROUTE" "$PHASH"
-	    exit
-	    ;;
-	*)
-	    echo Not sending.
-	    exit 1
-	    ;;
-    esac
-else
-    echo Routing failed >&2
-    exit 1
-fi

contrib/pylightning/lightning-pay

@@ -0,0 +1,54 @@
+#!/usr/bin/env python3
+
+import argparse
+import os
+import sys
+from lightning import LightningRpc
+
+parser = argparse.ArgumentParser(formatter_class=argparse.ArgumentDefaultsHelpFormatter)
+parser.add_argument("bolt11_or_destination_id")
+parser.add_argument("amount_in_milli_satoshi", default=None, type=int, nargs="?")
+parser.add_argument("payment_hash", nargs="?")
+args = parser.parse_args()
+
+
+def default_configdir():
+    home = os.getenv("HOME")
+    if home:
+        return os.path.join(home, ".lightning")
+    return "."
+
+
+rpc_path = os.path.join(default_configdir(), "lightning-rpc")
+ld = LightningRpc(rpc_path)
+
+assert len(args.bolt11_or_destination_id) > 2, "argument bolt11_or_destination_id is invalid"
+prefix = args.bolt11_or_destination_id[:2]
+
+if prefix == "ln":
+    bolt11 = ld.decodepay(args.bolt11_or_destination_id)
+    id_ = bolt11["payee"]
+    payment_hash = bolt11["payment_hash"]
+    if "msatoshi" in bolt11:
+        amount = bolt11["msatoshi"]
+    else:
+        assert args.amount_in_milli_satoshi, "need argument amount_in_milli_satoshi"
+        amount = args.amount_in_milli_satoshi
+else:
+    assert args.amount_in_milli_satoshi, "need argument amount_in_milli_satoshi"
+    assert args.payment_hash, "need argument payment_hash"
+    amount = args.amount_in_milli_satoshi
+    id_ = args.bolt11_or_destination_id
+    payment_hash = args.payment_hash
+
+route = ld.getroute(id_, amount, 1)
+
+fee = route["route"][0]["msatoshi"] - amount
+
+reply = input("Paying fee %s on amount %s (%.3f%%). Send [Y/n]?" % (fee, amount, fee / amount * 100.0))
+
+if reply in ["y", "Y"]:
+    ld.sendpay(route["route"], payment_hash)
+else:
+    print("Not sending.")
+    sys.exit(1)

contrib/pylightning/setup.py

@@ -8,4 +8,5 @@ setup(name='pylightning',
       author_email='decker.christian@gmail.com',
       license='MIT',
       packages=['lightning'],
+      scripts=['lightning-pay'],
       zip_safe=True)