mmgen-swaptxcreate: add --quote option

Display a swap quote and exit without creating a transaction.

All data is from the remote endpoint — no running daemons are required.

mmgen/data/version

@@ -1 +1 @@
-16.3.0dev14
+16.3.0dev15

mmgen/main_txcreate.py

@@ -78,6 +78,7 @@ opts_data = {
 			+                        Valid parameters: {tp}.
 			+                        If option is omitted, the default priority will be used
 			-- -q, --quiet           Suppress warnings; overwrite files without prompting
+			-s -Q, --quote           Get a swap quote and exit.  Do not create transaction
 			-s -r, --stream-interval=N Set block interval for streaming swap (default: {si})
 			bt -R, --no-rbf          Make transaction non-replaceable (non-replace-by-fee
 			+                        according to BIP 125)

mmgen/swap/proto/thorchain/thornode.py

@@ -51,7 +51,7 @@ class Thornode:
 		else:
 			self.data = self.rpc.get_quote(self.tx.send_asset, self.tx.recv_asset, self.in_amt)
 
-	async def format_quote(self, *, deduct_est_fee=False):
+	async def format_quote(self, *, deduct_est_fee=False, skip_est_fee=False):
 		from ....util import make_timestr, ymsg
 		from ....util2 import format_elapsed_hr
 		from ....color import blue, green, cyan, pink, orange, redbg, yelbg, grnbg
@@ -116,11 +116,11 @@ class Thornode:
   Vault address:                 {}""".format(cyan(self.inbound_address))
 
 		fee_info = '' if not tx.proto.has_usr_fee else """
-  Recommended fee:               {} {}
-  Network-estimated fee:         {} (from node)""".format(
-			pink(d['recommended_gas_rate']),
-			pink(_.disp if (_ := gas_unit_data.get(gas_unit)) else gas_unit),
-			await self.tx.network_fee_disp())
+  Recommended fee:               {} {}""".format(
+				pink(d['recommended_gas_rate']),
+				pink(_.disp if (_ := gas_unit_data.get(gas_unit)) else gas_unit)) + (
+			'' if skip_est_fee else """
+  Network-estimated fee:         {} (from node)""".format(await self.tx.network_fee_disp()))
 
 		return f"""
 {cyan(hdr)}

mmgen/tx/new_swap.py

@@ -10,11 +10,11 @@
 tx.new_swap: new swap transaction class
 """
 
-import time
+import sys, time
 from collections import namedtuple
 
 from ..amt import UniAmt
-from ..util import msg, ymsg
+from ..util import msg, ymsg, die
 from ..swap.util import get_swap_asset, init_swap_proto
 
 from .new import New
@@ -101,7 +101,8 @@ class NewSwap(New):
 					self.proto.is_vm or
 					arg in sa.recv): # is change arg
 				nonlocal chg_output
-				chg_output = await self.get_chg_output(arg, addrfiles)
+				if not self.cfg.quote:
+					chg_output = await self.get_chg_output(arg, addrfiles)
 				arg = get_arg()
 
 			# arg 4: recv_coin
@@ -125,6 +126,14 @@ class NewSwap(New):
 
 		self.swap_cfg = self.swap_proto_mod.SwapCfg(self.cfg)
 
+		if self.cfg.quote:
+			if not args.send_amt:
+				die(1, 'With --quote, you must supply a send amount')
+			await self.display_quote(
+				self.swap_proto_mod.rpc_client(self, args.send_amt),
+				skip_est_fee = True)
+			sys.exit(0)
+
 		self.check_swap_network()
 
 		for asset in (self.send_asset, self.recv_asset):
@@ -170,13 +179,13 @@ class NewSwap(New):
 
 		return tuple(ret + [f'data:{memo}'])
 
-	async def display_quote(self, qd, *, deduct_est_fee=False):
+	async def display_quote(self, qd, *, deduct_est_fee=False, skip_est_fee=False):
 		self.cfg._util.qmsg(f'Retrieving data from {qd.rpc.swap_api.host}...')
 		qd.get_quote(self.swap_cfg)
 		self.cfg._util.qmsg('OK')
 		self.swap_quote_refresh_time = time.time()
 		await self.set_gas(to_addr=qd.router if self.is_token else None)
-		msg(await qd.format_quote(deduct_est_fee=deduct_est_fee))
+		msg(await qd.format_quote(deduct_est_fee=deduct_est_fee, skip_est_fee=skip_est_fee))
 
 	def update_vault_addr(self, qd, *, addr='inbound_address'):
 		vault_idx = self.vault_idx

test/cmdtest_d/swap.py

@@ -333,6 +333,7 @@ class CmdTestSwap(
 			('swaptxcreate5',  'creating a swap transaction (chg and dest by addrlist ID)'),
 			('swaptxcreate6',  'creating a swap transaction (dest is non-wallet addr)'),
 			('swaptxcreate7',  'creating a swap transaction (coin-amt-coin)'),
+			('swaptxcreate8',  'creating a swap transaction (quote only)'),
 		),
 		'create_bad': (
 			'Swap TX create operations: error handling',
@@ -345,6 +346,7 @@ class CmdTestSwap(
 			('swaptxcreate_bad7',  'creating a swap transaction (bad, bad user input, user exit)'),
 			('swaptxcreate_bad8',  'creating a swap transaction (bad, non-MMGen change address)'),
 			('swaptxcreate_bad9',  'creating a swap transaction (bad, invalid addrtype)'),
+			('swaptxcreate_bad10', 'creating a swap transaction (bad, --quote with no amount)'),
 		),
 		'create_neterror': (
 			'Swap TX create operations: network error handling',
@@ -532,6 +534,11 @@ class CmdTestSwap(
 		t.expect('OK? (Y/n): ', 'y')
 		return self._swaptxcreate_ui_common(t, expect=':0/3/0')
 
+	def swaptxcreate8(self):
+		t = self._swaptxcreate(['BCH', '0.56789', 'LTC'], add_opts=['--quote', '--no-quiet'])
+		t.expect('SWAP QUOTE')
+		return t
+
 	def swaptxcreate_bad1(self):
 		t = self._swaptxcreate_bad(
 			['BCH', '1.234', f'{self.sid}:C:3', 'LTC', f'{self.sid}:S:1'],
@@ -576,6 +583,9 @@ class CmdTestSwap(
 	def swaptxcreate_bad9(self):
 		return self._swaptxcreate_bad(['BCH', '1.234', 'S', 'LTC', 'B'], exit_val=2, expect1='invalid command-')
 
+	def swaptxcreate_bad10(self):
+		return self._swaptxcreate_bad(['BCH', 'LTC'], add_opts=['--quote'], exit_val=1, expect1='send amount')
+
 	def swaptxcreate_neterror1(self):
 		return self._swaptxcreate_neterror('ltc_global_paused', 'Trading is paused on the')