Make COIN env variable mandatory.

- make a clean split between the  Cash and Segwit flavours of bitcoin
  by giving them their own COIN names.  They can then both have a NET
  of mainnet.
- The previous Bitcoin COIN names no longer exist, and the env var is
  now mandatory, so everyone will need to set COIN and NET appropriately
  for their flavour of bitcoin and mainnet or testnet.

docs/ENVIRONMENT.rst

@@ -13,6 +13,11 @@ Required
 
 These environment variables are always required:
 
+* **COIN**
+
+  Must be a *NAME* from one of the **Coin** classes in
+  `lib/coins.py`_.
+
 * **DB_DIRECTORY**
 
   The path to the database directory.  Relative paths should be
@@ -53,11 +58,6 @@ Miscellaneous
 
 These environment variables are optional:
 
-* **COIN**
-
-  Must be a *NAME* from one of the **Coin** classes in
-  `lib/coins.py`_.  Defaults to `Bitcoin`.
-
 * **NET**
 
   Must be a *NET* from one of the **Coin** classes in `lib/coins.py`_.

lib/coins.py

@@ -317,8 +317,7 @@ class AuxPowMixin(object):
         return deserializer.read_header(height, cls.BASIC_HEADER_SIZE)
 
 
-class Bitcoin(Coin):
-    NAME = "Bitcoin"
+class BitcoinMixin(object):
     SHORTNAME = "BTC"
     NET = "mainnet"
     XPUB_VERBYTES = bytes.fromhex("0488b21e")
@@ -332,6 +331,11 @@ class Bitcoin(Coin):
     TX_COUNT_HEIGHT = 464000
     TX_PER_BLOCK = 1800
     RPC_PORT = 8332
+
+
+class BitcoinCash(BitcoinMixin, Coin):
+    NAME = "BitcoinCash"
+    SHORTNAME = "BCC"
     PEERS = [
         'electroncash.bitcoinplug.com s t',
         'electrum-abc.criptolayer.net s50012',
@@ -344,10 +348,9 @@ class Bitcoin(Coin):
     ]
 
 
-class BitcoinSegwit(Bitcoin):
-    NET = "bitcoin-segwit"
+class BitcoinSegwit(BitcoinMixin, Coin):
+    NAME = "BitcoinSegwit"
     DESERIALIZER = DeserializerSegWit
-
     PEERS = [
         'btc.smsys.me s995',
         'electrum.be s t',
@@ -365,7 +368,8 @@ class BitcoinSegwit(Bitcoin):
         'ELEX01.blackpole.online s t',
     ]
 
-class BitcoinTestnet(Bitcoin):
+
+class BitcoinTestnetMixin(object):
     SHORTNAME = "XTN"
     NET = "testnet"
     XPUB_VERBYTES = bytes.fromhex("043587cf")
@@ -381,6 +385,11 @@ class BitcoinTestnet(Bitcoin):
     TX_PER_BLOCK = 21
     RPC_PORT = 18332
     PEER_DEFAULT_PORTS = {'t': '51001', 's': '51002'}
+
+
+class BitcoinCashTestnet(BitcoinTestnetMixin, Coin):
+    '''Bitcoin Testnet for Bitcoin Cash daemons.'''
+    NAME = "BitcoinCash"
     PEERS = [
         'electrum.akinbo.org s t',
         'he36kyperp3kbuxu.onion s t',
@@ -391,44 +400,34 @@ class BitcoinTestnet(Bitcoin):
     ]
 
 
-class BitcoinRegtest(BitcoinTestnet):
+class BitcoinSegwitTestnet(BitcoinTestnetMixin, Coin):
+    '''Bitcoin Testnet for Core bitcoind >= 0.13.1.'''
+    NAME = "BitcoinSegwit"
+    DESERIALIZER = DeserializerSegWit
+
+
+class BitcoinSegwitRegtest(BitcoinSegwitTestnet):
+    NAME = "BitcoinSegwit"
     NET = "regtest"
     GENESIS_HASH = ('0f9188f13cb7b2c71f2a335e3a4fc328'
                     'bf5beb436012afca590b1a11466e2206')
     PEERS= []
     TX_COUNT = 1
     TX_COUNT_HEIGHT = 1
-    DESERIALIZER = DeserializerSegWit
 
 
-class BitcoinTestnetSegWit(BitcoinTestnet):
-    '''Bitcoin Testnet for Core bitcoind >= 0.13.1.
-
-    Unfortunately 0.13.1 broke backwards compatibility of the RPC
-    interface's TX serialization, SegWit transactions serialize
-    differently than with earlier versions.  If you are using such a
-    bitcoind on testnet, you must use this class as your "COIN".
-    '''
-    NET = "testnet-segwit"
-    DESERIALIZER = DeserializerSegWit
-
-
-class BitcoinNolnet(Bitcoin):
+class BitcoinNolnet(BitcoinCash):
     '''Bitcoin Unlimited nolimit testnet.'''
-
     NET = "nolnet"
     GENESIS_HASH = ('0000000057e31bd2066c939a63b7b862'
                     '3bd0f10d8c001304bdfc1a7902ae6d35')
+    PEERS = []
     REORG_LIMIT = 8000
     TX_COUNT = 583589
     TX_COUNT_HEIGHT = 8617
     TX_PER_BLOCK = 50
-    IRC_PREFIX = "EN_"
     RPC_PORT = 28332
     PEER_DEFAULT_PORTS = {'t': '52001', 's': '52002'}
-    PEERS = [
-        '14.3.140.101 s t',
-    ]
 
 
 class Litecoin(Coin):

server/env.py

@@ -31,7 +31,7 @@ class Env(lib_util.LoggedClass):
         self.obsolete(['UTXO_MB', 'HIST_MB', 'NETWORK'])
         self.db_dir = self.required('DB_DIRECTORY')
         self.daemon_url = self.required('DAEMON_URL')
-        coin_name = self.default('COIN', 'Bitcoin')
+        coin_name = self.required('COIN')
         network = self.default('NET', 'mainnet')
         self.coin = Coin.lookup_coin_class(coin_name, network)
         self.cache_MB = self.integer('CACHE_MB', 1200)