outputs/inputs parsing

BTC.scratch.md

@@ -147,11 +147,19 @@ Can lookup in blockchain as:
 ```
 =btc -build-file %/lib/btc/hoon
 =in0 [%32^0x3d6a.f8a8.32b2.ef3f.82f4.dd9c.ccc9.a5af.23db.dbe9.2eae.86f0.7b06.fd41.9525.62b5 62 1 4^0xffff.ffff ~ ~ 10.950.904]
-=out0 [address=[%bech32 'bc1q59u5epktervh6fxqay2dlph0wxu9hjnx6v8n66'] value=10.944.414]
+=out0 [script-pubkey=(script-pubkey:btc [%bech32 'bc1q59u5epktervh6fxqay2dlph0wxu9hjnx6v8n66']) value=10.944.414]
 
 (get-id:txu:btc (encode:txu:btc [~[in0] ~[out0] 0 1]))
 ```
 
+## TX Decoding/Parsing
+Signed TX:
+`01000000000101bee955e95966c35c9b4f1b9b59b8d84b61044b1b6c5d5c380c3b6ed8938c1d6d0000000000ffffffff01385cb01000000000160014ea13bc0f69262d7ab1cb307668105473754b23bc0247304402204c0a3c2aed0d4fc7b6e9b70cc9bd0e489aa82547419ba7a209e5552d6659e2740220158043b25a7342cc231b15eb39217b29decc7d3ca55953f47a0461b3eb0255b2012102b791e56d195e0b597c84d351953176a255019dd5d0ad8b6210fa590d20f45b4c00000000`
+
+```
+=inputs 0x1be.e955.e959.66c3.5c9b.4f1b.9b59.b8d8.4b61.044b.1b6c.5d5c.380c.3b6e.d893.8c1d.6d00.0000.0000.ffff.ffff
+```
+
 ## Unsigned Transactions
 Using [BIP 143](https://github.com/bitcoin/bips/blob/master/bip-0143.mediawiki#P2SHP2WPKH) as a reference.
 

lib/btc.hoon

@@ -69,10 +69,76 @@
       |=  o=output:tx
       ^-  bytc
       %-  cat:byt
-      :~  (flip:byt 8^value.o)
-          (script-pubkey address.o)
+      ~[(flip:byt 8^value.o) script-pubkey.o]
+    --
+  ::
+  ++  de
+    |%
+    ++  nversion
+      |=  b=buffer
+      ^-  [nversion=@ud rest=buffer]
+      :_  (slag 4 b)
+      =<  dat
+      %-  flip:byt
+      (to-byts:buf (scag 4 b))
+    ::
+    ++  segwit
+      |=  b=buffer
+      ^-  [segwit=@ud rest=buffer]
+      :_  (slag 2 b)
+      =<  dat
+      (to-byts:buf (scag 2 b))
+    ::  returns value as 0 since we don't know when we decode
+    ::
+    ++  input
+      |=  b=buffer
+      ^-  input:tx
+      :*  (txid (to-byts:buf (scag 32 b)))
+          =<(dat (flip:byt (to-byts:buf (swag [32 4] b))))
+          (flip:byt (to-byts:buf (swag [37 4] b)))
+          ~
+          ~
+          0
+      ==
+    ::
+    ++  output
+      |=  b=buffer
+      ^-  output:tx
+      :-  (to-byts:buf (slag 8 b))
+      =<  dat
+      (flip:byt (to-byts:buf (scag 8 b)))
+    ::
+    ++  inputs
+      |=  b=buffer
+      ^-  [is=(list input:tx) rest=buffer]
+      =|  acc=(list input:tx)
+      =^  count  b
+        [(snag 0 b) (slag 1 b)]
+      |-
+      ?:  =(0 count)  [acc b]
+      %=  $
+          acc  %+  snoc  acc
+               (input (scag 41 b))
+          b  (slag 41 b)
+          count  (dec count)
+      ==
+    ::
+    ++  outputs
+      |=  b=buffer
+      ^-  [os=(list output:tx) rest=buffer]
+      =|  acc=(list output:tx)
+      =^  count  b
+        [(snag 0 b) (slag 1 b)]
+      |-
+      ?:  =(0 count)  [acc b]
+      %=  $
+          acc  %+  snoc  acc
+               (output (scag 31 b))
+          b  (slag 31 b)
+          count  (dec count)
       ==
     --
+  ::
   ++  encode
     |=  =data:tx
     ^-  bytc
@@ -92,11 +158,21 @@
     %-  txid
     %-  flip:byt
     (dsha256 b)
-  ++  decode
+  ::  TODO: check whether segwit is present by seeing whether the first byte after nversion is 0x0 or not
+  ::
+  ++  decode-signed
     |=  b=bytc
     ^-  data:tx
+    =/  bu=buffer  (from-byts:buf b)
+    =^  nversion  bu
+      (nversion:de bu)
+    =^  segwit  bu
+      (segwit:de bu)
+    =^  inputs  bu
+      (inputs:de bu)
+    =^  outputs  bu
+      (outputs:de bu)
     *data:tx
-    :: TODO parse out signatures
   --
 ::  core to handle BIP174 PSBTs
 ::

sur/btc.hoon

@@ -51,14 +51,13 @@
   +$  input
     $:  =txid
         pos=@ud
-        witness-ver=@ud
         sequence=bytc
         redeem-script=(unit bytc)
         pubkey=(unit bytc)
         value=sats
     ==
   +$  output
-    $:  =address
+    $:  script-pubkey=bytc
         value=sats
     ==
   --