Implement functions to make RPC calls to Zebra

CHANGELOG.md

@@ -7,12 +7,14 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
-## Added
+### Added
 
 - `Core` module
 - `CLI` module
 - `DB` module
 - Command line arguments to switch to legacy version
+- New configuration parameter for Zebra port
+- New functions to call `getinfo` and `getblockchaininfo` RPC methods
 
 ## [0.4.1]
 

package.yaml

@@ -30,6 +30,7 @@ library:
   - text
   - bytestring
   - http-conduit
+  - http-client
   - scientific
   - vector
   - regex-base

src/Zenith/CLI.hs

@@ -1,4 +1,5 @@
 {-# LANGUAGE TemplateHaskell #-}
+{-# LANGUAGE OverloadedStrings #-}
 
 module Zenith.CLI where
 
@@ -33,6 +34,8 @@ import Brick.Widgets.Core
   )
 import qualified Brick.Widgets.List as L
 import qualified Data.Vector as Vec
+import Network.HTTP.Simple
+import ZcashHaskell.Types
 import Zenith.Core
 
 data Name
@@ -85,15 +88,6 @@ listDrawElement sel a =
           else str s
    in C.hCenter $ selStr $ show a
 
-initialState :: State
-initialState =
-  State
-    "Main"
-    (L.list WList (Vec.fromList ["wall1"]) 1)
-    (L.list AList (Vec.fromList ["addr1", "addr2"]) 1)
-    (L.list TList (Vec.fromList ["tx1", "tx2", "tx3"]) 1)
-    "Start up Ok!"
-
 customAttr :: A.AttrName
 customAttr = L.listSelectedAttr <> A.attrName "custom"
 
@@ -129,10 +123,25 @@ theApp =
     , M.appAttrMap = const theMap
     }
 
-runZenithCLI :: T.Text -> IO ()
+runZenithCLI :: Int -> T.Text -> IO ()
-runZenithCLI dbName = do
+runZenithCLI port dbName = do
-  w <- checkWallets dbName
+  w <- checkZebra port
-  if (null w)
+  case (w :: Maybe ZebraGetInfo) of
-    then void $ M.defaultMain theApp initialState
+    Just zebra -> do
-    else do
+      bc <- checkBlockChain port
-      print "No wallet found. Create one? Y/N"
+      case (bc :: Maybe ZebraGetBlockChainInfo) of
+        Nothing -> print "Unable to determine blockchain status"
+        Just chainInfo -> do
+          void $
+            M.defaultMain theApp $
+            State
+              ((show . zgb_net) chainInfo)
+              (L.list WList (Vec.fromList ["wall1"]) 1)
+              (L.list AList (Vec.fromList ["addr1", "addr2"]) 1)
+              (L.list TList (Vec.fromList ["tx1", "tx2", "tx3"]) 1)
+              ("Start up Ok! Connected to Zebra " ++
+               (T.unpack . zgi_build) zebra ++ " on port " ++ show port ++ ".")
+    Nothing -> do
+      print $
+        "No Zebra node available on port " <>
+        show port <> ". Check your configuration"

src/Zenith/Core.hs

@@ -1,12 +1,48 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+-- Core wallet functionality for Zenith
 module Zenith.Core where
 
+import Data.Aeson
 import qualified Data.Text as T
 import Database.Persist
 import Database.Persist.Sqlite
+import Network.HTTP.Client
+import ZcashHaskell.Types
+import ZcashHaskell.Utils
 import Zenith.DB
 
-checkWallets :: T.Text -> IO [Entity ZcashWallet]
+-- * Database functions
+-- | Returns the list of wallets available in the given database
+checkWallets ::
+     T.Text -- ^ The database name to check
+  -> IO [Entity ZcashWallet]
 checkWallets dbName = do
   runSqlite dbName $ do runMigration migrateAll
-  wallets <- runSqlite dbName $ selectList [ZcashWalletBirthdayHeight >. 0] []
+  runSqlite dbName $ selectList [ZcashWalletBirthdayHeight >. 0] []
-  return wallets
+
+-- * Zebra Node interaction
+-- | Checks the status of the `zebrad` node
+checkZebra ::
+     Int -- ^ Port where `zebrad` is available 
+  -> IO (Maybe ZebraGetInfo)
+checkZebra port = do
+  res <- makeZebraCall port "getinfo" []
+  let body = responseBody (res :: Response (RpcResponse ZebraGetInfo))
+  return $ result body
+
+-- | Checks the status of the Zcash blockchain
+checkBlockChain ::
+     Int -- ^ Port where `zebrad` is available
+  -> IO (Maybe ZebraGetBlockChainInfo)
+checkBlockChain port = do
+  let f = makeZebraCall port
+  result <$> (responseBody <$> f "getblockchaininfo" [])
+
+-- | Generic RPC call function
+connectZebra ::
+     FromJSON a => Int -> T.Text -> [Data.Aeson.Value] -> IO (Maybe a)
+connectZebra port m params = do
+  res <- makeZebraCall port m params
+  let body = responseBody res
+  return $ result body