From 61868a9a7a23c21da51859a2dafa2c66d2b170b3 Mon Sep 17 00:00:00 2001
From: Radu Ometita <radu.ometita@gmail.com>
Date: Mon, 20 Jun 2022 15:04:37 +0300
Subject: [PATCH] First stab at implementing an tx status indexer.

---
 plutus-chain-index/plutus-chain-index.cabal   |   1 +
 .../src/Marconi/Index/TxConfirmationStatus.hs | 104 ++++++++++++++++++
 2 files changed, 105 insertions(+)
 create mode 100644 plutus-chain-index/src/Marconi/Index/TxConfirmationStatus.hs

diff --git a/plutus-chain-index/plutus-chain-index.cabal b/plutus-chain-index/plutus-chain-index.cabal
index d45e62fc2e..f624a393d1 100644
--- a/plutus-chain-index/plutus-chain-index.cabal
+++ b/plutus-chain-index/plutus-chain-index.cabal
@@ -42,6 +42,7 @@ library
   import:          lang
   exposed-modules:
     Marconi.Index.Datum
+    Marconi.Index.TxConfirmationStatus
     Marconi.Index.Utxo
     Plutus.ChainIndex.App
     Plutus.ChainIndex.CommandLine
diff --git a/plutus-chain-index/src/Marconi/Index/TxConfirmationStatus.hs b/plutus-chain-index/src/Marconi/Index/TxConfirmationStatus.hs
new file mode 100644
index 0000000000..abed80f2aa
--- /dev/null
+++ b/plutus-chain-index/src/Marconi/Index/TxConfirmationStatus.hs
@@ -0,0 +1,104 @@
+{-# LANGUAGE DerivingStrategies #-}
+{-# LANGUAGE OverloadedStrings  #-}
+{-# OPTIONS_GHC -fno-warn-orphans #-}
+
+module Marconi.Index.TxConfirmationStatus
+  ( -- * UtxoIndex
+    TCSIndex
+  , Depth(..)
+  , open
+  , Ix.insert
+  , Ix.rewind
+  ) where
+
+import Control.Applicative ((<|>))
+import Control.Lens.Operators ((^.))
+import Data.Foldable (forM_)
+import Data.Functor ((<&>))
+import Data.List (find)
+import Data.Maybe (fromJust)
+import Data.Monoid (Last (Last), Sum (Sum))
+import Data.String (fromString)
+import Database.SQLite.Simple (Only (Only), SQLData (SQLText))
+import Database.SQLite.Simple qualified as SQL
+import Database.SQLite.Simple.FromField (FromField (fromField))
+import Database.SQLite.Simple.ToField (ToField (toField))
+import Ledger (TxId)
+import Plutus.ChainIndex.Types (BlockNumber (BlockNumber),
+                                TxConfirmedState (TxConfirmedState, blockAdded, timesConfirmed, validity),
+                                TxValidity (TxValid))
+
+import Index.VSqlite (SqliteIndex)
+import Index.VSqlite qualified as Ix
+
+type Result = Maybe TxConfirmedState
+type Event  = (TxId, (Int, BlockNumber))
+
+type TCSIndex = SqliteIndex Event () TxId Result
+
+newtype Depth = Depth Int
+
+instance FromField TxId where
+  fromField f = fromString <$> fromField f
+
+instance ToField TxId where
+  toField = SQLText . fromString . show
+
+deriving newtype instance FromField BlockNumber
+
+deriving newtype instance ToField BlockNumber
+
+open
+  :: FilePath
+  -> Depth
+  -> IO TCSIndex
+open dbPath (Depth k) = do
+  ix <- fromJust <$> Ix.newBoxed query store onInsert k ((k + 1) * 4) dbPath
+  let c = ix ^. Ix.handle
+  SQL.execute_ c "CREATE TABLE IF NOT EXISTS tx_status (txId TEXT NOT NULL PRIMARY KEY, blockNo INT NOT NULL)"
+  pure ix
+
+query
+  :: TCSIndex
+  -> TxId
+  -> [Event]
+  -> IO Result
+query ix txId events = (<|>) <$> searchInMemory
+                             <*> searchOnDisk
+  where
+    searchInMemory :: IO Result
+    searchInMemory = do
+      buffered <- Ix.getBuffer $ ix ^. Ix.storage
+      let event = find ((== txId) . fst) $ events ++ buffered
+      pure $ event <&> \ (_, (cs, bn)) ->
+        TxConfirmedState { timesConfirmed = Sum    cs
+                         , blockAdded     = Last $ Just bn
+                         , validity       = Last $ Just TxValid
+                         }
+
+    searchOnDisk :: IO Result
+    searchOnDisk = do
+      txStatus :: [(TxId, BlockNumber)]
+        <- SQL.query (ix ^. Ix.handle) "SELECT (txId, blockNo) FROM tx_status WHERE txId = ?" (Only txId)
+      if null txStatus
+         then pure Nothing
+         else let slotNo = snd $ head txStatus
+              in  pure . Just $
+                TxConfirmedState { timesConfirmed = Sum 0
+                                 , blockAdded     = Last $ Just slotNo
+                                 , validity       = Last $ Just TxValid
+                                 }
+
+store :: TCSIndex -> IO ()
+store ix = do
+  events <- Ix.getEvents $ ix ^. Ix.storage
+  buffer <- Ix.getBuffer $ ix ^. Ix.storage
+  let all'  = buffer ++ events
+      c     = ix ^. Ix.handle
+  SQL.execute_ c "BEGIN"
+  forM_ all' $ \(txId, (block, _)) ->
+    SQL.execute c "INSERT INTO tx_status (txId, blockNumber) VALUES (?, ?)" (txId, block)
+  SQL.execute_ c "COMMIT"
+
+onInsert :: TCSIndex -> Event -> IO [()]
+onInsert _ix _update = pure []