From c67c2e7cd737e3f9e56f04f176d50c5e257d69a5 Mon Sep 17 00:00:00 2001
From: benbierens <thatbenbierens@gmail.com>
Date: Fri, 1 Mar 2024 14:25:48 +0100
Subject: [PATCH] Implements loading backend from cli files or previously
 downloaded local files

---
 codex/codex.nim                       | 22 -----------
 codex/slots/proofs/backendfactory.nim | 56 +++++++++++++++++++++------
 2 files changed, 45 insertions(+), 33 deletions(-)

diff --git a/codex/codex.nim b/codex/codex.nim
index f0b588cd..eb2b26e4 100644
--- a/codex/codex.nim
+++ b/codex/codex.nim
@@ -269,28 +269,6 @@ proc new*(
     engine = BlockExcEngine.new(repoStore, wallet, network, blockDiscovery, peerStore, pendingBlocks)
     store = NetworkStore.new(engine, repoStore)
     prover = if config.prover:
-      if not fileAccessible($config.circomR1cs, {AccessFlags.Read}) and
-        endsWith($config.circomR1cs, ".r1cs"):
-        error "Circom R1CS file not accessible"
-        raise (ref Defect)(
-          msg: "r1cs file not readable, doesn't exist or wrong extension (.r1cs)")
-
-      if not fileAccessible($config.circomWasm, {AccessFlags.Read}) and
-        endsWith($config.circomWasm, ".wasm"):
-        error "Circom wasm file not accessible"
-        raise (ref Defect)(
-          msg: "wasm file not readable, doesn't exist or wrong extension (.wasm)")
-
-      let zkey = if not config.circomNoZkey:
-          if not fileAccessible($config.circomZkey, {AccessFlags.Read}) and
-            endsWith($config.circomZkey, ".zkey"):
-            error "Circom zkey file not accessible"
-            raise (ref Defect)(
-              msg: "zkey file not readable, doesn't exist or wrong extension (.zkey)")
-
-          $config.circomZkey
-        else: ""
-
       some Prover.new(
         store,
         config.numProofSamples)
diff --git a/codex/slots/proofs/backendfactory.nim b/codex/slots/proofs/backendfactory.nim
index f08d7867..dd048e85 100644
--- a/codex/slots/proofs/backendfactory.nim
+++ b/codex/slots/proofs/backendfactory.nim
@@ -1,32 +1,66 @@
+import os
 import pkg/chronos
 import pkg/questionable
 import pkg/confutils/defs
+import pkg/stew/io2
 
 import ../../conf
 import ./backends
 
+proc initializeCircomBackend(
+  r1csFile: string,
+  wasmFile: string,
+  zKeyFile: string
+): AnyBackend =
+  CircomCompat.init(r1csFile, wasmFile, zKeyFile)
+
 proc initializeFromConfig(
   config: CodexConf): ?!AnyBackend =
+  if not fileAccessible($config.circomR1cs, {AccessFlags.Read}) and
+    endsWith($config.circomR1cs, ".r1cs"):
+    return failure("Circom R1CS file not accessible")
 
-  # check provided files exist
-  # initialize backend with files
-  # or failure
+  if not fileAccessible($config.circomWasm, {AccessFlags.Read}) and
+    endsWith($config.circomWasm, ".wasm"):
+    return failure("Circom wasm file not accessible")
 
-  success(CircomCompat.init($config.circomR1cs, $config.circomWasm, $config.circomZkey))
+  if not fileAccessible($config.circomZkey, {AccessFlags.Read}) and
+    endsWith($config.circomZkey, ".zkey"):
+    return failure("Circom zkey file not accessible")
 
-proc initializeFromCeremonyFiles(): ?!AnyBackend =
+  success(initializeCircomBackend(
+    $config.circomR1cs,
+    $config.circomWasm,
+    $config.circomZkey))
 
-  # initialize from previously-downloaded files if they exist
-  echo "todo"
-  failure("todo")
+proc r1csFilePath(config: CodexConf): string =
+  config.dataDir / "circuit.r1cs"
+
+proc wasmFilePath(config: CodexConf): string =
+  config.dataDir / "circuit.wasm"
+
+proc zkeyFilePath(config: CodexConf): string =
+  config.dataDir / "circuit.zkey"
+
+proc initializeFromCeremonyFiles(config: CodexConf): ?!AnyBackend =
+  if fileExists(config.r1csFilePath) and
+    fileExists(config.wasmFilePath) and
+    fileExists(config.zkeyFilePath):
+    return success(initializeCircomBackend(
+      config.r1csFilePath,
+      config.wasmFilePath,
+      config.zkeyFilePath))
+
+  failure("Ceremony files not found")
 
 proc initializeFromCeremonyUrl(
+  config: CodexConf,
   proofCeremonyUrl: ?string): Future[?!AnyBackend] {.async.} =
 
   # download the ceremony url
   # unzip it
 
-  without backend =? initializeFromCeremonyFiles(), err:
+  without backend =? initializeFromCeremonyFiles(config), err:
     return failure(err)
   return success(backend)
 
@@ -36,9 +70,9 @@ proc initializeBackend*(
 
   without backend =? initializeFromConfig(config), cliErr:
     info "Could not initialize prover backend from CLI options...", msg = cliErr.msg
-    without backend =? initializeFromCeremonyFiles(), localErr:
+    without backend =? initializeFromCeremonyFiles(config), localErr:
       info "Could not initialize prover backend from local files...", msg = localErr.msg
-      without backend =? (await initializeFromCeremonyUrl(proofCeremonyUrl)), urlErr:
+      without backend =? (await initializeFromCeremonyUrl(config, proofCeremonyUrl)), urlErr:
         warn "Could not initialize prover backend from ceremony url...", msg = urlErr.msg
         return failure(urlErr)
   return success(backend)