From bb5758a9f5884a4d6a0cd9224e5743b444ae822f Mon Sep 17 00:00:00 2001
From: Juan Cruz Viotti <jv@jviotti.com>
Date: Thu, 30 May 2024 13:31:50 +0100
Subject: [PATCH] Prepare a fallback resolver for HTTP resolution (#15)

Signed-off-by: Juan Cruz Viotti <jv@jviotti.com>
---
 src/utils.cc | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/utils.cc b/src/utils.cc
index d1925920..ae60857f 100644
--- a/src/utils.cc
+++ b/src/utils.cc
@@ -120,10 +120,25 @@ auto pretty_evaluate_callback(
   std::cerr << "\"\n";
 }
 
+static auto fallback_resolver(std::string_view identifier)
+    -> std::future<std::optional<sourcemeta::jsontoolkit::JSON>> {
+  auto official_result{
+      sourcemeta::jsontoolkit::official_resolver(identifier).get()};
+  if (official_result.has_value()) {
+    std::promise<std::optional<sourcemeta::jsontoolkit::JSON>> promise;
+    promise.set_value(std::move(official_result));
+    return promise.get_future();
+  }
+
+  std::promise<std::optional<sourcemeta::jsontoolkit::JSON>> promise;
+  promise.set_value(std::nullopt);
+  return promise.get_future();
+}
+
 auto resolver(const std::map<std::string, std::vector<std::string>> &options)
     -> sourcemeta::jsontoolkit::SchemaResolver {
   sourcemeta::jsontoolkit::MapSchemaResolver dynamic_resolver{
-      sourcemeta::jsontoolkit::official_resolver};
+      fallback_resolver};
 
   if (options.contains("resolve")) {
     for (const auto &schema_path : options.at("resolve")) {