fix: actually pull latest stable build

Author: mja00

src/content/docs/misc/downloads-service.mdx

@@ -78,26 +78,54 @@ PROJECT="paper"
 MINECRAFT_VERSION="\{LATEST_PAPER_RELEASE}"
 USER_AGENT="cool-project/1.0.0 ([email protected])"
 
-# First check if the version exists
-VERSION_CHECK=$(curl -s -H "User-Agent: $USER_AGENT" https://fill.papermc.io/v3/projects/${PROJECT}/versions/${MINECRAFT_VERSION}/builds)
+# First check if the requested version has a stable build
+BUILDS_RESPONSE=$(curl -s -H "User-Agent: $USER_AGENT" https://fill.papermc.io/v3/projects/${PROJECT}/versions/${MINECRAFT_VERSION}/builds)
 
 # Check if the API returned an error
-if echo "$VERSION_CHECK" | jq -e '.ok == false' > /dev/null 2>&1; then
-  ERROR_MSG=$(echo "$VERSION_CHECK" | jq -r '.message // "Unknown error"')
+if echo "$BUILDS_RESPONSE" | jq -e '.ok == false' > /dev/null 2>&1; then
+  ERROR_MSG=$(echo "$BUILDS_RESPONSE" | jq -r '.message // "Unknown error"')
   echo "Error: $ERROR_MSG"
   exit 1
 fi
 
-# Get the download URL directly, or null if no stable build exists
-PAPERMC_URL=$(curl -s -H "User-Agent: $USER_AGENT" https://fill.papermc.io/v3/projects/${PROJECT}/versions/${MINECRAFT_VERSION}/builds | \
-  jq -r 'first(.[] | select(.channel == "STABLE") | .downloads."server:default".url) // "null"')
+# Try to get a stable build URL for the requested version
+PAPERMC_URL=$(echo "$BUILDS_RESPONSE" | jq -r 'first(.[] | select(.channel == "STABLE") | .downloads."server:default".url) // "null"')
+FOUND_VERSION="$MINECRAFT_VERSION"
+
+# If no stable build for requested version, find the latest version with a stable build
+if [ "$PAPERMC_URL" == "null" ]; then
+  echo "No stable build for version $MINECRAFT_VERSION, searching for latest version with stable build..."
+
+  # Get all versions for the project (using the same endpoint structure as the "Getting the latest version" example)
+  # The versions are organized by version group, so we need to extract all versions from all groups
+  # Then sort them properly as semantic versions (newest first)
+  VERSIONS=$(curl -s -H "User-Agent: $USER_AGENT" https://fill.papermc.io/v3/projects/${PROJECT} | \
+    jq -r '.versions | to_entries[] | .value[]' | \
+    sort -V -r)
+
+  # Iterate through versions to find one with a stable build
+  for VERSION in $VERSIONS; do
+    VERSION_BUILDS=$(curl -s -H "User-Agent: $USER_AGENT" https://fill.papermc.io/v3/projects/${PROJECT}/versions/${VERSION}/builds)
+
+    # Check if this version has a stable build
+    STABLE_URL=$(echo "$VERSION_BUILDS" | jq -r 'first(.[] | select(.channel == "STABLE") | .downloads."server:default".url) // "null"')
+
+    if [ "$STABLE_URL" != "null" ]; then
+      PAPERMC_URL="$STABLE_URL"
+      FOUND_VERSION="$VERSION"
+      echo "Found stable build for version $VERSION"
+      break
+    fi
+  done
+fi
 
 if [ "$PAPERMC_URL" != "null" ]; then
   # Download the latest Paper version
   curl -o server.jar $PAPERMC_URL
-  echo "Download completed"
+  echo "Download completed (version: $FOUND_VERSION)"
 else
-  echo "No stable build for version $MINECRAFT_VERSION found :("
+  echo "No stable builds available for any version :("
+  exit 1
 fi
 ```