From 0f2cabd469bfeadf71181a4410cc3db5bbaa828d Mon Sep 17 00:00:00 2001
From: Dan Crosby <dan@danielcrosby.net>
Date: Tue, 16 Jun 2026 07:54:23 -0700
Subject: [PATCH] Build Unity protos as a Bazel DLL (#7291)

---
 .github/workflows/unity_build.yml             | 12 ++++
 scripts/build_protos.sh                       | 68 ++++---------------
 .../eagle0/clients/unity/eagle0/BUILD.bazel   | 37 ++++++++++
 .../protobuf/net/eagle0/common/BUILD.bazel    |  1 +
 .../protobuf/net/eagle0/eagle/api/BUILD.bazel |  2 +
 .../eagle0/eagle/api/command/util/BUILD.bazel |  1 +
 .../net/eagle0/eagle/common/BUILD.bazel       |  1 +
 .../net/eagle0/eagle/views/BUILD.bazel        |  1 +
 .../net/eagle0/shardok/api/BUILD.bazel        |  1 +
 .../net/eagle0/shardok/common/BUILD.bazel     |  1 +
 .../net/eagle0/shardok/storage/BUILD.bazel    |  1 +
 11 files changed, 73 insertions(+), 53 deletions(-)

diff --git a/.github/workflows/unity_build.yml b/.github/workflows/unity_build.yml
index 7570ffef99..d2e5fa1a51 100644
--- a/.github/workflows/unity_build.yml
+++ b/.github/workflows/unity_build.yml
@@ -104,6 +104,12 @@ jobs:
       - name: Clean stale files
         run: |
           git clean -ffd
+          UNITY_ROOT="src/main/csharp/net/eagle0/clients/unity/eagle0"
+          # These ignored proto outputs are mutually exclusive across proto-generation
+          # layouts. Clean both before regenerating to avoid stale DLL/source duplicates
+          # when a self-hosted runner switches between main and PR branches.
+          rm -rf "$UNITY_ROOT/Assets/GeneratedProtos"
+          rm -rf "$UNITY_ROOT/Assets/Plugins/Eagle0Protos"
           LIBRARY_DIR="src/main/csharp/net/eagle0/clients/unity/eagle0/Library"
           VERSION_CACHE="$LIBRARY_DIR/.last_unity_version"
           PROJECT_VERSION_FILE="src/main/csharp/net/eagle0/clients/unity/eagle0/ProjectSettings/ProjectVersion.txt"
@@ -213,6 +219,12 @@ jobs:
       - name: Clean stale files
         run: |
           git clean -ffd
+          UNITY_ROOT="src/main/csharp/net/eagle0/clients/unity/eagle0"
+          # These ignored proto outputs are mutually exclusive across proto-generation
+          # layouts. Clean both before regenerating to avoid stale DLL/source duplicates
+          # when a self-hosted runner switches between main and PR branches.
+          rm -rf "$UNITY_ROOT/Assets/GeneratedProtos"
+          rm -rf "$UNITY_ROOT/Assets/Plugins/Eagle0Protos"
           LIBRARY_DIR="src/main/csharp/net/eagle0/clients/unity/eagle0/Library"
           VERSION_CACHE="$LIBRARY_DIR/.last_unity_version"
           PROJECT_VERSION_FILE="src/main/csharp/net/eagle0/clients/unity/eagle0/ProjectSettings/ProjectVersion.txt"
diff --git a/scripts/build_protos.sh b/scripts/build_protos.sh
index ade59aa638..ccb8face13 100755
--- a/scripts/build_protos.sh
+++ b/scripts/build_protos.sh
@@ -1,68 +1,30 @@
 #!/bin/bash
 
-set -euxo pipefail
+set -euo pipefail
 
 REPO_ROOT="$(cd "$(dirname "$0")/.." && pwd)"
 UNITY_ROOT="$REPO_ROOT/src/main/csharp/net/eagle0/clients/unity/eagle0"
-OUTPUT_DIR="$UNITY_ROOT/Assets/GeneratedProtos"
+PLUGIN_DIR="$UNITY_ROOT/Assets/Plugins/Eagle0Protos"
+GENERATED_SOURCES_DIR="$UNITY_ROOT/Assets/GeneratedProtos"
+PROTO_DLL_TARGET="//src/main/csharp/net/eagle0/clients/unity/eagle0:eagle0_protos"
+PROTO_DLL_OUTPUT="$REPO_ROOT/bazel-bin/src/main/csharp/net/eagle0/clients/unity/eagle0/eagle0_protos/netstandard2.1"
 
-# All C# protobuf generation targets
-TARGETS=(
-    "//src/main/protobuf/net/eagle0/common:common_csharp_proto_srcs"
-    "//src/main/protobuf/net/eagle0/shardok/storage:storage_csharp_proto_srcs"
-    "//src/main/protobuf/net/eagle0/shardok/common:common_csharp_proto_srcs"
-    "//src/main/protobuf/net/eagle0/shardok/api:api_csharp_proto_srcs"
-    "//src/main/protobuf/net/eagle0/eagle/common:common_csharp_proto_srcs"
-    "//src/main/protobuf/net/eagle0/eagle/views:views_csharp_proto_srcs"
-    "//src/main/protobuf/net/eagle0/eagle/api:api_csharp_proto_srcs"
-    "//src/main/protobuf/net/eagle0/eagle/api:api_csharp_grpc_srcs"
-    "//src/main/protobuf/net/eagle0/eagle/api/command/util:util_csharp_proto_srcs"
-)
+/bin/echo "Building C# protobuf DLL..."
+bazel build "$PROTO_DLL_TARGET"
 
-# Subdirectory for each target (avoids filename collisions across packages)
-SUBDIRS=(
-    "net/eagle0/common"
-    "net/eagle0/shardok/storage"
-    "net/eagle0/shardok/common"
-    "net/eagle0/shardok/api"
-    "net/eagle0/eagle/common"
-    "net/eagle0/eagle/views"
-    "net/eagle0/eagle/api"
-    "net/eagle0/eagle/api"
-    "net/eagle0/eagle/api/command/util"
-)
+/bin/echo "Syncing generated protobuf DLL to $PLUGIN_DIR..."
 
-/bin/echo "Building C# protobuf sources..."
-bazel build "${TARGETS[@]}"
-
-/bin/echo "Syncing generated .cs files to $OUTPUT_DIR..."
-
-# Stage new files in a temp directory, then rsync to preserve timestamps
-# on unchanged files. This avoids triggering Unity reimport when protos
-# haven't changed, saving ~7 minutes of script recompilation.
 STAGING_DIR=$(mktemp -d)
 trap "rm -rf '$STAGING_DIR'" EXIT
 
-for i in "${!TARGETS[@]}"; do
-    target="${TARGETS[$i]}"
-    subdir="${SUBDIRS[$i]}"
-
-    # Convert target label to bazel-bin path
-    # //src/main/protobuf/net/eagle0/common:common_csharp_proto_srcs
-    # -> bazel-bin/src/main/protobuf/net/eagle0/common/common_csharp_proto_srcs
-    target_path="${target#//}"
-    pkg="${target_path%%:*}"
-    name="${target_path##*:}"
-    bin_dir="$REPO_ROOT/bazel-bin/$pkg/$name"
-
-    dest_dir="$STAGING_DIR/$subdir"
-    mkdir -p "$dest_dir"
-    find "$bin_dir" -name "*.cs" -exec cp {} "$dest_dir/" \;
-done
+cp "$PROTO_DLL_OUTPUT/Eagle0Protos.dll" "$STAGING_DIR/"
+cp "$PROTO_DLL_OUTPUT/Eagle0Protos.xml" "$STAGING_DIR/"
 
 # Sync only changed files and delete removed ones; --checksum compares
 # content not timestamps so unchanged files keep their original mtime.
-mkdir -p "$OUTPUT_DIR"
-rsync -rc --delete "$STAGING_DIR/" "$OUTPUT_DIR/"
+mkdir -p "$PLUGIN_DIR"
+rsync -rc --delete --exclude "*.meta" "$STAGING_DIR/" "$PLUGIN_DIR/"
 
-/bin/echo "Done. Generated C# proto sources in $OUTPUT_DIR"
+rm -rf "$GENERATED_SOURCES_DIR"
+
+/bin/echo "Done. Generated C# proto DLL in $PLUGIN_DIR"
diff --git a/src/main/csharp/net/eagle0/clients/unity/eagle0/BUILD.bazel b/src/main/csharp/net/eagle0/clients/unity/eagle0/BUILD.bazel
index 79f6557c93..46c15ea3d9 100644
--- a/src/main/csharp/net/eagle0/clients/unity/eagle0/BUILD.bazel
+++ b/src/main/csharp/net/eagle0/clients/unity/eagle0/BUILD.bazel
@@ -1,3 +1,5 @@
+load("@rules_dotnet//dotnet:defs.bzl", "csharp_library", "import_dll")
+
 #unity3d_binary(
 #    name = "windows",
 #    build_command = "buildWindows64Player",
@@ -13,3 +15,38 @@ genrule(
     outs = ["eagle0.exe"],
     cmd = "",
 )
+
+# Compile against Unity's vendored package DLLs so the Bazel-built proto
+# assembly references the same runtime assemblies Unity imports.
+import_dll(
+    name = "google_protobuf_dll",
+    dll = "Assets/Packages/Google.Protobuf.3.27.3/lib/netstandard2.0/Google.Protobuf.dll",
+    version = "3.27.3",
+)
+
+import_dll(
+    name = "grpc_core_api_dll",
+    dll = "Assets/Packages/Grpc.Core.Api.2.65.0/lib/netstandard2.1/Grpc.Core.Api.dll",
+    version = "2.65.0",
+)
+
+csharp_library(
+    name = "eagle0_protos",
+    srcs = [
+        "//src/main/protobuf/net/eagle0/common:common_csharp_proto_srcs",
+        "//src/main/protobuf/net/eagle0/eagle/api:api_csharp_grpc_srcs",
+        "//src/main/protobuf/net/eagle0/eagle/api:api_csharp_proto_srcs",
+        "//src/main/protobuf/net/eagle0/eagle/api/command/util:util_csharp_proto_srcs",
+        "//src/main/protobuf/net/eagle0/eagle/common:common_csharp_proto_srcs",
+        "//src/main/protobuf/net/eagle0/eagle/views:views_csharp_proto_srcs",
+        "//src/main/protobuf/net/eagle0/shardok/api:api_csharp_proto_srcs",
+        "//src/main/protobuf/net/eagle0/shardok/common:common_csharp_proto_srcs",
+        "//src/main/protobuf/net/eagle0/shardok/storage:storage_csharp_proto_srcs",
+    ],
+    out = "Eagle0Protos",
+    target_frameworks = ["netstandard2.1"],
+    deps = [
+        ":google_protobuf_dll",
+        ":grpc_core_api_dll",
+    ],
+)
diff --git a/src/main/protobuf/net/eagle0/common/BUILD.bazel b/src/main/protobuf/net/eagle0/common/BUILD.bazel
index 4eacc89184..12344a731f 100644
--- a/src/main/protobuf/net/eagle0/common/BUILD.bazel
+++ b/src/main/protobuf/net/eagle0/common/BUILD.bazel
@@ -227,6 +227,7 @@ csharp_proto_compile(
         ":tutorial_battle_config_proto",
         ":victory_condition_proto",
     ],
+    visibility = ["//src/main/csharp/net/eagle0/clients/unity/eagle0:__pkg__"],
 )
 
 # keep: gazelle wants go_grpc_v2 and shardok_internal_interface_proto, but that breaks Go compilation
diff --git a/src/main/protobuf/net/eagle0/eagle/api/BUILD.bazel b/src/main/protobuf/net/eagle0/eagle/api/BUILD.bazel
index 0e72d26fad..0e9449775c 100644
--- a/src/main/protobuf/net/eagle0/eagle/api/BUILD.bazel
+++ b/src/main/protobuf/net/eagle0/eagle/api/BUILD.bazel
@@ -168,6 +168,7 @@ csharp_proto_compile(
         ":selected_command_proto",
         ":streaming_text_response_proto",
     ],
+    visibility = ["//src/main/csharp/net/eagle0/clients/unity/eagle0:__pkg__"],
 )
 
 csharp_grpc_compile(
@@ -176,6 +177,7 @@ csharp_grpc_compile(
         ":auth_grpc",
         ":eagle_grpc",
     ],
+    visibility = ["//src/main/csharp/net/eagle0/clients/unity/eagle0:__pkg__"],
 )
 
 # Non-gRPC message protos
diff --git a/src/main/protobuf/net/eagle0/eagle/api/command/util/BUILD.bazel b/src/main/protobuf/net/eagle0/eagle/api/command/util/BUILD.bazel
index 5b3e2af519..bfaee86313 100644
--- a/src/main/protobuf/net/eagle0/eagle/api/command/util/BUILD.bazel
+++ b/src/main/protobuf/net/eagle0/eagle/api/command/util/BUILD.bazel
@@ -280,6 +280,7 @@ csharp_proto_compile(
         ":prisoner_management_type_proto",
         ":province_orders_proto",
     ],
+    visibility = ["//src/main/csharp/net/eagle0/clients/unity/eagle0:__pkg__"],
 )
 
 go_proto_library(
diff --git a/src/main/protobuf/net/eagle0/eagle/common/BUILD.bazel b/src/main/protobuf/net/eagle0/eagle/common/BUILD.bazel
index 75192079f6..bcfab640b2 100644
--- a/src/main/protobuf/net/eagle0/eagle/common/BUILD.bazel
+++ b/src/main/protobuf/net/eagle0/eagle/common/BUILD.bazel
@@ -409,6 +409,7 @@ csharp_proto_compile(
         ":unaffiliated_hero_quest_proto",
         ":unaffiliated_hero_type_proto",
     ],
+    visibility = ["//src/main/csharp/net/eagle0/clients/unity/eagle0:__pkg__"],
 )
 
 go_proto_library(
diff --git a/src/main/protobuf/net/eagle0/eagle/views/BUILD.bazel b/src/main/protobuf/net/eagle0/eagle/views/BUILD.bazel
index dd97be2e83..99aff08f73 100644
--- a/src/main/protobuf/net/eagle0/eagle/views/BUILD.bazel
+++ b/src/main/protobuf/net/eagle0/eagle/views/BUILD.bazel
@@ -269,6 +269,7 @@ csharp_proto_compile(
         ":shardok_battle_view_proto",
         ":stat_with_condition_proto",
     ],
+    visibility = ["//src/main/csharp/net/eagle0/clients/unity/eagle0:__pkg__"],
 )
 
 go_proto_library(
diff --git a/src/main/protobuf/net/eagle0/shardok/api/BUILD.bazel b/src/main/protobuf/net/eagle0/shardok/api/BUILD.bazel
index 059165454e..d728d39b63 100644
--- a/src/main/protobuf/net/eagle0/shardok/api/BUILD.bazel
+++ b/src/main/protobuf/net/eagle0/shardok/api/BUILD.bazel
@@ -156,6 +156,7 @@ csharp_proto_compile(
         ":roll_request_proto",
         ":unit_view_proto",
     ],
+    visibility = ["//src/main/csharp/net/eagle0/clients/unity/eagle0:__pkg__"],
 )
 
 go_proto_library(
diff --git a/src/main/protobuf/net/eagle0/shardok/common/BUILD.bazel b/src/main/protobuf/net/eagle0/shardok/common/BUILD.bazel
index ea11776c87..d0a2492b39 100644
--- a/src/main/protobuf/net/eagle0/shardok/common/BUILD.bazel
+++ b/src/main/protobuf/net/eagle0/shardok/common/BUILD.bazel
@@ -223,6 +223,7 @@ csharp_proto_compile(
         ":victory_condition_proto",
         ":weather_proto",
     ],
+    visibility = ["//src/main/csharp/net/eagle0/clients/unity/eagle0:__pkg__"],
 )
 
 go_proto_library(
diff --git a/src/main/protobuf/net/eagle0/shardok/storage/BUILD.bazel b/src/main/protobuf/net/eagle0/shardok/storage/BUILD.bazel
index 591583899e..83fdd31833 100644
--- a/src/main/protobuf/net/eagle0/shardok/storage/BUILD.bazel
+++ b/src/main/protobuf/net/eagle0/shardok/storage/BUILD.bazel
@@ -69,6 +69,7 @@ csharp_proto_compile(
         ":action_with_resulting_state_proto",
         ":odds_proto",
     ],
+    visibility = ["//src/main/csharp/net/eagle0/clients/unity/eagle0:__pkg__"],
 )
 
 go_proto_library(