#!/bin/bash
# Pin bazel to the Xcode that `xcode-select` points at.
#
# Bazel finds Xcodes through LaunchServices, and on macOS 27 LaunchServices reports only the
# newest installed Xcode. With a beta next to the release Xcode bazel silently takes the beta:
# wrong Info.plist stamps, a different cache key for every action, and a stub Metal toolchain.
# (Same problem and fix as exteraGram's XTGXcodeConfig.sh on this Mac.)
#
# Writes two gitignored files:
#   build-system/GGXcode/BUILD     explicit xcode_version + xcode_config for the selected Xcode
#   build-system/GGXcode.bazelrc   --xcode_version_config and DEVELOPER_DIR for every action,
#                                  XCODE_VERSION for repository rules and module extensions
# `.bazelrc` try-imports the rc file, so a checkout without it falls back to bazel's detection.
# The strip action does not take the shell env; build-system/GGPatches/ fixes that in rules_apple.

set -euo pipefail
cd "$(dirname "$0")/.."

OUT_DIR="build-system/GGXcode"
OUT_RC="build-system/GGXcode.bazelrc"

developer_dir="$(xcode-select -p)"
run() { env -i DEVELOPER_DIR="$developer_dir" PATH=/usr/bin:/bin "$@"; }

version_output="$(run xcodebuild -version)"
short="$(printf '%s\n' "$version_output" | sed -n 's/^Xcode //p' | head -1)"
build="$(printf '%s\n' "$version_output" | sed -n 's/^Build version //p' | head -1)"
if [ -z "$short" ] || [ -z "$build" ]; then
    echo "GGXcodeConfig: cannot read 'xcodebuild -version' for $developer_dir" >&2
    exit 1
fi

# bazel names a version major.minor.patch.build and accepts every shorter spelling as an alias.
IFS=. read -r major minor patch <<< "$short"
expanded="${major}.${minor:-0}.${patch:-0}"
full="${expanded}.${build}"
name="version$(printf '%s' "$full" | tr . _)"
aliases=""
for alias in "$full" "$build" "$short" "$expanded" "$major"; do
    case ",$aliases," in *",'$alias',"*) continue ;; esac
    aliases="${aliases:+$aliases, }'$alias'"
done

sdk_version() { run xcrun --sdk "$1" --show-sdk-version 2>/dev/null || true; }

mkdir -p "$OUT_DIR"
{
    echo "# Generated by build-system/GGXcodeConfig.sh for $developer_dir — do not edit."
    echo "load('@build_bazel_apple_support//xcode:xcode_config.bzl', 'xcode_config')"
    echo "load('@build_bazel_apple_support//xcode:xcode_version.bzl', 'xcode_version')"
    echo
    echo "package(default_visibility = ['//visibility:public'])"
    echo
    echo "xcode_version("
    echo "    name = '$name',"
    echo "    version = '$full',"
    echo "    aliases = [$aliases],"
    for pair in ios:iphoneos tvos:appletvos macos:macosx visionos:xros watchos:watchos; do
        sdk="$(sdk_version "${pair##*:}")"
        [ -n "$sdk" ] && echo "    default_${pair%%:*}_sdk_version = '$sdk',"
    done
    echo ")"
    echo
    echo "xcode_config("
    echo "    name = 'host_xcodes',"
    echo "    versions = [':$name'],"
    echo "    default = ':$name',"
    echo ")"
} > "$OUT_DIR/BUILD"

{
    echo "# Generated by build-system/GGXcodeConfig.sh — do not edit."
    echo "build --xcode_version_config=//build-system/GGXcode:host_xcodes"
    echo "build --action_env=DEVELOPER_DIR=$developer_dir"
    # rules_swift's system_sdk extension lists the installed Xcodes once and keeps the list until
    # DEVELOPER_DIR or XCODE_VERSION changes. An update in place (App Store: Xcode.app 27.1 -> 27.2,
    # 2026-10-31) keeps the path, so the stale list matched no Xcode and analysis failed. The version
    # here makes every Xcode update re-run it.
    echo "build --repo_env=XCODE_VERSION=$full"
} > "$OUT_RC"

echo "xcode      : $full ($developer_dir) -> $OUT_DIR/BUILD, $OUT_RC"