#!/usr/bin/env bash
# Build the Go static library for iOS using go build -buildmode=c-archive.
#
# This is the production-grade approach (same as Tailscale's own iOS app).
# No gomobile dependency — just the standard Go compiler + Xcode SDK.
#
# Prerequisites:
#   - Go 1.23+
#   - Xcode with iOS SDK
#
# Usage:
#   cd /path/to/tailscale_kit
#   ./build_go.sh
#
# Output: ios/TailscaleKit.xcframework (static library xcframework)

set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
GO_DIR="$SCRIPT_DIR/ios/Go"
BUILD_DIR="$SCRIPT_DIR/ios/build"
OUTPUT="$SCRIPT_DIR/ios/TailscaleKit.xcframework"
MIN_IOS="14.0"

# Omit Tailscale features we don't need — we only use tsnet.Dial() for proxying.
OMIT_TAGS="ts_omit_ssh,ts_omit_drive,ts_omit_taildrop,ts_omit_serve"
OMIT_TAGS="$OMIT_TAGS,ts_omit_webclient,ts_omit_capture,ts_omit_appconnectors"
OMIT_TAGS="$OMIT_TAGS,ts_omit_debug,ts_omit_doctor,ts_omit_portlist,ts_omit_posture"
OMIT_TAGS="$OMIT_TAGS,ts_omit_cli,ts_omit_kube,ts_omit_aws,ts_omit_bird"
OMIT_TAGS="$OMIT_TAGS,ts_omit_synology,ts_omit_tpm,ts_omit_tap,ts_omit_conn25"
OMIT_TAGS="$OMIT_TAGS,ts_omit_qrcodes,ts_omit_relayserver,ts_omit_systray"
OMIT_TAGS="$OMIT_TAGS,ts_omit_webbrowser,ts_omit_completion,ts_omit_completion_scripts"
OMIT_TAGS="$OMIT_TAGS,ts_omit_colorable,ts_omit_clientupdate,ts_omit_wakeonlan"
OMIT_TAGS="$OMIT_TAGS,ts_omit_usermetrics,ts_omit_desktop_sessions,ts_omit_ace"
OMIT_TAGS="$OMIT_TAGS,ts_omit_acme,ts_omit_hujsonconf,ts_omit_tailnetlock"
OMIT_TAGS="$OMIT_TAGS,ts_omit_netlog,ts_omit_syspolicy,ts_omit_cachenetmap"

rm -rf "$BUILD_DIR" "$OUTPUT"
mkdir -p "$BUILD_DIR/ios-arm64/Headers" "$BUILD_DIR/ios-arm64-simulator/Headers"

cd "$GO_DIR"

echo "==> Tidying Go modules..."
go mod tidy

# --- Build for iOS device (arm64) ---
echo "==> Building for iOS device (arm64)..."
IPHONEOS_SDK=$(xcrun --sdk iphoneos --show-sdk-path)
IPHONEOS_CC=$(xcrun --sdk iphoneos --find clang)

CGO_ENABLED=1 \
GOOS=ios \
GOARCH=arm64 \
CC="$IPHONEOS_CC" \
CGO_CFLAGS="-isysroot $IPHONEOS_SDK -arch arm64 -miphoneos-version-min=$MIN_IOS" \
CGO_LDFLAGS="-isysroot $IPHONEOS_SDK -arch arm64 -miphoneos-version-min=$MIN_IOS" \
go build \
  -buildmode=c-archive \
  -tags "$OMIT_TAGS" \
  -ldflags="-s -w" \
  -o "$BUILD_DIR/ios-arm64/libtailscale.a" \
  .

# Helper: create a framework bundle from a static library
create_framework() {
  local lib_path="$1"
  local header_path="$2"
  local framework_dir="$3"

  mkdir -p "$framework_dir/Headers" "$framework_dir/Modules"

  # Copy the static library as the framework binary
  cp "$lib_path" "$framework_dir/TailscaleKit"

  # Copy and clean the header (remove Go-internal types)
  cp "$header_path" "$framework_dir/Headers/tailscale.h"

  # Module map
  cat > "$framework_dir/Modules/module.modulemap" <<'MODMAP'
framework module TailscaleKit {
    header "tailscale.h"
    export *
}
MODMAP

  # Info.plist
  cat > "$framework_dir/Info.plist" <<PLIST
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
  <key>CFBundleIdentifier</key>
  <string>com.constellation-heating.TailscaleKit</string>
  <key>CFBundleName</key>
  <string>TailscaleKit</string>
  <key>CFBundleVersion</key>
  <string>1</string>
  <key>CFBundlePackageType</key>
  <string>FMWK</string>
</dict>
</plist>
PLIST
}

create_framework \
  "$BUILD_DIR/ios-arm64/libtailscale.a" \
  "$BUILD_DIR/ios-arm64/libtailscale.h" \
  "$BUILD_DIR/ios-arm64/TailscaleKit.framework"

# --- Build for iOS simulator (arm64) ---
echo "==> Building for iOS simulator (arm64)..."
SIMULATOR_SDK=$(xcrun --sdk iphonesimulator --show-sdk-path)
SIMULATOR_CC=$(xcrun --sdk iphonesimulator --find clang)

CGO_ENABLED=1 \
GOOS=ios \
GOARCH=arm64 \
CC="$SIMULATOR_CC" \
CGO_CFLAGS="-isysroot $SIMULATOR_SDK -arch arm64 -miphoneos-version-min=$MIN_IOS -target arm64-apple-ios${MIN_IOS}-simulator" \
CGO_LDFLAGS="-isysroot $SIMULATOR_SDK -arch arm64 -miphoneos-version-min=$MIN_IOS -target arm64-apple-ios${MIN_IOS}-simulator" \
go build \
  -buildmode=c-archive \
  -tags "$OMIT_TAGS" \
  -ldflags="-s -w" \
  -o "$BUILD_DIR/ios-arm64-simulator/libtailscale.a" \
  .

create_framework \
  "$BUILD_DIR/ios-arm64-simulator/libtailscale.a" \
  "$BUILD_DIR/ios-arm64-simulator/libtailscale.h" \
  "$BUILD_DIR/ios-arm64-simulator/TailscaleKit.framework"

# --- Create xcframework from framework bundles ---
echo "==> Creating xcframework..."
xcodebuild -create-xcframework \
  -framework "$BUILD_DIR/ios-arm64/TailscaleKit.framework" \
  -framework "$BUILD_DIR/ios-arm64-simulator/TailscaleKit.framework" \
  -output "$OUTPUT"

# Clean up build artifacts
rm -rf "$BUILD_DIR"

# Also copy the header to Classes/ for CocoaPods umbrella header
cp "$OUTPUT/ios-arm64/TailscaleKit.framework/Headers/tailscale.h" "$SCRIPT_DIR/ios/Classes/tailscale.h"

echo "==> Built: $OUTPUT"
du -sh "$OUTPUT"
echo "==> Device framework:"
ls -lh "$OUTPUT/ios-arm64/TailscaleKit.framework/TailscaleKit"