#!/usr/bin/env bash
#
# Clean-build the release APK and install it on the attached device.
#
#   scripts/build-android.sh              # build + install
#   ABIS=arm64-v8a,x86_64 scripts/…       # add an emulator ABI
#   MINIFY=1 scripts/…                    # turn R8 on (see the note below — not the default)
set -uo pipefail

ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
LOGS="${TMPDIR:-/tmp}offscale-build"
mkdir -p "$LOGS"
log="$LOGS/android.log"
: >"$log"
cd "$ROOT" || exit 1

# The vendored Tailscale core is built by hand, per platform, and forgetting it fails much later as a
# missing symbol rather than a missing rebuild — Android says "Unresolved reference 'loginTo'" at
# Kotlin compile time. Do it here instead of relying on anyone remembering.
. "$ROOT/scripts/ensure-core.sh" android

echo "logs: $log"

# `bun run prebuild`, NOT `bunx expo prebuild`: the package.json script runs gen-adaptive-icon.sh
# first, and calling expo directly silently skips it — which ships an icon the Android launcher mask
# crops. Trailing args append to that script, and `expo prebuild` is its last command.
if ! bun run prebuild --platform android --clean --no-install >>"$log" 2>&1; then
	echo "PREBUILD FAILED — $log"; exit 1
fi

# Build for phones only.
#
# Expo's generated gradle.properties asks for `armeabi-v7a,arm64-v8a,x86,x86_64`, and the native
# libraries are most of an APK — for an app this shape, roughly 65 MB of it is lib/x86 and lib/x86_64,
# Intel builds for emulators that no phone will ever execute, and another 21 MB is armeabi-v7a for
# 32-bit devices. The Tailscale core is a large .so and gets built once per ABI, so this matters more
# here than in an app without one.
#
# Overridden here rather than in gradle.properties because `expo prebuild --clean` on the line above
# regenerates that file every single build, so an edit there survives exactly nothing.
#
# ABIS=… to override — an emulator needs x86_64 and will refuse an APK without it.
ABIS="${ABIS:-arm64-v8a}"

# MINIFY=1 turns R8 on. OFF by default, and that default is the honest one.
#
# R8 deletes every class nothing reaches from an entry point. It decides "nothing reaches this" by
# reading the code — so anything reached by REFLECTION looks dead and gets deleted. React Native and
# Expo both do that, and so does the gomobile binding layer. The build still succeeds; the app crashes
# on the device. This cannot be verified by looking at a file size, and it must not become the default
# until a build with it has been opened on a real phone, connected to a tailnet, and used.
# Expanded below as ${MINIFY_ARGS[@]+...} rather than bare: macOS ships bash 3.2, where expanding an
# EMPTY array under `set -u` is itself an unbound-variable error. The monorepo's copy of this script
# survives the bare form only because it does not set -u — the bug was latent there and real here.
MINIFY_ARGS=()
if [[ "${MINIFY:-0}" == "1" ]]; then
	MINIFY_ARGS=(-Pandroid.enableMinifyInReleaseBuilds=true)
fi

# assembleRelease, always. A debug build needs Metro attached and behaves differently from what ships,
# so testing it answers the wrong question.
if ! (cd android && ./gradlew :app:assembleRelease -PreactNativeArchitectures="$ABIS" \
	${MINIFY_ARGS[@]+"${MINIFY_ARGS[@]}"} --console=plain) >>"$log" 2>&1; then
	echo "GRADLE FAILED — $log"; exit 1
fi

apk="$(find android/app/build/outputs/apk/release -name '*.apk' | head -1)"
[[ -z "$apk" ]] && { echo "NO APK"; exit 1; }

if ! adb install -r "$apk" >>"$log" 2>&1; then
	# Almost always the cable, not the build. The APK is on disk either way: rerun just the install
	# rather than the whole thing.
	echo "INSTALL FAILED (device attached?) — apk at $apk"; exit 1
fi
echo "OK"