#!/usr/bin/env bash
# Installs the Android toolchain needed to build a Capacitor APK on Pop!_OS 24.04.
# Headless: JDK 21 + cmdline-tools + platform-tools (adb). No Android Studio.
# Idempotent - safe to re-run.
set -euo pipefail

# Versions below are verified against Capacitor 8.5.2's capacitor/build.gradle
# (compileSdk 36, targetSdk 36, minSdk 24, Java 21) - do not bump blind.
SDK_ROOT="${ANDROID_HOME:-$HOME/Android/Sdk}"
CMDLINE_BUILD="15859902"          # newest per developer.android.com/studio
BUILD_TOOLS="36.1.0"              # pairs with compileSdk 36
SHELL_RC="$HOME/.zshrc"
MARKER="# >>> android sdk (sp404-layers) >>>"

[ "$(id -u)" -ne 0 ] || { echo "Run as your normal user, not root. It will sudo when needed."; exit 1; }

echo "==> 1/6  apt packages (needs sudo)"
sudo apt-get update -qq
# android-sdk-platform-tools-common ships the udev rules that let adb see the phone.
sudo apt-get install -y openjdk-21-jdk android-sdk-platform-tools-common unzip curl

echo "==> 2/6  command-line tools -> $SDK_ROOT"
if [ ! -x "$SDK_ROOT/cmdline-tools/latest/bin/sdkmanager" ]; then
  tmp="$(mktemp -d)"; trap 'rm -rf "$tmp"' EXIT
  url="https://dl.google.com/android/repository/commandlinetools-linux-${CMDLINE_BUILD}_latest.zip"
  echo "    downloading $url"
  curl -fL --progress-bar -o "$tmp/cmdline.zip" "$url"
  unzip -q "$tmp/cmdline.zip" -d "$tmp"
  mkdir -p "$SDK_ROOT/cmdline-tools"
  rm -rf "$SDK_ROOT/cmdline-tools/latest"
  # the zip unpacks to cmdline-tools/, sdkmanager insists on being at cmdline-tools/latest/
  mv "$tmp/cmdline-tools" "$SDK_ROOT/cmdline-tools/latest"
else
  echo "    already present, skipping"
fi

# Derive JAVA_HOME from the javac we just installed rather than hardcoding a path.
JAVA_HOME="$(dirname "$(dirname "$(readlink -f "$(command -v javac)")")")"
[ -x "$JAVA_HOME/bin/javac" ] || { echo "Could not locate JAVA_HOME (got '$JAVA_HOME')"; exit 1; }
case "$("$JAVA_HOME/bin/javac" -version 2>&1)" in
  *"javac 21."*) : ;;
  *) echo "WARNING: Capacitor 8 wants Java 21, found: $("$JAVA_HOME/bin/javac" -version 2>&1)" ;;
esac
export JAVA_HOME
export ANDROID_HOME="$SDK_ROOT"
export ANDROID_SDK_ROOT="$SDK_ROOT"
export PATH="$SDK_ROOT/cmdline-tools/latest/bin:$SDK_ROOT/platform-tools:$JAVA_HOME/bin:$PATH"

echo "==> 3/6  accepting SDK licenses"
yes 2>/dev/null | sdkmanager --licenses >/dev/null || true

echo "==> 4/6  SDK packages (this is the slow part, ~1-2 GB)"
sdkmanager --install \
  "platform-tools" \
  "platforms;android-35" \
  "platforms;android-36" \
  "build-tools;${BUILD_TOOLS}"

echo "==> 5/6  persisting env to $SHELL_RC"
if ! grep -qF "$MARKER" "$SHELL_RC" 2>/dev/null; then
  cat >> "$SHELL_RC" <<EOF

$MARKER
export JAVA_HOME=$JAVA_HOME
export ANDROID_HOME=$SDK_ROOT
export ANDROID_SDK_ROOT=$SDK_ROOT
export PATH=\$ANDROID_HOME/cmdline-tools/latest/bin:\$ANDROID_HOME/platform-tools:\$JAVA_HOME/bin:\$PATH
# <<< android sdk (sp404-layers) <<<
EOF
  echo "    added"
else
  echo "    already there, skipping"
fi

echo "==> 6/6  usb device access"
if ! id -nG "$USER" | grep -qw plugdev; then
  sudo usermod -aG plugdev "$USER"
  echo "    added $USER to plugdev - LOG OUT AND BACK IN for this to take effect"
else
  echo "    already in plugdev"
fi
sudo udevadm control --reload-rules && sudo udevadm trigger || true

cat <<'EOF'

------------------------------------------------------------
Done. Open a NEW terminal, then verify:

  java -version      # expect 21.x
  sdkmanager --list_installed
  adb devices        # plug the phone in, tap "Allow USB debugging"

If adb shows "no permissions" or nothing, log out and back in
(the plugdev group change needs a fresh session).
------------------------------------------------------------
EOF