#!/usr/bin/env bash
# Global device launcher — always runs on Android (Waydroid or adb device).
#
#   nix run .#global
#   just run
#
# Pipeline:
#   1. cargo apk build --target x86_64-linux-android --no-default-features
#   2. adb install -r target/debug/apk/global-dist-ui.apk
#   3. show device UI + Gleam dist_driver over erl_dist
#
# Env:
#   COOKIE            Erlang cookie (default: global)
#   GLOBAL_ROOT       checkout root
#   GLOBAL_VIDYA_SRC  flake-locked vidya tree (set by nix run .#global)
#   ANDROID_NDK_HOME  default: ~/.local/share/android-ndk-r29
#   ANDROID_HOME      default: ~/.local/share/android-sdk
#   GLOBAL_APK_SKIP_BUILD=1   skip cargo apk (use existing APK only)
#   GLOBAL_SKIP_SHOW_UI=1     skip waydroid show-full-ui
set -euo pipefail

# Accept legacy args for a while, then ignore them.
case "${1:-}" in
  host | desktop | waydroid | local | device)
    shift
    ;;
esac

COOKIE="${COOKIE:-global}"
PKG="uk.nandi.global.distui"
ACTIVITY="${PKG}/android.app.NativeActivity"
APK_REL="dist-ui/target/debug/apk/global-dist-ui.apk"

need() { command -v "$1" >/dev/null || { echo "missing: $1" >&2; exit 1; }; }

resolve_root() {
  if [[ -n "${GLOBAL_ROOT:-}" ]]; then
    echo "$GLOBAL_ROOT"
    return
  fi
  if git rev-parse --show-toplevel >/dev/null 2>&1; then
    git rev-parse --show-toplevel
    return
  fi
  if [[ -d ./dist_driver && -d ./dist-ui ]]; then
    pwd
    return
  fi
  echo "Run from the Global git checkout (needs dist_driver/ + dist-ui/)." >&2
  exit 1
}

ROOT="$(resolve_root)"
cd "$ROOT"

# Stage flake-input vidya for cargo path dep: dist-ui → ../.flake/vidya
ensure_vidya() {
  local dest="$ROOT/.flake/vidya"
  mkdir -p "$ROOT/.flake"
  if [[ -n "${GLOBAL_VIDYA_SRC:-}" && -d "${GLOBAL_VIDYA_SRC}" ]]; then
    rm -rf "$dest"
    cp -aL "$GLOBAL_VIDYA_SRC" "$dest"
    chmod -R u+w "$dest" 2>/dev/null || true
    echo "[global] vidya ← flake input ($GLOBAL_VIDYA_SRC)" >&2
    return 0
  fi
  # Local overrides for non-nix cargo apk
  if [[ -d "$HOME/code/vidya" && -f "$HOME/code/vidya/Cargo.toml" ]]; then
    rm -rf "$dest"
    ln -sfn "$HOME/code/vidya" "$dest"
    echo "[global] vidya ← $HOME/code/vidya" >&2
    return 0
  fi
  if [[ -d "$ROOT/vidya" && -f "$ROOT/vidya/Cargo.toml" ]]; then
    rm -rf "$dest"
    ln -sfn "$ROOT/vidya" "$dest"
    echo "[global] vidya ← $ROOT/vidya (in-tree fallback)" >&2
    return 0
  fi
  echo "[global] vidya sources missing. Use nix run .#global, or clone nandi.uk/vidya." >&2
  echo "  override: nix run .#global --override-input vidya path:\$HOME/code/vidya" >&2
  exit 1
}

waydroid_ip() {
  waydroid status 2>/dev/null | awk -F': *' '/IP address/{gsub(/[[:space:]]/,"",$2); print $2; exit}'
}

ensure_waydroid() {
  need waydroid
  if ! waydroid status 2>/dev/null | grep -q 'Session:.*RUNNING'; then
    echo "[global] starting waydroid session…"
    waydroid session start >/dev/null 2>&1 &
    local i
    for i in $(seq 1 60); do
      waydroid status 2>/dev/null | grep -q 'Session:.*RUNNING' && break
      sleep 1
    done
  fi
  waydroid status 2>/dev/null | grep -q 'Session:.*RUNNING' || {
    echo "[global] Waydroid session not RUNNING" >&2
    waydroid status >&2 || true
    exit 1
  }
  local ip i
  for i in $(seq 1 45); do
    ip="$(waydroid_ip)"
    if [[ -n "$ip" && "$ip" != "UNKNOWN" ]]; then
      echo "$ip"
      return 0
    fi
    sleep 1
  done
  echo "192.168.240.112"
}

ensure_adb() {
  local ip="$1"
  need adb
  mkdir -p "$HOME/.android" "$HOME/.local/share/waydroid/data/misc/adb"
  if [[ ! -f "$HOME/.android/adbkey" ]]; then
    adb keygen "$HOME/.android/adbkey"
  fi
  cp -f "$HOME/.android/adbkey.pub" "$HOME/.local/share/waydroid/data/misc/adb/adb_keys" 2>/dev/null || true
  waydroid adb connect >/dev/null 2>&1 || adb connect "${ip}:5555" >/dev/null 2>&1 || true
  local _
  for _ in $(seq 1 40); do
    if adb devices 2>/dev/null | tr -d '\r' | grep -qE "${ip}:5555[[:space:]]+device"; then
      export ANDROID_SERIAL="${ip}:5555"
      return 0
    fi
    adb connect "${ip}:5555" >/dev/null 2>&1 || true
    sleep 0.5
  done
  echo "[global] ADB not ready for ${ip}:5555" >&2
  adb devices -l >&2 || true
  exit 1
}

setup_android_ndk() {
  export ANDROID_NDK_HOME="${ANDROID_NDK_HOME:-$HOME/.local/share/android-ndk-r29}"
  export ANDROID_NDK_ROOT="$ANDROID_NDK_HOME"
  export ANDROID_HOME="${ANDROID_HOME:-$HOME/.local/share/android-sdk}"
  unset ANDROID_SDK_ROOT 2>/dev/null || true

  local prebuilt="$ANDROID_NDK_HOME/toolchains/llvm/prebuilt/linux-x86_64"
  if [[ ! -d "$prebuilt" ]]; then
    echo "[global] ANDROID_NDK_HOME missing toolchain: $ANDROID_NDK_HOME" >&2
    echo "  Install NDK r29 (or set ANDROID_NDK_HOME)." >&2
    exit 1
  fi
  # Prefer rustup toolchain with android std over nixpkgs rustc (no android target).
  if command -v rustup >/dev/null 2>&1; then
    rustup target add x86_64-linux-android >/dev/null 2>&1 || true
  fi
  local rust_bin="" tc
  if command -v rustup >/dev/null 2>&1; then
    local c
    c="$(rustup which cargo 2>/dev/null || true)"
    if [[ -n "$c" && -x "$c" ]]; then
      local sr
      sr="$("$(dirname "$c")/rustc" --print sysroot 2>/dev/null || true)"
      if [[ -d "${sr}/lib/rustlib/x86_64-linux-android/lib" ]]; then
        rust_bin="$(dirname "$c")"
      fi
    fi
  fi
  if [[ -z "$rust_bin" && -d "${HOME}/.rustup/toolchains" ]]; then
    for tc in "${HOME}/.rustup/toolchains"/*; do
      [[ -x "${tc}/bin/cargo" ]] || continue
      if [[ -d "${tc}/lib/rustlib/x86_64-linux-android/lib" ]]; then
        rust_bin="${tc}/bin"
        break
      fi
    done
  fi
  if [[ -z "$rust_bin" ]]; then
    echo "[global] error: no rustc with x86_64-linux-android std (nixpkgs rustc is not enough)" >&2
    echo "  rustup target add x86_64-linux-android" >&2
    exit 1
  fi
  export PATH="${rust_bin}:${HOME}/.cargo/bin:${prebuilt}/bin:${ANDROID_HOME}/platform-tools:${PATH}"
  export CC_x86_64_linux_android="${CC_x86_64_linux_android:-x86_64-linux-android28-clang}"
  export CARGO_TARGET_X86_64_LINUX_ANDROID_LINKER="$CC_x86_64_linux_android"
  export AR_x86_64_linux_android="${AR_x86_64_linux_android:-llvm-ar}"
  echo "[global] cargo=$(command -v cargo) $(cargo --version 2>/dev/null || true)" >&2
  echo "[global] rustc=$(command -v rustc) sysroot=$(rustc --print sysroot)" >&2
}

build_apk() {
  ensure_vidya
  setup_android_ndk
  need cargo
  if ! cargo apk --help >/dev/null 2>&1; then
    echo "[global] cargo-apk not found; installing…" >&2
    cargo install cargo-apk --locked
  fi
  echo "[global] cargo apk build --lib --target x86_64-linux-android --no-default-features" >&2
  local before after apk
  apk="$ROOT/$APK_REL"
  before=0
  [[ -f "$apk" ]] && before=$(stat -c %Y "$apk" 2>/dev/null || echo 0)
  (
    cd "$ROOT/dist-ui"
    # --lib: only the cdylib (avoids cargo-apk "Bin is not compatible with Cdylib").
    # All cargo/apk chatter → stderr; stdout is only the APK path.
    cargo apk build --lib --target x86_64-linux-android --no-default-features >&2
  ) || {
    echo "[global] cargo apk build failed — not installing a stale APK" >&2
    exit 1
  }
  [[ -f "$apk" ]] || {
    echo "[global] APK missing after build: $apk" >&2
    exit 1
  }
  after=$(stat -c %Y "$apk" 2>/dev/null || echo 0)
  if [[ "$after" -le "$before" ]]; then
    echo "[global] error: APK mtime unchanged after build — refusing stale install" >&2
    exit 1
  fi
  echo "[global] APK updated: $apk" >&2
  printf '%s\n' "$apk"
}

ensure_show_full_ui() {
  [[ "${GLOBAL_SKIP_SHOW_UI:-0}" == "1" ]] && return 0
  export DISPLAY="${DISPLAY:-:0}"
  export WAYLAND_DISPLAY="${WAYLAND_DISPLAY:-wayland-0}"
  export XDG_RUNTIME_DIR="${XDG_RUNTIME_DIR:-/run/user/$(id -u)}"
  if pgrep -a waydroid 2>/dev/null | grep -q show-full-ui; then
    echo "[global] show-full-ui already running"
    return 0
  fi
  echo "[global] waydroid show-full-ui"
  setsid waydroid show-full-ui </dev/null >/tmp/waydroid-full-ui.log 2>&1 &
  sleep 2
}

stop_prior_driver() {
  local p
  for p in $(pgrep -f 'dist_driver@@main' 2>/dev/null || true); do
    kill "$p" 2>/dev/null || true
  done
  sleep 0.3
}

echo "[global] device pipeline (APK → adb install → UI → Gleam)"

need adb
need gleam
need erl
need waydroid

ip="$(ensure_waydroid)"
ensure_adb "$ip"

if [[ "${GLOBAL_APK_SKIP_BUILD:-0}" == "1" ]]; then
  apk="$ROOT/$APK_REL"
  [[ -f "$apk" ]] || {
    echo "[global] GLOBAL_APK_SKIP_BUILD set but no APK at $apk" >&2
    exit 1
  }
else
  apk="$(build_apk)"
fi

echo "[global] adb install -r $apk"
adb install -r "$apk"

ensure_show_full_ui

# Single launch only — a second start kills winit ("EventLoop can't be recreated").
adb shell am force-stop "$PKG" 2>/dev/null || true
sleep 0.4
if ! adb shell am start -n "$ACTIVITY" >/dev/null 2>&1; then
  waydroid app launch "$PKG" >/dev/null 2>&1 || true
fi
echo "[global] launched ${ACTIVITY} on ${ip}"

stop_prior_driver

ui="ui@${ip}"
echo "[global] Gleam → ${ui} (cookie=${COOKIE})"
cd "$ROOT/dist_driver"
export ERL_FLAGS="-name global@127.0.0.1 -setcookie ${COOKIE}"
gleam build
erlc -o build/dev/erlang/dist_driver/ebin src/dist_driver_ffi.erl 2>/dev/null || true
exec gleam run -- "$ui"