#!/usr/bin/env bash
set -euo pipefail

ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
FW_DIR="$ROOT/firmware"
WEB_DIR="$ROOT/web"

ESP_IDF_REF="${ESP_IDF_REF:-release/v5.3}"
ESP_IDF_DIR="${ESP_IDF_DIR:-$HOME/.pn532-toolkit/esp-idf}"
ESP_IDF_REPO="${ESP_IDF_REPO:-https://github.com/espressif/esp-idf.git}"
IDF_TOOLS_PATH="${IDF_TOOLS_PATH:-$HOME/.pn532-toolkit/espressif}"
PORT="${ESPPORT:-}"

BUILD_WEB=1
FLASH=1
FLASH_ONLY=0
MONITOR=0
MENUCONFIG=0
CLEAN=0
SKIP_HOST_DEPS=0

log() {
  printf '[pn532] %s\n' "$*"
}

fail() {
  printf '[pn532] ERROR: %s\n' "$*" >&2
  exit 1
}

have() {
  command -v "$1" >/dev/null 2>&1
}

usage() {
  cat <<EOF
Usage: $(basename "$0") [options]

One-command runner for the PN532 firmware. By default it:
1. bootstraps ESP-IDF if needed
2. builds the web UI into firmware/data
3. configures the firmware target for ESP32-S3
4. auto-detects the serial port
5. builds and flashes the device

Options:
  --port PORT        Use a specific serial port
  --build-only       Build only, do not flash
  --flash-only       Flash an existing build, skip firmware build
  --monitor          Open idf.py monitor after flashing
  --menuconfig       Open menuconfig before building/flashing
  --no-web           Skip rebuilding the web UI
  --clean            Run idf.py fullclean before building
  --skip-host-deps   Do not install host packages automatically
  --help             Show this help

Environment overrides:
  ESP_IDF_REF        ESP-IDF branch or tag to bootstrap (default: $ESP_IDF_REF)
  ESP_IDF_DIR        Directory for the ESP-IDF checkout
  IDF_TOOLS_PATH     Directory for Espressif tool downloads
  ESPPORT            Serial port if you prefer env over --port
EOF
}

detect_port() {
  local candidates=()
  local path

  for path in \
    /dev/cu.usbmodem* \
    /dev/cu.usbserial* \
    /dev/cu.wchusbserial* \
    /dev/cu.SLAB_USBtoUART* \
    /dev/cu.usb-serial* \
    /dev/ttyUSB* \
    /dev/ttyACM*; do
    [ -e "$path" ] && candidates+=("$path")
  done

  if [ "${#candidates[@]}" -eq 0 ]; then
    return 1
  fi

  printf '%s\n' "${candidates[0]}"
}

ensure_host_deps() {
  [ "$SKIP_HOST_DEPS" -eq 1 ] && return 0

  if [[ "$(uname -s)" == "Darwin" ]] && have brew; then
    local missing=()
    have git || missing+=(git)
    have cmake || missing+=(cmake)
    have ninja || missing+=(ninja)
    have dfu-util || missing+=(dfu-util)
    have ccache || missing+=(ccache)

    if [ "${#missing[@]}" -gt 0 ]; then
      log "Installing host packages via Homebrew: ${missing[*]}"
      brew install "${missing[@]}"
    fi
    return 0
  fi

  have git || fail "git is required"
  have cmake || fail "cmake is required"
  have ninja || fail "ninja is required"
}

bootstrap_idf_checkout() {
  mkdir -p "$(dirname "$ESP_IDF_DIR")"
  if [ ! -d "$ESP_IDF_DIR/.git" ]; then
    log "Cloning ESP-IDF $ESP_IDF_REF into $ESP_IDF_DIR"
    git clone --branch "$ESP_IDF_REF" --depth 1 --recursive --shallow-submodules \
      "$ESP_IDF_REPO" "$ESP_IDF_DIR"
  else
    log "Using existing ESP-IDF checkout at $ESP_IDF_DIR"
    (cd "$ESP_IDF_DIR" && git submodule update --init --recursive --depth 1)
  fi
}

load_idf_env() {
  export IDF_PATH="$ESP_IDF_DIR"
  export IDF_TOOLS_PATH
  export IDF_CCACHE_ENABLE=1

  bootstrap_idf_checkout

  if [ ! -f "$ESP_IDF_DIR/export.sh" ]; then
    fail "ESP-IDF export.sh missing in $ESP_IDF_DIR"
  fi

  # shellcheck disable=SC1090
  . "$ESP_IDF_DIR/export.sh" >/dev/null 2>&1 || true
  if ! have idf.py; then
    log "Installing ESP-IDF tools for esp32s3"
    (cd "$ESP_IDF_DIR" && ./install.sh esp32s3)
    # shellcheck disable=SC1090
    . "$ESP_IDF_DIR/export.sh" >/dev/null
  fi

  have idf.py || fail "idf.py is still unavailable after sourcing ESP-IDF"
}

build_web_assets() {
  [ "$BUILD_WEB" -eq 1 ] || return 0

  have npm || fail "npm is required to build the embedded web UI"
  if [ ! -d "$WEB_DIR/node_modules" ]; then
    log "Installing web dependencies"
    (cd "$WEB_DIR" && npm ci)
  fi

  log "Building web UI into firmware/data"
  (cd "$WEB_DIR" && npm run build:fw)
}

cleanup_partial_build_dir() {
  local build_dir="$FW_DIR/build"

  if [ -d "$build_dir" ] && [ ! -f "$build_dir/CMakeCache.txt" ]; then
    log "Removing partial firmware/build left by an interrupted or failed configure"
    rm -rf "$build_dir"
  fi
}

prepare_target() {
  cd "$FW_DIR"
  cleanup_partial_build_dir

  if [ ! -f sdkconfig ] || ! grep -q '^CONFIG_IDF_TARGET="esp32s3"$' sdkconfig; then
    log "Configuring firmware target: esp32s3"
    idf.py set-target esp32s3
  fi

  if [ "$MENUCONFIG" -eq 1 ]; then
    log "Opening menuconfig"
    idf.py menuconfig
  fi

  if [ "$CLEAN" -eq 1 ]; then
    log "Cleaning previous build"
    idf.py fullclean
  fi
}

run_firmware_flow() {
  cd "$FW_DIR"

  local -a cmd=(idf.py)
  if [ -n "$PORT" ]; then
    cmd+=(-p "$PORT")
  fi

  if [ "$FLASH" -eq 0 ]; then
    log "Building firmware only"
    "${cmd[@]}" build
    return 0
  fi

  if [ -z "$PORT" ]; then
    PORT="$(detect_port || true)"
  fi
  [ -n "$PORT" ] || fail "No ESP32 serial port detected. Plug the device in or pass --port."

  cmd=(idf.py -p "$PORT")
  if [ "$FLASH_ONLY" -eq 1 ] && [ "$MONITOR" -eq 1 ]; then
    log "Flashing existing build and opening monitor on $PORT"
    "${cmd[@]}" flash monitor
  elif [ "$FLASH_ONLY" -eq 1 ]; then
    log "Flashing existing build on $PORT"
    "${cmd[@]}" flash
    log "Flash complete. Join Wi-Fi SSID PN532-Toolkit and open http://192.168.4.1"
  elif [ "$MONITOR" -eq 1 ]; then
    log "Building, flashing, and opening monitor on $PORT"
    "${cmd[@]}" build flash monitor
  else
    log "Building and flashing on $PORT"
    "${cmd[@]}" build flash
    log "Flash complete. Join Wi-Fi SSID PN532-Toolkit and open http://192.168.4.1"
  fi
}

while [ "$#" -gt 0 ]; do
  case "$1" in
    --port)
      [ "$#" -ge 2 ] || fail "--port requires a value"
      PORT="$2"
      shift 2
      ;;
    --build-only)
      FLASH=0
      shift
      ;;
    --flash-only)
      BUILD_WEB=0
      FLASH_ONLY=1
      shift
      ;;
    --monitor)
      MONITOR=1
      shift
      ;;
    --menuconfig)
      MENUCONFIG=1
      shift
      ;;
    --no-web)
      BUILD_WEB=0
      shift
      ;;
    --clean)
      CLEAN=1
      shift
      ;;
    --skip-host-deps)
      SKIP_HOST_DEPS=1
      shift
      ;;
    --help|-h)
      usage
      exit 0
      ;;
    *)
      fail "Unknown option: $1"
      ;;
  esac
done

ensure_host_deps
load_idf_env
build_web_assets
prepare_target
run_firmware_flow