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

# Must be run as root
if [[ $EUID -ne 0 ]]; then
  echo "This script must be run as root. Try sudo $0 ..." >&2
  exit 1
fi

# Default env file
ENV_FILE="./.env"

# PiCorePlayer version to use
PCP_VERSION="10.0.0"
BASE_URL="https://repo.pcplayer.org/insitu/piCorePlayer${PCP_VERSION}"
IMG_ZIP="piCorePlayer${PCP_VERSION}.img.xz"
DOWNLOAD_URL="${BASE_URL}/${IMG_ZIP}"

# Print usage
usage() {
  cat <<EOF
Usage: sudo $0 --sdcard </dev/sdX> \
              [--env-file /path/to/.env]

  --sdcard     Device node of the SD card (e.g. /dev/sdb)
  --env-file   File containing WIFI_SSID and WIFI_PSK (defaults to ./.env)
EOF
  exit 1
}

# Parse args
SDCARD=""
while [[ $# -gt 0 ]]; do
  case "$1" in
    --sdcard)   SDCARD="$2";   shift 2;;
    --env-file) ENV_FILE="$2"; shift 2;;
    -h|--help)  usage;;
    *) echo "Unknown option: $1" >&2; usage;;
  esac
done

# Validate
if [[ -z "$SDCARD" ]]; then
  usage
fi
if [[ ! -b "$SDCARD" ]]; then
  echo "Error: $SDCARD is not a block device." >&2
  exit 1
fi
if [[ ! -f "$ENV_FILE" ]]; then
  echo "Error: env file '$ENV_FILE' not found." >&2
  exit 1
fi

# Load Wi-Fi credentials
source "$ENV_FILE"
if [[ -z "${WIFI_SSID:-}" || -z "${WIFI_PSK:-}" ]]; then
  echo "Error: WIFI_SSID and WIFI_PSK must be set in $ENV_FILE" >&2
  exit 1
fi

# Download if needed
if [[ ! -f "$IMG_ZIP" ]]; then
  echo "Downloading $IMG_ZIP ..."
  wget -q --show-progress "$DOWNLOAD_URL"
fi

# Flash image
echo "Flashing $IMG_ZIP to $SDCARD (will overwrite everything!)"
sync
xzcat "$IMG_ZIP" | dd of="$SDCARD" bs=4M status=progress
sync

# Determine partition suffixes (/dev/sdX1 vs /dev/mmcblk0p1)
if [[ "$SDCARD" =~ [0-9]$ ]]; then
  PART1="${SDCARD}p1"; PART2="${SDCARD}p2"
else
  PART1="${SDCARD}1";  PART2="${SDCARD}2"
fi

# Mount partitions
BOOT_MNT=$(mktemp -d)
ROOT_MNT=$(mktemp -d)
mount "$PART1" "$BOOT_MNT"
mount "$PART2" "$ROOT_MNT"

# Create hidden Wi-Fi config on boot partition
cat > "$BOOT_MNT/wpa_supplicant.conf" <<EOF
ctrl_interface=/var/run/wpa_supplicant
ctrl_interface_group=staff
country=AT
update_config=1

network={
    ssid="$WIFI_SSID"
    psk="$WIFI_PSK"
    scan_ssid=1
    key_mgmt=WPA-PSK
    auth_alg=OPEN
}
EOF

# Cleanup
umount "$BOOT_MNT" "$ROOT_MNT"
rmdir "$BOOT_MNT" "$ROOT_MNT"

echo "Done! SD card is ready with PiCorePlayer ${PCP_VERSION},"
echo "hidden Wi-Fi '$WIFI_SSID'."
echo "Insert the SD card into the Pi and power it on."
echo "You can now connect to the PiCorePlayer web interface at http://pcp.local"