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

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
FIRMWARE_SRC="$SCRIPT_DIR/firmware"
BOOT="/boot/firmware"

if [[ $EUID -ne 0 ]]; then
    echo "ERROR: this script must be run as root (use sudo)" >&2
    exit 1
fi

echo "=== IOT-GATE-RPI4 layer install ==="
echo "Source : $FIRMWARE_SRC"
echo "Target : $BOOT"
echo

# --- config.txt ---
echo "[1/2] Installing config.txt"

if [[ -f "$BOOT/config.txt" ]]; then
    echo "  Backing up $BOOT/config.txt -> $BOOT/config.bak"
    cp -v "$BOOT/config.txt" "$BOOT/config.bak"
else
    echo "  WARNING: $BOOT/config.txt not found, skipping backup"
fi

echo "  Copying $FIRMWARE_SRC/config.txt -> $BOOT/config.txt"
cp -v "$FIRMWARE_SRC/config.txt" "$BOOT/config.txt"

# --- overlays ---
echo
echo "[2/2] Installing device tree overlays"

OVERLAY_SRC="$FIRMWARE_SRC/overlays/iotg-rpi4"
OVERLAY_DST="$BOOT/overlays/iotg-rpi4"

if [[ ! -d "$OVERLAY_SRC" ]]; then
    echo "  ERROR: overlay source directory not found: $OVERLAY_SRC" >&2
    exit 1
fi

echo "  Creating $OVERLAY_DST"
mkdir -p "$OVERLAY_DST"

for f in "$OVERLAY_SRC"/*; do
    echo "  Copying $(basename "$f")"
    cp -v "$f" "$OVERLAY_DST/"
done

echo
echo "=== Done ==="
echo "Reboot for overlay changes to take effect."