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

BOOTFS=${1:-/run/media/jet/bootfs}
ROOTFS=${2:-/run/media/jet/rootfs}
HOSTNAME=noisebell-pi
WIFI_SSID=Noisebridge
WIFI_PASSWORD=noisebridge
PI_USERNAME=pi
SSH_KEY='ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIE40ISu3ydCqfdpb26JYD5cIN0Fu0id/FDS+xjB5zpqu'

if [[ $EUID -ne 0 ]]; then
  echo "Run with sudo: sudo $0 [bootfs] [rootfs]" >&2
  exit 1
fi

if [[ ! -d "$BOOTFS" ]]; then
  echo "Expected mounted boot partition." >&2
  echo "Boot: $BOOTFS" >&2
  exit 1
fi

CONFIG_TXT="$BOOTFS/config.txt"
if [[ ! -f "$CONFIG_TXT" && -f "$BOOTFS/firmware/config.txt" ]]; then
  CONFIG_TXT="$BOOTFS/firmware/config.txt"
fi

if [[ ! -f "$CONFIG_TXT" ]]; then
  echo "Could not find config.txt in $BOOTFS" >&2
  exit 1
fi

ROOTFS_READY=0
if [[ -d "$ROOTFS" && -f "$ROOTFS/etc/shadow" ]]; then
  ROOTFS_READY=1
fi

cat > "$BOOTFS/network-config" <<EOF
network:
  version: 2

  wifis:
    wlan0:
      dhcp4: true
      optional: true
      access-points:
        ${WIFI_SSID}:
          password: "${WIFI_PASSWORD}"
      regulatory-domain: US
EOF

cat > "$BOOTFS/user-data" <<EOF
#cloud-config
hostname: ${HOSTNAME}
manage_etc_hosts: true
ssh_pwauth: false
package_update: false
packages:
  - avahi-daemon
users:
  - name: pi
    ssh_authorized_keys:
      - ${SSH_KEY}
runcmd:
  - [ systemctl, enable, --now, avahi-daemon ]
EOF

cat > "$BOOTFS/meta-data" <<EOF
dsmode: local
instance_id: ${HOSTNAME}-bootstrap-1
EOF

grep -q '^enable_uart=1$' "$CONFIG_TXT" || printf '\nenable_uart=1\n' >> "$CONFIG_TXT"
: > "$BOOTFS/ssh"

if [[ "$ROOTFS_READY" -eq 1 ]]; then
  cat > "$ROOTFS/etc/hostname" <<EOF
${HOSTNAME}
EOF

  cat > "$ROOTFS/etc/hosts" <<EOF
127.0.0.1	localhost
::1		localhost ip6-localhost ip6-loopback
ff02::1		ip6-allnodes
ff02::2		ip6-allrouters

127.0.1.1		${HOSTNAME}
EOF

  mkdir -p "$ROOTFS/home/pi/.ssh"
  cat > "$ROOTFS/home/pi/.ssh/authorized_keys" <<EOF
${SSH_KEY}
EOF
  chown -R 1000:1000 "$ROOTFS/home/pi/.ssh"
  chmod 700 "$ROOTFS/home/pi/.ssh"
  chmod 600 "$ROOTFS/home/pi/.ssh/authorized_keys"
fi

sync

echo "Configured Raspberry Pi OS SD card."
echo "- Hostname: ${HOSTNAME}"
echo "- Wi-Fi: ${WIFI_SSID}"
echo "- SSH enabled on first boot"
echo "- Serial UART enabled"
echo "- Username: ${PI_USERNAME}"
echo "- Pi user authorized key installed"
if [[ "$ROOTFS_READY" -ne 1 ]]; then
  echo "- Note: rootfs was not mounted; only boot partition config was updated"
fi