#!/usr/bin/env bash

# SPDX-FileCopyrightText: 2026 Laborratte5 laborratte5@gmail.com
# SPDX-License-Identifier: GPL-3.0-only

flash_sd () {
    img_file=$1
    sd_card=$2
    echo "Flashing $img_file to $sd_card ..."
    xzcat --stdout $img_file | dd of=$sd_card status=progress
}

enlarge_partition () {
    device=$1
    partnr=2
    echo "Resize main partition"
    sfdisk --backup $device -N $partnr << EOF
,+
print
EOF
    echo "Resize filesystem"
    e2fsck -f "$device"p$partnr
    resize2fs -p "$device"p$partnr
}

mount_temporary () {
    partnr=$1
    temp_mnt_point=$(mktemp -d)
    mount "$SD_CARD"p"$partnr" $temp_mnt_point
    echo $temp_mnt_point
}

unmount_temporary () {
    handle=$1
    umount $1
    rmdir $1
}

provision_network () {
    mnt_point=$1

    echo "Provision network"
    cat > $mnt_handle/network-config <<EOF
network:
    version: 2
    ethernets:
        eth0:
            addresses: [$NET_ADDR]
            routes:
                - to: default
                  via: $DEFAULT_GATEWAY
EOF
}

provision_user () {
    mnt_point=$1

    echo "Provision user"
    if [ -f $ssh_key ]; then
        # Load key from file
        echo "Loading ssh key from file $ssh_key"
        ssh_key=$(<$ssh_key)
    fi

    cat > $mnt_point/user-data <<EOF
#cloud-config

hostname: raspberry-pi
manage_etc_hosts: true

timezone: Europe/Berlin

package_update: true
package_upgrade: true

enable_ssh: true

users:
    - name: $username
      group: users,adm,dialout,audio,netdev,video,plugdev,cdrom,games,input,gpio,spi,i2c,render,sudo
      shell: /bin/bash
      lock_passwd: false
      plain_text_passwd: $userpw
      sudo: ALL=(ALL) ALL
      ssh_authorized_keys:
          - $ssh_key
EOF
}

read -e -p "Compressed Image file: " IMG_FILE
read -e -p "SD Card: " SD_CARD
read -e -p "IP-Address with prefix (comma separated): " NET_ADDR
read -e -p "Default Gateway: " DEFAULT_GATEWAY
read -e -p "Username: " username
read -s -p "Password: " userpw
echo
read -e -p "SSH-Key: " ssh_key
echo

flash_sd "$IMG_FILE" "$SD_CARD"
enlarge_partition "$SD_CARD"
mnt_handle=$(mount_temporary "1")

provision_network $mnt_handle
provision_user $mnt_handle

unmount_temporary $mnt_handle