#!/usr/bin/env bash
#
#
# https://sharats.me/posts/shell-script-best-practices/
set -o errexit
set -o nounset
set -o pipefail
if [[ "${TRACE-0}" == "1" ]]; then set -o xtrace; fi
# Change to script dir
cd "$(dirname "$0")"
#
if [[ "${1-}" =~ ^-*h(elp)?$ ]]; then
    echo 'Usage: ./pilpil-server.sh path_to_device

This is an awesome bash script to make your life better.

'
    exit
fi
# Options
# Device block to write on 
# Colored output
#~ set +x
bold=$(tput bold)
function red(){
    echo -e "${bold}\x1B[31m$1 \x1B[0m"
    if [ ! -z "${2}" ]; then
    echo -e "\x1B[31m $($2) \x1B[0m"
    fi
}
function green(){
    echo -e "${bold}\x1B[32m$1 \x1B[0m"
    if [ ! -z "${2}" ]; then
    echo -e "\x1B[32m $($2) \x1B[0m"
    fi
}
function yellow(){
    echo -e "${bold}\x1B[33m$1 \x1B[0m"
    if [ ! -z "${2}" ]; then
    echo -e "\x1B[33m $($2) \x1B[0m"
    fi
}

SDCARD=$1
# TODO : accomodate for devices block with name mmcblk0p1|p2
if [[ "$SDCARD" == "" ]] || [[ ! -e "$SDCARD" ]]
then 
    red "Please specify an existing device block for your sd-card, e.g: '/dev/sda'." >&2
    exit 0
fi
DD_BS="128K"
DISK_IMAGE="$HOME/niels/imgs/2022-10-25-pilpil-WIP.img.xz"
if [[ ! -f "$DISK_IMAGE" ]]
then 
    red "Disk image not found, aborting..." >&2
    exit 0
fi
CONFIG_DIR="$HOME/niels/pilpil-server"
if [[ ! -d "$CONFIG_DIR" ]]
then 
    red "Config directory not found, aborting..." >&2
    exit 0
fi
HTTP_SECRET=$(openssl rand -base64 12)
PI_USER="pil"
BOOT_MOUNT="/run/media/$USER/boot"
ROOTFS_MOUNT="/run/media/$USER/rootfs"
#~ LOCAL_MEDIA_DIR="$HOME/Videos"
LOCAL_MEDIA_DIR="$HOME/niels/medias"
if [[ ! -d "$LOCAL_MEDIA_DIR" ]]
then 
    red "Medias directory not found, aborting..." >&2
    exit 0
fi
REMOTE_MEDIA_DIR="$ROOTFS_MOUNT/home/$PI_USER/Videos"
# WIFI AP config
IP_RANGE="10.42.0.1"
SSID="omen"
PASSWD="EpQmSmXH123"
IFW="wlo1"
#Band (bg = 2.4Ghz, a= 5Ghz)
BAND="bg"
# Hidden SSID
#~ HIDE="802-11-wireless.hidden false"
# Set channel manually
CHAN="802-11-wireless.channel 1"
#
#
#  0. Create AP connection
#
# If connection exists, delete it
nmcli con delete $SSID
nmcli con add type wifi ifname $IFW con-name $SSID autoconnect yes ssid $SSID
nmcli con modify $SSID 802-11-wireless.mode ap 802-11-wireless.band $BAND $CHAN $HIDE ipv4.method shared
nmcli con modify $SSID wifi-sec.key-mgmt wpa-psk
nmcli con modify $SSID 802-11-wireless-security.proto rsn
nmcli con modify $SSID 802-11-wireless-security.pairwise ccmp
nmcli con modify $SSID wifi-sec.psk $PASSWD

# 0.a set IP range on server
echo -e "Setting IP range $IP_RANGE/24 in /etc/NetworkManager/system-connections/$SSID.nmconnection ... \n"
sudo sed -i "/method=shared/a address1=$IP_RANGE/24, $IP_RANGE" /etc/NetworkManager/system-connections/$SSID.nmconnection
# Remove existing leases
sudo rm /var/lib/NetworkManager/dnsmasq-$IFW.leases
sudo systemctl restart NetworkManager

nmcli radio wifi on
nmcli con up $SSID

# 0.b ask for number of clients
# This will be used to determine static IP
yellow "Nombre de clients à configurer : "
read -n 4 CLIENT_NUMBER
green "Got $CLIENT_NUMBER...\n"
# For some reason networkmanager finds it clever to offer only IPs in range 10-255 even when asked for a /24, /28, etc...
# So IPs start at 10
# Get first IP in specified range
#~ IP=$(echo $IP_RANGE | awk -F. '{print $4}')
FIRST=1
IP=10
echo -e "First IP is $(($RANGE_START)) ...\n"
# Remove IP's last byte
IP_RANGE_3B=$(echo $IP_RANGE | awk -F. '{print $1"."$2"."$3"."}')
# Generate SSL cert with IPs in IP_RANGE
IP_CNT=$IP
IP_ARRAY=()
while [[ "$IP_CNT" -lt $(($CLIENT_NUMBER+$IP)) ]] 
do
    IP_ARRAY+=("IP:$IP_RANGE_3B$IP_CNT")
    ((IP_CNT++))
done
# Convert array to string
HOST_LIST="$(IFS=","; echo "${IP_ARRAY[*]}")"
yellow "Got host list : $HOST_LIST \n"
#  5. Generate valid ssl cert/key for every IP in range
# https://unix.stackexchange.com/questions/104171/create-ssl-certificate-non-interactively
yellow "Generating SSL crt/key for $HOST_LIST...\n"
openssl req -new -newkey rsa:4096 -days 1825 -nodes -x509 \
-subj "/C=/ST=Denial/L=/O=/CN=$IP_RANGE$FIRST" \
-addext "subjectAltName=$HOST_LIST" \
-keyout "$CONFIG_DIR/selfCA.key" -out "$CONFIG_DIR/selfCA.crt"
#sudo openssl req -x509 -nodes -days 3650 -newkey rsa:2048 -keyout "$ROOTFS_MOUNT/etc/ssl/private/nginx-selfsigned.key" -out "$ROOTFS_MOUNT/etc/ssl/certs/nginx-selfsigned.crt"

# Proceed with each host
for HOST in "${IP_ARRAY[@]}"
do
    HOST=$(echo $HOST | awk -F: '{print $2}')
    HOST_NAME="pilpil-$(echo $HOST | awk -F. '{print $4}')"
    #  1. Copy img to sd
    green "Operation 1/13 : Imaging $SDCARD with the file $DISK_IMAGE ...\n"
    red  "Are you sure you want to ERASE THE CONTENT of $SDCARD ? Type uppercase 'yes' to confirm."
    read -n 4 GO_DD
    if [[ "$GO_DD" != "YES" ]]
    then
        red "Answer was different from 'YES'. Aborting..." >&2
        break
    fi
    red "Received answer $GO_DD. Running dd on $SDCARD in 5 seconds."
    sleep 5
    GO_DD=0
    # unmount / remount new filesystem
    green "Unmounting $BOOT_MOUNT and $ROOTFS_MOUNT ...\n" 
    umount $BOOT_MOUNT
    umount $ROOTFS_MOUNT
    xzcat "$DISK_IMAGE" | sudo dd of=$SDCARD bs="$DD_BS" oflag=dsync status=progress && sync
    green "Operation 3/13 : Remounting $BOOT_MOUNT and $ROOTFS_MOUNT ...\n" 
    echo "Remounting..."
    sleep 1
    systemctl --user restart gvfs-udisks2-volume-monitor
    sleep 3
    green "Operation 4/13 : Changing hostname to $HOST_NAME ...\n" 
    # Change hostname
    echo "$HOST_NAME" | sudo tee "$ROOTFS_MOUNT/etc/hostname"
    # Reflect that in /etc/hosts
    sudo sed -i "$ d" "$ROOTFS_MOUNT/etc/hosts"
    echo -e "127.0.1.1\t$HOST_NAME" | sudo tee -a "$ROOTFS_MOUNT/etc/hosts"
    ## Enable SSH
    green "Operation 5/13 : Enabling SSH server on boot ...\n" 
    touch "$BOOT_MOUNT/ssh"
    sync
    ## Generate SSH private/public key and install it - Disable passwd login
    green "Operation 6/13 : Generating private/public SSH key as $HOME/.ssh/$HOST_NAME ...\n" 
    ssh-keygen -t ed25519 -f "$HOME/.ssh/$HOST_NAME" -N ""
    red "New SSH key pair generated as $HOME/.ssh/$HOST_NAME. Add to ~/.ssh/config ? (y/n)"
    read -n 2 ADD_SSH_CONF
    if [[ "$ADD_SSH_CONF" == "y" ]]
    then
        # Add to ~/.ssh/config
        echo -e "\nHost $HOST_NAME\n\tHostname $HOST\n\tIdentityFile ~/.ssh/$HOST_NAME\n\tUser $PI_USER" | tee -a "$HOME/.ssh/config"
    fi
    # Copy public key to rpi
    green "Operation 7/13 : Installing public SSH key $HOME/.ssh/$HOST.pub in $ROOTFS_MOUNT/home/$PI_USER/.ssh/authorized_keys...\n" 
    sudo cp "$HOME/.ssh/$HOST_NAME.pub" "$ROOTFS_MOUNT/home/$PI_USER/.ssh/authorized_keys"
    sync
    # Disable PW login
    green "Operation 8/13 : Disabling SSH password based login in $ROOTFS_MOUNT/etc/ssh/sshd_config ...\n" 
    echo -e "PasswordAuthentication no\nChallengeResponseAuthentication no\nUsePAM no" | sudo tee -a "$ROOTFS_MOUNT/etc/ssh/sshd_config"
    sync
    #  3. Configure wifi with static IP
    green "Operation 9/13 : Configuring wireless connection to $SSID with pw $PASSWD :  ...\n" 
    echo "ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
country=FR

network={
    ssid=\"$SSID\" # Nom du réseau auquel on se connecte
    psk=\"$PASSWD\" # Mot de passe wifi
    # Optional parameters
    # scan_ssid=1 # hidden ssid 
    # Specify 2.4 or 5G freq
    # https://w1.fi/cgit/hostap/tree/wpa_supplicant/wpa_supplicant.conf#n910
    # https://fr.wikipedia.org/wiki/Liste_des_canaux_Wi-Fi#Bande_2,4_GHz
    # scan_freq=2412 2437 2462
}" | sudo tee "$ROOTFS_MOUNT/etc/wpa_supplicant/wpa_supplicant.conf"
    sync
    # Request specific IP to dhcp server
    green "Operation 10/13 : Setting static IP $HOST in $ROOTFS_MOUNT/etc/dhcpcd.conf...\n" 
    echo -e "interface wlan0\nrequest $HOST" | sudo tee -a "$ROOTFS_MOUNT/etc/dhcpcd.conf"
    sync
    #  5. Install previously generated SSL key/crt
    #sudo openssl req -x509 -nodes -days 3650 -newkey rsa:2048 -keyout "$ROOTFS_MOUNT/etc/ssl/private/nginx-selfsigned.key" -out "$ROOTFS_MOUNT/etc/ssl/certs/nginx-selfsigned.crt"
    green "Operation 11/13 : Installing public SSH key $CONFIG_DIR/selfCA.crt in $ROOTFS_MOUNT/etc/ssl/certs/ ...\n" 
    sudo cp "$CONFIG_DIR/selfCA.crt" "$ROOTFS_MOUNT/etc/ssl/certs/nginx-selfsigned.crt" 
    sudo cp "$CONFIG_DIR/selfCA.key" "$ROOTFS_MOUNT/etc/ssl/private/nginx-selfsigned.key"
    sync
    #~ Change VLC/pilpil http auth secret
    sed -i "s:secret:$HTTP_SECRET:g" "$CONFIG_DIR/pilpil-server.toml"
    sed -i "s:secret:$HTTP_SECRET:g" "$ROOTFS_MOUNT/home/pil/.config/systemd/user/vlc.service" 
    sed -i "s:secret:$HTTP_SECRET:g" "$ROOTFS_MOUNT/home/pil/pilpil-client/defaults.toml" 
    #~ #  6. Copy medias
    green "Operation 12/13 : Syncing media folder $LOCAL_MEDIA_DIR/ with $REMOTE_MEDIA_DIR/ \n" 
    # Remove filler file
    if [[ -f "$REMOTE_MEDIA_DIR/remove_me"  ]]
    then 
        sudo rm "$REMOTE_MEDIA_DIR/remove_me"
    fi
    # Get available space on rootfs
    ROOTFS_AVAILABLE_SPACE=$(df -t ext4 -P $ROOTFS_MOUNT  | tail -1 | awk '{print $4}')
    # Get Media folder size
    MEDIA_SIZE=$(du -c $LOCAL_MEDIA_DIR | tail -1 | awk '{print $1}')
    # Only copy files if enough space available
    if [[ "$MEDIA_SIZE" -lt "$ROOTFS_AVAILABLE_SPACE" ]]
    then
        USER_ID=$( cat "$ROOTFS_MOUNT/etc/passwd" | grep $PI_USER | awk -F: '{print $3}' )
        GROUP_ID=$( cat "$ROOTFS_MOUNT/etc/passwd" | grep $PI_USER | awk -F: '{print $4}' )
        sudo cp "$LOCAL_MEDIA_DIR/"* "$REMOTE_MEDIA_DIR/"
        sudo chown -R $USER_ID:$GROUP_ID "$REMOTE_MEDIA_DIR"
        sync
    else
        red "Not enough space on $ROOTFS_MOUNT, skipping..." 
    fi
    # Unmount FS
    green "Operation 13/13 : Unmounting filesystems"
    umount $BOOT_MOUNT
    umount $ROOTFS_MOUNT
    yellow "Client $(($IP-9))/$CLIENT_NUMBER done."
    if [[ "$IP" -le "$IP_CNT" ]]
    then
        red "Please swap sd card in reader and enter uppercase 'yes' to proceed with next client or hit Ctrl-C:"
        read -n 4 GO_ON
        if [ "$GO_ON" != "YES" ]
        then
            red "Answer was different from 'YES'. Aborting...\n" >&2
            break
        fi
        GO_ON=0
        ((IP++))
    else
        green "All done !"
        exit 1
    fi
done
yellow "Nothing more to do."
exit 0
#~ rm "$CONFIG_DIR/selfCA.key"