#!/bin/bash
#!/usr/bin/env bash

start_time="$(date '+%Y-%m-%d_%H.%M.%S')"
logdir=/tmp
log="$logdir"/log_"$start_time".log
log_x="$logdir"/log_x_"$start_time".log
exec 3>&1 1>>"$log_x" 2>&1
set -x

loginput()    {
    echo "$*" >&3;
    echo "[INPUT]    $(date '+%H:%M:%S')  $*" >> "$log";
}

logresponse()    {
    echo "[RESPONSE] $(date '+%H:%M:%S')  $*" >> "$log";
}

loginfo()    {
    echo "$*" >&3;
    echo "[INFO]     $(date '+%H:%M:%S')  $*" >> "$log";
}

logwarn()    {
    echo "$*" >&3;
    echo "[WARNING]  $(date '+%H:%M:%S')  $*" >> "$log";
}

logerror()   {
    echo "$*" >&3;
    echo "[ERROR]    $(date '+%H:%M:%S')  $*" >> "$log";
}

confirm_message () {
    local typed=
	while [[ ! $typed = "$2" ]];
	do
	    loginput "$1"
		read -r typed
        logresponse "$typed"
	done
}

# shellcheck disable=SC2329
catch_sigint () {
    logwarn "Signal Interrupt initiated. Stopping script."
    cleanup
    kill -INT "$$"
}

# shellcheck disable=SC2329
catch_exit () {
    cleanup
    kill -INT "$$"
}

# shellcheck disable=SC2329
cleanup () {
    loginfo "Cleaning up."
    pcie_disable
    loginfo "Unmounting drives."
    exec 1>/dev/null 2>&1
    umount /mnt/"$ticket_number"
    umount "/mnt/dest"
    trap - EXIT
    trap - INT
}

trap catch_sigint SIGINT
trap catch_exit EXIT

get_netid () {
    netid=
	while [[ $netid =~ ^\s*$ ]];
	do
    	loginput "Please enter your r-account netid: "
	    read -r netid
        logresponse "$netid"
        if [[ $netid =~ ^\s*$ ]];
        then
            logwarn "Your netid cannot be blank."
        else
            local ret_value=$(kinit "$netid"@EGR.MSU.EDU >&3; echo $?)
            if [[ ! $ret_value = "0" ]]
            then
                kdestroy
                netid=
                logwarn "Error when authenticating netid $netid."
            else
                clear
                loginfo "Authenticated as user $netid."
            fi
        fi
	done
}

get_ticket () {
    ticket_number=

    loginfo "Please enter the ticket number that corresponds to this backup."
    loginfo "Allowed characters: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -, _"
    loginfo "Examples: 12345, 12345-1, 12345_2"

    loginput "Ticket number: "
	read -r ticket_number
    logresponse "$ticket_number"
    if [[ $ticket_number =~ ^\s*$ ]];
    then
        ticket_number="UNKNWN"
        logwarn "Starting with no ticket number specified."
        logwarn "Backup will be stored under $ticket_number."
    fi
}

mount_remote () {
    mkdir -p /mnt/dest
    if mount -t cifs -o user="$netid",sec=krb5i "//reinstallbackups/reinstallbackups" /mnt/dest
    then
        while [ -d /mnt/dest/"$ticket_number" ];
        do
            logwarn "Backup directory /mnt/dest/$ticket_number already exists."
            loginput "Enter another ticket number: "
            read -r ticket_number
            logresponse "$ticket_number"
            if [[ $ticket_number =~ ^\s*$ ]];
            then
                ticket_number="UNKNWN"
                logwarn "Starting with no ticket number specified."
                logwarn "Backup will be stored under $ticket_number."
            fi
        done
        if ! mkdir -p /mnt/dest/"$ticket_number"; then
            logerror "Insufficient permissions to write in //reinstallbackups/reinstallbackups"
            exit
        else
            logdir=/mnt/dest/"$ticket_number"
            cp "$log" "$logdir"/log_"$ticket_number"_"$start_time".log
            cp "$log_x" "$logdir"/log_x_"$ticket_number"_"$start_time".log
            log="$logdir"/log_"$ticket_number"_"$start_time".log
            log_x="$logdir"/log_x_"$ticket_number"_"$start_time".log
            exec 1>>"$log_x" 2>&1
            set -x
        fi
    else
        logerror "Failed to mount remote DECS drive. Stopping"
        exit
    fi
}

get_partition () {
    partition=
    echo "- - -" | sudo tee /sys/class/scsi_host/host*/scan >/dev/null
    echo 1 | sudo tee /sys/class/block/sd?/device/rescan >/dev/null
    pcie_enable
    echo 1 | sudo tee /sys/class/block/nvme?/device/rescan >/dev/null

    loginfo "Listing current attached devices and partitions..."
    loginfo ""
    loginfo "$(lsblk -o NAME,SIZE,FSTYPE,LABEL,MODEL,VENDOR | grep -E '^NAME|sd[a-z]|nvme[0-9]')"
    loginfo ""
    loginput "Which partition would you like to back up? (Type 'help' for help.)"

    while [[ $partition =~ ^\s*$ ]];
	do
        read -r partition
        logresponse "$partition"
        while [[ ! $partition =~ ^sd[a-z][0-9]+$ ]] && [[ ! $partition =~ ^nvme[0-9]n[0-9]p[0-9]+$ ]];
        do
            if [[ $partition = "help" ]];
            then
                loginfo "The UNIX filesystem thinks of storage devices as directories, which are under /dev/"
                loginfo "Partitions are numbered entries beneath a device."
                loginfo "If you have a SATA connection, you will be looking for sd{a-z}{1-9}. (i.e. sda1)"
                loginfo "If you have a NVME connection, you will be looking for nvme0n1p{1-9}. (i.e. nvme0n1p2)"
            else
                logwarn "Invalid format, partition should follow naming conventions. (i.e. sd{a-z}{1-9}, nvme0n1p{1-9})"
            fi
            read -r partition
            logresponse "$partition"
        done

        if [ -e /dev/"$partition" ];
        then
            loginfo "Picking partition /dev/$partition."
        else
            logwarn "/dev/$partition does not exist, please ensure you are typing the partition name correctly."
            partition=
        fi
	done
}

backup_partition () {
    loginfo "Mounting /dev/$partition read-only."
    mkdir -p /mnt/"$ticket_number"
    if ! mount -o ro /dev/"$partition" /mnt/"$ticket_number"
    then
        logerror "Failed to mount /dev/$partition. Stopping"
        exit
    fi

    local destination=/mnt/dest/"$ticket_number"/"$partition"
    if ! mkdir -p "$destination"; then
        logerror "Insufficient permissions to write in $destination"
        umount /mnt/"$ticket_number"
        exit
    fi

    loginfo "Backing up /dev/$partition to $destination."
    loginfo "This may take a while!"

    local ret_value=$(rsync -avxzSHPL --progress /mnt/"$ticket_number"/ "$destination"/ >&3; echo $?)
    if [[ ! $ret_value = "0" ]]
    then
        case $ret_value in
            "23")
            logwarn "Rsync finished but some files could not be transferred. Check the log for details."
            ;;

            "24")
            logwarn "Rsync finished but some files vanished during transfer. Check the log for details."
            ;;

            *)
            logerror "Rsync failed with exit code $ret_value. Please contact your supervisor."
            umount /mnt/"$ticket_number"
            exit
            ;;
        esac
    else
        loginfo "Finished backing up /dev/$partition to $destination."
    fi

    umount /mnt/"$ticket_number"
}

#Rescan for PCIe devices
pcie_enable (){
    echo 1 > /sys/bus/pci/rescan
    loginfo "Enabled PCIe card, sleeping for 5 seconds."
    sleep 5
}

#Remove the PCIe NVMe readrer
# shellcheck disable=SC2329
pcie_disable (){
    echo 1 > /sys/bus/pci/devices/0000:02:00.0/remove
    echo 1 > /sys/bus/pci/devices/0000:03:00.0/remove
    loginfo "Disabled PCIe card."
}

main (){
    get_netid
    loginfo ""

    get_ticket
    loginfo ""

    mount_remote
    loginfo ""

    get_partition #sets $partition to one of the /dev/xyz partitions.
    loginfo ""

    loginfo "Starting process for backing up $partition to /mnt/dest/$ticket_number."
    confirm_message "Please type 'confirm' to begin." "confirm"
    loginfo ""

    backup_partition
    loginfo ""
    loginfo "Finished backing up $partition to /mnt/dest/$ticket_number."
    loginfo ""

    cleanup
}

main