#!/usr/bin/env bash
#
# status of mounted filesystems in 2 steps
#     1. use "df" for general fs except zfs, squashfs, tmpfs, devtmpfs and overlay
#     2. use "zpool" for ZFS pools
# + displays name, filesystem type, used blocks and inodes or pool health when relevant
# + custom warn threshold for blocks
# + warn threshold for inodes (80%), flashing danger threshold for health, blocks (95%) and inodes (90%)
#
# requirements: sudo apt install coreutils
# optionnal:    sudo apt install zfsutils-linux

# GENERAL ###########################################################

# locale env
unset LC_ALL
export LC_MESSAGES=C

# check if module was disabled
module_disable=${module_filesystem_disable:=0}
if (($module_disable == 1)); then
    exit 1
fi

# colors
c_txt=${c_txt:="39"}
c_txt_emphase=${c_txt_emphase:="35"}
c_txt_deco=${c_txt_deco:="97"}
c_txt_invert=${c_txt_invert:="30"}
c_bg=${c_bg_sec:="47"}
c_danger=${c_danger:="31"}
c_warning=${c_warning:="33"}
c_success=${c_success:="32"}
c_title=${c_title:="${c_bg};1;${c_txt_invert}m"}

# OPTIONS ###########################################################

# max usage warning threshold
max_usage=${module_filesystem_max_usage:="85"}

# disable ZFS section
zfs_disable=${module_filesystem_zfs_disable:=0}

# PREPARATIONS ######################################################

# disk usage: ignore zfs, squashfs & tmpfs, standard error output because of a bug with /run/user/1000/doc
dfcmd=$(/usr/bin/df -H -x zfs -x squashfs -x tmpfs -x devtmpfs -x overlay --output 2>/dev/null)
mapfile -t dfoutput < <(echo "$dfcmd" | tail -n+2)

# determine best width for the bar
largesttarget=$(echo "$dfcmd" | awk '{if (length ($12)>max) max=length($12)} END {print max}')
if [[ $((largesttarget+30)) -gt 50 ]]; then
    bar_width=$((largesttarget+30))
else
    bar_width="50"
fi

# OUTPUT ############################################################

# general filesystems
linecounter=0
if [[ "${dfoutput[@]}" ]]; then
    # output header
    echo -e "\n\e[${c_title} Filesystem usage  \e[0m\n"
    # output filesystem status except ZFS
    for line in "${dfoutput[@]}"; do
        # parse df output
        diskid=$(echo "$line" | awk '{print $12}')
        diskused=$(echo "$line" | awk '{print $10}'| sed 's/%//')
        disktotal=$(echo "$line" | awk '{print $7}')
        fsformat=$(echo "$line" | awk '{print $2}')
        inodesused=$(echo "$line" | awk '{print $6}'| sed 's/%//')
        inodestotal=$(echo "$line" | awk '{print $3}')
        
        # bar & blocks coloration, danger red above 95%
        if [[ "${diskused}" -ge "95" ]]; then
            barcolor="\e[1;${c_danger}m"
            blockscolor="\e[1;${c_danger}m"
            flashing="\e[5m"
        elif [ "${diskused}" -ge "${max_usage}" ]; then
            barcolor="\e[1;${c_warning}m"
            blockscolor="\e[1;${c_warning}m"
            flashing=""
        else
            barcolor="\e[1;${c_success}m"
            blockscolor="\e[${c_txt}m"
            flashing=""
        fi
        # print colored bar until used_width
        used_width=$(((diskused*$bar_width)/100))
        bar="[${barcolor}"
        for ((i=0; i<$used_width; i++)); do
            bar+="="
        done
        # print dimmmed bar until end
        bar+="\e[${c_txt}m\e[0m"
        for ((i=$used_width; i<$bar_width; i++)); do
            bar+="="
        done
        bar+="\e[0m]"
        
        # print blocks usage line & bar
        padding=$((bar_width-28))
        if [[ $linecounter -ge 1 ]]
        then
            echo -e "\n"
        fi
        echo "${line}" | printf "\e[1;${c_txt_emphase}m%-${padding}s\e[0m${blockscolor}%+3s%% used ${flashing}blocks\e[0m out of %+4s\n" $diskid $diskused $disktotal | sed 's/^/   /'
        echo -e "${bar}" | sed 's/^/  /'
        
        # print filesystem type & inodes usage line
        if [[ ! "$inodesused" == "-" ]]
        then
            padding=$((bar_width-34))
            # inodes coloration, danger red above 90%
            if [[ "${inodesused}" -ge "90" ]]; then
                inodescolor="\e[1;${c_danger}m"
                flashing="\e[5m"
            elif [[ "${inodesused}" -ge "80" ]]; then
                inodescolor="\e[1;${c_warning}m"
                flashing=""
            else
                inodescolor="\e[${c_txt}m"
                flashing=""
            fi
            echo "${line}" | printf "Type: %-${padding}s${inodescolor}%+3s%% used ${flashing}inodes\e[0m out of %+4s\n" $fsformat $inodesused $inodestotal | sed 's/^/   /'
        else
            echo "${line}" | printf "Type: %-10s\n" $fsformat | sed 's/^/   /'
        fi
        linecounter=$((linecounter+1))
    done
else
    echo "  no general filesystem available, ZFS expected in next section"
fi

# check if ZFS section was disabled
if [[ $zfs_disable == 1 ]]; then
    exit 1
fi

# output ZFS header
echo -e "\n\e[${c_title} Zpool usage  \e[0m\n"

# check if zpool is available
if ! command -v zpool 1> /dev/null; then
    echo "  no ZFS tools available"
    exit 1
fi

# ZFS zpool usage & health status
zlistcmd=$(zpool list -o name,cap,size,health 2> /dev/null)
if [[ $zlistcmd == "no pools available" ]]; then
    echo "  no ZFS pool available"
else
    mapfile -t zpools < <(echo "$zlistcmd" | tail -n+2)
    
    # determine best width for the bar
    largesttarget=$(echo "zlistcmd" | awk '{if (length ($1)>max) max=length($1)} END {print max}')
    if [[ $((largesttarget+30)) -gt 50 ]]; then
        bar_width=$((largesttarget+30))
    else
        bar_width="50"
    fi
    
    linecounter=0
    for line in "${zpools[@]}"; do
        # parse zpool list output
        poolid=$(echo "$line" | awk '{print $1}')
        poolused=$(echo "$line" | awk '{print $2}'| sed 's/%//')
        pooltotal=$(echo "$line" | awk '{print $3}')
        poolhealth=$(echo "$line" | awk '{print $4}')
                    
        # bar & pools coloration, danger red above 95%
        if [[ "${poolused}" -ge "95" ]]; then
            barcolor="\e[1;${c_danger}m"
            poolscolor="\e[1;${c_danger}m"
            flashing="\e[5m"
        elif [[ "${poolused}" -ge "${max_usage}" ]]; then
            barcolor="\e[1;${c_warning}m"
            poolscolor="\e[1;${c_warning}m"
            flashing=""
        else
            barcolor="\e[1;${c_success}m"
            poolscolor="\e[${c_txt}m"
            flashing=""
        fi
        # print colored bar until used_width
        used_width=$(((poolused*$bar_width)/100))
        bar="[${barcolor}"
        for ((i=0; i<$used_width; i++)); do
            bar+="="
        done
        # print dimmmed bar until end
        bar+="\e[${c_txt}m\e[0m"
        for ((i=$used_width; i<$bar_width; i++)); do
            bar+="="
        done
        bar+="\e[0m]"
        
        # print pool usage line & bar
        padding=$((bar_width-29))
        if [[ $linecounter -ge 1 ]]
        then
            echo -e "\n"
        fi
        echo "${line}" | printf "\e[1;${c_txt_emphase}m%-${padding}s\e[0m${poolscolor}%+3s%% used ${flashing}blocks\e[0m out of %+5s\n" $poolid $poolused $pooltotal | sed 's/^/   /'
        echo -e "${bar}" | sed 's/^/  /'
        
        # print pool health line
        padding=$((bar_width-34))
        # health coloration, danger red for FAULTED
        if [[ "${poolhealth}" == "FAULTED" ]]; then
               healthcolor="\e[1;${c_danger}m"
               flashing="\e[5m"
        elif [[ "${poolhealth}" == "OFFLINE" ]] || [[ "${poolhealth}" == "UNAVAIL" ]] || [[ "${poolhealth}" == "REMOVED" ]] || [[ "${poolhealth}" == "DEGRADED" ]]; then
               healthcolor="\e[1;${c_warning}m"
               flashing=""
        else
               healthcolor="\e[${c_txt}m"
               flashing=""
        fi
        padding=$((bar_width-17))
        text="health"
        echo "${line}" | printf "%+${padding}s status: ${healthcolor}${flashing}%+8s\e[0m\n" $text ${poolhealth,,} | sed 's/^/   /'
        linecounter=$((linecounter+1))
    done
fi