#!/bin/bash

function convert_to_bytes() {
    awk '
    {
        val=$0
        num=val
        sub(/[KMGT]$/, "", num)

        unit=substr(val, length(val), 1)
        mul=1
        if (unit=="K") mul=1024
        else if (unit=="M") mul=1024^2
        else if (unit=="G") mul=1024^3
        else if (unit=="T") mul=1024^4

        printf "%.0f\n", num * mul
    }' <<< "$1"
}

function ensure_comma() {
    if [[ $FIRST -eq 1 ]]
    then
        FIRST=
    else
        echo -n ,
    fi
}

FSPATH="/mnt"

PARSER_STATE=0
while IFS= read -r line; do
    case $PARSER_STATE in
    0)
        if [[ $line =~ ^Filesystem:[[:space:]]+([^[:space:]]+)$ ]]
        then
            uuid="${BASH_REMATCH[1]}"
        elif [[ $line == Data\ type* ]]
        then
            PARSER_STATE=1
        elif [[ $line == "Compression:" ]]
        then
            echo -n "bcachefs_compression,fspath=\"$FSPATH\",uuid=\"$uuid\" "
            FIRST=1
            PARSER_STATE=2
        elif [[ $line == "Btree usage:" ]]
        then
            echo -n "bcachefs_btree_usage,fspath=\"$FSPATH\",uuid=\"$uuid\" "
            FIRST=1
            PARSER_STATE=3
        elif [[ $line =~ ^Pending\ reconcile: ]]
        then
            echo -n "bcachefs_reconcile,fspath=\"$FSPATH\",uuid=\"$uuid\" "
            FIRST=1
            PARSER_STATE=4
            REMAINING=(replicas checksum erasure_code compression target high_priority pending)
        elif [[ $line =~ ^([^ ]+)\ \(device\ ([0-9]+)\):[[:space:]]+([^[:space:]]+)[[:space:]]+([^[:space:]]+)[[:space:]]+([0-9]+)%$ ]]
        then
            blockdev="${BASH_REMATCH[3]}"
            if [[ ! $blockdev == /dev/* ]]
            then
                blockdev="/dev/$blockdev"
            fi
            echo -n "bcachefs_devices,fspath=\"$FSPATH\",uuid=\"$uuid\",devlabel=\"${BASH_REMATCH[1]}\",devid=${BASH_REMATCH[2]},blockdev=\"$blockdev\" mode=\"${BASH_REMATCH[4]}\",usage=${BASH_REMATCH[5]}"

            PARSER_STATE=5
        #else
            #echo unknown?
        fi
        ;;
    1)
        if [[ "$line" == "" ]]
        then
            PARSER_STATE=0
        fi
        ;;
    2)
        if [[ "$line" == "" ]]
        then
            echo
            PARSER_STATE=0
        elif [[ $line =~ ^([^[:space:]]+)[[:space:]]*(.*)$ ]]
        then
            field="${BASH_REMATCH[1]// /_}"
            rest="${BASH_REMATCH[2]}"

            read -r val1 val2 val3 <<<"$rest"
            val1="$(convert_to_bytes "$val1")"

            ensure_comma

            echo -n "${field}_compressed=$val1"
            if [[ ! -z "$val2" ]]
            then
                val2="$(convert_to_bytes "$val2")"
                echo -n ",${field}_uncompressed=$val2"
            fi
            if [[ ! -z "$val3" ]]
            then
                val3="$(convert_to_bytes "$val3")"
                echo -n ",${field}_avgextsize=$val3"
            fi
        #else
            #echo unknown?
        fi
        ;;
    3)
        if [[ "$line" == "" ]]
        then
            echo
            PARSER_STATE=0
        elif [[ $line =~ ^([^:]+)[:space:]+(.*)$ ]]
        then
            field="${BASH_REMATCH[1]// /_}"
            val="${BASH_REMATCH[2]}"
            val="$(convert_to_bytes "$val")"

            ensure_comma

            echo -n "$field=$val"
        #else
            #echo unknown?
        fi
        ;;
    4)
        if [[ "$line" == "" ]]
        then
            for field in "${REMAINING[@]}"
            do
                ensure_comma
                echo -n "${field}_data=0,${field}_metadata=0"
            done

            echo
            PARSER_STATE=0
        elif [[ $line =~ ^([^:]+):[[:space:]]*(.*)$ ]]
        then
            field="${BASH_REMATCH[1]// /_}"
            rest="${BASH_REMATCH[2]}"

            read -r val1 val2 <<<"$rest"
            val1="$(convert_to_bytes "$val1")"
            val2="$(convert_to_bytes "$val2")"

            ensure_comma

            echo -n "${field}_data=$val1,${field}_metadata=$val2"

            REMAINING=( "${REMAINING[@]/$field}" )
        #else
            #echo unknown?
        fi
        ;;
    5)
        if [[ "$line" == "" ]]
        then
            echo
            PARSER_STATE=0
        elif [[ $line =~ ^[[:space:]]*([^:]+):[[:space:]]*(.*)$ ]]
        then
            field="${BASH_REMATCH[1]// /_}"
            rest="${BASH_REMATCH[2]}"

            read -r val1 val2 val3 <<<"$rest"
            val1="$(convert_to_bytes "$val1")"

            echo -n ",${field}_data=$val1"
            if [[ ! -z "$val2" ]]
            then
                echo -n ",${field}_buckets=$val2"
            fi
            if [[ ! -z "$val3" ]]
            then
                val3="$(convert_to_bytes "$val3")"
                echo -n ",${field}_fragmented=$val3"
            fi
        #else
            #echo unknown?
        fi
        ;;
    esac

    #if [[ $PARSER_STATE -ne 1 ]]
    #then
    #    echo "Got line: $line"
    #fi
done < <(sudo bcachefs fs usage -a "$FSPATH")

cd "/sys/fs/bcachefs/${uuid}/options" || exit 1
echo -n "bcachefs_options,fspath=\"$FSPATH\",uuid=\"$uuid\" "
FIRST=1
for i in *
do
    if [[ $FIRST == 1 ]]
    then
        FIRST=
    else
        echo -n ,
    fi

    echo -n "${i}=\"$(cat "$i")\""
done

echo