CSV Column REGEX Filter REPL

#!/usr/bin/env bash

csv_filter() {
    # csv_filter <file|stdin>
    # interactively filters a csv-column via case-insensitive regex
    local data=${1:-'-'}
    if [ "$data" = "-" ]; then
        local data=$(mktemp)
        cp /dev/stdin "$data"
    fi
    headers=$(head -1 < "$data" | csvquote)
    colname=$(
        awk -v RS=',' '{print NR, $0}' <<< "$headers" \
        | grep . \
        | fzf --prompt "column-to-filter: " \
        --preview-window='down:80%' --preview "batcat -p --language 'csv' \
        --color=always --line-range=:50 \"$data\""
    )
    colnum=$(cut -d ' ' -f 1 <<< "$colname")
    reggie=$(
        csvquote < "$data" \
        | awk -v colnum="$colnum" -F, '!seen[$colnum]++ { print $colnum }' \
        | fzf --prompt "$colname ~ " \
        --print-query --preview-window='down:80%' --preview \
        "csvquote < \"$data\" \
        | awk -v colnum=\"$colnum\" -v reggie={q} -F, \
        '{ IGNORECASE=1; if (NR==1) { print \$0 } else if (\$colnum ~ reggie) { print \$0 } }' \
        | batcat -p --language 'csv' --color=always" | head -1
    )
    csvquote < "$data" \
    | awk -v colnum="$colnum" -v reggie="$reggie" -F, \
    '{ IGNORECASE=1; if (NR==1) { print $0 } else if ($colnum ~ reggie) { print $0 } }'
}
alias csv-filter=csv_filter