#!/bin/sh

set -eu

if [ "$#" -lt 1 ] || [ "$#" -gt 2 ]; then
    printf 'Usage: %s INPUT.csv [OUTPUT.csv]\n' "$0" >&2
    exit 2
fi

input=$1
output=${2:--}

process_csv() {
    awk -F '\",\"' '
    function clean_account(value) {
        if (length(value) > 0 && substr(value, length(value), 1) !~ /[0-9]/) {
            while (length(value) > 0 && substr(value, length(value), 1) !~ /[0-9]/) {
                value = substr(value, 1, length(value) - 1)
            }
        }

        return value
    }

    function zero_amount_to_empty(value) {
        if (value == "0.00") {
            return ""
        }

        return value
    }

    BEGIN {
        OFS = FS
    }

    NR == 1 {
        print
        next
    }

    {
        cleaned = clean_account($10)

        if (cleaned == "") {
            cleaned = "000"
        }

        key = cleaned
        key_count[key]++
        if (!(key in key_order)) {
            key_order[key] = ++key_total
        }

        $10 = cleaned
        $11 = zero_amount_to_empty($11)
        $12 = zero_amount_to_empty($12)
        print
    }

    END {
        for (key in key_order) {
            if (key_count[key] > 1) {
                printf "Non-unique column 10 key: %s (%d rows)\n", key, key_count[key] > "/dev/stderr"
            }
        }
    }
' "$input"
}

if [ "$output" = "-" ]; then
    process_csv
else
    process_csv > "$output"
fi