txns

#!/usr/bin/env -S gawk -f
# Converts sorted postings to transactions using pta format
# On stdin expects postings sorted by date, payee, price asc
# so that postings are grouped together
# transaction is created every time running balance is near zero <0.0001

{
    balance += +$2
    if (date) {
        if (date == $1) {
            date = $1
            $1 = ""
        }
        if (common == $4)
            $4 = ""
    } else {
        date = $1
        $1 = ""
        common = $4
        $4 = ""
    }
    gsub(/^[[:space:]]*|[[:space:]]*$/, "")  # strip spaces on ends
    gsub(/[[:space:]]+/, " ")  # collapse spaces
    lines[i++] = $0
    if (-0.0001 < balance && balance < 0.0001) {
        # print transactions
        printf "%s %s\n", date, common
        for (j in lines) {
            print lines[j]
        }
        printf "\n"
        # reset array
        i = 0
        delete lines
        date = ""
    }
}