invoice

#!/usr/bin/env sh
# Generate a PDF invoice from a plain text time log using groff and m4
#
# Usage:
#
#   invoice myjobdata.m4 timesheet1.txt [outfile]
#
# Outfile will be derived from the timesheet name if not given.
# Can also be - for stdout.
#
# The timesheet is a text file in the form of:
#
#   <date>
#   <hours>
#   <description>
#
#   <date>
#   <hours>
#   <description>
#
# The same date can be repeated for multiple entries.
# The description can span multiple lines.
#
# The job metadata file is in the form of:
#
#   m4_divert(-1)
#
#   m4_define(`xVALUE', `Value here')
#   m4_define(`xRATE', 10)
#
#   m4_divert(0)m4_dnl
#
# for each of the values listed below.
# _Do not_ put blank lines above or below the divert lines.

_gen_timesheet () {
    awk -v rate="${1:?'Rate required'}" '
    BEGIN { RS=""; FS="\n"; }

    {
        date=$1; hours=$2; total_hours += hours

        printf("%s\tT{\n", prevdate == date ? " " : date)
        for (i = 3; i <= NF; i += 1) print $i
        printf("T}\t%s\n", hours)

        prevdate = date
    }

    END {
        printf("=\nTotal\t%s hours at $%s per hour\t$%.2f\n",
            total_hours, rate, (total_hours * rate))
    }
    '
}

_invoice_tmpl () {
    cat <<'EOF'
.AUTHOR "xAUTHOR"
.DOCTYPE LETTER
.PRINTSTYLE TYPESET
.START
.DATE
xDATE
.FROM
.RIGHT
xFROM
.TO
xTO
.PP
.TS H
expand,box;
cb s s
l l l
lb lw55 rb .
Development Breakdown
.SP
Date	Description	Hours
.TH
.SP
m4_divert(2)m4_dnl
.TE
.PP
.HI
xPAYMENT
.CLOSING
xCLOSING
m4_divert(1)m4_dnl
EOF
}

_help () {
    awk 'NR == 1 { next } /^$/ { exit } { print substr($0, 3) }' "$0"
    printf '\nJob data m4 fields:\n'
    _invoice_tmpl | grep -P -o 'x[A-Z]+'
    printf '\n'
}

_main () {
    while getopts h opt; do
        case $opt in
        h) _help; exit;;
        esac
    done
    shift $(( OPTIND - 1 ))

    if [ $# -eq 0 ]; then _help; exit; fi

    job_data="${1:?'Job data m4 file required.'}"
    timesheet="${2:?'Timesheet file required.'}"
    outfile="${3:-${timesheet%.*}.pdf}"

    rate="$(printf xRATE | m4 -P "$job_data" -)"

    {
        _invoice_tmpl
        _gen_timesheet "$rate" < "$timesheet";
    } \
        | m4 -P -D xDATE="$(date '+%B %d, %Y')" "$job_data" - \
        | groff -t -mom -Tps \
        | ps2pdf - "$outfile"
}

_main "$@"