#!/bin/bash

# What you charge an hour
RATE=50

short_help() {
	echo "$0 <hrs.csv> <items.csv> <Paying Company Name> [output file]"
	echo "--help for help"
}
long_help() {
	short_help
	echo ""
	echo "The csv file should be setup as:"
	echo ""
	echo "Job <string>, Hours <number>"
	echo ""
	echo "With no empty line at the end."
	echo "Paying company name is any string"
	echo "The output argument is optional and will by default output to invoice-<num>.pdf"
}

CSV=""
if [[ -z $1 ]]; then
	short_help
	exit
elif [[ $1 = "--help" ]]; then
	long_help	
	exit
else
	CSV=$1
fi

CSV2=""
if [[ -z $2 ]]; then
	short_help
	exit
else
	CSV2=$2
fi

COMPANY=""
if [[ -z $3 ]]; then
	short_help
	exit
else
	COMPANY=$3
fi

# Increment a global invoice number
INV_FILE="last_invoice_number"
INV_NUM=0
if [[ -f $INV_FILE ]]; then
	INV_NUM=$(expr $(cat $INV_FILE) + 1)
else
	INV_NUM=1
fi
echo $INV_NUM > $INV_FILE

# 3rd argument is output location (optional)
OUTPUT="invoice-${INV_NUM}.pdf"
if [[ ! -z $4 ]]; then
	OUTPUT=$4
fi

# Parse the CSV into: Label;Hrs;Cost
HRS_TMP=$(mktemp)
cat $CSV | RATE=$RATE awk -F, '{ sum += $2 }; { print $1 ";" $2 ";" $2 * ENVIRON["RATE"] }  END { print "Sub-Total" ";" sum ";" sum * ENVIRON["RATE"]}' > $HRS_TMP

CONSUME_TMP=$(mktemp)
cat $CSV2 | awk -F, '{ sum += $2 }; { print $1 ";" $2 } END { print "Sub-Total" ";" sum }' > $CONSUME_TMP

HRS_COST=$(cat $HRS_TMP | tail -n 1 | awk -F";" '{ print $3 }')
CONSUME_COST=$(cat $CONSUME_TMP | tail -n 1 | awk -F";" '{ print $2 }')

TOTAL_COST=$(A=$HRS_COST B=$CONSUME_COST awk 'BEGIN{ print ENVIRON["A"] + ENVIRON["B"] }')

# TOTAL = Last line
# BODY = Everything but the last line
COMPANY=$COMPANY \
	INVOICE_NUM=$INV_NUM \
	envsubst < start.mm > 1.tmp
HRS_TOTAL=$(cat $HRS_TMP | tail -n 1) \
	HRS_BODY=$(cat $HRS_TMP | head -n -1) \
	envsubst < hours.tbl > 2.tmp
ITEM_TOTAL=$(cat $CONSUME_TMP | tail -n 1) \
	ITEM_BODY=$(cat $CONSUME_TMP | head -n -1) \
	envsubst < item.tbl > 3.tmp
TOTAL=$TOTAL_COST \
	RATE=$RATE \
	envsubst < end.mm > 4.tmp

cat 1.tmp 2.tmp 3.tmp 4.tmp | groff -t -mm -T pdf > $OUTPUT

rm $HRS_TMP
rm $CONSUME_TMP