#!/bin/bash
# Well-behaved repeating TeX builder -- Matt McCutchen
# usage: retex <cmd> <input-file-minus-.tex>

set -e

cmd="$1"
in="$2"
shift 2

function run {
	echo "[$iter] Running $2..."
	yes X | "$cmd" -file-line-error-style "$in"
}

function compare {
	echo "Comparing files..."
	for f in "$in"*; do
		# ignore pdfs because they have a nonreproducible "ID" at the end
		# and logs because they aren't read
		if ! [ "$f" != "${f%.keep*}" ] && ! [ "$f" != "${f%.pdf}" ] \
			&& ! [ "$f" != "${f%.log}" ]; then
			suf="${f#$in}"
			cmp "$in$suf" "$in.keep$suf" || return $?
		fi
	done
	echo "Reached a fixed point."
}

function keep {
	echo "Keeping files..."
	for f in "$in"*; do
		if ! [ "$f" != "${f%.keep*}" ]; then
			suf="${f#$in}"
			\cp -p "$in$suf" "$in.keep$suf"
		fi
	done
}

function clean {
	echo "Cleaning up kept files..."
	rm -f "$in.keep"*
}

function fail {
	echo "Compiler exited with code $1."
	# Remove output files here, a la .DELETE_ON_ERROR?
	exit $1
}

iter=0
keep
run || fail $?
limit=10
while ! compare; do
	iter=$(($iter + 1))
	if [ $iter -ge $limit ]; then
		echo "Did not reach a fixed point in $limit tries."
		exit 2
	fi
	keep
	run || fail $?
done
clean
echo "Successful."