#!/bin/bash
set -e

# Parameters
# Allow environmental overrides
if [ -z "${RECODE_MIN_RATIO}" ]; then
	RECODE_MIN_RATIO=40
fi
if [ -z "${RECODE_MAX_DIFF}" ]; then
	RECODE_MAX_DIFF=8
fi
if [ -z "${KEEP_IN}" ]; then
	KEEP_IN=0
fi

# Command-line parameters
IN="${1}"
OUT="${2}"

# Sanity check
if [ ! -r "${IN}" ]; then
	echo "Usage: `basename "${0}"` in_file [out_file]" 1>&2
	exit 1
fi
if [ -e "${OUT}" ]; then
	echo "`basename "${0}"`: Output file exists: ${OUT}" 1>&2
	exit 1
fi

# Recode
export RECODE_OUTFILE=1
OUT="`~/bin/video/encode.pl "${IN}" "${OUT}"`"

# Remove the original if all went well
# Some sanity checking here, but mostly relying on the -e flag
if [ -r "${IN}" ]; then

	# Ensure the output file exists
	if [ -z "${OUT}" ] || [ ! -r "${OUT}" ]; then
		echo "`basename "${0}"`: Output file not defined or does not exist. Aborting..." 1>&2
		exit 1
	fi

	# Check to be sure the output video has a reasonable file size
	SIZE_RATIO=0
	SIZE_IN="`stat -f %z "${IN}" 2>/dev/null`"
	SIZE_OUT="`stat -f %z "${OUT}" 2>/dev/null`"
	if [ -n "${SIZE_IN}" ] && [ -n "${SIZE_OUT}" ]; then
		SIZE_RATIO=$(( $SIZE_OUT * 100 / $SIZE_IN ))
	fi
	if [ $SIZE_RATIO -lt $RECODE_MIN_RATIO ]; then
		echo "`basename "${0}"`: Output file too small: ${OUT}. Aborting..." 1>&2
		rm -f "${OUT}"
		exit 1
	fi

	# Check to be sure the videos are (about) the same duration
	LENGTH_DIFF=$(( $RECODE_MAX_DIFF + 1 ))
	LENGTH_IN="`~/bin/video/movInfo.pl "${IN}" LENGTH | sed 's%\..*$%%'`"
	LENGTH_OUT="`~/bin/video/movInfo.pl "${OUT}" LENGTH | sed 's%\..*$%%'`"
	if [ -z "${LENGTH_IN}" ] || [ -z "${LENGTH_OUT}" ]; then
		echo "`basename "${0}"`: Unable to determine length_in or length_out. Leaving all files in place." 1>&2
		exit 1
	fi
	if [ -n "${LENGTH_OUT}" ] && [ -n "${LENGTH_IN}" ]; then
		LENGTH_DIFF=$(( 100 -  ( $LENGTH_OUT * 100 / $LENGTH_IN ) ))
		if [ $LENGTH_DIFF -lt 0 ]; then
			LENGTH_DIFF=$(( $LENGTH_DIFF * -1 ))
		fi
	fi
	if [ $LENGTH_DIFF -gt $RECODE_MAX_DIFF ] ; then
		KEEP_IN=1
		echo "`basename "${0}"`: Output file duration (${LENGTH_OUT}) does not match input file duration (${LENGTH_IN}): ${IN}" 1>&2
	fi

	# Remove the input file if all is well
	if [ $KEEP_IN -eq 0 ]; then
		rm -f "${IN}"
	fi
fi