#!/bin/bash
set -e

# 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

# Parameters
# Allow environmental overrides
# Provide looser default matching to TS, MPEG, and MPG sources
if [ -z "${RECODE_SIZE_RATIO}" ]; then
	RECODE_SIZE_RATIO=20
	if echo "${IN}" | grep -E -i -q "\.(ts|mpe?g)$"; then
		RECODE_SIZE_RATIO=10
	fi
fi
if [ -z "${RECODE_LENGTH_RATIO}" ]; then
	RECODE_LENGTH_RATIO=90
	if echo "${IN}" | grep -E -i -q "\.(ts|mpe?g)$"; then
		RECODE_LENGTH_RATIO=70
	fi
fi
if [ -z "${RECODE_OVERSIZE}" ]; then
	# ~2 GB
	RECODE_OVERSIZE=$((2000 * 1024 * 1024))
fi

# Delayed error indicator
if [ -z "${KEEP_IN}" ]; then
	KEEP_IN=0
fi

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

# 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

# Bail if the original disappeared
if [ ! -r "${IN}" ]; then
	echo "`basename "${0}"`: Input file does not exist. Aborting..." 1>&2
	exit 1
fi

# Check to be sure the output video has a minimum file size
SIZE_RATIO=0
SIZE_IN="`stat -f %z "${IN}" 2>/dev/null`"
SIZE_OUT="`stat -f %z "${OUT}" 2>/dev/null`"
if [ -z "${SIZE_IN}" ] || [ -z "${SIZE_OUT}" ]; then
	KEEP_IN=1
	echo "`basename "${0}"`: Unable to determine size_in or size_out." 1>&2
else
	SIZE_RATIO=$(( $SIZE_OUT * 100 / $SIZE_IN ))
	if [ $SIZE_RATIO -lt $RECODE_SIZE_RATIO ] && [ $SIZE_IN -lt $RECODE_OVERSIZE ]; then
		KEEP_IN=1
		echo "`basename "${0}"`: Output file size (${SIZE_OUT}) is not at least ${RECODE_SIZE_RATIO}% of the input file size (${SIZE_IN}): ${IN}" 1>&2
	fi
fi

# Check to be sure the videos are (about) the same duration
LENGTH_RATIO=0
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}" ] || [ $LENGTH_IN == 0 ] || [ $LENGTH_OUT == 0 ]; then
	KEEP_IN=1
	echo "`basename "${0}"`: Unable to determine length_in or length_out." 1>&2
else
	LENGTH_RATIO=$(( $LENGTH_OUT * 100 / LENGTH_IN ))
	if [ $LENGTH_RATIO -gt 100 ]; then
		LENGTH_RATIO=$(( $LENGTH_IN * 100 / LENGTH_OUT ))
	fi
	if [ $LENGTH_RATIO -lt $RECODE_LENGTH_RATIO ]; then
		KEEP_IN=1
		echo "`basename "${0}"`: Output file duration (${LENGTH_OUT}) does not match input file duration (${LENGTH_IN}) to within ${RECODE_LENGTH_RATIO}%: ${IN}" 1>&2
	fi
fi

# Re-label undefined audio tracks in files with no English tracks
~/bin/video/undToEng.pl "${OUT}"

# Remove the input file(s) if all is well
if [ $KEEP_IN -eq 0 ]; then
	rm -f "${IN}"
	SRT="`echo "${IN}" | sed 's%\.[^\.]*$%%'`.srt"
	if [ ! -e "${SRT}" ]; then
		SRT="`echo "${IN}" | sed 's%\.[^\.]*$%%'`.ssa"
	fi
	if [ -e "${SRT}" ]; then
		rm -f "${SRT}"
	fi
	RENAME="`echo "${OUT}" | sed 's%^\(.*\)-recode\(\.[^\.]*\)$%\1\2%'`"
	if [ "${RENAME}" == "${IN}" ] && [ ! -e "${IN}" ]; then
		mv "${OUT}" "${IN}"
	fi
else
	echo -e "`basename "${0}"`: Delayed error: Refusing to delete input file.\n" 1>&2
fi