#!/bin/bash
# Deduplicate. Works on BSD.
# Port to GNU by replacing
# -E with -regex-type posix-extended
set -e
if [ "$#" -ne 1 ]; then
	echo "usage: dedupe.sh <dir>"
	exit 2
elif [ "$(uname)" != 'Darwin' ]; then
	echo "Only Mac supported, see comments"
	exit 2
fi

CKSUMS=$(find -E "$1" -type f \
		-iregex '.*\.(jpe?g|png)' \
		-exec cksum {} \; | sort -n)

FILES=$(echo "$CKSUMS" | cut -d' ' -f3-)
CRCS=$(echo "$CKSUMS" | cut -d' ' -f1)
if [ "$(echo "$CRCS" | uniq -d)" = '' ]
then
	echo "No duplicates"
	exit 0
fi

declare -a CK
while IFS= read -r line; do
    CK+=( "$line" )
done < <( echo "$CKSUMS" )
N=${#CK[@]}
for (( i=0; i<${N}-1; i++ ));
do
	CRC1=$(echo "${CK[$i]}" | cut -d' ' -f1)
	CRC2=$(echo "${CK[$i+1]}" | cut -d' ' -f1)
	if [ "$CRC1" -eq "$CRC2" ]; then
		FN1=$(echo "${CK[$i]}" | cut -d' ' -f3-)
		FN2=$(echo "${CK[$i+1]}" | cut -d' ' -f3-)
		L1=$(basename "$FN1" | wc -c)
		L2=$(basename "$FN2" | wc -c)
		if [ "$L1" -gt "$L2" ]; then
			echo "Removing $FN1"
			rm -f "$FN1"
		else
			echo "Removing $FN2"
			rm -f "$FN2"
		fi
	fi
done