#!/bin/bash
# Copyright © 2013-2014, 2019 Luke Shumaker <lukeshu@sbcglobal.net>
# This work is free. You can redistribute it and/or modify it under the
# terms of the Do What The Fuck You Want To Public License, Version 2,
# as published by Sam Hocevar. See the COPYING file for more details.

# Regular expressions are POSIX EREs, and must match the entirety of the string

safe_dirs_glob=(.{git,hg,svn} '*.git')
safe_types_regexp=(
	'(inode|text|image|video|audio)/.*'
	'application/(json|pdf|postscript|xml|ogg|x-java-keystore)'
	'application/vnd\.ms-(office|powerpoint)'
)
safe_files_regexp=('.*/po/[^/]*.gmo' '.*\.(flw|odg)')
safe_files_string=()

# don't care about files less than 3 bytes ('c' is for characters)
min_size=3c

sep='<no-filename-ever-contains-this>'

################################################################################

cwd="$(readlink -m -- "$PWD")"

normalize_filenames() {
	while IFS='' read -r filename; do
		readlink -m -- "$filename"
	done | sed "s|^$cwd/|./|"
}

print-human() {
	libremessages warning "The source directory %s contains binary files:" "$PWD"
	sed 's/^/  -> /'
}

print-machine() {
	cat
}

main() {
	local format=human
	# Parse arguments
	local arg
	for arg in "$@"; do
		case "$arg" in
			-m) format=machine;;
			*) safe_files_string+=("$(normalize_filenames <<<"$arg")");;
		esac
	done

	# Init
	local unsafe_files="$(mktemp --tmpdir "${0##*/}.XXXXXXXXXX")"
	trap "$(printf 'rm -f -- %q' "$unsafe_files")" EXIT

	# Turn the variables up top into a bunch of `find(1)` filters
	local filters=()
	local glob
	for glob in "${safe_dirs_glob[@]}"; do
		filters+=(-type d -name "$glob" -prune -o)
	done
	filters+=(-type f -size +"${min_size}")

	# Heavy lifting
	find . "${filters[@]}" -print | # find all files
	normalize_filenames |
	grep -Fxvf <(printf '%s\n' "${safe_files_string[@]}") |
	grep -Exvf <(printf '%s\n' "${safe_files_regexp[@]}") |
	xargs -r -d'\n' file --mime-type -r -F "$sep" | # identify the filetypes
	sed -r "s@(.*)${sep}\s*(.*)@\2:\1@" |  # reformat the output to be easier to parse
	grep -Exvf <(printf '%s:.*\n' "${safe_types_regexp[@]}") |
	cut -d: -f2- > "$unsafe_files"

	if [[ "$(stat -c '%s' -- "$unsafe_files")" -gt 0 ]]; then
		<"$unsafe_files" sort | print-$format
		exit 1
	fi
}

main "$@"