import-sources

#!/bin/bash -eu
#
# Import Rogue sources to src/ dir, preparing them for initial git commit
#
#    Copyright (C) 2015 Rodrigo Silva (MestreLion) <linux@rodrigosilva.com>
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation, either version 3 of the License, or
#    (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with this program. See <http://www.gnu.org/licenses/gpl.html>
#------------------------------------------------------------------------------

myname=$(basename "$0")
mydir=$(dirname "$(readlink -f "$0")")

targetdir=$mydir/src
force=0

#------------------------------------------------------------------------------

usage(){
	cat <<-USAGE
	Usage: ${myname} [-h|--help] [-f|--force] [--] SOURCE_DIR [TARGET_DIR]

	Copy original sources from SOURCE_DIR to TARGET_DIR and:
	- Remove executable bit (if any)
	- Lowercase all file names (MAKEFILE is renamed Makefile)
	- Remove 0x1A (^Z) char (usually as last char in file)
	- Change newline from Windows/DOS (CRLF) to Unix (LF)
	- Remove blank lines from end of file
	- Fix indentations using tabs

	TARGET_DIR defaults to: ${targetdir}
	Will refuse to copy to a non-empty directory unless '--force' is used.
	USAGE
	exit
}

fatal() { [[ "${1:-}" ]] && echo "$myname: error: $1" >&2 || :; exit ${2:-1} ; }


# emulate sed's --in-place for commands that lack it, such as unexpand
inplace() {
	local cmd=()
	local outfile
	local tmpfile

	while (( $# )); do
		case "$1" in
		--) shift; break;;
		*) cmd+=( "$1" );;
		esac
		shift
	done

	if ! (( $# && ${#cmd[@]} )); then
		fatal "usage: inplace <command> [cmdargs...] -- FILE(s)..."
	fi

	for outfile; do
		tmpfile=$(mktemp) || fatal
		trap 'rm -f -- "$tmpfile"' RETURN

		"${cmd[@]}" -- "$outfile" > "$tmpfile" && {
		chmod --reference "$outfile" "$tmpfile" # GNU-only
		mv "$tmpfile" -- "$outfile"; }
	done
}

#------------------------------------------------------------------------------

# Pre-parse for `help`
for arg in "$@"; do [[ "$arg" == "-h" || "$arg" == "--help" ]] && usage ; done
dirs=()
while (( $# )); do
	case "$1" in
	-f|--force) force=1;;
	--) shift; dirs+=( "$@" ); break;;
	-*) fatal "invalid option: $1";;
	*) dirs+=( "$1" );;
	esac
	shift
done
if (( "${#dirs[@]}" < 1 || "${#dirs[@]}" > 2 )); then usage; fi

sourcedir=${dirs[0]}
targetdir=${dirs[1]:-$targetdir}

if   [[ -z "$sourcedir" ]]; then usage; fi
if ! [[ -d "$sourcedir" ]]; then fatal "SOURCE_DIR is not a directory: $sourcedir"; fi

sources=()
while read -r src; do sources+=( "$src" )
done < <(find "$sourcedir" -maxdepth 1 -type f)

if ! (( "${#sources[@]}" )); then fatal "source directory is empty: $sourcedir"; fi

if ! ((force)) && [[ "$(command ls "$targetdir" 2>/dev/null)" ]]; then
	fatal "target directory is not empty, and --force was not used: $targetdir"
fi

if ! type rename &>/dev/null; then
	printf '%s\n' "Required command 'rename' not found." \
		"On Debian/Ubuntu this can be installed with:" \
		"	sudo apt install rename" >&2
	exit 1
fi

#------------------------------------------------------------------------------

mkdir --parents -- "$targetdir"
cp --no-preserve mode --target-directory "$targetdir" -- "${sources[@]}" ||
	fatal "could not copy cource files"

cd "$targetdir"

chmod -x *
rename 'y/A-Z/a-z/' *

shopt -s nullglob
files=(*.{asm,bat,c,h,opt} makefile? objs? tags?)
if ! ((${#files[@]})); then exit; fi

sed -i 's/\x1A//'                 -- "${files[@]}"  # ^Z
sed -i 's/\r//'                   -- "${files[@]}"  # CRLF to LF
sed -i 's/[ \t]*$//'              -- "${files[@]}"  # trailing blanks
sed -i ':a;/^\n*$/{$d;N;ba;}'     -- "${files[@]}"  # EOF blank lines
inplace unexpand -t4 --first-only -- "${files[@]}"  # indentations

mv {m,M}akefile