#!/usr/bin/env bash
# librefetch
#
# Copyright (C) 2013-2014 Luke Shumaker <lukeshu@sbcglobal.net>
#
# This file is part of Parabola.
#
# Parabola 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.
#
# Parabola 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 Parabola. If not, see <http://www.gnu.org/licenses/>.

. $(librelib conf)
. $(librelib messages)
setup_traps

declare -r tempdir="$(mktemp -d --tmpdir ${0##*/}.XXXXXXXXXXX)"
trap "rm -rf -- $(printf '%q' "$tempdir")" EXIT

cmd=${0##*/}
usage() {
	print "Usage: %s [OPTIONS] SOURCE_URL [OUTPUT_FILE]" "$cmd"
	print "Usage: %s -[g|P|h]" "$cmd"
	print "Downloads or creates a liberated source tarball."
	echo
	prose "The default mode is to create OUTPUT_FILE, first by trying
	       download mode, then create mode."
	echo
	prose "If OUTPUT_FILE isn't specified, it defaults to the non-directory
	       part of SOURCE_URL, in the current directory."
	echo
	prose "Unless '-C' is specified, if SOURCE_URL does not begin with a
	       configured mirror, create mode is inhibited."
	echo
	prose "In download mode, it simply tries to download SOURCE_URL.  At the
	       beginning of a URL, 'libre://' expands to the first configured
	       mirror."
	echo
	prose "In create mode, it looks at a build script, and uses that to
	       create the source tarball.  SOURCE_URL is ignored, except that it
	       is used to set the default value of OUTPUT_FILE."
	echo
	prose "The default build script is 'PKGBUILD', or 'SRCBUILD' if it
	       exists."
	echo
	prose "Unrecognized options are passed straight to makepkg."
	echo
	prose "%s does NOT support getopt-style flag combining.  You must use
	       '-a -b', not '-ab'." "$cmd"
	echo
	print "Example usage:"
	print '  $ %s https://repo.parabolagnulinux.org/other/mypackage/mypackage-1.0.tar.gz' "$cmd"
	echo
	print "Options:"
	print " Settings:"
	flag "-C"               "Force create mode (don't download)"
	flag "-D"               "Force download mode (don't create)"
	flag "-p <$(_ FILE)>"   "Use an alternate build script (instead of
	                         'PKGBUILD') If an SRCBUILD exists in the same
	                         directory, it is used instead"
	print " Alternate modes:"
	flag "-g, --geninteg"   "Generage integrity checks for source files"
	flag "-P, --print"      "Print the effective build script (SRCBUILD)"
	flag "-h, --help"       "Show this message"
}

main() {
	BUILDFILE="$(readlink -m PKGBUILD)"
	makepkg_opts=()
	extra_opts=()
	mode=download-create
	parse_options "$@"

	# Mode: help ###########################################################

	if [[ $mode =~ help ]]; then
		usage
		return 0
	fi

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

	local BUILDFILEDIR="${BUILDFILE%/*}"
	if [[ -f "${BUILDFILEDIR}/SRCBUILD" ]]; then
		BUILDFILE="${BUILDFILEDIR}/SRCBUILD"
	fi
	if [[ ! -f "$BUILDFILE" ]]; then
		error "%s does not exist." "$BUILDFILE"
		exit 1
	fi
	case "$BUILDFILE" in
		*/SRCBUILD) srcbuild="$(modified_srcbuild "$BUILDFILE")";;
		*)          srcbuild="$(modified_pkgbuild "$BUILDFILE")";;
	esac
	makepkg="$(modified_makepkg "$(which makepkg)")"

	# Mode: checksums ######################################################

	if [[ $mode =~ checksums ]]; then
		"$makepkg" "${makepkg_opts[@]}" -g -p "$srcbuild" |
		case ${BUILDFILE##*/} in
			PKGBUILD) sed -e 's/^[a-z]/mk&/' -e 's/^\s/  &/';;
			SRCBUILD) cat;;
		esac
		return 0
	fi

	# Mode: print ##########################################################

	if [[ $mode =~ print ]]; then
		cat "$srcbuild"
		return 0
	fi

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

	local src="${extra_opts[0]}"
	local dst="${extra_opts[1]:-${src##*/}}"

	# Don't canonicalize $src unless mode =~ download, and we've validated
	# that $MIRRORS is configured.

	# Canonicalize $dst
	dst="$(readlink -m -- "$dst")"

	# Mode: download #######################################################

	if [[ $mode =~ download ]]; then
		load_files librefetch
		check_vars librefetch MIRRORS DOWNLOADER || return 1

		# Canonicalize $src
		if [[ "$src" == libre://* ]]; then
			src="${MIRRORS[0]}/${src#libre://}"
		fi

		# check to see if $src is a candidate for create mode
		local inmirror=false;
		local mirror
		for mirror in "${MIRRORS[@]}"; do
			if [[ "$src" == "$mirror"* ]]; then
				inmirror=true
				break
			fi
		done
		if ! $inmirror; then
			# inhibit create
			mode=download
		fi

		local dlcmd="${DOWNLOADER}"
		[[ $dlcmd = *%u* ]] || dlcmd="$dlcmd %u"
		dlcmd="${dlcmd//\%o/"\$dst"}"
		dlcmd="${dlcmd//\%u/"\$src"}"

		{ eval "$dlcmd"; } >&2 && return 0
	fi

	# Mode: create #########################################################

	if [[ $mode =~ create ]]; then
		PKGEXT=${dst##*/}
		export PKGEXT=${PKGEXT%.part}
		export PKGDEST=${dst%/*}
		export pkg_file=$dst

		cd "$BUILDFILEDIR"
		"$makepkg" "${makepkg_opts[@]}" -p "$srcbuild" >&2 || return $?
	fi
}

# sets the variables BUILDFILE, makepkg_opts, extra_opts, mode
parse_options() {
	# Detect makepkg options
	local makepkg_orig="$(which makepkg)"
	# --long flags that take a second argument
	local makepkg_opt2long=( $(LC_ALL=C "${makepkg_orig}" -h | sed -rn 's/\s*(--\S*) <.*/\1/p'))
	# -s hort flags that take a second argument
	local makepkg_opt2short=($(LC_ALL=C "${makepkg_orig}" -h | sed -rn 's/\s*(-.) <.*/\1/p'))
	# all flags
	local makepkg_argall=(   $(LC_ALL=C "${makepkg_orig}" -h | sed -rn \
		-e 's/^ +(-.) .*/\1/p' \
		-e 's/^ +(-.), (--\S*) .*/\1\n\2/p' \
		-e 's/^ +(--\S*) .*/\1/p'))

	local opt
	local have_opt
	while [[ $# -gt 0 ]]; do
		arg=$1
		have_opt=false
		if in_array "${arg%%=*}" "${makepkg_opt2long[@]}"; then
			opt="${arg#*=}"
			arg="${arg%%=*}"
			have_opt=true
		fi
		if in_array "${arg}" "${makepkg_opt2short[@]}"; then
			shift
			opt=$1
			have_opt=true
		fi
		case "$arg" in
			-C) mode=create;;
			-D) mode=download;;
			-g|--geninteg) mode=checksums;;
			-P|--print) mode=print;;
			-p) BUILDFILE="$(readlink -m -- "$opt")";;
			-h|--help) mode=help;;
			--) shift; break;;
			-*)
				if in_array "${arg}" "${makepkg_argall[@]}"; then
					makepkg_opts+=("$arg")
					$have_opt && makepkg_opts+=("$opt")
				else
					printf '%s: invalid flag: %s' "$cmd" "$arg"
					return 1
				fi
				;;
			*) extra_opts+=("$arg");;
		esac
		shift
	done
	extra_opts+=("$@")

	# check the number of extra_opts
	case "$mode" in
		help) # don't worry about it
			:;;
		checksums|print) # don't take any extra arguments
			if [[ ${#extra_opts[@]} != 0 ]]; then
				print "%s: found extra non-flag arguments: %s" "$cmd" "${extra_opts[*]}" >&2
				usage >&2
				return 1
			fi
			;;
		*download*|*create*) # take 1 or 2 extra arguments
			if [[ ${#extra_opts[@]} != 1 ]] && [[ ${#extra_opts[@]} != 2 ]]; then
				print "%s: %d non-flag arguments found, expected 1 or 2: %s" "$cmd" ${#extra_opts[@]} >&2
				usage >&2
				return 1
			fi
			;;
	esac
}

# Modify makepkg ###############################################################

# an ERE
makepkg_modify='
/create_package\(\) \{/,/^\}$/ {
	/pkg_file=/d                  # allow us to set pkg_file
	s/"?\$\{comp_files\[@\]\}"?// # do not include .{PKGINFO,INSTALL,CHANGELOG}
	s/bsdtar /&--format=ustar /   # ustar, not pax
	s/create_signature .*/&; return $?/ # do not procede to create symlinks
}

/tidy_install\(\) \{/,/^\}$/ {
        /for .*PURGE_TARGETS/itidy_install_purge
	/for .*PURGE_TARGETS/,/done/d
	/^\}$/ifind . -exec touch --date="1990-01-01 0:0:0 +0" {} +
}

/download_sources\(\) \{/ {
	arm -rf "$srcdir"\nmkdir "$srcdir"
}

s|srcdir=.*|&-libre|
s|pkgdirbase=.*|&-libre|
s|check_build_status$|:|
'

tidy_install_purge() {
	local pt
	for pt in "${PURGE_TARGETS[@]}"; do
		if [[ ${pt} = "${pt%/}" ]]; then
			if [[ ${pt} = "${pt//\/}" ]]; then
				find . ! -type d -name "${pt}" -exec rm -f -- '{}' +
			else
				rm -f "${pt}"
			fi
		else
			if [[ ${pt%/} = "${pt//\/}" ]]; then
				find . -type d -name "${pt%/}" -exec rm -rf -- '{}' +
			else
				rm -rf "${pt}"
			fi
		fi
	done
}

modified_makepkg() {
	local makepkg_orig=$1
	local makepkg_mine="$tempdir/makepkg"
	{
		echo '#!/bin/bash'
		declare -f tidy_install_purge
		sed -r "$makepkg_modify" < "$makepkg_orig"
	} > "$makepkg_mine"
	chmod 755 "$makepkg_mine"
	printf "%s\n" "$makepkg_mine"
}

# Modify PKGBUILD ##############################################################

# a string to be appended
pkgbuild_append='
# do not do split packages
if [[ ${#pkgname[@]} -gt 1 ]]; then
  if [[ -n $pkgbase ]]; then
    pkgname=("$pkgbase")
  else
    pkgname=("$pkgname")
  fi
fi

# copy source variables
source=("${mksource[@]}")
noextract=("${mknoextract[@]}")
md5sums=("${mkmd5sums[@]}")
sha1sums=("${mksha1sums[@]}")
sha256sums=("${mksha256sums[@]}")
sha384sums=("${mksha384sums[@]}")
sha512sums=("${mksha512sums[@]}")

depends=()
checkdepends=()
makedepends=("${mkdepends[@]}")

####
options=(!strip docs libtool staticlibs emptydirs !zipman purge !upx)
PURGE_TARGETS=(.bzr/ .cvs/ .git/ .hg/ .svn/ .makepkg/)

####
if ! declare -f mksource >/dev/null; then
  mksource() { :; }
fi
prepare() { :; }
build() { mksource; }
check() { :; }
package() { cp -a "$srcdir"/*/ "$pkgdir/"; }
'

modified_pkgbuild() {
	local pkgbuild=$1
	local srcbuild="$tempdir/SRCBUILD"
	printf '%s' "$pkgbuild_append" | cat "$pkgbuild" - > "$srcbuild"
	printf '%s\n' "$srcbuild"
}


# Modify SRCBUILD ##############################################################

modified_srcbuild() {
	local orig=$1
	local new="$tempdir/SRCBUILD"
	sed -e '/PKGDEST=/d' -e '/PKGEXT=/d' < "$orig" > "$new"
	printf '%s\n' "$new"
}

main "$@"