#!/bin/bash

# Copyright (C) 2016 Paul Kocialkowski <contact@paulk.fr>
#
# 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.  If not, see <http://www.gnu.org/licenses/>.

BUILD_SYSTEM="libreboot"

PROJECTS="projects"
SOURCES="sources"
BUILD="build"
INSTALL="install"
RELEASE="release"
SYSTEMS="systems"
IMAGES="images"
TOOLS="tools"

CONFIGS="configs"
PATCHES="patches"
TARGETS="targets"
REVISION="revision"
BLOBS="blobs"
BLOBS_IGNORE="blobs-ignore"
BLOBS_DISCOVER="blobs-discover"

DOTEPOCH=".epoch"
DOTVERSION=".version"
DOTREVISION=".revision"
DOTTARFILES=".tarfiles"
TAR_XZ="tar.xz"
SHA256SUM="sha256sum"
ASC="asc"

function_check() {
	local function=$1

	declare -f -F "$function" > /dev/null
}

variable_check() {
	local variable=$1

	test ! -z "${!variable}"
}

arguments_list() {
	local argument

	for argument in "$@"
	do
		echo "$argument"
	done
}

path_wildcard_expand() {
	local path=$@

	# Evaluation fails with unescaped whitespaces.
	path=$( echo "$path" | sed "s/ /\\\ /g" )

	eval "arguments_list "$path""
}

file_checksum_create() {
	local path=$1

	local checksum_path="$path.$SHA256SUM"
	local name=$( basename "$path" )
	local directory_path=$( dirname "$path" )

	(
		cd "$directory_path"
		sha256sum "$name" > "$checksum_path"
	)
}

file_checksum_check() {
	local path=$1

	local checksum_path="$path.$SHA256SUM"
	local name=$( basename "$path" )
	local directory_path=$( dirname "$path" )

	if ! [ -f "$checksum_path" ]
	then
		printf "Could not verify file checksum!\n" >&2
		return 1
	fi

	(
		cd "$directory_path"
		sha256sum -c "$checksum_path"
	)
}

file_signature_create() {
	local path=$1

	local signature_path="$path.$ASC"

	if [ -z "$RELEASE_KEY" ]
	then
		return 0
	fi

	gpg --default-key "$RELEASE_KEY" --armor --output "$signature_path" --detach-sign --yes "$path"
}

file_signature_check() {
	local path=$1

	local signature_path="$path.$ASC"

	if ! [ -f "$signature_path" ]
	then
		printf "Could not verify file signature!\n" >&2
		return 1
	fi

	gpg --armor --verify "$signature_path" "$path"
}

file_verification_create() {
	local path=$1

	file_checksum_create "$path"
	file_signature_create "$path"
}

file_verification_check() {
	local path=$1

	file_checksum_check "$path"
	file_signature_check "$path"
}

file_exists_check() {
	local path=$1

	test -f "$path"
}

directory_filled_check() {
	local path=$1

	if [ -z "$( ls -A "$path" 2> /dev/null )" ]
	then
		return 1
	else
		return 0
	fi
}

archive_files_create() {
	local source_path=$1

	local directory=$( basename "$source_path" )
	local tarfiles_path="$source_path/$DOTTARFILES"
	local revision_path="$source_path/$DOTREVISION"
	local version_path="$source_path/$DOTVERSION"

	if git_check "$source_path"
	then
		git_files "$source_path" | tr -d '\0' > "$tarfiles_path"
		echo "$DOTTARFILES" | tr -d '\0' >> "$tarfiles_path"
	else
		touch "$tarfiles_path"

		(
			cd "$source_path"
			find
		) | LC_ALL=C sort | sed "s,^./,," | grep -vP "^\.$" > "$tarfiles_path"
	fi

	if [ -f "$revision_path" ]
	then
		echo "$DOTREVISION" | tr -d '\0' >> "$tarfiles_path"
	fi

	if [ -f "$version_path" ]
	then
		echo "$DOTVERSION" | tr -d '\0' >> "$tarfiles_path"
	fi

	if [ -f "$epoch_path" ]
	then
		echo "$DOTEPOCH" | tr -d '\0' >> "$tarfiles_path"
	fi
}

archive_files_date() {
	local source_path=$1

	local epoch_path="$source_path/$DOTEPOCH"

	if ! [ -z "$SOURCE_DATE_EPOCH" ]
	then
		(
			cd "$source_path"
			find -exec touch --no-dereference --date="@$SOURCE_DATE_EPOCH" {} \;
		)
	fi
}

archive_create() {
	local archive_path=$1
	local source_path=$2
	local directory=$3

	local tarfiles_path="$source_path/$DOTTARFILES"
	local directory_path=$( dirname "$archive_path" )

	mkdir -p "$directory_path"

	if [ -z "$directory" ]
	then
		directory=$( basename "$source_path" )
	fi

	archive_files_create "$source_path"
	archive_files_date "$source_path"

	(
		cd "$source_path"
		tar -cJf "$archive_path" --no-recursion -T "$tarfiles_path" --transform="s,^,$directory/,S" --owner=root --group=root --numeric-owner
	)
}

archive_extract() {
	local archive_path=$1
	local destination_path=$2

	if [ -z "$destination_path" ]
	then
		destination_path=$( dirname "$archive_path" )
	fi

	tar -xf "$archive_path" -ps -C "$destination_path"
}

rootfs_files_create() {
	local source_path=$1

	local directory=$( basename "$source_path" )
	local tarfiles_path="$source_path/$DOTTARFILES"

	touch "$tarfiles_path"

	(
		cd "$source_path"
		execute_root find
	) | LC_ALL=C sort | sed "s,^./,," | grep -vP "^$DOTTARFILES|^\.$" > "$tarfiles_path"
}

rootfs_files_date() {
	local source_path=$1

	local epoch_path="$source_path/$DOTEPOCH"

	if ! [ -z "$SOURCE_DATE_EPOCH" ]
	then
		(
			cd "$source_path"
			execute_root find -exec touch --no-dereference --date="@$SOURCE_DATE_EPOCH" {} \;
		)
	fi
}

rootfs_create() {
	local rootfs_path=$1
	local source_path=$2
	local directory=$3

	local tarfiles_path="$source_path/$DOTTARFILES"
	local directory_path=$( dirname "$rootfs_path" )

	mkdir -p "$directory_path"

	if [ -z "$directory" ]
	then
		directory=$( basename "$source_path" )
	fi

	rootfs_files_create "$source_path"
	rootfs_files_date "$source_path"

	(
		cd "$source_path"
		execute_root tar -cJf "$rootfs_path" --no-recursion -T "$tarfiles_path" --numeric-owner
	)

	execute_root chmod 644 "$rootfs_path"
	execute_root chown $USER:$USER "$rootfs_path"
}

requirements() {
	local requirement
	local requirement_path

	for requirement in "$@"
	do
		requirement_path=$( which "$requirement" || true )

		if [ -z "$requirement_path" ]
		then
			printf "Missing requirement: $requirement\n" >&2
			exit 1
		fi
	done
}

requirements_root() {
	local requirement
	local requirement_path

	for requirement in "$@"
	do
		# We need to keep stdout output to show the command.
		requirement_path=$( execute_root which "$requirement" || true )

		if [ -z "$requirement_path" ]
		then
			printf "Missing requirement: $requirement\n" >&2
			exit 1
		fi
	done
}

arguments_concat() {
	local delimiter=$1
	shift

	local concat

	for argument in "$@"
	do
		if ! [ -z "$concat" ]
		then
			concat="$concat""$delimiter""$argument"
		else
			concat="$argument"
		fi
	done

	echo "$concat"
}

execute_root() {
	local sudo=$( which sudo 2> /dev/null || true )
	local arguments

	printf "Running command as root: " >&2
	echo "$@" >&2

	if ! [ -z "$sudo" ]
	then
		sudo "$@"
	else
		# Quote arguments for eval through su.
		arguments=$( printf "%q " "$@" )
		su -c "$arguments"
	fi
}