#!/usr/bin/env 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"
DOTRNDSEED=".rndseed"
DOTVERSION=".version"
DOTREVISION=".revision"
DOTTARFILES=".tarfiles"
ARCHIVE="tar.xz"
CHECKSUM="sha256sum"
DSIG="asc"

CONFIG_SHELL="${CONFIG_SHELL:-$(which bash)}"
EDITOR="${EDITOR:-$(which vi || true)}"
TASKS="${TASKS:-1}"

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 "$@"
	do
		printf '%s\n' "$argument"
	done
}

download_wrapper() {
	local download_dir="$1"
	shift
	local uris=($@)

	local wget_options=(
		'--config=/dev/null'
		'--secure-protocol=PFS'
		"--directory-prefix=$download_dir"
		'--continue'
		'--'
	)

	local curl_options=(
		'-q'
		'--continue-at -'
		'--remote-name'
		'--retry 20'
		'--ssl'
		'--tlsv1.2'
		'--'
	)

	if hash wget > /dev/null 2>&1; then

		wget "${wget_options[@]}" "${uris[@]}"

	elif hash curl > /dev/null 2>&1; then
		(
			cd "$download_dir"

			curl "${curl_options[@]}" "${uris[@]}"
		)
	else
		printf '\n%s\n\n' 'Error: Neither wget nor curl were found' 1>&2

		return 1
	fi
}

diff_patch_file() {
	local repository_path="$1"
	local patch_file_path="$2"

	# TODO: Improve handling of filenames to avoid gotchas w/ \n, \t, etc.
	local filename_in_diff="$(sed -rne 's/^-{3}\s+([^ 	\r\n]*).*/\1/p' "$patch_file_path")"

	local source_file_path

	if ! ( grep -E '^-{3}.*/' "$patch_file_path" >/dev/null 2>&1 ); then
		source_file_path="$repository_path/$filename_in_diff"
	else
		source_file_path="$repository_path/${filename_in_diff##*/}"
	fi

	patch "$source_file_path" "$patch_file_path"
}

path_wildcard_expand() {
	local path=$@

	# Evaluation fails with unescaped whitespaces.
	path=$( printf '%s\n' "$path" | sed "s/ /\\\ /g" )

	eval "arguments_list "$path""
}

file_checksum_create() {
	local path=$1

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

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

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

file_signature_create() {
	local path=$1

	local signature_path="$path.$DSIG"

	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="$path.$DSIG"

	if ! [[ -f "$signature_path" ]]
	then
		printf 1>&2 '%s\n' 'Could not verify file signature!'
		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"
	local epoch_path="$source_path/$DOTEPOCH"
	local rnd_seed_path="$source_path/$DOTRNDSEED"

	# Files in "$tarfiles_path" are NUL terminated.
	# `tr '\0' '\n'` for human-readable output.
	if git_check "$source_path"; then
		git_files "$source_path" > "$tarfiles_path"
		printf '%s\0' "$DOTTARFILES" >> "$tarfiles_path"
	else
		find "$source_path" -print0 | env LC_ALL='C.UTF-8' sort -z | sed -z "1d;s,^$source_path/\\?,,;/^$DOTTARFILES\$/d" > "$tarfiles_path"
	fi

	for dotfile in "$revision_path" \
			"$version_path" \
			"$epoch_path" \
			"$rnd_seed_path"
	do
		if [[ -f "$dotfile" ]]; then
			printf '%s\0' ".${dotfile##*.}" >> "$tarfiles_path"
		fi
	done
}

archive_files_date() {
	local source_path="$1"

	local epoch_path="$source_path/$DOTEPOCH"

	if [[ -n "$SOURCE_DATE_EPOCH" ]]; then
		find "$source_path" -execdir 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"

	local tar_options=(
		--create
		--xz
		--file="$archive_path"
		--files-from="$tarfiles_path"
		--transform="s,^,$directory/,S"
		--no-recursion
		--warning=no-filename-with-nuls
		--null
		--owner=0
		--group=0
		--numeric-owner
	)

	(
		cd "$source_path"
		tar "${tar_options[@]}"
	)
}

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"

	# Files in "$tarfiles_path" are NUL terminated.
	# `tr '\0' '\n'` for human-readable output.
	execute_root find "$source_path" -print0 | env LC_ALL='C.UTF-8' sort -z | sed -z "1d;s,^$source_path/\\?,,;/^$DOTTARFILES\$/d" > "$tarfiles_path"
}

rootfs_files_date() {
	local source_path="$1"

	local epoch_path="$source_path/$DOTEPOCH"

	if [[ -n "$SOURCE_DATE_EPOCH" ]]; then
		execute_root find "$source_path" -execdir 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"

	local tar_options=(
		--create
		--xz
		--file="$rootfs_path"
		--files-from="$tarfiles_path"
		--no-recursion
		--warning=no-filename-with-nuls
		--null
		--owner=0
		--group=0
		--numeric-owner
	)

	(
		cd "$source_path"
		execute_root tar "${tar_options[@]}"
	)

	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 1>&2 '%s\n' "Missing requirement: $requirement"
			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 1>&2 '%s\n' "Missing requirement: $requirement"
			exit 1
		fi
	done
}

arguments_concat() {
	local delimiter=$1
	shift

	local concat

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

	printf '%s\n' "$concat"
}

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

	printf 1>&2 '%s' 'Running command as root: '
	printf 1>&2 '%b\n' "$*"

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