#!/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/>.

DOTGIT=".git"
HEAD="HEAD"
ORIGIN_HEAD="origin/HEAD"
WILDDOTPATCH="*.patch"
GIT_NAME="Libreboot"
GIT_EMAIL="libreboot@libreboot.org"

git_check() {
	local repository_path=$1

	directory_filled_check "$repository_path/$DOTGIT"
}

git_clone() {
	local repository_path=$1
	local url=$2

	git clone "$url" "$repository_path"
}

git_submodule_update() {
	local repository_path=$1

	(
		cd "$repository_path"
		git submodule update --init
	)
}

git_merge() {
	local repository_path=$1
	local revision=$2

	(
		cd "$repository_path"
		git merge "$revision"
	)
}

git_branch_create() {
	local repository_path=$1
	local branch=$2
	local revision=$3

	(
		cd "$repository_path"
		git checkout -B "$branch"

		if ! [ -z "$revision" ]
		then
			git reset --hard "$revision"
		fi
	)
}

git_branch_delete() {
	local repository_path=$1
	local branch=$2

	(
		cd "$repository_path"
		git branch -D "$branch"
	)
}

git_branch_checkout() {
	local repository_path=$1
	local branch=$2

	(
		cd "$repository_path"
		git checkout "$branch" > /dev/null
	)
}

git_branch_check() {
	local repository_path=$1
	local branch=$2

	(
		cd "$repository_path" 2> /dev/null > /dev/null
		if [ $? -ne 0 ]
		then
			return 1
		fi

		git rev-parse --verify "$branch" 2> /dev/null > /dev/null
		if [ $? -ne 0 ]
		then
			return 1
		fi
	)
}

git_fetch() {
	local repository_path=$1

	(
		cd "$repository_path"
		git fetch origin
	)
}

git_fetch_check() {
	local repository_path=$1

	(
		cd "$repository_path" 2> /dev/null > /dev/null
		if [ $? -ne 0 ]
		then
			return 1
		fi

		local output=$( git fetch --dry-run origin 2>&1 )
		if ! [ -z "$output" ]
		then
			return 1
		fi
	)
}

git_clean() {
	local repository_path=$1

	(
		cd "$repository_path"
		git clean -df
	)
}

git_remove() {
	local repository_path=$1
	local path=$2

	(
		cd "$repository_path"
		git rm -rf "$path"
	)
}

git_commit() {
	local repository_path=$1
	local message=$2

	(
		export GIT_COMMITTER_NAME=$GIT_NAME
		export GIT_COMMITTER_EMAIL=$GIT_EMAIL

		cd "$repository_path"
		git commit --author="$GIT_NAME <$GIT_EMAIL>" -m "$message"
	)
}

git_patch() {
	local repository_path=$1
	local branch=$2
	local patch=$3

	(
		export GIT_COMMITTER_NAME=$GIT_NAME
		export GIT_COMMITTER_EMAIL=$GIT_EMAIL

		cd "$repository_path"
		git checkout "$branch" 2> /dev/null > /dev/null
		git am "$patch"
	)
}

git_revision() {
	local repository_path=$1

	(
		cd "$repository_path"
		git rev-parse "$HEAD"
	)
}

git_describe() {
	local repository_path=$1

	(
		cd "$repository_path"
		git describe --tags
	)
}

git_files() {
	local repository_path=$1

	(
		cd "$repository_path"
		# Reproducible sorting.
		git ls-files | LC_ALL=C sort -z
	)
}

git_project_repository_path() {
	local repository=$1

	echo "$root/$SOURCES/$repository"
}

git_project_check() {
	local repository=$1

	local repository_path=$( git_project_repository_path "$repository" )

	git_check "$repository_path"
}

git_project_patch_recursive() {
	local project=$1
	local repository=$2
	local branch=$3
	local path=$4

	local repository_path=$( git_project_repository_path "$repository" )
	local project_path=$( project_path "$project" )
	local patches_path="$project_path/$PATCHES/$path/$WILDDOTPATCH"
	local patch_path

	if ! [ -z "$path" ] && [ "$path" != "." ]
	then
		git_project_patch_recursive "$project" "$repository" "$branch" "$( dirname "$path" )"
	fi

	path_wildcard_expand "$patches_path" | while read patch_path
	do
		if ! [ -f "$patch_path" ]
		then
			continue
		fi

		git_patch "$repository_path" "$branch" "$patch_path"
	done
}

git_project_clone() {
	local repository=$1
	shift
	local urls=$@

	local repository_path=$( git_project_repository_path "$repository" )
	local directory_path=$( dirname "$repository_path" )
	local url

	mkdir -p "$directory_path"

	(
		set +e

		for url in $urls
		do
			git_clone "$repository_path" "$url"

			if [ $? -eq 0 ]
			then
				return 0
			fi
		done

		return 1
	)
}

git_project_prepare() {
	local project=$1
	shift
	local repository=$1
	shift

	git_project_prepare_revision "$project" "$repository" "$@"
	git_project_prepare_blobs "$project" "$repository" "$@"
	git_project_prepare_patch "$project" "$repository" "$@"
}

git_project_prepare_blobs() {
	local project=$1
	shift
	local repository=$1
	shift

	local repository_path=$( git_project_repository_path "$repository" )
	local blobs_path=$( project_blobs_path "$project" "$@" )
	local blob

	if ! [ -f "$blobs_path" ]
	then
		return
	fi

	while read blob
	do
		git_remove "$repository_path" "$blob"
	done < "$blobs_path"

	git_commit "$repository_path" "Removed blobs"
}

git_project_prepare_patch() {
	local project=$1
	shift
	local repository=$1
	shift

	local project_path=$( project_path "$project" )
	local configs_path="$project_path/$CONFIGS"
	local prepare_branch
	local prepare_path
	local branch=$project
	local argument
	local path

	for argument in "" "$@"
	do
		if ! [ -z "$argument" ]
		then
			if [ -z "$path" ]
			then
				path="$argument"
			else
				path="$path/$argument"
			fi

			branch="$branch-$argument"
		fi

		local revision_path="$configs_path/$path/$REVISION"

		if ! [ -f "$revision_path" ]
		then
			continue
		fi

		prepare_branch=$branch
		prepare_path=$path
	done

	if ! [ -z "$prepare_branch" ]
	then
		git_project_patch_recursive "$project" "$repository" "$prepare_branch" "$prepare_path"
	fi
}

git_project_prepare_revision() {
	local project=$1
	shift
	local repository=$1
	shift

	local repository_path=$( git_project_repository_path "$repository" )
	local project_path=$( project_path "$project" )
	local configs_path="$project_path/$CONFIGS"
	local prepare_branch
	local prepare_revision
	local branch=$project
	local argument
	local path

	for argument in "" "$@"
	do
		if ! [ -z "$argument" ]
		then
			if [ -z "$path" ]
			then
				path="$argument"
			else
				path="$path/$argument"
			fi

			branch="$branch-$argument"
		fi

		local revision_path="$configs_path/$path/$REVISION"

		if ! [ -f "$revision_path" ]
		then
			continue
		fi

		prepare_branch=$branch
		prepare_revision=$( cat "$revision_path" )
	done

	if ! [ -z "$prepare_branch" ]
	then
		git_branch_create "$repository_path" "$prepare_branch" "$prepare_revision"
	fi
}

git_project_prepare_check() {
	local project=$1
	shift
	local repository=$1
	shift

	local repository_path=$( git_project_repository_path "$repository" )
	local project_path=$( project_path "$project" )
	local configs_path="$project_path/$CONFIGS"
	local prepare_branch
	local branch=$project
	local argument
	local path

	for argument in "" "$@"
	do
		if ! [ -z "$argument" ]
		then
			if [ -z "$path" ]
			then
				path="$argument"
			else
				path="$path/$argument"
			fi

			branch="$branch-$argument"
		fi

		local revision_path="$configs_path/$path/$REVISION"

		if ! [ -f "$revision_path" ]
		then
			continue
		fi

		prepare_branch=$branch
	done

	if ! [ -z "$prepare_branch" ]
	then
		git_branch_check "$repository_path" "$prepare_branch"
	fi
}

git_project_prepare_clean() {
	local project=$1
	shift
	local repository=$1
	shift

	local repository_path=$( git_project_repository_path "$repository" )
	local prepare_branch
	local branch=$project
	local argument

	for argument in "" "$@"
	do
		if ! [ -z "$argument" ]
		then
			branch="$branch-$argument"
		fi

		if ! git_branch_check "$repository_path" "$branch"
		then
			continue
		fi

		prepare_branch=$branch
	done

	if ! [ -z "$prepare_branch" ]
	then
		# Let's not worry about missing branches.
		(
			set +e

			git_branch_delete "$repository_path" "$prepare_branch"

			if [ $? -ne 0 ]
			then
				return 0
			fi
		)
	fi
}

git_project_checkout() {
	local project=$1
	shift
	local repository=$1
	shift

	local repository_path=$( git_project_repository_path "$repository" )
	local checkout_branch
	local branch=$project
	local argument

	for argument in "" "$@"
	do
		if ! [ -z "$argument" ]
		then
			branch="$branch-$argument"
		fi

		if ! git_branch_check "$repository_path" "$branch"
		then
			continue
		fi

		checkout_branch=$branch
	done

	if ! [ -z "$checkout_branch" ]
	then
		git_branch_checkout "$repository_path" "$checkout_branch"
		git_submodule_update "$repository_path"
	fi
}

git_project_update() {
	local project=$1
	shift
	local repository=$1
	shift

	local repository_path=$( git_project_repository_path "$repository" )

	git_fetch "$repository_path"
	git_branch_checkout "$repository_path" "$ORIGIN_HEAD"

	git_project_prepare_clean "$project" "$repository" "$@"
	git_project_prepare "$project" "$repository" "$@"
}

git_project_update_check() {
	local project=$1
	shift
	local repository=$1
	shift

	git_project_prepare_check "$project" "$repository" "$@"

	git_fetch_check "$repository_path"
}

git_project_release() {
	local project=$1
	shift
	local repository=$1
	shift
	local arguments=$@

	local repository_path=$( git_project_repository_path "$repository" )
	local release_branch
	local branch=$project
	local argument

	for argument in "" "$@"
	do
		if ! [ -z "$argument" ]
		then
			branch="$branch-$argument"
		fi

		if ! git_branch_check "$repository_path" "$branch"
		then
			continue
		fi

		release_branch=$branch
	done

	if ! [ -z "$release_branch" ]
	then
		local archive_path="$root/$RELEASE/$SOURCES/$project/$release_branch.$TAR_XZ"
		local sources_path="$root/$SOURCES/$repository"

		printf "Releasing sources archive for $project (with ${arguments:-no argument}) from "$repository" git\n"

		git_branch_checkout "$repository_path" "$release_branch"
		git_submodule_update "$repository_path"
		git_clean "$repository_path"
		archive_create "$archive_path" "$sources_path" "$release_branch"
		file_verification_create "$archive_path"
	fi
}

git_project_release_check() {
	local project=$1
	shift
	local repository=$1
	shift

	local repository_path=$( git_project_repository_path "$repository" )
	local release_branch
	local branch=$project
	local argument

	for argument in "" "$@"
	do
		if ! [ -z "$argument" ]
		then
			branch="$branch-$argument"
		fi

		if ! git_branch_check "$repository_path" "$branch"
		then
			continue
		fi

		release_branch=$branch
	done

	if ! [ -z "$release_branch" ]
	then
		local archive_path="$root/$RELEASE/$SOURCES/$project/$release_branch.$TAR_XZ"

		file_exists_check "$archive_path"

		if [ $? -ne 0 ]
		then
			return 1
		else
			return 0
		fi
	fi
}