#!/bin/bash
set -eu
cd "$( dirname "${BASH_SOURCE[0]}" )/.."

version=
version_next=

main() {
	local opt_auto=0
	while [[ $# -gt 0 ]] ; do
		case $1 in
		-auto)
			opt_auto=1
			;;
		*)
			echo "Usage: $0 [-auto]" >&2
			exit 0
			;;
		esac
		shift
	done
	if [[ "$opt_auto" -eq 1 ]] ; then
		auto_prepare_release
	else
		interactive
	fi
}

auto_prepare_release() {
	echo 'script/release: auto mode for CI, will check or modify version based on tag' >&2

	assert_tree_clean

	local is_tag=0
	local version_tag=
	if version_tag=$(git describe --candidates=0 --tags HEAD 2>/dev/null) ; then
		is_tag=1
		version_tag=${version_tag##v}
		version_check "$version_tag"
	fi

	local last_tag=
	local version_replace=
	if [[ "$is_tag" -eq 0 ]] ; then
		last_tag=$(git tag --sort=-version:refname |head -n1)
		last_tag=${last_tag##v}
		version_replace="${last_tag}.post$(date -u +%y%m%d%H%M)"
		update_version "setup.py" "s/VERSION =.+/VERSION = \"$version_replace\"/"
		update_version "httplib2/__init__.py" "s/__version__ =.+/__version__ = \"$version_replace\"/"
		version_check "$version_replace"
	fi
}

interactive() {
	echo 'script/release: interactive mode for creating new tagged releases with human assistance' >&2

	local branch="${1-$(git symbolic-ref --short HEAD)}"
	version=$(python -Es -c "$(egrep '^__version__' httplib2/__init__.py);print(__version__)")
	printf "\nbranch: %s httplib2.__version__: '%s'\n" $branch $version >&2

	if [[ "$branch" != "master" ]] ; then
		echo "Must be on master" >&2
		exit 1
	fi
	assert_tree_clean

	last_commit_message=$(git show --format="%s" --no-patch HEAD)
	expect_commit_message="v$version release"
	if [[ "$last_commit_message" != "$expect_commit_message" ]] ; then
		printf "Last commit message: '%s' expected: '%s'\n" "$last_commit_message" "$expect_commit_message" >&2
		if confirm "Create release commit? [yN] " ; then
			create_commit
		elif ! confirm "Continue without proper release commit? [yN] " ; then
			exit 1
		fi
	fi
	confirm "Continue? [yN] " || exit 1

	echo "Creating tag v$version" >&2
	if ! git tag "v$version" ; then
		echo "git tag failed " >&2
		confirm "Continue still? [yN] " || exit 1
	fi

	echo "Building package" >&2
	find . -name '*.pyc' -o -name '*.pyo' -o -name '*.orig' -delete
	rm -rf .cache
	rm -rf build dist
	local venv=./venv-release
	if [[ ! -d "$venv" ]] ; then
		virtualenv $venv
		$venv/bin/pip install -U check-manifest pip 'setuptools>=43.0' wheel twine
	fi
	$venv/bin/python setup.py clean --all
	$venv/bin/python setup.py sdist bdist_wheel
	$venv/bin/check-manifest

	if confirm "Upload to PyPI? Use in special situation, normally CI/CD will upload to PyPI. [yN] " ; then
		$venv/bin/twine upload dist/* || exit 1
	fi

	git push --verbose origin master "v$version"
}

create_commit() {
	echo "" >&2
	echo "Plan:" >&2
	echo "1. bump version" >&2
	echo "2. update CHANGELOG" >&2
	echo "3. commit" >&2
	echo "4. run bin/release again" >&2
	echo "" >&2

	bump_version
	edit_news

	git diff
	confirm "Ready to commit? [Yn] " || exit 1
	git commit -a -m "v$version_next release"

	echo "Re-exec $0 to continue" >&2
	exec $0
}

bump_version() {
	local current=$version
	echo "Current version: '$current'" >&2
	echo -n "Enter next version (empty to abort): " >&2
	read version_next
	if [[ -z "$version_next" ]] ; then
		exit 1
	fi
	echo "Next version:    '$version_next'" >&2

	update_version "httplib2/__init__.py" "s/__version__ =.+/__version__ = \"$version_next\"/"
	update_version "setup.py" "s/VERSION =.+/VERSION = \"$version_next\"/"

	confirm "Confirm changes? [yN] " || exit 1
}

update_version() {
	local path="$1"
	local sed_expr="$2"
		# sed -E --in-place='' -e "s/VERSION =.+/VERSION = \"$version_replace\"/" setup.py
		# sed -E --in-place='' -e "s/__version__ =.+/__version__ = \"$version_replace\"/" httplib2/__init__.py
	echo "Updating file '$path'" >&2
	if ! sed -E --in-place='' -e "$sed_expr" "$path" ; then
		echo "sed error $?" >&2
		exit 1
	fi
	assert_modified "$path"
	echo "" >&2
}

edit_news() {
	echo "Changes since last release:" >&2
	git log --format='%h   %an   %s' "v$version"^.. -- || exit 1
	echo "" >&2

	patch -p1 <<EOT
diff a/CHANGELOG b/CHANGELOG
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -0,0 +1,4 @@
+$version_next
+
+  EDIT HERE. Describe important changes and link to more information.
+
EOT

	local editor=$(which edit 2>/dev/null)
	[[ -z "$editor" ]] && editor="$EDITOR"
	if [[ -n "$editor" ]] ; then
		if confirm "Open default editor for CHANGELOG? [Yn] " ; then
			$editor CHANGELOG
		else
			confirm "Edit CHANGELOG manually and press any key"
		fi
	else
		echo "Unable to determine default text editor." >&2
		confirm "Edit CHANGELOG manually and press any key"
	fi
	echo "" >&2

	assert_modified CHANGELOG

	echo "" >&2
	confirm "Confirm changes? [yN] " || exit 1
}

assert_modified() {
	local path="$1"
	if git diff --exit-code "$path" ; then
		echo "File '$path' is not modified" >&2
		exit 1
	fi
}

assert_tree_clean() {
	if [[ -n "$(git status --short -uall)" ]] ; then
		echo "Tree must be clean. git status:" >&2
		echo "" >&2
		git status --short -uall
		echo "" >&2
		exit 1
	fi
}

version_check() {
	local need=$1
	local version_setup=$(python setup.py --version)
	local version_have=$(python -Es -c "$(egrep '^__version__' httplib2/__init__.py);print(__version__)")
	if [[ "$version_setup" != "$need" ]] ; then
		echo "error: setup.py version=$version_setup expected=$need" >&1
		exit 1
	fi
	if [[ "$version_have" != "$need" ]] ; then
		echo "error: httplib2/__init__.py:__version__=$version_have expected=$need" >&1
		exit 1
	fi
}

confirm() {
	local reply
	local prompt="$1"
	read -n1 -p "$prompt" reply >&2
	echo "" >&2
	rc=0
	local default_y=" \[Yn\] $"
	if [[ -z "$reply" ]] && [[ "$prompt" =~ $default_y ]] ; then
		reply="y"
	fi
	[[ "$reply" != "y" ]] && rc=1
	return $rc
}

main "$@"