#!/usr/bin/env bash

# Usage: ./generate_release_notes.sh --old-version <old version> --new-version <new version> --ref <ref>
#
# Example: ./generate_release_notes.sh --old-version v0.13.0 --new-version v0.13.1 --ref 1e6b244c
#
# This script generates release notes for the given version. It will generate
# release notes for all commits between the old version and the new version.
#
# Ref must be set to the commit that the new version will be tagget at. This
# is used to determine the commits that are included in the release. If the
# commit is already tagged, ref can be set to the tag name.

set -euo pipefail
# shellcheck source=scripts/lib.sh
source "$(dirname "$(dirname "${BASH_SOURCE[0]}")")/lib.sh"

old_version=
new_version=
ref=
check_for_changelog=0

args="$(getopt -o '' -l check-for-changelog,old-version:,new-version:,ref: -- "$@")"
eval set -- "$args"
while true; do
	case "$1" in
	--check-for-changelog)
		check_for_changelog=1
		shift
		;;
	--old-version)
		old_version="$2"
		shift 2
		;;
	--new-version)
		new_version="$2"
		shift 2
		;;
	--ref)
		ref="$2"
		shift 2
		;;
	--)
		shift
		break
		;;
	*)
		error "Unrecognized option: $1"
		;;
	esac
done

# Check dependencies.
dependencies gh sort

if [[ -z $old_version ]]; then
	error "No old version specified"
fi
if [[ -z $new_version ]]; then
	error "No new version specified"
fi
if [[ $new_version != v* ]]; then
	error "New version must start with a v"
fi
if [[ -z $ref ]]; then
	error "No ref specified"
fi

# Use a manual changelog, if present
changelog_path="$(git rev-parse --show-toplevel)/docs/changelogs/$new_version.md"
if [ "$check_for_changelog" -eq 1 ]; then
	if [ -f "$changelog_path" ]; then
		cat "$changelog_path"
		exit 0
	fi
fi

# shellcheck source=scripts/release/check_commit_metadata.sh
source "$SCRIPT_DIR/check_commit_metadata.sh" "$old_version" "$ref"

# Sort commits by title prefix, then by date, only return sha at the end.
git_log_out="$(git log --no-merges --pretty=format:"%ct %h %s" "$old_version..$ref" | sort -k3,3 -k1,1n | cut -d' ' -f2)"
mapfile -t commits <<<"$git_log_out"

# From: https://github.com/commitizen/conventional-commit-types
# NOTE(mafredri): These need to be supported in check_commit_metadata.sh as well.
declare -a section_order=(
	breaking
	security
	feat
	fix
	docs
	refactor
	perf
	test
	build
	ci
	chore
	revert
	other
	experimental
)

declare -A section_titles=(
	[breaking]='BREAKING CHANGES'
	[security]='SECURITY'
	[feat]='Features'
	[fix]='Bug fixes'
	[docs]='Documentation'
	[refactor]='Code refactoring'
	[perf]='Performance improvements'
	[test]='Tests'
	[build]='Builds'
	[ci]='Continuous integration'
	[chore]='Chores'
	[revert]='Reverts'
	[other]='Other changes'
	[experimental]='Experimental changes'
)

# Verify that all items in section_order exist as keys in section_titles and
# vice-versa.
for cat in "${section_order[@]}"; do
	if [[ " ${!section_titles[*]} " != *" $cat "* ]]; then
		error "BUG: category $cat does not exist in section_titles"
	fi
done
for cat in "${!section_titles[@]}"; do
	if [[ " ${section_order[*]} " != *" $cat "* ]]; then
		error "BUG: Category $cat does not exist in section_order"
	fi
done

for commit in "${commits[@]}"; do
	line="- $commit ${COMMIT_METADATA_TITLE[$commit]}"
	if [[ -v COMMIT_METADATA_AUTHORS[$commit] ]]; then
		line+=" (${COMMIT_METADATA_AUTHORS[$commit]})"
	fi

	# Default to "other" category.
	cat=other
	for c in "${!section_titles[@]}"; do
		if [[ $c == "${COMMIT_METADATA_CATEGORY[$commit]}" ]]; then
			cat=$c
			break
		fi
	done
	declare "$cat"_changelog+="$line"$'\n'
done

changelog="$(
	for cat in "${section_order[@]}"; do
		changes="$(eval "echo -e \"\${${cat}_changelog:-}\"")"
		if ((${#changes} > 0)); then
			echo -e "\n### ${section_titles["$cat"]}\n"
			if [[ $cat == experimental ]]; then
				echo -e "These changes are feature-flagged and can be enabled with the \`--experiments\` server flag. They may change or be removed in future releases.\n"
			fi
			echo -e "$changes"
		fi
	done
)"

image_tag="$(execrelative ../image_tag.sh --version "$new_version")"

echo -e "## Changelog
$changelog

Compare: [\`$old_version...$new_version\`](https://github.com/coder/coder/compare/$old_version...$new_version)

## Container image

- \`docker pull $image_tag\`

## Install/upgrade

Refer to our docs to [install](https://coder.com/docs/v2/latest/install) or [upgrade](https://coder.com/docs/v2/latest/admin/upgrade) Coder, or use a release asset below.
"