#!/usr/bin/env bash

set -Eeuo pipefail

DEPLOY_ROOT="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd -P)"
SCRIPT_PATH="${DEPLOY_ROOT}/$(basename -- "${BASH_SOURCE[0]}")"
cd "$DEPLOY_ROOT"

fail() {
	printf 'ERROR: %s\n' "$*" >&2
	exit 1
}

command -v git >/dev/null 2>&1 || fail "git is required"
command -v docker >/dev/null 2>&1 || fail "docker is required"
docker compose version >/dev/null 2>&1 ||
	fail "Docker Compose v2 is required"
[[ -f .env ]] || fail ".env was not found in ${DEPLOY_ROOT}"

post_pull=0
if [[ "${1:-}" == "--post-pull" ]]; then
	post_pull=1
elif [[ $# -ne 0 ]]; then
	fail "usage: ${0} [--post-pull]"
fi

if ((post_pull == 0)); then
	branch="$(git symbolic-ref --quiet --short HEAD)" ||
		fail "the repository is in detached HEAD state"
	upstream="$(git rev-parse --abbrev-ref --symbolic-full-name '@{upstream}' 2>/dev/null)" ||
		fail "branch ${branch} does not have an upstream branch"
	remote="$(git config --get "branch.${branch}.remote")" ||
		fail "branch ${branch} does not have a configured remote"

	git diff --quiet && git diff --cached --quiet ||
		fail "tracked local changes must be committed or stashed before updating"

	printf 'Checking %s against %s...\n' "$branch" "$upstream"
	git fetch --quiet --prune "$remote"

	local_commit="$(git rev-parse HEAD)"
	upstream_commit="$(git rev-parse '@{upstream}')"
	if [[ "$local_commit" == "$upstream_commit" ]]; then
		printf 'Deployment is already up to date.\n'
	elif git merge-base --is-ancestor "$local_commit" "$upstream_commit"; then
		git merge --quiet --ff-only "$upstream_commit"
		# Restart using the newly pulled copy so changes to this script apply.
		exec "$SCRIPT_PATH" --post-pull
	elif git merge-base --is-ancestor "$upstream_commit" "$local_commit"; then
		fail "local branch ${branch} is ahead of ${upstream}; refusing to update"
	else
		fail "local branch ${branch} has diverged from ${upstream}"
	fi
fi

printf 'Updating the local Gitea image and deployment stack...\n'
docker compose --env-file .env pull gitea nginx certbot
"${DEPLOY_ROOT}/manage.sh" start

container_id="$(docker compose -f compose.yaml -f compose.tls.yaml ps -q broker)"
[[ -n "$container_id" ]] ||
	fail "Docker Compose did not return the local broker container"

printf 'Waiting for the local broker health check'
for ((attempt = 1; attempt <= 75; attempt++)); do
	status="$(
		docker inspect \
			--format '{{if .State.Health}}{{.State.Health.Status}}{{else}}{{.State.Status}}{{end}}' \
			"$container_id"
	)"
	case "$status" in
	healthy)
		printf ' healthy.\n'
		docker compose -f compose.yaml -f compose.tls.yaml ps
		printf 'Local deployment updated successfully.\n'
		exit 0
		;;
	exited | dead | unhealthy)
		printf ' %s.\n' "$status"
		docker compose -f compose.yaml -f compose.tls.yaml logs --tail=100 broker
		fail "the local broker failed its health check"
		;;
	esac
	printf '.'
	sleep 2
done

printf ' timed out.\n'
docker compose -f compose.yaml -f compose.tls.yaml logs --tail=100 broker
fail "the local broker did not become healthy within 150 seconds"