#!/bin/sh
set -eu

deployment_directory=${1:-/opt/shd-build-stage}
source_directory=${2:-}
candidate_image=${3:-}
candidate_directory=${4:-}
if [ -z "$source_directory" ] || [ ! -f "$source_directory/Dockerfile" ] || [ -z "$candidate_image" ] || [ ! -f "$candidate_directory/compose.staging.yml" ] || [ ! -f "$candidate_directory/.env.deploy" ]; then
	echo "Usage: deploy-staging.sh <deployment-directory> <source-directory> <candidate-image> <candidate-directory>" >&2
	exit 2
fi
case "$candidate_directory" in
	"$deployment_directory"/candidate-*) ;;
	*) echo "Candidate directory must be a candidate-* child of the deployment directory." >&2; exit 2 ;;
esac
candidate_compose_file="$candidate_directory/compose.staging.yml"
candidate_environment="$candidate_directory/.env.deploy"
canonical_compose_file="$deployment_directory/compose.staging.yml"
canonical_environment="$deployment_directory/.env.deploy"
previous_directory="$deployment_directory/.previous-release"
healthy_marker="$deployment_directory/.deployment-healthy"
release_files="compose.staging.yml .env.deploy .infisical.app.client-id .infisical.app.client-secret .infisical.scheduler.client-id .infisical.scheduler.client-secret deploy-staging.sh bootstrap-staging.sh"
rollback_required=false
candidate_promoted=false
had_previous_release=false

candidate_compose() {
	docker compose --env-file "$candidate_environment" -f "$candidate_compose_file" "$@"
}

canonical_compose() {
	docker compose --env-file "$canonical_environment" -f "$canonical_compose_file" "$@"
}

release_is_healthy() {
	health_environment=$1
	health_compose_file=$2
	health_attempt=0
	while [ "$health_attempt" -lt 30 ]; do
		health_app_container=$(docker compose --env-file "$health_environment" -f "$health_compose_file" ps -q app)
		health_scheduler_container=$(docker compose --env-file "$health_environment" -f "$health_compose_file" ps -q scheduler)
		health_app_status=missing
		health_scheduler_status=missing
		if [ -n "$health_app_container" ]; then
			health_app_status=$(docker inspect --format '{{if .State.Health}}{{.State.Health.Status}}{{else}}{{.State.Status}}{{end}}' "$health_app_container" 2>/dev/null || echo missing)
		fi
		if [ -n "$health_scheduler_container" ]; then
			health_scheduler_status=$(docker inspect --format '{{.State.Status}}' "$health_scheduler_container" 2>/dev/null || echo missing)
		fi
		if [ "$health_app_status" = healthy ] && [ "$health_scheduler_status" = running ]; then return 0; fi
		if [ "$health_app_status" = unhealthy ] || [ "$health_app_status" = exited ] || [ "$health_app_status" = dead ] || [ "$health_scheduler_status" = exited ] || [ "$health_scheduler_status" = dead ]; then return 1; fi
		health_attempt=$((health_attempt + 1))
		sleep 2
	done
	return 1
}

copy_release() {
	copy_source=$1
	copy_target=$2
	copy_status=0
	for release_file in $release_files; do
		if [ -f "$copy_source/$release_file" ]; then
			copy_temporary=$(mktemp "$copy_target/.release.XXXXXX") || return 1
			if cp -p "$copy_source/$release_file" "$copy_temporary"; then
				mv "$copy_temporary" "$copy_target/$release_file" || copy_status=1
			else
				rm -f "$copy_temporary"
				copy_status=1
			fi
		else
			rm -f "$copy_target/$release_file" || copy_status=1
		fi
	done
	return "$copy_status"
}

cleanup_candidate() {
	case "$candidate_directory" in
		"$deployment_directory"/candidate-*) rm -rf "$candidate_directory" ;;
	esac
}

rollback() {
	rollback_exit_status=$?
	trap - EXIT HUP INT TERM
	set +e
	if [ "$rollback_required" = true ]; then
		echo "Restoring the previous healthy staging release." >&2
		restore_status=0
		candidate_compose stop scheduler app >/dev/null 2>&1 || restore_status=1
		if [ "$candidate_promoted" = true ]; then copy_release "$previous_directory" "$deployment_directory" || restore_status=1; fi
		if [ "$had_previous_release" = true ]; then
			canonical_compose up -d --no-build app scheduler || restore_status=1
			if [ "$restore_status" -eq 0 ] && ! release_is_healthy "$canonical_environment" "$canonical_compose_file"; then restore_status=1; fi
		else
			echo "No previous staging release is available." >&2
			restore_status=1
		fi
		if [ "$restore_status" -ne 0 ]; then
			echo "The previous staging release could not be restored." >&2
			if [ "$rollback_exit_status" -eq 0 ]; then rollback_exit_status=1; fi
		fi
	fi
	cleanup_candidate
	exit "$rollback_exit_status"
}

trap rollback EXIT
trap 'exit 129' HUP
trap 'exit 130' INT
trap 'exit 143' TERM

echo "Building the candidate image while the current staging service remains online."
docker build --label org.opencontainers.image.title=shd-build -t "$candidate_image" "$source_directory"

echo "Validating Infisical access and the candidate runtime configuration."
candidate_compose run --rm --no-deps app node scripts/validate-runtime-environment.mjs app
candidate_compose run --rm --no-deps scheduler node scripts/validate-runtime-environment.mjs scheduler

rm -rf "$previous_directory"
mkdir -p "$previous_directory"
if [ -f "$canonical_compose_file" ] && [ -f "$canonical_environment" ]; then
	had_previous_release=true
	copy_release "$deployment_directory" "$previous_directory"
fi

echo "Stopping SHD staging processes before accessing the embedded database."
rollback_required=true
candidate_compose stop scheduler app

echo "Creating a timestamped database backup when a staging database exists."
candidate_compose run --rm --no-deps app sh -c \
	'if [ -f "$TDR_DATABASE_PATH" ]; then node scripts/db-backup.mjs; else echo "No staging database exists yet; skipping backup."; fi'

echo "Applying additive schema migrations."
candidate_compose run --rm --no-deps app node scripts/db-migrate.mjs

candidate_promoted=true
copy_release "$candidate_directory" "$deployment_directory"

echo "Starting the application and notification scheduler."
canonical_compose up -d --no-build --remove-orphans app scheduler

if release_is_healthy "$canonical_environment" "$canonical_compose_file"; then
	echo "SHD staging deployment is healthy."
	rollback_required=false
	umask 077
	: > "$healthy_marker"
	cleanup_candidate
	trap - EXIT HUP INT TERM
	exit 0
fi

echo "SHD staging failed its health check."
canonical_compose logs --tail=150 app scheduler
exit 1