// Copyright 2024 The Kubetail Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package graph

import (
	"fmt"
	"strings"
	"time"

	"github.com/sosodev/duration"
)

// Parse an input either as an ISO timestamp or an ISO duration string
func parseTimeArg(arg string) (time.Time, error) {
	var zero time.Time

	arg = strings.TrimSpace(arg)
	if arg == "" {
		return zero, nil
	} else if timeAgo, err := duration.Parse(arg); err == nil {
		// Parsed as ISO duration
		return time.Now().Add(-1 * timeAgo.ToTimeDuration()), nil
	} else if ts, err := time.Parse(time.RFC3339Nano, arg); err == nil {
		// Parsed as ISO timestamp
		return ts, nil
	}

	return zero, fmt.Errorf("unable to parse arg %s", arg)
}
