// GoToSocial
// Copyright (C) GoToSocial Authors admin@gotosocial.org
// SPDX-License-Identifier: AGPL-3.0-or-later
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package util

import (
	"fmt"
	"strconv"
)

// ParseDuration parses the given raw interface belonging to
// the given fieldName as an integer duration.
//
// Will return nil, nil if rawI is the zero value of its type.
func ParseDuration(rawI any, fieldName string) (*int, error) {
	var (
		asInteger int
		err       error
	)

	switch raw := rawI.(type) {
	case float64:
		// Submitted as JSON number
		// (casts to float64 by default).
		asInteger = int(raw)

	case string:
		// Submitted as JSON string or form field.
		asInteger, err = strconv.Atoi(raw)
		if err != nil {
			err = fmt.Errorf(
				"could not parse %s value %s as integer: %w",
				fieldName, raw, err,
			)
		}

	default:
		// Submitted as god-knows-what.
		err = fmt.Errorf(
			"could not parse %s type %T as integer",
			fieldName, rawI,
		)
	}

	if err != nil {
		return nil, err
	}

	// Someone submitted 0,
	// don't point to this.
	if asInteger == 0 {
		return nil, nil
	}

	return &asInteger, nil
}