// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause

package setting

import (
	"fmt"

	"tailscale.com/types/structs"
)

// RawItem contains a raw policy setting value as read from a policy store, or an
// error if the requested setting could not be read from the store. As a special
// case, it may also hold a value of the [Visibility], [PreferenceOption],
// or [time.Duration] types. While the policy store interface does not support
// these types natively, and the values of these types have to be unmarshalled
// or converted from strings, these setting types predate the typed policy
// hierarchies, and must be supported at this layer.
type RawItem struct {
	_      structs.Incomparable
	value  any
	err    *ErrorText
	origin *Origin // or nil
}

// RawItemOf returns a [RawItem] with the specified value.
func RawItemOf(value any) RawItem {
	return RawItemWith(value, nil, nil)
}

// RawItemWith returns a [RawItem] with the specified value, error and origin.
func RawItemWith(value any, err *ErrorText, origin *Origin) RawItem {
	return RawItem{value: value, err: err, origin: origin}
}

// Value returns the value of the policy setting, or nil if the policy setting
// is not configured, or an error occurred while reading it.
func (i RawItem) Value() any {
	return i.value
}

// Error returns the error that occurred when reading the policy setting,
// or nil if no error occurred.
func (i RawItem) Error() error {
	if i.err != nil {
		return i.err
	}
	return nil
}

// Origin returns an optional [Origin] indicating where the policy setting is
// configured.
func (i RawItem) Origin() *Origin {
	return i.origin
}

// String implements [fmt.Stringer].
func (i RawItem) String() string {
	var suffix string
	if i.origin != nil {
		suffix = fmt.Sprintf(" - {%v}", i.origin)
	}
	if i.err != nil {
		return fmt.Sprintf("Error{%q}%s", i.err.Error(), suffix)
	}
	return fmt.Sprintf("%v%s", i.value, suffix)
}