package iam

import (
	"context"

	"atlas9.dev/c/core"
)

type Principal interface {
	PrincipalID() core.ID
}

func Anonymous() Principal {
	return anonymous{}
}

type anonymous struct{}

func (anonymous) PrincipalID() core.ID { return core.ID{} }

type principalContextKey struct{}

// GetPrincipal retrieves a Principal from the context.
// If not found, returns a zero value (anonymous) principal.
func GetPrincipal(ctx context.Context) Principal {
	if op, ok := ctx.Value(principalContextKey{}).(Principal); ok {
		return op
	}
	return Anonymous()
}

// PutPrincipal stores a Principal in the context.
func PutPrincipal(ctx context.Context, op Principal) context.Context {
	return context.WithValue(ctx, principalContextKey{}, op)
}