// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
// All rights reserved.

// iter-factory.go
package expr

import (
	"fmt"
	"slices"

	"git.portale-stac.it/go-pkg/expr/kern"
)

func NewIterator(ctx kern.ExprContext, value any, args map[string]any) (it kern.Iterator, err error) {
	if value == nil {
		return NewArrayIterator([]any{}), nil
	}

	switch v := value.(type) {
	case *kern.ListType:
		it = NewListIterator(v, nil)
	case *kern.DictType:
		it, err = NewDictIterator(v, nil)
	case []any:
		it = NewArrayIterator(v)
	case kern.Iterator:
		// it = v
		var op kern.Functor
		if len(args) >= 1 {
			if opArg, ok := args["op"]; ok {
				if op, ok = opArg.(kern.Functor); !ok {
					err = fmt.Errorf("the 'op' argument must be a kern.Functor, got %T", opArg)
				}
			}
		}
		if err == nil {
			it, err = NewIterIter(v, ctx, op, args)
		}
	default:
		it = NewArrayIterator([]any{value})
	}
	return
}

func HasStandardOperation(name string) bool {
	return slices.Contains([]string{kern.NextName, kern.ResetName, kern.IndexName, kern.CountName, kern.CurrentName, kern.CleanName}, name)
}