package fieldgroups

import (
	"fmt"

	"pdf-wizard/internal/models"
)

// SingleSelectHandler handles groups of checkboxes where exactly one must be selected.
type SingleSelectHandler struct{}

func init() {
	Register(SingleSelectHandler{})
}

func (SingleSelectHandler) Type() string {
	return "single_select"
}

func (SingleSelectHandler) Validate(fields []models.FormField, fieldValues map[int]string) error {
	count := 0
	for _, f := range fields {
		if v, ok := fieldValues[f.ID]; ok && v == "1" {
			count++
			if count > 1 {
				return fmt.Errorf("only one option may be selected in this group")
			}
		}
	}
	if count == 0 {
		return fmt.Errorf("exactly one option must be selected in this group")
	}
	return nil
}

func (SingleSelectHandler) ConvertToFillValues(fields []models.FormField, fieldValues map[int]string) map[int]string {
	result := make(map[int]string)
	for _, f := range fields {
		if v, ok := fieldValues[f.ID]; ok {
			result[f.ID] = v
		} else {
			result[f.ID] = ""
		}
	}
	return result
}