import type { ManifestFieldDefinition } from "@solspace/freeform-core";
import type { FreeformReactTheme, FreeformThemeClassNames } from "../types.js";
import { joinClassNames } from "./mergeClassNames.js";

const CHOICE_TYPES = new Set([
  "checkbox",
  "checkboxes",
  "radio",
  "radios",
  "radiobox",
  "rating",
  "opinion-scale",
  "cards",
]);

function overlay(
  base: FreeformThemeClassNames,
  extra: Partial<FreeformThemeClassNames> | undefined,
): FreeformThemeClassNames {
  if (!extra) {
    return base;
  }

  return { ...base, ...extra };
}

/**
 * Global classNames, then overlays for field type / frontend renderer / extension.
 * Error styles append `inputError` onto the control (`optionInput` for choice fields).
 */
export function resolveThemeClassNames(
  theme: FreeformReactTheme,
  field: ManifestFieldDefinition,
  hasErrors = false,
): FreeformThemeClassNames {
  const byType = theme.classNamesByType;
  let classNames = overlay({}, theme.classNames);

  classNames = overlay(classNames, byType?.[field.type]);

  const renderer = field.frontend?.renderer;
  if (renderer) {
    classNames = overlay(classNames, byType?.[renderer]);
  }

  const extension = field.frontend?.extension;
  if (extension) {
    classNames = overlay(classNames, byType?.[extension]);
  }

  if (hasErrors && classNames.inputError) {
    if (CHOICE_TYPES.has(field.type)) {
      classNames = {
        ...classNames,
        optionInput: joinClassNames(
          classNames.optionInput,
          classNames.inputError,
        ),
      };
    } else {
      classNames = {
        ...classNames,
        input: joinClassNames(classNames.input, classNames.inputError),
      };
    }
  }

  return classNames;
}