import { isObject, isString } from '../utils';
import { EntityType } from '../schema';
import type {
  SectionSpec,
  ParagraphSpec,
  CustomBlockElement,
  StandardSectionSpec,
  TextParagraphSpec,
  BulletsParagraphSpec,
  HeadingParagraphSpec,
  PhraseSpec,
  CustomPhraseSpec,
  EntityPhraseSpec,
  TextPhraseSpec,
} from '../schema';

export function isCustomSection(spec: SectionSpec): spec is CustomBlockElement {
  return isObject(spec) && 'customType' in spec;
}

export function isCustomParagraph(spec: ParagraphSpec): spec is CustomBlockElement {
  return isObject(spec) && 'customType' in spec;
}

export function isStandardSection(spec: SectionSpec): spec is StandardSectionSpec {
  return isObject(spec) && 'paragraphs' in spec && Array.isArray(spec?.paragraphs);
}

export function isTextParagraph(spec: ParagraphSpec): spec is TextParagraphSpec {
  return isObject(spec) && spec?.type === 'normal' && Array.isArray(spec?.phrases);
}

export function isBulletParagraph(spec: ParagraphSpec): spec is BulletsParagraphSpec {
  return isObject(spec) && spec?.type === 'bullets' && Array.isArray(spec?.bullets);
}

export function isHeadingParagraph(spec: ParagraphSpec): spec is HeadingParagraphSpec {
  if (isObject(spec) && 'type' in spec && isString(spec.type)) {
    const weight = getHeadingWeight(spec?.type);
    return spec.type.startsWith('heading') && !Number.isNaN(weight);
  }
  return false;
}

export function isCustomPhrase(spec: PhraseSpec): spec is CustomPhraseSpec {
  return spec?.type === 'custom' && !!spec?.metadata?.customType;
}

export function isEntityPhrase(spec: PhraseSpec): spec is EntityPhraseSpec {
  return spec?.type === 'entity' && EntityType.includes(spec?.metadata?.entityType);
}

export function isTextPhrase(spec: PhraseSpec): spec is TextPhraseSpec {
  return spec?.type === 'text';
}

export function getHeadingWeight(pType: string) {
  if (pType?.startsWith('heading')) {
    const weight = Number(pType?.slice(-1));
    if (weight >= 1 && weight <= 6) return weight;
  }
  return NaN;
}