// Based on: https://github.com/HubSpot/draft-convert/issues/107#issuecomment-488581709 by <https://github.com/sbusch>
// Grabbed from https://github.com/DefinitelyTyped/DefinitelyTyped/blob/master/types/draft-convert/index.d.ts

import {
  ContentState,
  DraftBlockType,
  DraftEntityMutability,
  DraftInlineStyleType,
  Entity,
  RawDraftContentBlock,
  RawDraftEntity,
} from 'draft-js'
import { ReactNode } from 'react'

export type RawDraftContentBlockWithCustomType<T> = Omit<RawDraftContentBlock, 'type'> & {
  type: T
}

export type ExtendedHTMLElement<T> = (HTMLElement | HTMLLinkElement) & T

export type EntityKey = string

export type ContentStateConverter = (contentState: ContentState) => string
export type HTMLConverter = (html: string) => ContentState

export type Tag =
  | ReactNode
  | { start: string; end: string; empty?: string | undefined }
  | {
      element: ReactNode
      empty?: ReactNode | undefined
    }

export interface IConvertToHTMLConfig<
  S = DraftInlineStyleType,
  B extends DraftBlockType = DraftBlockType,
  E extends RawDraftEntity = RawDraftEntity,
> {
  // Inline styles:
  styleToHTML?: ((style: S) => Tag | null | undefined | undefined) | undefined

  // Block styles:
  blockToHTML?:
    | ((block: RawDraftContentBlockWithCustomType<B>) => Tag | null | undefined)
    | undefined

  // Entity styling:
  entityToHTML?: ((entity: E, originalText: string) => Tag | null | undefined) | undefined

  // HTML validation:
  validateHTML?: ((html: string) => boolean) | undefined
}

export interface IConvertFromHTMLConfig<
  S extends {
    [name: string]: unknown
  } = DOMStringMap,
  B extends DraftBlockType = DraftBlockType,
  E extends RawDraftEntity = RawDraftEntity,
> {
  // Inline styles:
  htmlToStyle?:
    | ((nodeName: string, node: ExtendedHTMLElement<S>, currentStyle: Set<string>) => Set<string>)
    | undefined

  // Block styles:
  htmlToBlock?:
    | ((
        nodeName: string,
        node: ExtendedHTMLElement<S>
      ) => B | { type: B; data: object } | false | undefined)
    | undefined

  // Html entities
  htmlToEntity?:
    | ((
        nodeName: string,
        node: ExtendedHTMLElement<S>,
        createEntity: (
          type: E['type'],
          mutability: DraftEntityMutability,
          data: E['data']
        ) => EntityKey,
        getEntity: (key: EntityKey) => Entity,
        mergeEntityData: (key: string, data: object) => void,
        replaceEntityData: (key: string, data: object) => void
      ) => EntityKey | undefined)
    | undefined

  // Text entities
  textToEntity?:
    | ((
        text: string,
        createEntity: (
          type: E['type'],
          mutability: DraftEntityMutability,
          data: E['data']
        ) => EntityKey,
        getEntity: (key: EntityKey) => Entity,
        mergeEntityData: (key: string, data: object) => void,
        replaceEntityData: (key: string, data: object) => void
      ) => Array<{
        entity: EntityKey
        offset: number
        length: number
        result?: string | undefined
      }>)
    | undefined
}

export function convertToHTML<
  S = DraftInlineStyleType,
  B extends DraftBlockType = DraftBlockType,
  E extends RawDraftEntity = RawDraftEntity,
>(config: IConvertToHTMLConfig<S, B, E>): ContentStateConverter
export function convertToHTML(contentState: ContentState): string

export function convertFromHTML<
  S extends {
    [name: string]: unknown
  } = DOMStringMap,
  B extends DraftBlockType = DraftBlockType,
  E extends RawDraftEntity = RawDraftEntity,
>(config: IConvertFromHTMLConfig<S, B, E>): HTMLConverter
export function convertFromHTML(html: string): ContentState

export function parseHTML(html: string): HTMLBodyElement