import { CurrentUserMark, Mark } from '../types/mark.ts'
import { hexToNpub } from './nostr.ts'
import { Meta, SignedEventContent } from '../types'
import { Event } from 'nostr-tools'

/**
 * Takes in an array of Marks already filtered by User.
 * Returns an array of CurrentUserMarks with correct values mix-and-matched.
 * @param marks - default Marks extracted from Meta
 * @param signedMetaMarks - signed user Marks extracted from DocSignatures
 */
const getCurrentUserMarks = (marks: Mark[], signedMetaMarks: Mark[]): CurrentUserMark[] => {
  return marks.map((mark, index, arr) => {
    const signedMark = signedMetaMarks.find((m) => m.id === mark.id);
    if (signedMark && !!signedMark.value) {
      mark.value = signedMark.value
    }
    return {
      mark,
      isLast: isLast(index, arr),
      isCompleted: !!mark.value
    }
  })
}

/**
 * Returns next incomplete CurrentUserMark if there is one
 * @param usersMarks
 */
const findNextCurrentUserMark = (usersMarks: CurrentUserMark[]): CurrentUserMark | undefined => {
  return usersMarks.find((mark) => !mark.isCompleted);
}

/**
 * Returns Marks that are assigned to a specific user
 * @param marks
 * @param pubkey
 */
const filterMarksByPubkey = (marks: Mark[], pubkey: string): Mark[] => {
  return marks.filter(mark => mark.npub === hexToNpub(pubkey))
}

/**
 * Takes Signed Doc Signatures part of Meta and extracts
 * all Marks into one flar array, regardless of the user.
 * @param meta
 */
const extractMarksFromSignedMeta = (meta: Meta): Mark[] => {
  return Object.values(meta.docSignatures)
    .map((val: string) => JSON.parse(val as string))
    .map((val: Event) => JSON.parse(val.content))
    .flatMap((val: SignedEventContent) => val.marks)
}

/**
 * Checks the CurrentUserMarks array that every element in that array has been
 * marked as complete.
 * @param currentUserMarks
 */
const isCurrentUserMarksComplete = (currentUserMarks: CurrentUserMark[]): boolean => {
  return currentUserMarks.every((mark) => mark.isCompleted)
}

/**
 * Inserts an updated mark into an existing array of marks. Returns a copy of the
 * existing array with a new value inserted
 * @param marks
 * @param markToUpdate
 */
const updateMarks = (marks: Mark[], markToUpdate: Mark): Mark[] => {
  const indexToUpdate = marks.findIndex(mark => mark.id === markToUpdate.id);
  return [
    ...marks.slice(0, indexToUpdate),
    markToUpdate,
    ...marks.slice(indexToUpdate + 1)
  ]
}

const updateCurrentUserMarks = (currentUserMarks: CurrentUserMark[], markToUpdate: CurrentUserMark): CurrentUserMark[] => {
  const indexToUpdate = currentUserMarks.findIndex((m) => m.mark.id === markToUpdate.mark.id)
  return [
    ...currentUserMarks.slice(0, indexToUpdate),
    markToUpdate,
    ...currentUserMarks.slice(indexToUpdate + 1)
  ]
}

const isLast = <T>(index: number, arr: T[]) => (index === (arr.length -1))

export {
  getCurrentUserMarks,
  filterMarksByPubkey,
  extractMarksFromSignedMeta,
  isCurrentUserMarksComplete,
  findNextCurrentUserMark,
  updateMarks,
  updateCurrentUserMarks,
}