import type { Event } from 'nostr-tools'
import { extractTagsFromEvent } from '../nostrTagSystem'
import { generateReviewHashId } from '../hashIdGenerator'
import type { ExtractedReview } from './types'
import { getMetadataFromEvent } from './metadataJson'
import { firstString } from './utils'

export async function extractReviewFromEvent(event: Event): Promise<ExtractedReview | null> {
  const tags = extractTagsFromEvent(event)
  if (tags.type !== 'quote') {
    return null
  }

  const metadata = getMetadataFromEvent(event)
  const fromMetadata = await extractReviewFromMetadata({ event, tags, metadata })
  if (fromMetadata) {
    return fromMetadata
  }

  return extractReviewFromTags({ event, tags })
}

async function extractReviewFromMetadata(params: {
  event: Event
  tags: ReturnType<typeof extractTagsFromEvent>
  metadata: Record<string, unknown> | null
}): Promise<ExtractedReview | null> {
  if (params.metadata?.type !== 'review') {
    return null
  }
  const reviewData = buildReviewDataFromMetadata({ event: params.event, tags: params.tags, metadata: params.metadata })
  if (!reviewData) {
    return null
  }
  const id = await generateReviewHashId(reviewData)
  return { type: 'review', id, ...reviewData, eventId: params.event.id }
}

async function extractReviewFromTags(params: { event: Event; tags: ReturnType<typeof extractTagsFromEvent> }): Promise<ExtractedReview | null> {
  if (!params.tags.articleId || !params.tags.reviewerPubkey) {
    return null
  }
  const base = {
    pubkey: params.event.pubkey,
    articleId: params.tags.articleId,
    reviewerPubkey: params.tags.reviewerPubkey,
    content: params.event.content,
    ...(params.tags.title ? { title: params.tags.title } : {}),
    eventId: params.event.id,
  }
  return buildExtractedReviewFromTags(base)
}

function buildReviewDataFromMetadata(params: {
  event: Event
  tags: ReturnType<typeof extractTagsFromEvent>
  metadata: Record<string, unknown>
}): { pubkey: string; articleId: string; reviewerPubkey: string; content: string; title?: string } | null {
  const articleId = firstString(params.metadata.articleId, params.tags.articleId) ?? ''
  const reviewerPubkey = firstString(params.metadata.reviewerPubkey, params.tags.reviewerPubkey, params.event.pubkey) ?? params.event.pubkey
  if (!articleId || !reviewerPubkey) {
    return null
  }
  const title = firstString(params.metadata.title, params.tags.title)
  const base: { pubkey: string; articleId: string; reviewerPubkey: string; content: string; title?: string } = {
    pubkey: firstString(params.metadata.pubkey, params.event.pubkey) ?? params.event.pubkey,
    articleId,
    reviewerPubkey,
    content: firstString(params.metadata.content, params.event.content) ?? params.event.content,
  }
  if (title) {
    base.title = title
  }
  return base
}

async function buildExtractedReviewFromTags(params: {
  pubkey: string
  articleId: string
  reviewerPubkey: string
  content: string
  title?: string
  eventId: string
}): Promise<ExtractedReview> {
  const id = await generateReviewHashId({
    pubkey: params.pubkey,
    articleId: params.articleId,
    reviewerPubkey: params.reviewerPubkey,
    content: params.content,
    ...(params.title ? { title: params.title } : {}),
  })
  return { type: 'review', id, pubkey: params.pubkey, articleId: params.articleId, reviewerPubkey: params.reviewerPubkey, content: params.content, eventId: params.eventId, ...(params.title ? { title: params.title } : {}) }
}