import { mapDefined } from '@atproto/common'
import { AtUriString } from '@atproto/lex'
import { InvalidRequestError, Server } from '@atproto/xrpc-server'
import { AppContext } from '../../../../context.js'
import { DataPlaneClient } from '../../../../data-plane/index.js'
import { FeedItem } from '../../../../hydration/feed.js'
import {
  HydrateCtx,
  HydrationState,
  Hydrator,
} from '../../../../hydration/hydrator.js'
import { parseString } from '../../../../hydration/util.js'
import { app } from '../../../../lexicons/index.js'
import { createPipeline } from '../../../../pipeline.js'
import { uriToDid as creatorFromUri } from '../../../../util/uris.js'
import { Views } from '../../../../views/index.js'
import { clearlyBadCursor, resHeaders } from '../../../util.js'

export default function (server: Server, ctx: AppContext) {
  const getActorLikes = createPipeline(
    skeleton,
    hydration,
    noPostBlocks,
    presentation,
  )
  server.add(app.bsky.feed.getActorLikes, {
    auth: ctx.authVerifier.standardOptional,
    handler: async ({ params, auth, req }) => {
      const viewer = auth.credentials.iss
      const labelers = ctx.reqLabelers(req)
      const hydrateCtx = await ctx.hydrator.createContext({ labelers, viewer })

      const result = await getActorLikes({ ...params, hydrateCtx }, ctx)

      const repoRev = await ctx.hydrator.actor.getRepoRevSafe(viewer)

      return {
        encoding: 'application/json',
        body: result,
        headers: resHeaders({
          repoRev,
          labelers: hydrateCtx.labelers,
        }),
      }
    },
  })
}

const skeleton = async (inputs: {
  ctx: Context
  params: Params
}): Promise<Skeleton> => {
  const { ctx, params } = inputs
  const { actor, limit, cursor } = params
  const viewer = params.hydrateCtx.viewer
  if (clearlyBadCursor(cursor)) {
    return { items: [] }
  }
  const [actorDid] = await ctx.hydrator.actor.getDids([actor])
  if (!actorDid || !viewer || viewer !== actorDid) {
    throw new InvalidRequestError('Profile not found')
  }

  const likesRes = await ctx.dataplane.getActorLikes({
    actorDid,
    limit,
    cursor,
  })

  const items = likesRes.likes.map((l) => ({
    post: { uri: l.subject as AtUriString },
  }))

  return {
    items,
    cursor: parseString(likesRes.cursor),
  }
}

const hydration = async (inputs: {
  ctx: Context
  params: Params
  skeleton: Skeleton
}) => {
  const { ctx, params, skeleton } = inputs
  return await ctx.hydrator.hydrateFeedItems(skeleton.items, params.hydrateCtx)
}

const noPostBlocks = (inputs: {
  ctx: Context
  skeleton: Skeleton
  hydration: HydrationState
}) => {
  const { ctx, skeleton, hydration } = inputs
  skeleton.items = skeleton.items.filter((item) => {
    const creator = creatorFromUri(item.post.uri)
    return !ctx.views.viewerBlockExists(creator, hydration)
  })
  return skeleton
}

const presentation = (inputs: {
  ctx: Context
  skeleton: Skeleton
  hydration: HydrationState
}) => {
  const { ctx, skeleton, hydration } = inputs
  const feed = mapDefined(skeleton.items, (item) =>
    ctx.views.feedViewPost(item, hydration),
  )
  return {
    feed,
    cursor: skeleton.cursor,
  }
}

type Context = {
  hydrator: Hydrator
  views: Views
  dataplane: DataPlaneClient
}

type Params = app.bsky.feed.getActorLikes.$Params & { hydrateCtx: HydrateCtx }

type Skeleton = {
  items: FeedItem[]
  cursor?: string
}