import type { CfTypes } from '@livestore/common-cf'
import { Effect, HttpApp, Layer, RpcSerialization, RpcServer } from '@livestore/utils/effect'

import { SyncHttpRpc } from '../../../common/http-rpc-schema.ts'
import * as SyncMessage from '../../../common/sync-message-types.ts'
import { headersRecordToMap } from '../../shared.ts'
import { DoCtx } from '../layer.ts'
import { makeEndingPullStream } from '../pull.ts'
import { makePush } from '../push.ts'

export const createHttpRpcHandler = Effect.fn('createHttpRpcHandler')(function* ({
  request,
  responseHeaders,
  forwardedHeaders,
}: {
  request: CfTypes.Request
  responseHeaders?: Record<string, string>
  forwardedHeaders?: Record<string, string>
}) {
  const handlerLayer = createHttpRpcLayer(forwardedHeaders)
  const httpApp = RpcServer.toHttpApp(SyncHttpRpc).pipe(Effect.provide(handlerLayer))
  const webHandler = yield* httpApp.pipe(Effect.map(HttpApp.toWebHandler))

  const response = yield* Effect.promise(
    () => webHandler(request as TODO as Request) as TODO as Promise<CfTypes.Response>,
  ).pipe(Effect.timeout(10000))

  if (responseHeaders !== undefined) {
    for (const [key, value] of Object.entries(responseHeaders)) {
      response.headers.set(key, value)
    }
  }

  return response
})

const createHttpRpcLayer = (forwardedHeaders: Record<string, string> | undefined) => {
  const headers = headersRecordToMap(forwardedHeaders)

  // TODO implement admin requests
  return SyncHttpRpc.toLayer({
    'SyncHttpRpc.Pull': (req) => makeEndingPullStream({ req, payload: req.payload, headers }),

    'SyncHttpRpc.Push': (req) =>
      Effect.gen(function* () {
        const { ctx, env, doOptions, storeId } = yield* DoCtx
        const push = makePush({ payload: undefined, headers, options: doOptions, storeId, ctx, env })

        return yield* push(req)
      }),

    'SyncHttpRpc.Ping': () => Effect.succeed(SyncMessage.Pong.make({})),
  }).pipe(
    Layer.provideMerge(RpcServer.layerProtocolHttp({ path: '/http-rpc' })),
    Layer.provideMerge(RpcSerialization.layerJson),
  )
}