import { Effect } from "effect"
import { HttpServerResponse } from "effect/unstable/http"
import { HttpApiMiddleware } from "effect/unstable/httpapi"
import * as Log from "@opencode-ai/core/util/log"

const log = Log.create({ service: "server" })

// Effect's Issue formatter recursively dumps the rejected `actual` value with
// no truncation, so a 5KB invalid array produces a ~360KB string. Cap to keep
// 4xx responses small and avoid mirroring entire request payloads (which may
// contain secrets) into the response body and log file.
const REASON_LIMIT = 1024
function truncateReason(reason: string) {
  if (reason.length <= REASON_LIMIT) return reason
  return reason.slice(0, REASON_LIMIT) + `… (${reason.length - REASON_LIMIT} more chars)`
}

// Default Respondable returns an empty 400 body. Match the NamedError shape
// used by other 4xx/5xx so the SDK's `wrapClientError` extracts `.data.message`.
export class SchemaErrorMiddleware extends HttpApiMiddleware.Service<SchemaErrorMiddleware>()(
  "@opencode/HttpApiSchemaError",
) {}

export const schemaErrorLayer = HttpApiMiddleware.layerSchemaErrorTransform(SchemaErrorMiddleware, (error) => {
  const reason = truncateReason(error.cause.message)
  log.warn("schema rejection", { kind: error.kind, reason })
  return Effect.succeed(
    HttpServerResponse.jsonUnsafe({ name: "BadRequest", data: { message: reason, kind: error.kind } }, { status: 400 }),
  )
})