import { AppError } from "@/server/errors";
import {
  RAG_REQUEST_TIMEOUT_MS,
  RAG_SERVICE_SECRET,
  RAG_SERVICE_URL,
} from "@/lib/constants";

type RagHistoryTurn = {
  question: string;
  answer: string;
};

type RagAnswerResponse = {
  answer: string;
  sources: Array<{
    file_id: string;
    file_name: string;
    page_number: number | null;
    score: number | null;
    snippet: string;
  }>;
};

async function callRagService<T>(
  path: string,
  body: Record<string, unknown>,
): Promise<T> {
  const response = await fetch(`${RAG_SERVICE_URL}${path}`, {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
      "x-rag-service-secret": RAG_SERVICE_SECRET,
    },
    body: JSON.stringify(body),
    signal: AbortSignal.timeout(RAG_REQUEST_TIMEOUT_MS),
  });

  const payload = (await response.json().catch(() => null)) as
    | { detail?: string; message?: string }
    | T
    | null;

  if (!response.ok) {
    throw new AppError(
      (payload as { detail?: string; message?: string } | null)?.detail ||
        (payload as { detail?: string; message?: string } | null)?.message ||
        "تعذر التواصل مع خدمة الذكاء الاصطناعي.",
      502,
    );
  }

  return payload as T;
}

export async function ingestCaseFileIntoRag(params: {
  ownerId: string;
  caseId: string;
  fileId: string;
  bucket: string;
  objectKey: string;
  fileName: string;
}) {
  return callRagService<{ indexed_chunks: number }>("/ingest", {
    owner_id: params.ownerId,
    case_id: params.caseId,
    file_id: params.fileId,
    bucket: params.bucket,
    object_key: params.objectKey,
    file_name: params.fileName,
  });
}

export async function askCaseRagQuestion(params: {
  ownerId: string;
  caseId: string;
  question: string;
  history: RagHistoryTurn[];
}) {
  return callRagService<RagAnswerResponse>("/answer", {
    owner_id: params.ownerId,
    case_id: params.caseId,
    question: params.question,
    history: params.history,
  });
}