import type { NextApiRequest, NextApiResponse } from "next";
import { DocumentValidationError, documentHistoryPage, documentRevision, readDocument } from "@/lib/docs";
import { authorizeDocuments, documentApiError, pagination } from "@/lib/documents-api";

export default function handler(request: NextApiRequest, response: NextApiResponse) {
  try {
    if (!authorizeDocuments(request, response)) return;
    if (request.method !== "GET") {
      response.setHeader("Allow", "GET");
      return response.status(405).end();
    }
    const slug = request.query.slug;
    if (!Array.isArray(slug)) throw new DocumentValidationError("Invalid document slug");
    const doc = readDocument(slug.join("/"));
    if (!doc) return response.status(404).json({ error: "文档不存在", code: "not_found" });
    if (request.query.revision !== undefined) {
      if (request.query.history !== undefined || typeof request.query.revision !== "string" || !/^\d+$/.test(request.query.revision))
        throw new DocumentValidationError("Invalid revision query");
      const prior = documentRevision(doc.sourceSlug, Number(request.query.revision));
      if (!prior) return response.status(404).json({ error: "修订不存在", code: "not_found" });
      return response.status(200).json(prior);
    }
    if (request.query.history !== undefined) {
      if (request.query.history !== "1") throw new DocumentValidationError("Use history=1");
      const { limit, offset } = pagination(request);
      return response.status(200).json(documentHistoryPage(doc.sourceSlug, limit, offset));
    }
    return response.status(200).json(doc);
  } catch (error) { return documentApiError(response, error); }
}