import { AppError, getInstructionVersion, uploadInstruction } from "@autoscholar/core";
import { INSTRUCTION_MAX_BYTES, UploadInstructionRequest } from "@autoscholar/schemas";
import { handler, json, parseBody } from "@/lib/server/api";
import { db } from "@/lib/server/db";
import { requireAdmin, uploadLimiter } from "@/lib/server/session";

export const runtime = "nodejs";

/** Upload (multipart `file`) or paste (JSON {content}) a research CLAUDE.md. Stores exact bytes + SHA-256 as a new immutable version. */
export const POST = handler(async (req, { params }) => {
  const sess = await requireAdmin(req, { mutation: true });
  if (!uploadLimiter.check(sess.userId).allowed) throw new AppError("rate_limited", "too many uploads", 429);
  const { id } = (await params) as { id: string };
  const ct = req.headers.get("content-type") ?? "";
  let bytes: Buffer;
  let filename = "CLAUDE.md";
  let note: string | undefined;
  if (ct.startsWith("multipart/form-data")) {
    const len = Number(req.headers.get("content-length") ?? 0);
    if (len > INSTRUCTION_MAX_BYTES * 2) throw new AppError("too_large", "upload too large", 413);
    const form = await req.formData();
    const file = form.get("file");
    if (!(file instanceof File)) throw new AppError("invalid", "multipart field `file` required", 400);
    if (file.size > INSTRUCTION_MAX_BYTES)
      throw new AppError("too_large", `file exceeds ${INSTRUCTION_MAX_BYTES} bytes`, 413);
    const allowed = ["text/markdown", "text/plain", "text/x-markdown", "application/octet-stream", ""];
    if (!allowed.includes(file.type))
      throw new AppError("invalid", `unsupported content type ${file.type}`, 400);
    bytes = Buffer.from(await file.arrayBuffer());
    filename = file.name || "CLAUDE.md";
    const n = form.get("note");
    if (typeof n === "string" && n) note = n.slice(0, 500);
  } else {
    const body = await parseBody(req, UploadInstructionRequest, INSTRUCTION_MAX_BYTES * 2);
    bytes = Buffer.from(body.content, "utf8");
    filename = body.filename;
    note = body.note;
  }
  const result = await uploadInstruction(db(), id, bytes, filename, note, { id: sess.userId, ip: sess.ip });
  const { text: _t, ...validation } = result.validation;
  return json(
    { id: result.id, version: result.version, deduplicated: result.deduplicated, validation },
    { status: result.deduplicated ? 200 : 201 },
  );
});

export const GET = handler(async (req) => {
  await requireAdmin(req);
  const url = new URL(req.url);
  const versionId = url.searchParams.get("versionId");
  if (!versionId) throw new AppError("invalid", "versionId required", 400);
  const v = await getInstructionVersion(db(), versionId);
  return json({
    id: v.id,
    version: v.version,
    filename: v.filename,
    sha256: v.sha256,
    byteSize: v.byteSize,
    content: v.contentText,
    frontmatter: v.frontmatter,
    validation: v.validation,
    createdAt: v.createdAt,
  });
});