import { NextRequest, NextResponse } from "next/server";
import { auth } from "@/auth";
import { generateHetznerPresignedUploadUrl } from "@/lib/storage";
import { randomUUID } from "crypto";

export const maxDuration = 10;

/**
 * POST /api/batch-upload/presign
 * Body: { fileName: string }
 *
 * Returns a presigned PUT URL for uploading a high-res file directly from
 * the browser to Hetzner Object Storage, together with the storage key that
 * must be passed to POST /api/batch-upload/upload (action=update-highres) to
 * commit the shot record after the direct upload completes.
 *
 * This two-phase approach avoids routing large MOV files through the app
 * server / reverse proxy, removing any client_max_body_size limits.
 */
export async function POST(req: NextRequest) {
  const session = await auth();
  if (!session?.user) {
    return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
  }

  let body: unknown;
  try {
    body = await req.json();
  } catch {
    return NextResponse.json({ error: "Invalid JSON" }, { status: 400 });
  }

  const { fileName } = body as { fileName?: unknown };

  if (!fileName || typeof fileName !== "string") {
    return NextResponse.json({ error: "fileName is required" }, { status: 400 });
  }

  const ext = fileName.split(".").pop()?.toLowerCase();
  const contentType =
    ext === "mov" ? "video/quicktime" :
    ext === "mp4" ? "video/mp4" :
    "application/octet-stream";

  const key = `highres/${randomUUID()}-${fileName}`;

  try {
    const presignedUrl = await generateHetznerPresignedUploadUrl(key, contentType);
    return NextResponse.json({ presignedUrl, key });
  } catch (err) {
    console.error("[batch-upload/presign]", err);
    return NextResponse.json(
      { error: "Failed to generate upload URL. Check Hetzner storage configuration." },
      { status: 500 }
    );
  }
}