import { desc, eq } from "drizzle-orm";
import { Hono } from "hono";
import { randomUUID } from "node:crypto";
import { mkdirSync } from "node:fs";
import { join } from "node:path";
import type { Db } from "../db";
import { labDrafts } from "../db/schema";
import { extractFromText } from "../lib/extract";
import { pdfToText } from "../lib/pdf";

export type LabsDeps = { db: Db; key: Buffer; dataDir: string; llmFetch?: typeof fetch };

const MAX_UPLOAD = 15 * 1024 * 1024;

export function labsRoutes(deps: LabsDeps) {
  const app = new Hono();

  app.post("/labs/upload", async (c) => {
    const body = await c.req.parseBody();
    const file = body.file;
    if (!(file instanceof File)) return c.json({ error: "file field required" }, 400);
    if (!file.name.toLowerCase().endsWith(".pdf") && file.type !== "application/pdf") {
      return c.json({ error: "not_a_pdf" }, 400);
    }
    if (file.size > MAX_UPLOAD) return c.json({ error: "too_large" }, 400);

    const id = randomUUID();
    const uploadsDir = join(deps.dataDir, "uploads");
    mkdirSync(uploadsDir, { recursive: true });
    const filePath = join(uploadsDir, `${id}.pdf`);
    const bytes = new Uint8Array(await file.arrayBuffer());
    await Bun.write(filePath, bytes);

    // Extraction failures land on the draft row so the user sees them in the
    // review UI instead of the upload 500ing.
    let extracted: string | null = null;
    let error: string | null = null;
    try {
      const text = await pdfToText(bytes);
      if (text.trim().length < 20) throw new Error("pdf_error: no text layer (scanned PDFs are not supported yet)");
      const draft = await extractFromText({ db: deps.db, key: deps.key, fetchImpl: deps.llmFetch }, text);
      extracted = JSON.stringify(draft);
    } catch (e) {
      error = e instanceof Error ? e.message : "extraction failed";
    }

    await deps.db.insert(labDrafts).values({
      id, filename: file.name, filePath, status: "pending", extracted, error, createdAt: Date.now(),
    });
    return c.json({ id }, 201);
  });

  app.get("/labs/drafts", async (c) => {
    const rows = await deps.db.select().from(labDrafts).orderBy(desc(labDrafts.createdAt));
    return c.json({
      drafts: rows.map((r) => ({
        id: r.id,
        filename: r.filename,
        status: r.status,
        error: r.error,
        markerCount: r.extracted ? (JSON.parse(r.extracted).markers?.length ?? 0) : 0,
        createdAt: r.createdAt,
      })),
    });
  });

  return app;
}