import { FreshContext, Handlers } from "$fresh/server.ts";
import { db } from "$root/databases/db.ts";
import { students } from "$root/databases/schema.ts";
import { AuthenticatedState } from "$root/defaults/interfaces.ts";

// #9 POST /students/import-csv
export const handler: Handlers<null, AuthenticatedState> = {
  async POST(
    request: Request,
    context: FreshContext<AuthenticatedState>,
  ): Promise<Response> {
    if (context.state.session.eduPersonPrimaryAffiliation !== "employee") {
      return new Response(null, { status: 403 });
    }

    const formData = await request.formData();
    const file = formData.get("file") as File | null;
    const idPromo = formData.get("idPromo") as string | null;

    if (!file || !idPromo) {
      return new Response(null, { status: 400 });
    }

    const text = await file.text();
    const lines = text.trim().split("\n");

    let imported = 0;
    const errors: { line: number; message: string }[] = [];

    for (let i = 0; i < lines.length; i++) {
      const lineNum = i + 1;
      const cols = lines[i].split(",").map((c) => c.trim());

      const [numEtudStr, nom, prenom] = cols;

      if (!numEtudStr) {
        errors.push({ line: lineNum, message: "Numéro étudiant manquant" });
        continue;
      }

      const numEtud = Number(numEtudStr);
      if (isNaN(numEtud)) {
        errors.push({ line: lineNum, message: "Numéro étudiant invalide" });
        continue;
      }

      if (!nom || !prenom) {
        errors.push({ line: lineNum, message: "Nom ou prénom manquant" });
        continue;
      }

      await db
        .insert(students)
        .values({ nom, prenom, idPromo })
        .onConflictDoNothing();

      imported++;
    }

    return new Response(JSON.stringify({ imported, errors }), {
      headers: { "content-type": "application/json" },
    });
  },
};