// Utilitaires communs des routes API : gestion d'erreurs uniforme + validation zod.
import { NextResponse } from "next/server";
import { ZodError, type ZodType, type ZodTypeDef } from "zod";
import { AuthError } from "./auth/session.ts";
import { get } from "./db/index.ts";

export function apiError(e: unknown): NextResponse {
  if (e instanceof AuthError) return NextResponse.json({ error: e.message }, { status: e.status });
  if (e instanceof ZodError)
    return NextResponse.json({ error: "Requête invalide : " + e.issues.map((i) => i.message).join(" ; ") }, { status: 400 });
  console.error("[api]", e);
  return NextResponse.json({ error: "Erreur interne du serveur." }, { status: 500 });
}

export async function parseBody<T>(req: Request, schema: ZodType<T, ZodTypeDef, unknown>): Promise<T> {
  const json = await req.json().catch(() => {
    throw new ZodError([{ code: "custom", message: "corps JSON manquant", path: [] }]);
  });
  return schema.parse(json);
}

export function requireEnrollment(userId: number, courseCode: string) {
  const row = get("SELECT 1 as ok FROM enrollments WHERE user_id = ? AND course_code = ?", userId, courseCode);
  if (!row) throw new AuthError(403, "Vous n'êtes pas inscrit à ce cours.");
}