T3 - app dir - tRPC + Prisma + Custom auth

interface CreateContextOptions {
  headers: Headers;
  prisma: typeof prisma;
  user: User | null;
}

export const createInnerTRPCContext = async (opts: CreateContextOptions) => ({
  headers: opts.headers,
  prisma,
  user: opts.user,
});

export const createTRPCContext = async (opts: FetchCreateContextFnOptions) => {
  const { req } = opts;
  const reqWithCookies = req as NextRequest;
  const token = await getTokens(reqWithCookies.cookies, AUTH_CONFIG);

  return createInnerTRPCContext({
    headers: opts.req.headers,
    prisma,
    user: token ? mapFirebaseTokensToUser(token) : null,
  });
};



const t = initTRPC.context<typeof createTRPCContext>().create({
  transformer: superjson,
  errorFormatter({ shape, error }) {
    return {
      ...shape,
      data: {
        ...shape.data,
        zodError: error.cause instanceof ZodError ? error.cause.flatten() : null,
      },
    };
  },
});


export const createAction = experimental_createServerActionHandler(t, {
  async createContext() {
    const ctx = await createInnerTRPCContext({
      headers: headers(),
      user: null,
      prisma,
    });
    return ctx;
  },
});



export const createTRPCRouter = t.router;


export const publicProcedure = t.procedure;

const enforceUserIsAuthed = t.middleware(async ({ ctx, next }) => {
  if (!ctx.user) {
    throw new TRPCError({
    });
  }
  return next({
    ctx: {
      prisma: ctx.prisma,
      user: ctx.user,
    },
  });
});

export const privateProcedure = t.procedure.use(enforceUserIsAuthed);