import { describe, it, expect } from "vitest";
import { parseCsv } from "../loader";
import * as path from "path";
import { fixturesDir, readFixture } from "../test-utils";

describe("parseCsv - circular reference detection", () => {
  it("should detect self-referencing circular reference", () => {
    const csv = ["id,name,parent", "string,string,@self_ref", "1,Root,2"].join(
      "\n",
    );

    expect(() =>
      parseCsv(csv, {
        emitTypes: false,
        currentFilePath: path.join(fixturesDir, "self_ref.csv"),
      }),
    ).toThrow(/Circular reference detected/);
  });

  it("should detect mutual circular reference (A -> B -> A)", () => {
    const csv = readFixture("circular_a.csv");

    expect(() =>
      parseCsv(csv, {
        emitTypes: false,
        currentFilePath: path.join(fixturesDir, "circular_a.csv"),
      }),
    ).toThrow(/Circular reference detected/);
  });

  it("should allow same table referenced from multiple columns without circular reference", () => {
    const usersCsv = readFixture("users.csv");
    const csv = ["id,creator,reviewer", "string,@users,@users", "1,1,2"].join(
      "\n",
    );

    const result = parseCsv(csv, {
      emitTypes: false,
      currentFilePath: path.join(fixturesDir, "test.csv"),
    });

    expect(result.data[0].creator).toEqual({
      id: "1",
      name: "Alice",
      email: "alice@example.com",
    });
    expect(result.data[0].reviewer).toEqual({
      id: "2",
      name: "Bob",
      email: "bob@example.com",
    });
  });
});