/**
 * create-db pg-mode test — covers the `pg` Pool branch (lines 29-53).
 *
 * Mocks the `pg` module so we don't need a real Postgres. Verifies that
 * createDb(mode='pg') returns a client that delegates to Pool.connect().
 */

import { describe, it, expect, vi, beforeEach } from "vitest";

describe("createDb (pg mode)", () => {
  beforeEach(() => {
    vi.resetModules();
  });

  it("throws if DATABASE_URL is missing in pg mode", async () => {
    const { createDb } = await import("../src/create-db.js");
    delete process.env.DATABASE_URL;
    await expect(createDb({ mode: "pg" })).rejects.toThrow("DATABASE_URL");
  });

  it("returns a client backed by pg.Pool", async () => {
    const fakeQuery = vi.fn().mockResolvedValue({ rows: [{ x: 1 }], rowCount: 1 });
    const fakeRelease = vi.fn();
    const fakeConnect = vi.fn().mockResolvedValue({ query: fakeQuery, release: fakeRelease });
    const fakePool = { connect: fakeConnect };
    vi.doMock("pg", () => ({ Pool: vi.fn(() => fakePool) }));

    const { createDb } = await import("../src/create-db.js");
    const db = await createDb({ mode: "pg", databaseUrl: "postgres://localhost/test" });

    const res = await db.query("SELECT $1::int AS x", [1]);
    expect(res.rows).toHaveLength(1);
    expect(res.rows[0]).toEqual({ x: 1 });
    expect(fakeQuery).toHaveBeenCalledWith("SELECT $1::int AS x", [1]);
    expect(fakeRelease).toHaveBeenCalled();
  });

  it("exec delegates to Pool.connect().query with multi-statement", async () => {
    const fakeQuery = vi.fn().mockResolvedValue({ rows: [], rowCount: 0 });
    const fakeRelease = vi.fn();
    const fakeConnect = vi.fn().mockResolvedValue({ query: fakeQuery, release: fakeRelease });
    const fakePool = { connect: fakeConnect };
    vi.doMock("pg", () => ({ Pool: vi.fn(() => fakePool) }));

    const { createDb } = await import("../src/create-db.js");
    const db = await createDb({ mode: "pg", databaseUrl: "postgres://localhost/test" });
    await db.exec("CREATE TABLE x (a int); CREATE TABLE y (b int);");
    expect(fakeQuery).toHaveBeenCalledWith("CREATE TABLE x (a int); CREATE TABLE y (b int);");
  });
});