import { describe, it, expect } from "vitest";
import {
  existsSync,
  mkdtempSync,
  mkdirSync,
  writeFileSync,
  readFileSync,
} from "node:fs";
import { tmpdir } from "node:os";
import { join } from "node:path";
import {
  assertOptionalPackageNotPresent,
  addToTranspilePackages,
} from "./core-package-utils";

describe("assertOptionalPackageNotPresent", () => {
  it("throws if packages/<name>/ exists in cwd", () => {
    const tmp = mkdtempSync(join(tmpdir(), "core-pkg-"));
    mkdirSync(join(tmp, "packages", "core-foo"), { recursive: true });
    expect(() => assertOptionalPackageNotPresent("core-foo", tmp)).toThrow(/already exists/);
  });

  it("returns silently if packages/<name>/ is absent", () => {
    const tmp = mkdtempSync(join(tmpdir(), "core-pkg-"));
    expect(() => assertOptionalPackageNotPresent("core-foo", tmp)).not.toThrow();
  });
});

describe("addToTranspilePackages", () => {
  it("inserts package name alphabetically into transpilePackages array", () => {
    const tmp = mkdtempSync(join(tmpdir(), "core-pkg-"));
    const cfgPath = join(tmp, "next.config.mjs");
    writeFileSync(
      cfgPath,
      `const nextConfig = {
  transpilePackages: [
    "@repo/core-cms",
    "@repo/core-shared",
  ],
};
`,
    );
    addToTranspilePackages(cfgPath, "@repo/core-realtime");
    const result = readFileSync(cfgPath, "utf8");
    // Order should be: core-cms, core-realtime, core-shared
    const order = result.match(/@repo\/core-\w+/g) ?? [];
    expect(order).toEqual(["@repo/core-cms", "@repo/core-realtime", "@repo/core-shared"]);
  });

  it("is idempotent — duplicate insertion is a no-op", () => {
    const tmp = mkdtempSync(join(tmpdir(), "core-pkg-"));
    const cfgPath = join(tmp, "next.config.mjs");
    writeFileSync(
      cfgPath,
      `const nextConfig = {
  transpilePackages: ["@repo/core-realtime"],
};
`,
    );
    addToTranspilePackages(cfgPath, "@repo/core-realtime");
    const result = readFileSync(cfgPath, "utf8");
    expect(result.match(/@repo\/core-realtime/g)?.length).toBe(1);
  });
});