import { describe, it } from "vitest";
import { RuleTester } from "eslint";
import path from "node:path";
import os from "node:os";
import fs from "node:fs";
import rule from "./component-must-have-story.js";

function makeFixture({ withStory, location = "core-ui" }) {
  const root = fs.mkdtempSync(path.join(os.tmpdir(), "cmhs-"));
  const dir =
    location === "core-ui"
      ? path.join(root, "packages", "core-ui", "src", "atoms", "Button")
      : path.join(root, "packages", "demo", "src", "ui", "atoms", "Button");
  fs.mkdirSync(dir, { recursive: true });
  const component = path.join(dir, "Button.tsx");
  fs.writeFileSync(component, `export const Button = () => <button>x</button>;`);
  if (withStory) {
    fs.writeFileSync(path.join(dir, "Button.stories.tsx"), `export default { title: "Button" };`);
  }
  return { component };
}

const tester = new RuleTester({
  languageOptions: {
    parser: await import("@typescript-eslint/parser"),
    ecmaVersion: "latest",
    sourceType: "module",
    parserOptions: { ecmaFeatures: { jsx: true } },
  },
});

describe("component-must-have-story", () => {
  it("passes for a core-ui component with a sibling .stories.tsx", () => {
    const { component } = makeFixture({ withStory: true });
    tester.run("component-must-have-story", rule, {
      valid: [{ filename: component, code: fs.readFileSync(component, "utf8") }],
      invalid: [],
    });
  });

  it("fires for a core-ui component without a sibling .stories.tsx", () => {
    const { component } = makeFixture({ withStory: false });
    tester.run("component-must-have-story", rule, {
      valid: [],
      invalid: [{
        filename: component,
        code: fs.readFileSync(component, "utf8"),
        errors: [{ messageId: "missingStory" }],
      }],
    });
  });

  it("passes for a feature ui component with a sibling .stories.tsx", () => {
    const { component } = makeFixture({ withStory: true, location: "feature" });
    tester.run("component-must-have-story", rule, {
      valid: [{ filename: component, code: fs.readFileSync(component, "utf8") }],
      invalid: [],
    });
  });

  it("is a no-op for index.tsx", () => {
    const root = fs.mkdtempSync(path.join(os.tmpdir(), "cmhs-"));
    const dir = path.join(root, "packages", "core-ui", "src", "atoms", "Button");
    fs.mkdirSync(dir, { recursive: true });
    const file = path.join(dir, "index.tsx");
    fs.writeFileSync(file, `export * from "./Button";`);
    tester.run("component-must-have-story", rule, {
      valid: [{ filename: file, code: fs.readFileSync(file, "utf8") }],
      invalid: [],
    });
  });

  it("is a no-op for files outside packages/core-ui/ and packages/*/src/ui/", () => {
    const root = fs.mkdtempSync(path.join(os.tmpdir(), "cmhs-"));
    const dir = path.join(root, "packages", "auth", "src", "application", "use-cases");
    fs.mkdirSync(dir, { recursive: true });
    const file = path.join(dir, "sign-in.use-case.tsx");
    fs.writeFileSync(file, `export const x = 1;`);
    tester.run("component-must-have-story", rule, {
      valid: [{ filename: file, code: fs.readFileSync(file, "utf8") }],
      invalid: [],
    });
  });
});