import { afterAll, expect, test } from "bun:test";
import { mkdtempSync, readFileSync, readdirSync, rmSync, writeFileSync } from "node:fs";
import { tmpdir } from "node:os";
import { join } from "node:path";

import { assertReactAvailable, buildIslands, generateIslandEntry } from "../src/island-bundle.ts";

const created: string[] = [];
afterAll(() => {
  for (const dir of created) rmSync(dir, { recursive: true, force: true });
});

test("generates an entry that re-exports the island component", () => {
  const entry = generateIslandEntry({ name: "Chart", sourcePath: "/app/Chart.tsx" });
  expect(entry).toContain("/app/Chart.tsx");
  expect(entry).toContain("Chart");
  expect(entry).not.toContain("react-dom/server");
});

test("island .tsx compiles against React's JSX runtime, not WRNexus's", async () => {
  // The root tsconfig points jsxImportSource at @wrnexus/core, so an island
  // would otherwise compile to WRNexus's HTML-string renderer and never mount.
  // A pragma applies only to the file carrying it, so this asserts the built
  // output rather than the generated entry text.
  // The fixture must live inside the repo: Bun resolves `react` from the
  // importing file's location, exactly as a real island resolves it from the
  // app that installed react.
  const root = mkdtempSync(join(process.cwd(), ".island-jsx-test-"));
  created.push(root);
  const source = join(root, "Chart.tsx");
  writeFileSync(
    source,
    `export default function Chart({ title }: { title: string }) {
       return <div className="chart">{title}</div>;
     }`,
  );

  const outDir = join(root, "out");
  await buildIslands({ islands: [{ name: "Chart", sourcePath: source }], outDir });

  const built = readdirSync(outDir)
    .filter((file) => file.endsWith(".js"))
    .map((file) => readFileSync(join(outDir, file), "utf8"))
    .join("\n");

  expect(built).not.toContain("wrnexus");
  expect(built).toMatch(/react\/jsx|jsxDEV|jsx_runtime/);
});

test("reports WRN-ISLAND-REACT-MISSING when react is not installed", () => {
  const root = mkdtempSync(join(tmpdir(), "wrnexus-noreact-"));
  writeFileSync(join(root, "package.json"), JSON.stringify({ name: "app" }));

  const diagnostic = assertReactAvailable(root);
  expect(diagnostic?.code).toBe("WRN-ISLAND-REACT-MISSING");
  expect(diagnostic?.message).toContain("bun add react react-dom");
});

test("returns null when react resolves", () => {
  expect(assertReactAvailable(process.cwd())).toBeNull();
});