import { readdir, readFile } from "node:fs/promises";
import path from "node:path";
import { fileURLToPath } from "node:url";
import { ekklesiaDesignTokens } from "@ekklesia/design-tokens";
import { describe, expect, it } from "vitest";
import {
  EKKLESIA_UI_STYLE_ATTRIBUTE,
  EKKLESIA_UI_STYLESHEET,
  installEkklesiaUiStyles,
} from "../src/index.js";

const packageDirectory = path.dirname(path.dirname(fileURLToPath(import.meta.url)));

async function sourceFiles(): Promise<readonly string[]> {
  const directory = path.join(packageDirectory, "src");
  return (await readdir(directory))
    .filter((entry) => entry.endsWith(".ts") || entry.endsWith(".tsx"))
    .map((entry) => path.join(directory, entry));
}

/** Any literal that would be a theme decision rather than a layout one. */
const THEME_LITERAL_PATTERN =
  /#[0-9a-f]{3,8}\b|\brgba?\s*\(|\bhsla?\s*\(|\boklch\s*\(|\bsystem-ui\b|\bsans-serif\b/giu;

describe("the shared elements consume design tokens, never hardcoded theme values", () => {
  it("expresses every theme value in the stylesheet as a token reference", () => {
    expect(EKKLESIA_UI_STYLESHEET.match(THEME_LITERAL_PATTERN)).toBeNull();
    expect(EKKLESIA_UI_STYLESHEET).toContain("var(--ekklesia-");
  });

  it("references only registered tokens", () => {
    const referenced = [...EKKLESIA_UI_STYLESHEET.matchAll(/var\((--ekklesia-[a-z0-9-]+)\)/gu)].map(
      ([, variable]) => String(variable),
    );
    const registered = new Set(ekklesiaDesignTokens.list().map((token) => token.cssVariable));

    expect(referenced.length).toBeGreaterThan(0);
    expect([...new Set(referenced)].filter((variable) => !registered.has(variable))).toEqual([]);
  });

  it("never defines a global Ekklesia theme variable of its own", () => {
    // Referencing `--ekklesia-*` is the contract; *declaring* one would invent a global theme
    // variable outside the registry, which is precisely what the design-token contract forbids.
    expect(EKKLESIA_UI_STYLESHEET).not.toMatch(/--ekklesia-[a-z0-9-]+\s*:/u);
  });

  it("hardcodes no theme value in component source either", async () => {
    for (const file of await sourceFiles()) {
      if (path.basename(file) === "styles.ts") {
        continue;
      }
      expect(await readFile(file, "utf8")).not.toMatch(THEME_LITERAL_PATTERN);
    }
  });

  it("never names a Node built-in or reads the environment", async () => {
    for (const file of await sourceFiles()) {
      const source = await readFile(file, "utf8");

      expect(source).not.toContain('"node:');
      expect(source).not.toContain("process.env");
    }
  });

  it("depends only on the design tokens and React", async () => {
    const manifest = JSON.parse(
      await readFile(path.join(packageDirectory, "package.json"), "utf8"),
    ) as {
      dependencies?: Record<string, string>;
      devDependencies?: Record<string, string>;
      peerDependencies?: Record<string, string>;
    };

    // React is a peer only (ADR 0053): the consumer's React is the one in every bundle these
    // elements are built into. The development dependency resolves the package's own imports for its
    // builds and tests; nothing loads it from this workspace in a production Node.js process
    // (`runtime-imports-are-production-dependencies` allows exactly this peer).
    expect(Object.keys(manifest.dependencies ?? {})).toEqual(["@ekklesia/design-tokens"]);
    expect(manifest.devDependencies?.react).toBeDefined();
    expect(Object.keys(manifest.peerDependencies ?? {})).toEqual(["react"]);
  });

  it("installs its stylesheet into a document root exactly once", () => {
    const remove = installEkklesiaUiStyles(document);
    installEkklesiaUiStyles(document);

    expect(document.querySelectorAll(`style[${EKKLESIA_UI_STYLE_ATTRIBUTE}]`).length).toBe(1);

    remove();
    remove();
    expect(document.querySelectorAll(`style[${EKKLESIA_UI_STYLE_ATTRIBUTE}]`).length).toBe(0);
  });
});