// @vitest-environment happy-dom
import { readFile } from "node:fs/promises";
import path from "node:path";
import { fileURLToPath } from "node:url";
import { buildModuleUi } from "@ekklesia/module-ui-build";
import type { ModuleUiHostContext } from "@ekklesia/module-ui-sdk";
import { beforeAll, describe, expect, it } from "vitest";
import {
  loadModuleUi,
  MODULE_UI_ISOLATION_ATTRIBUTE,
  MODULE_UI_ISOLATION_ROOT_ATTRIBUTE,
} from "../src/index.js";

/** What the artifact rendered, reached through the open shadow root the loader created (ADR 0040). */
function artifactText(container: Element): string {
  const shadowHost = container.querySelector(`[${MODULE_UI_ISOLATION_ATTRIBUTE}]`);
  return (
    shadowHost?.shadowRoot?.querySelector(`[${MODULE_UI_ISOLATION_ROOT_ATTRIBUTE}]`)?.textContent ??
    ""
  );
}

const fixtureDirectory = path.join(
  path.dirname(fileURLToPath(import.meta.url)),
  "fixtures",
  "artifact-module",
);

let artifactUrl: string;
let artifactSource: string;

/** An Ekklesia-shaped host: module routes live under a Core-owned prefix. */
function ekklesiaContext(requested: string[]): ModuleUiHostContext {
  return {
    moduleId: "example",
    api: {
      async request(pathname) {
        requested.push(`/api/v1/modules/example/${pathname.replace(/^\//u, "")}`);
        return new Response(null, { status: 200 });
      },
    },
    principal: { kind: "authenticated", userId: "user-123" },
    permissions: { has: () => true },
    realtime: { subscribe: () => ({ close: () => undefined }) },
  };
}

/** A standalone host: one module, a different origin, a completely different URL shape, no Core. */
function standaloneContext(requested: string[]): ModuleUiHostContext {
  return {
    moduleId: "example",
    api: {
      async request(pathname) {
        requested.push(`https://example.test/api/${pathname.replace(/^\//u, "")}`);
        return new Response(null, { status: 200 });
      },
    },
    principal: { kind: "anonymous" },
    permissions: { has: () => false },
    realtime: { subscribe: () => ({ close: () => undefined }) },
  };
}

/**
 * Proves the loader consumes exactly the browser ESM artifact `@ekklesia/module-ui-build` produces
 * (ADR 0023) — no second output format, no checked-in build output. The artifact is rebuilt from
 * source each run and served through a `data:` URL, a real module URL rather than a filesystem path.
 */
describe("loading a real compiled artifact", () => {
  beforeAll(async () => {
    const result = await buildModuleUi({ moduleDirectory: fixtureDirectory });
    const primaryArtifact = result.artifacts.find((artifact) => artifact.kind === "ui");
    if (!primaryArtifact) {
      throw new Error("The real-artifact fixture must declare a primary UI artifact.");
    }
    artifactSource = await readFile(primaryArtifact.outputFile, "utf8");
    artifactUrl = `data:text/javascript;base64,${Buffer.from(artifactSource, "utf8").toString("base64")}`;
  }, 60_000);

  it("produces a self-contained artifact with no bare imports for a host to resolve", () => {
    expect(artifactSource).not.toMatch(/^import\s.*from\s*["'][^.]/mu);
    expect(artifactSource).toContain("export {");
    expect(artifactSource).not.toContain("/api/v1/modules");
  });

  it("mounts the real artifact through the generic loader and unmounts it", async () => {
    const container = document.createElement("div");
    const requested: string[] = [];

    const mounted = await loadModuleUi({
      source: { moduleId: "example", version: "0.1.0", url: artifactUrl },
      container,
      context: ekklesiaContext(requested),
    });

    expect(artifactText(container)).toBe("example:200:user-123");
    await mounted.unmount();
    expect(container.children).toHaveLength(0);
    expect(mounted.mounted).toBe(false);
  });

  it("compiles the fixture's stylesheet into the artifact and installs it in the isolated root", async () => {
    const container = document.createElement("div");

    // No sidecar: the whole stylesheet travels inside the one declared JavaScript artifact.
    expect(artifactSource).toContain(".artifact-label");

    const mounted = await loadModuleUi({
      source: { moduleId: "example", version: "0.1.0", url: artifactUrl },
      container,
      context: ekklesiaContext([]),
    });

    const stylesheet = mounted.shadowRoot.querySelector("style")?.textContent ?? "";
    expect(stylesheet).toContain(".artifact-label");
    expect(stylesheet).toContain("var(--ekklesia-text-primary)");
    expect(document.head.textContent ?? "").not.toContain(".artifact-label");

    await mounted.unmount();
  });

  it("still rejects the real artifact when the host expects a different version", async () => {
    await expect(
      loadModuleUi({
        source: { moduleId: "example", version: "0.2.0", url: artifactUrl },
        container: document.createElement("div"),
        context: ekklesiaContext([]),
      }),
    ).rejects.toMatchObject({ code: "MODULE_UI_IDENTITY_MISMATCH" });
  });

  it("runs the same artifact under an Ekklesia host and a standalone host", async () => {
    const ekklesiaRequests: string[] = [];
    const standaloneRequests: string[] = [];
    const ekklesiaContainer = document.createElement("div");
    const standaloneContainer = document.createElement("div");
    const source = { moduleId: "example", version: "0.1.0", url: artifactUrl };

    const inEkklesia = await loadModuleUi({
      source,
      container: ekklesiaContainer,
      context: ekklesiaContext(ekklesiaRequests),
    });
    const inStandalone = await loadModuleUi({
      source,
      container: standaloneContainer,
      context: standaloneContext(standaloneRequests),
    });

    // One artifact, one loader, two hosts. Every difference lives in the context the host supplied:
    // the module asked for "records" both times and resolved nothing itself.
    expect(ekklesiaRequests).toEqual(["/api/v1/modules/example/records"]);
    expect(standaloneRequests).toEqual(["https://example.test/api/records"]);
    expect(artifactText(ekklesiaContainer)).toBe("example:200:user-123");
    expect(artifactText(standaloneContainer)).toBe("example:200:guest");

    await inEkklesia.unmount();
    await inStandalone.unmount();
  });
});