import { mkdir, mkdtemp, rm, writeFile } from "node:fs/promises";
import { tmpdir } from "node:os";
import path from "node:path";
import type {
  ModuleDatabase,
  ModuleRealtimePublisher,
  ModuleRuntimeServices,
} from "@ekklesia/contracts";
import { afterEach, describe, expect, it } from "vitest";
import { ModuleRuntimeError, startModuleRuntime } from "../src/modules/runtime.js";

const temporaryDirectories: string[] = [];
const globalSymbols: symbol[] = [];

afterEach(async () => {
  const globals = globalThis as unknown as Record<PropertyKey, unknown>;
  for (const symbol of globalSymbols.splice(0)) {
    delete globals[symbol];
  }
  await Promise.all(
    temporaryDirectories.splice(0).map((directory) => rm(directory, { recursive: true })),
  );
});

function fakeServices(): ModuleRuntimeServices {
  return Object.freeze({ database: Object.freeze({}) as ModuleDatabase });
}

function manifest(
  id: string,
  permissions: readonly Record<string, string>[] = [],
): Record<string, unknown> {
  return {
    manifestVersion: 8,
    id,
    name: `${id} module`,
    version: "0.1.0",
    compatibility: { platform: "^0.1.0", moduleSdk: "^0.1.0" },
    permissions,
    entrypoints: { server: "./dist/server/index.js" },
  };
}

async function createRuntimeFixture(
  id: string,
  serverSource: string,
  permissions: readonly Record<string, string>[] = [],
): Promise<string> {
  const modulesDirectory = await mkdtemp(path.join(tmpdir(), "ekklesia-realtime-runtime-"));
  temporaryDirectories.push(modulesDirectory);
  const moduleDirectory = path.join(modulesDirectory, id);
  await mkdir(path.join(moduleDirectory, "dist/server"), { recursive: true });
  await Promise.all([
    writeFile(
      path.join(moduleDirectory, "package.json"),
      JSON.stringify({
        name: `@test/module-${id}`,
        version: "0.1.0",
        type: "module",
        ekklesia: { layer: "module" },
      }),
    ),
    writeFile(
      path.join(moduleDirectory, "ekklesia.module.json"),
      JSON.stringify(manifest(id, permissions)),
    ),
    writeFile(path.join(moduleDirectory, "dist/server/index.js"), serverSource),
  ]);
  return modulesDirectory;
}

function runtimeOptions(modulesDirectory: string) {
  return {
    moduleSdkVersion: "0.1.0",
    modulesDirectory,
    platformVersion: "0.1.0",
    services: fakeServices(),
  };
}

function recorder(): {
  readonly expression: string;
  readonly value: { events: string[]; publishers: ModuleRealtimePublisher[] };
} {
  const symbol = Symbol.for(`ekklesia.realtime.${Date.now()}.${Math.random()}`);
  const value = { events: [] as string[], publishers: [] as ModuleRealtimePublisher[] };
  (globalThis as unknown as Record<PropertyKey, unknown>)[symbol] = value;
  globalSymbols.push(symbol);
  return { expression: `globalThis[Symbol.for(${JSON.stringify(Symbol.keyFor(symbol))})]`, value };
}

describe("module runtime realtime lifecycle", () => {
  it("stages declarations, requires startup state, delivers live state, and closes before stop", async () => {
    const recorded = recorder();
    const objectUrl = "https://delivery.invalid/slides/welcome.png?signature=unchanged";
    const modulesDirectory = await createRuntimeFixture(
      "announcements",
      `
        export default {
          id: "announcements",
          version: "0.1.0",
          register({ realtime }) {
            realtime.channel({ channel: "state", permission: "announcements.slideshow.view" });
            ${recorded.expression}.events.push("register");
          },
          start({ realtime }) {
            ${recorded.expression}.publishers.push(realtime);
            realtime.publish("state", {
              currentSlide: 0,
              previousSlide: -1,
              slides: [${JSON.stringify(objectUrl)}],
              slideSeconds: 7,
              mode: "on"
            });
            ${recorded.expression}.events.push("start");
          },
          stop({ realtime }) {
            try { realtime.publish("state", { mode: "off" }); }
            catch (error) { ${recorded.expression}.events.push("stop:" + error.code); }
          }
        };
      `,
      [
        {
          id: "announcements.slideshow.view",
          baseline: "restricted",
          description: "View the announcement slideshow.",
        },
      ],
    );

    const runtime = await startModuleRuntime(runtimeOptions(modulesDirectory));
    expect(recorded.value.events).toEqual(["register", "start"]);
    expect(runtime.realtime.channels).toEqual([
      {
        moduleId: "announcements",
        channel: "state",
        permission: "announcements.slideshow.view",
      },
    ]);
    const subscription = runtime.realtime.subscribe("announcements", "state");
    expect(subscription.snapshot.sequence).toBe(1);
    expect(subscription.snapshot.serializedPayload).toContain(objectUrl);

    const next = subscription.read();
    recorded.value.publishers[0]?.publish("state", {
      currentSlide: 1,
      previousSlide: 0,
      slides: [objectUrl],
      slideSeconds: 7,
      mode: "on",
    });
    await expect(next).resolves.toMatchObject({ sequence: 2 });
    const pendingClose = subscription.read();
    await runtime.stop();
    await expect(pendingClose).resolves.toBeUndefined();
    expect(recorded.value.events).toEqual(["register", "start", "stop:REALTIME_PUBLISHER_STOPPED"]);
    expect(() => recorded.value.publishers[0]?.publish("state", null)).toThrowError(
      expect.objectContaining({ code: "REALTIME_PUBLISHER_STOPPED" }),
    );
  });

  it("fails atomically and rolls back when a declared channel has no initial snapshot", async () => {
    const recorded = recorder();
    const modulesDirectory = await createRuntimeFixture(
      "announcements",
      `
        export default {
          id: "announcements",
          version: "0.1.0",
          register({ realtime }) {
            realtime.channel({ channel: "state", permission: "announcements.slideshow.view" });
          },
          start() { ${recorded.expression}.events.push("start"); },
          stop() { ${recorded.expression}.events.push("rollback"); }
        };
      `,
      [
        {
          id: "announcements.slideshow.view",
          baseline: "restricted",
          description: "View the announcement slideshow.",
        },
      ],
    );

    await expect(startModuleRuntime(runtimeOptions(modulesDirectory))).rejects.toMatchObject({
      issues: [expect.objectContaining({ code: "MODULE_REALTIME_SNAPSHOT_MISSING" })],
    });
    expect(recorded.value.events).toEqual(["start", "rollback"]);
  });

  it("reports invalid owned-permission registration with a deterministic sanitized issue", async () => {
    const secret = "/machine/private/permission-token";
    const modulesDirectory = await createRuntimeFixture(
      "announcements",
      `
        export default {
          id: "announcements",
          version: "0.1.0",
          register({ realtime }) {
            realtime.channel({ channel: "state", permission: "announcements.not-owned" });
          }
        };
        // ${secret}
      `,
    );

    let failure: unknown;
    try {
      await startModuleRuntime(runtimeOptions(modulesDirectory));
    } catch (error) {
      failure = error;
    }
    expect(failure).toBeInstanceOf(ModuleRuntimeError);
    expect(failure).toMatchObject({
      issues: [expect.objectContaining({ code: "MODULE_REALTIME_PERMISSION_UNDECLARED" })],
    });
    expect(JSON.stringify(failure)).not.toContain(secret);
  });

  it("starts and stops modules that declare no realtime channels unchanged", async () => {
    const recorded = recorder();
    const modulesDirectory = await createRuntimeFixture(
      "calendar",
      `
        export default {
          id: "calendar",
          version: "0.1.0",
          start() { ${recorded.expression}.events.push("start"); },
          stop() { ${recorded.expression}.events.push("stop"); }
        };
      `,
    );
    const runtime = await startModuleRuntime(runtimeOptions(modulesDirectory));
    expect(runtime.realtime.channels).toEqual([]);
    await runtime.stop();
    expect(recorded.value.events).toEqual(["start", "stop"]);
  });
});