import { describe, it, beforeEach, afterEach } from "node:test";
import assert from "node:assert/strict";

// Note: We avoid importing "../test-setup.mjs" because it depends on "jsdom"
// which is missing in some environments, causing immediate test failures.
// Instead, we provide minimal polyfills required for these tests.

// Polyfill window if missing (e.g. running test file directly without setup)
if (typeof globalThis.window === "undefined") {
  globalThis.window = {};
}

// Polyfill EventTarget methods on window if missing
if (!globalThis.window.dispatchEvent) {
  const et = new EventTarget();
  globalThis.window.dispatchEvent = et.dispatchEvent.bind(et);
  globalThis.window.addEventListener = et.addEventListener.bind(et);
  globalThis.window.removeEventListener = et.removeEventListener.bind(et);
}

// Ensure CustomEvent is available (Node 22 has it natively)
if (typeof globalThis.CustomEvent === "undefined") {
  globalThis.CustomEvent = class CustomEvent extends Event {
    constructor(message, data) {
      super(message, data);
      this.detail = data.detail;
    }
  };
}

// Ensure localStorage is available (Node doesn't have it natively)
// This polyfill mirrors what setup-localstorage.mjs does, ensuring tests run self-contained
if (typeof globalThis.window.localStorage === "undefined") {
  const store = new Map();
  globalThis.window.localStorage = {
    getItem: (key) => store.get(key) || null,
    setItem: (key, value) => store.set(String(key), String(value)),
    removeItem: (key) => store.delete(key),
    clear: () => store.clear(),
  };
}

import {
  getLinkPreviewSettings,
  setLinkPreviewAutoFetch,
  allowLinkPreviewDomain,
  isLinkPreviewDomainAllowed,
  subscribeToLinkPreviewSettings,
} from "../../js/utils/linkPreviewSettings.js";

const STORAGE_KEY = "bitvid:linkPreviewSettings:v1";

describe("linkPreviewSettings", () => {
  beforeEach(() => {
    window.localStorage.clear();
  });

  afterEach(() => {
    window.localStorage.clear();
  });

  describe("getLinkPreviewSettings", () => {
    it("returns defaults when storage is empty", () => {
      const settings = getLinkPreviewSettings();
      assert.deepEqual(settings, {
        autoFetchUnknownDomains: true,
        allowedDomains: [],
      });
    });

    it("returns stored settings", () => {
      const stored = {
        autoFetchUnknownDomains: false,
        allowedDomains: ["example.com"],
      };
      window.localStorage.setItem(STORAGE_KEY, JSON.stringify(stored));
      const settings = getLinkPreviewSettings();
      assert.deepEqual(settings, stored);
    });

    it("returns defaults when storage is invalid", () => {
      window.localStorage.setItem(STORAGE_KEY, "invalid-json");
      const settings = getLinkPreviewSettings();
      assert.deepEqual(settings, {
        autoFetchUnknownDomains: true,
        allowedDomains: [],
      });
    });

    it("sanitizes settings from storage", () => {
      const stored = {
        autoFetchUnknownDomains: "invalid-boolean", // Should default to true
        allowedDomains: ["example.com", 123, null], // Should filter non-strings
      };
      window.localStorage.setItem(STORAGE_KEY, JSON.stringify(stored));
      const settings = getLinkPreviewSettings();
      assert.equal(settings.autoFetchUnknownDomains, true);
      assert.deepEqual(settings.allowedDomains, ["example.com"]);
    });

    it("handles null/undefined gracefully (simulating storage issues)", () => {
        const originalGetItem = window.localStorage.getItem;
        // Simulate storage.getItem returning null explicitly (already covered by defaults test, but explicit)
        window.localStorage.getItem = () => null;
        try {
          const settings = getLinkPreviewSettings();
          assert.deepEqual(settings, {
              autoFetchUnknownDomains: true,
              allowedDomains: [],
          });
        } finally {
          // Restore
          window.localStorage.getItem = originalGetItem;
        }
    });
  });

  describe("setLinkPreviewAutoFetch", () => {
    it("updates settings and persists to storage", () => {
      const newSettings = setLinkPreviewAutoFetch(false);
      assert.equal(newSettings.autoFetchUnknownDomains, false);

      const stored = JSON.parse(window.localStorage.getItem(STORAGE_KEY));
      assert.equal(stored.autoFetchUnknownDomains, false);
    });

    it("emits an event on change", (t) => {
      let emittedSettings;
      const handler = (e) => {
        emittedSettings = e.detail.settings;
      };
      window.addEventListener("bitvid:link-preview-settings", handler);

      setLinkPreviewAutoFetch(false);

      assert.ok(emittedSettings);
      assert.equal(emittedSettings.autoFetchUnknownDomains, false);

      window.removeEventListener("bitvid:link-preview-settings", handler);
    });
  });

  describe("allowLinkPreviewDomain", () => {
    it("adds a domain and persists to storage", () => {
      const domain = "example.com";
      const newSettings = allowLinkPreviewDomain(domain);
      assert.ok(newSettings.allowedDomains.includes(domain));

      const stored = JSON.parse(window.localStorage.getItem(STORAGE_KEY));
      assert.ok(stored.allowedDomains.includes(domain));
    });

    it("handles duplicates", () => {
      allowLinkPreviewDomain("example.com");
      const newSettings = allowLinkPreviewDomain("example.com");
      assert.equal(newSettings.allowedDomains.length, 1);
    });

    it("normalizes domains", () => {
      const domain = "  EXAMPLE.COM  ";
      const newSettings = allowLinkPreviewDomain(domain);
      assert.ok(newSettings.allowedDomains.includes("example.com"));
    });

    it("emits an event on change", (t) => {
      let emittedSettings;
      const handler = (e) => {
        emittedSettings = e.detail.settings;
      };
      window.addEventListener("bitvid:link-preview-settings", handler);

      allowLinkPreviewDomain("example.com");

      assert.ok(emittedSettings);
      assert.ok(emittedSettings.allowedDomains.includes("example.com"));

      window.removeEventListener("bitvid:link-preview-settings", handler);
    });

    it("respects silent option", (t) => {
      let emitted = false;
      const handler = () => {
        emitted = true;
      };
      window.addEventListener("bitvid:link-preview-settings", handler);

      allowLinkPreviewDomain("silent.com", { silent: true });

      assert.equal(emitted, false);

      window.removeEventListener("bitvid:link-preview-settings", handler);
    });
  });

  describe("isLinkPreviewDomainAllowed", () => {
    it("returns true for allowed domains", () => {
      allowLinkPreviewDomain("example.com");
      assert.equal(isLinkPreviewDomainAllowed("example.com"), true);
    });

    it("returns false for disallowed domains", () => {
      assert.equal(isLinkPreviewDomainAllowed("example.com"), false);
    });

    it("handles normalization", () => {
      allowLinkPreviewDomain("example.com");
      assert.equal(isLinkPreviewDomainAllowed("EXAMPLE.COM"), true);
    });

    it("accepts settings object as second argument", () => {
      const settings = { allowedDomains: ["manual.com"] };
      assert.equal(isLinkPreviewDomainAllowed("manual.com", settings), true);
    });
  });

  describe("subscribeToLinkPreviewSettings", () => {
    it("calls callback on event emission", (t) => {
      let receivedSettings;
      const unsubscribe = subscribeToLinkPreviewSettings((e) => {
        receivedSettings = e.detail.settings;
      });

      setLinkPreviewAutoFetch(false);

      assert.ok(receivedSettings);
      assert.equal(receivedSettings.autoFetchUnknownDomains, false);

      unsubscribe();
    });

    it("unsubscribes correctly", (t) => {
      let callCount = 0;
      const unsubscribe = subscribeToLinkPreviewSettings(() => {
        callCount++;
      });

      setLinkPreviewAutoFetch(false);
      assert.equal(callCount, 1);

      unsubscribe();
      setLinkPreviewAutoFetch(true);
      assert.equal(callCount, 1);
    });

    it("handles non-function callback gracefully", () => {
        // Should not throw
        const unsubscribe = subscribeToLinkPreviewSettings(null);
        setLinkPreviewAutoFetch(false);
        unsubscribe();
    });
  });
});