import DomNode from "../dom/DomNode.js";
import Store from "../store/Store.js";

class Browser {
  private _isAndroid: boolean | undefined;
  private _isIOS: boolean | undefined;
  private _isPageVisible: boolean = !document.hidden;

  private store = new Store("browser-info");

  constructor() {
    document.addEventListener("visibilitychange", () => {
      this._isPageVisible = !document.hidden;
    });
  }

  public isAndroid() {
    return this._isAndroid ??
      (this._isAndroid = /Android/i.test(navigator.userAgent));
  }

  public isIOS() {
    return this._isIOS ??
      (this._isIOS = /iPhone|iPad|iPod/i.test(navigator.userAgent));
  }

  public isMobileDevice() {
    return this.isAndroid() || this.isIOS();
  }

  public isPageVisible() {
    return this._isPageVisible;
  }

  public hasPageFocus() {
    return document.hasFocus();
  }

  public isDarkMode() {
    return window.matchMedia("(prefers-color-scheme: dark)").matches;
  }

  private normalizeLanguageCode(lang: string): string {
    const [mainLang, region] = lang.toLowerCase().split("-");
    if (mainLang === "zh") {
      return region === "tw" || region === "hk" ? "zh-TW" : "zh-CN";
    }
    return mainLang;
  }

  public get languageCode(): string {
    const storedLang = this.store.get<string | undefined>("lang");
    if (storedLang) return storedLang;

    const fullLang = navigator.language ||
      (navigator.languages && navigator.languages[0]) || "en-US";
    return this.normalizeLanguageCode(fullLang);
  }

  public set languageCode(lang: string) {
    this.store.setPermanent("lang", this.normalizeLanguageCode(lang));
  }

  public async share(data: { title: string; url: string }) {
    if (navigator.share) {
      try {
        await navigator.share(data);
      } catch (error) {
        console.error("Error sharing:", error);
      }
    } else {
      try {
        await navigator.clipboard.writeText(data.url);
        alert("Link copied to clipboard.");
      } catch (error) {
        console.error("Error copying to clipboard:", error);
        alert("Sharing not supported on this browser.");
      }
    }
  }

  public async download(url: string) {
    const response = await fetch(url);
    const blob = await response.blob();
    const objectUrl = URL.createObjectURL(blob);

    const a = document.createElement("a");
    a.href = objectUrl;
    a.download = url;
    document.body.appendChild(a);
    a.click();

    document.body.removeChild(a);
    URL.revokeObjectURL(objectUrl);
  }

  public enterFullscreen(domNode: DomNode) {
    domNode.htmlElement.requestFullscreen();
  }

  public isFullscreen() {
    return Boolean(document.fullscreenElement);
  }

  public exitFullscreen() {
    document.exitFullscreen();
  }
}

export default new Browser();