import 'dart:async';
import 'dart:io';

import 'package:device_info/device_info.dart';
import 'package:flutter/services.dart';
import 'package:intl/intl.dart';

import 'in_app_webview_controller.dart';
import 'headless_in_app_webview.dart';
import 'types.dart';

///Class that implements a singleton object (shared instance) which manages the cookies used by WebView instances.
///On Android, it is implemented using [CookieManager](https://developer.android.com/reference/android/webkit/CookieManager).
///On iOS, it is implemented using [WKHTTPCookieStore](https://developer.apple.com/documentation/webkit/wkhttpcookiestore).
///
///**NOTE for iOS below 11.0 (LIMITED SUPPORT!)**: in this case, almost all of the methods ([CookieManager.deleteAllCookies] and [IOSCookieManager.getAllCookies] are not supported!)
///has been implemented using JavaScript because there is no other way to work with them on iOS below 11.0.
///See https://developer.mozilla.org/en-US/docs/Web/HTTP/Cookies#restrict_access_to_cookies for JavaScript restrictions.
class CookieManager {
  static CookieManager? _instance;
  static const MethodChannel _channel = const MethodChannel(
      'com.pichillilorenzo/flutter_inappwebview_cookiemanager');

  ///Contains only iOS-specific methods of [CookieManager].
  late IOSCookieManager ios;

  ///Gets the [CookieManager] shared instance.
  static CookieManager instance() {
    return (_instance != null) ? _instance! : _init();
  }

  static CookieManager _init() {
    _channel.setMethodCallHandler(_handleMethod);
    _instance = CookieManager();
    _instance!.ios = IOSCookieManager.instance();
    return _instance!;
  }

  static Future<dynamic> _handleMethod(MethodCall call) async {}

  ///Sets a cookie for the given [url]. Any existing cookie with the same [host], [path] and [name] will be replaced with the new cookie.
  ///The cookie being set will be ignored if it is expired.
  ///
  ///The default value of [path] is `"/"`.
  ///If [domain] is `null`, its default value will be the domain name of [url].
  ///
  ///[iosBelow11WebViewController] could be used if you need to set a session-only cookie using JavaScript (so [isHttpOnly] cannot be set, see: https://developer.mozilla.org/en-US/docs/Web/HTTP/Cookies#restrict_access_to_cookies)
  ///on the current URL of the [WebView] managed by that controller when you need to target iOS below 11. In this case the [url] parameter is ignored.
  ///
  ///**NOTE for iOS below 11.0**: If [iosBelow11WebViewController] is `null` or JavaScript is disabled for it, it will try to use a [HeadlessInAppWebView]
  ///to set the cookie (session-only cookie won't work! In that case, you should set also [expiresDate] or [maxAge]).
  Future<void> setCookie(
      {required String url,
      required String name,
      required String value,
      String? domain,
      String path = "/",
      int? expiresDate,
      int? maxAge,
      bool? isSecure,
      bool? isHttpOnly,
      HTTPCookieSameSitePolicy? sameSite,
      InAppWebViewController? iosBelow11WebViewController}) async {
    if (domain == null) domain = _getDomainName(url);

    assert(url.isNotEmpty);
    assert(name.isNotEmpty);
    assert(value.isNotEmpty);
    assert(domain.isNotEmpty);
    assert(path.isNotEmpty);

    if (Platform.isIOS) {
      DeviceInfoPlugin deviceInfo = DeviceInfoPlugin();
      IosDeviceInfo iosInfo = await deviceInfo.iosInfo;

      var version = double.tryParse(iosInfo.systemVersion);

      if (version != null && version < 11.0) {
        var cookieValue = name + "=" + value + "; Domain=" + domain + "; Path=" + path;

        if (expiresDate != null)
          cookieValue += "; Expires=" + _getCookieExpirationDate(expiresDate);

        if (maxAge != null)
          cookieValue += "; Max-Age=" + maxAge.toString();

        if (isSecure != null && isSecure)
          cookieValue += "; Secure";

        if (sameSite != null)
          cookieValue += "; SameSite=" + sameSite.toValue();

        cookieValue += ";";

        if (iosBelow11WebViewController != null) {
          InAppWebViewGroupOptions? options = await iosBelow11WebViewController.getOptions();
          if (options != null && options.crossPlatform != null &&
              options.crossPlatform!.javaScriptEnabled == true) {
            await iosBelow11WebViewController.evaluateJavascript(
                source: 'document.cookie="$cookieValue"');
            return;
          }
        }

        var setCookieCompleter = Completer<void>();
        var headlessWebView = new HeadlessInAppWebView(
          initialUrl: url,
          onLoadStop: (controller, url) async {
            await controller.evaluateJavascript(
                source: 'document.cookie="$cookieValue"');
            setCookieCompleter.complete();
          },
        );
        await headlessWebView.run();
        await setCookieCompleter.future;
        await headlessWebView.dispose();

        return;
      }
    }

    Map<String, dynamic> args = <String, dynamic>{};
    args.putIfAbsent('url', () => url);
    args.putIfAbsent('name', () => name);
    args.putIfAbsent('value', () => value);
    args.putIfAbsent('domain', () => domain);
    args.putIfAbsent('path', () => path);
    args.putIfAbsent('expiresDate', () => expiresDate?.toString());
    args.putIfAbsent('maxAge', () => maxAge);
    args.putIfAbsent('isSecure', () => isSecure);
    args.putIfAbsent('isHttpOnly', () => isHttpOnly);
    args.putIfAbsent('sameSite', () => sameSite?.toValue());

    await _channel.invokeMethod('setCookie', args);
  }

  ///Gets all the cookies for the given [url].
  ///
  ///[iosBelow11WebViewController] is used for getting the cookies (also session-only cookies) using JavaScript (cookies with `isHttpOnly` enabled cannot be found, see: https://developer.mozilla.org/en-US/docs/Web/HTTP/Cookies#restrict_access_to_cookies)
  ///from the current context of the [WebView] managed by that controller when you need to target iOS below 11. JavaScript must be enabled in order to work.
  ///In this case the [url] parameter is ignored.
  ///
  ///**NOTE for iOS below 11.0**: All the cookies returned this way will have all the properties to `null` except for [Cookie.name] and [Cookie.value].
  ///If [iosBelow11WebViewController] is `null` or JavaScript is disabled for it, it will try to use a [HeadlessInAppWebView]
  ///to get the cookies (session-only cookies and cookies with `isHttpOnly` enabled won't be found!).
  Future<List<Cookie>> getCookies({required String url, InAppWebViewController? iosBelow11WebViewController}) async {
    assert(url.isNotEmpty);

    List<Cookie> cookies = [];

    if (Platform.isIOS) {
      DeviceInfoPlugin deviceInfo = DeviceInfoPlugin();
      IosDeviceInfo iosInfo = await deviceInfo.iosInfo;

      var version = double.tryParse(iosInfo.systemVersion);

      if (version != null && version < 11.0) {

        if (iosBelow11WebViewController != null) {
          InAppWebViewGroupOptions? options = await iosBelow11WebViewController.getOptions();
          if (options != null && options.crossPlatform != null &&
              options.crossPlatform!.javaScriptEnabled == true) {
            List<String> documentCookies = (await iosBelow11WebViewController.evaluateJavascript(source: 'document.cookie') as String)
                .split(';').map((documentCookie) => documentCookie.trim()).toList();
            documentCookies.forEach((documentCookie) {
              List<String> cookie = documentCookie.split('=');
              cookies.add(Cookie(
                name: cookie[0],
                value: cookie[1],
              )
              );
            });
            return cookies;
          }
        }

        var pageLoaded = Completer<void>();
        var headlessWebView = new HeadlessInAppWebView(
          initialUrl: url,
          onLoadStop: (controller, url) async {
            pageLoaded.complete();
          },
        );
        await headlessWebView.run();
        await pageLoaded.future;

        List<String> documentCookies = (await headlessWebView.webViewController.evaluateJavascript(source: 'document.cookie') as String)
            .split(';').map((documentCookie) => documentCookie.trim()).toList();
        documentCookies.forEach((documentCookie) {
          List<String> cookie = documentCookie.split('=');
          cookies.add(Cookie(
            name: cookie[0],
            value: cookie[1],
          )
          );
        });
        await headlessWebView.dispose();
        return cookies;
      }
    }

    Map<String, dynamic> args = <String, dynamic>{};
    args.putIfAbsent('url', () => url);
    List<dynamic> cookieListMap =
        await _channel.invokeMethod('getCookies', args);
    cookieListMap = cookieListMap.cast<Map<dynamic, dynamic>>();

    cookieListMap.forEach((cookieMap) {
      cookies.add(Cookie(
          name: cookieMap["name"],
          value: cookieMap["value"],
          expiresDate: cookieMap["expiresDate"],
          isSessionOnly: cookieMap["isSessionOnly"],
          domain: cookieMap["domain"],
          sameSite:
          HTTPCookieSameSitePolicy.fromValue(cookieMap["sameSite"]),
          isSecure: cookieMap["isSecure"],
          isHttpOnly: cookieMap["isHttpOnly"],
          path: cookieMap["path"]));
    });
    return cookies;
  }

  ///Gets a cookie by its [name] for the given [url].
  ///
  ///[iosBelow11WebViewController] is used for getting the cookie (also session-only cookie) using JavaScript (cookie with `isHttpOnly` enabled cannot be found, see: https://developer.mozilla.org/en-US/docs/Web/HTTP/Cookies#restrict_access_to_cookies)
  ///from the current context of the [WebView] managed by that controller when you need to target iOS below 11. JavaScript must be enabled in order to work.
  ///In this case the [url] parameter is ignored.
  ///
  ///**NOTE for iOS below 11.0**: All the cookies returned this way will have all the properties to `null` except for [Cookie.name] and [Cookie.value].
  ///If [iosBelow11WebViewController] is `null` or JavaScript is disabled for it, it will try to use a [HeadlessInAppWebView]
  ///to get the cookie (session-only cookie and cookie with `isHttpOnly` enabled won't be found!).
  Future<Cookie?> getCookie(
      {required String url, required String name, InAppWebViewController? iosBelow11WebViewController}) async {

    assert(url.isNotEmpty);
    assert(name.isNotEmpty);

    if (Platform.isIOS) {
      DeviceInfoPlugin deviceInfo = DeviceInfoPlugin();
      IosDeviceInfo iosInfo = await deviceInfo.iosInfo;

      var version = double.tryParse(iosInfo.systemVersion);

      if (version != null && version < 11.0) {

        if (iosBelow11WebViewController != null) {
          InAppWebViewGroupOptions? options = await iosBelow11WebViewController.getOptions();
          if (options != null && options.crossPlatform != null &&
              options.crossPlatform!.javaScriptEnabled == true) {
            List<String> documentCookies = (await iosBelow11WebViewController.evaluateJavascript(source: 'document.cookie') as String)
                .split(';').map((documentCookie) => documentCookie.trim()).toList();
            for (var i = 0; i < documentCookies.length; i++) {
              List<String> cookie = documentCookies[i].split('=');
              if (cookie[0] == name)
                return Cookie(
                    name: cookie[0],
                    value: cookie[1]);
            }
            return null;
          }
        }

        var pageLoaded = Completer<void>();
        var headlessWebView = new HeadlessInAppWebView(
          initialUrl: url,
          onLoadStop: (controller, url) async {
            pageLoaded.complete();
          },
        );
        await headlessWebView.run();
        await pageLoaded.future;

        List<String> documentCookies = (await headlessWebView.webViewController.evaluateJavascript(source: 'document.cookie') as String)
            .split(';').map((documentCookie) => documentCookie.trim()).toList();
        await headlessWebView.dispose();

        for (var i = 0; i < documentCookies.length; i++) {
          List<String> cookie = documentCookies[i].split('=');
          if (cookie[0] == name)
            return Cookie(
                name: cookie[0],
                value: cookie[1]);
        }
        return null;
      }
    }

    Map<String, dynamic> args = <String, dynamic>{};
    args.putIfAbsent('url', () => url);
    List<dynamic> cookies = await _channel.invokeMethod('getCookies', args);
    cookies = cookies.cast<Map<dynamic, dynamic>>();
    for (var i = 0; i < cookies.length; i++) {
      cookies[i] = cookies[i].cast<String, dynamic>();
      if (cookies[i]["name"] == name)
        return Cookie(
            name: cookies[i]["name"],
            value: cookies[i]["value"],
            expiresDate: cookies[i]["expiresDate"],
            isSessionOnly: cookies[i]["isSessionOnly"],
            domain: cookies[i]["domain"],
            sameSite:
                HTTPCookieSameSitePolicy.fromValue(cookies[i]["sameSite"]),
            isSecure: cookies[i]["isSecure"],
            isHttpOnly: cookies[i]["isHttpOnly"],
            path: cookies[i]["path"]);
    }
    return null;
  }

  ///Removes a cookie by its [name] for the given [url], [domain] and [path].
  ///
  ///The default value of [path] is `"/"`.
  ///If [domain] is empty, its default value will be the domain name of [url].
  ///
  ///[iosBelow11WebViewController] is used for deleting the cookie (also session-only cookie) using JavaScript (cookie with `isHttpOnly` enabled cannot be deleted, see: https://developer.mozilla.org/en-US/docs/Web/HTTP/Cookies#restrict_access_to_cookies)
  ///from the current context of the [WebView] managed by that controller when you need to target iOS below 11. JavaScript must be enabled in order to work.
  ///In this case the [url] parameter is ignored.
  ///
  ///**NOTE for iOS below 11.0**: If [iosBelow11WebViewController] is `null` or JavaScript is disabled for it, it will try to use a [HeadlessInAppWebView]
  ///to delete the cookie (session-only cookie and cookie with `isHttpOnly` enabled won't be deleted!).
  Future<void> deleteCookie(
      {required String url,
      required String name,
      String domain = "",
      String path = "/",
      InAppWebViewController? iosBelow11WebViewController}) async {
    if (domain.isEmpty) domain = _getDomainName(url);

    assert(url.isNotEmpty);
    assert(name.isNotEmpty);

    if (Platform.isIOS) {
      DeviceInfoPlugin deviceInfo = DeviceInfoPlugin();
      IosDeviceInfo iosInfo = await deviceInfo.iosInfo;
      var version = double.tryParse(iosInfo.systemVersion);
      if (version != null && version < 11.0) {
        await setCookie(url: url, name: name, value: "", path: path, domain: domain, maxAge: -1, iosBelow11WebViewController: iosBelow11WebViewController);
        return;
      }
    }

    Map<String, dynamic> args = <String, dynamic>{};
    args.putIfAbsent('url', () => url);
    args.putIfAbsent('name', () => name);
    args.putIfAbsent('domain', () => domain);
    args.putIfAbsent('path', () => path);
    await _channel.invokeMethod('deleteCookie', args);
  }

  ///Removes all cookies for the given [url], [domain] and [path].
  ///
  ///The default value of [path] is `"/"`.
  ///If [domain] is empty, its default value will be the domain name of [url].
  ///
  ///[iosBelow11WebViewController] is used for deleting the cookies (also session-only cookies) using JavaScript (cookies with `isHttpOnly` enabled cannot be deleted, see: https://developer.mozilla.org/en-US/docs/Web/HTTP/Cookies#restrict_access_to_cookies)
  ///from the current context of the [WebView] managed by that controller when you need to target iOS below 11. JavaScript must be enabled in order to work.
  ///In this case the [url] parameter is ignored.
  ///
  ///**NOTE for iOS below 11.0**: If [iosBelow11WebViewController] is `null` or JavaScript is disabled for it, it will try to use a [HeadlessInAppWebView]
  ///to delete the cookies (session-only cookies and cookies with `isHttpOnly` enabled won't be deleted!).
  Future<void> deleteCookies(
      {required String url, String domain = "", String path = "/",
        InAppWebViewController? iosBelow11WebViewController}) async {
    if (domain.isEmpty) domain = _getDomainName(url);

    assert(url.isNotEmpty);

    if (Platform.isIOS) {
      DeviceInfoPlugin deviceInfo = DeviceInfoPlugin();
      IosDeviceInfo iosInfo = await deviceInfo.iosInfo;
      var version = double.tryParse(iosInfo.systemVersion);
      if (version != null && version < 11.0) {
        List<Cookie> cookies = await getCookies(url: url, iosBelow11WebViewController: iosBelow11WebViewController);
        for (var i = 0; i < cookies.length; i++) {
          await setCookie(url: url, name: cookies[i].name, value: "", path: path, domain: domain, maxAge: -1, iosBelow11WebViewController: iosBelow11WebViewController);
        }
        return;
      }
    }

    Map<String, dynamic> args = <String, dynamic>{};
    args.putIfAbsent('url', () => url);
    args.putIfAbsent('domain', () => domain);
    args.putIfAbsent('path', () => path);
    await _channel.invokeMethod('deleteCookies', args);
  }

  ///Removes all cookies.
  ///
  ///**NOTE for iOS**: available from iOS 11.0+.
  Future<void> deleteAllCookies() async {
    Map<String, dynamic> args = <String, dynamic>{};
    await _channel.invokeMethod('deleteAllCookies', args);
  }

  String _getDomainName(String url) {
    Uri uri = Uri.parse(url);
    String domain = uri.host;
    // ignore: unnecessary_null_comparison
    if (domain == null) return "";
    return domain.startsWith("www.") ? domain.substring(4) : domain;
  }

  String _getCookieExpirationDate(int expiresDate) {
    var dateTime = DateTime.fromMillisecondsSinceEpoch(expiresDate).toUtc();
    return DateFormat('EEE, d MMM yyyy hh:mm:ss', "en_US").format(dateTime) + ' GMT';
  }
}

///Class that contains only iOS-specific methods of [CookieManager].
class IOSCookieManager {
  static IOSCookieManager? _instance;

  ///Gets the [IOSCookieManager] shared instance.
  static IOSCookieManager instance() {
    return (_instance != null) ? _instance! : _init();
  }

  static IOSCookieManager _init() {
    _instance = IOSCookieManager();
    return _instance!;
  }

  ///Fetches all stored cookies.
  ///
  ///**NOTE**: available on iOS 11.0+.
  ///
  ///**Official iOS API**: https://developer.apple.com/documentation/webkit/wkhttpcookiestore/2882005-getallcookies
  Future<List<Cookie>> getAllCookies() async {
    List<Cookie> cookies = [];

    Map<String, dynamic> args = <String, dynamic>{};
    List<dynamic> cookieListMap =
    await CookieManager._channel.invokeMethod('getAllCookies', args);
    cookieListMap = cookieListMap.cast<Map<dynamic, dynamic>>();

    cookieListMap.forEach((cookieMap) {
      cookies.add(Cookie(
          name: cookieMap["name"],
          value: cookieMap["value"],
          expiresDate: cookieMap["expiresDate"],
          isSessionOnly: cookieMap["isSessionOnly"],
          domain: cookieMap["domain"],
          sameSite:
          HTTPCookieSameSitePolicy.fromValue(cookieMap["sameSite"]),
          isSecure: cookieMap["isSecure"],
          isHttpOnly: cookieMap["isHttpOnly"],
          path: cookieMap["path"]));
    });
    return cookies;
  }
}