//
//  NCLoginWeb.swift
//  Nextcloud
//
//  Created by Marino Faggiana on 21/08/2019.
//  Copyright © 2019 Marino Faggiana. All rights reserved.
//
//  Author Marino Faggiana <marino.faggiana@nextcloud.com>
//
//  This program is free software: you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  (at your option) any later version.
//
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
//

import Foundation
import WebKit
import NCCommunication
import FloatingPanel

class NCLoginWeb: UIViewController {
    
    var activityIndicator: UIActivityIndicatorView!
    var webView: WKWebView?
    let appDelegate = UIApplication.shared.delegate as! AppDelegate

    @objc var urlBase = ""
    
    @objc var loginFlowV2Available = false
    @objc var loginFlowV2Token = ""
    @objc var loginFlowV2Endpoint = ""
    @objc var loginFlowV2Login = ""
    
    // MARK: - Life Cycle
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        let accountCount = NCManageDatabase.shared.getAccounts()?.count ?? 0
        
        if NCBrandOptions.shared.use_login_web_personalized  && accountCount > 0 {
            navigationItem.leftBarButtonItem = UIBarButtonItem.init(barButtonSystemItem: .stop, target: self, action: #selector(self.closeView(sender:)))
        }
        
        if accountCount > 0 {
            navigationItem.rightBarButtonItem = UIBarButtonItem.init(image: UIImage(named: "users")!.image(color: NCBrandColor.shared.textView, size: 35), style: .plain, target: self, action:  #selector(self.changeUser(sender:)))
        }
        
        let config = WKWebViewConfiguration()
        config.websiteDataStore = WKWebsiteDataStore.nonPersistent()

        webView = WKWebView(frame: CGRect.zero, configuration: config)
        webView!.navigationDelegate = self
        view.addSubview(webView!)
        
        webView!.translatesAutoresizingMaskIntoConstraints = false
        webView!.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 0).isActive = true
        webView!.rightAnchor.constraint(equalTo: view.rightAnchor, constant: 0).isActive = true
        webView!.topAnchor.constraint(equalTo: view.topAnchor, constant: 0).isActive = true
        webView!.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: 0).isActive = true
        
        // ADD end point for Web Flow
        if urlBase != NCBrandOptions.shared.linkloginPreferredProviders {
            if loginFlowV2Available {
                urlBase = loginFlowV2Login
            } else {
                urlBase = urlBase + "/index.php/login/flow"
            }
        }
        
        activityIndicator = UIActivityIndicatorView(style: .gray)
        activityIndicator.center = self.view.center
        activityIndicator.startAnimating()
        self.view.addSubview(activityIndicator)
        
        if let url = URL(string: urlBase) {
            loadWebPage(webView: webView!, url: url)
        } else {
            NCContentPresenter.shared.messageNotification("_error_", description: "_login_url_error_", delay: NCGlobal.shared.dismissAfterSecond, type: NCContentPresenter.messageType.error, errorCode: NCGlobal.shared.ErrorInternalError, forced: true)
        }
    }
    
    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        
        // Stop timer error network
        appDelegate.timerErrorNetworking?.invalidate()
    }
    
    override func viewDidDisappear(_ animated: Bool) {
        super.viewDidDisappear(animated)
        
        // Start timer error network
        appDelegate.startTimerErrorNetworking()
    }
    
    func loadWebPage(webView: WKWebView, url: URL)  {
        
        let language = NSLocale.preferredLanguages[0] as String
        var request = URLRequest(url: url)
        
        request.addValue("true", forHTTPHeaderField: "OCS-APIRequest")
        request.addValue(language, forHTTPHeaderField: "Accept-Language")
        webView.customUserAgent = CCUtility.getUserAgent()
        
        webView.load(request)
    }
    
    @objc func closeView(sender: UIBarButtonItem) {
        self.dismiss(animated: true, completion: nil)
    }
    
    @objc func changeUser(sender: UIBarButtonItem) {
        toggleMenu()
    }
}

extension NCLoginWeb: WKNavigationDelegate {
    
    public func webView(_ webView: WKWebView, didReceiveServerRedirectForProvisionalNavigation navigation: WKNavigation!) {
        
        guard let url = webView.url else { return }
        
        let urlString: String = url.absoluteString.lowercased()
        
        if (urlString.hasPrefix(NCBrandOptions.shared.webLoginAutenticationProtocol) == true && urlString.contains("login") == true) {
            
            var server: String = ""
            var user: String = ""
            var password: String = ""
            
            let keyValue = url.path.components(separatedBy: "&")
            for value in keyValue {
                if value.contains("server:") { server = value }
                if value.contains("user:") { user = value }
                if value.contains("password:") { password = value }
            }
            
            if server != "" && user != "" && password != "" {
                
                let server: String = server.replacingOccurrences(of: "/server:", with: "")
                let username: String = user.replacingOccurrences(of: "user:", with: "").replacingOccurrences(of: "+", with: " ")
                let password: String = password.replacingOccurrences(of: "password:", with: "")
                
                createAccount(server: server, username: username, password: password)
            }
        }
    }
    
    public func webView(_ webView: WKWebView, didReceive challenge: URLAuthenticationChallenge, completionHandler: @escaping (URLSession.AuthChallengeDisposition, URLCredential?) -> Void) {
        if let serverTrust = challenge.protectionSpace.serverTrust {
            completionHandler(Foundation.URLSession.AuthChallengeDisposition.useCredential, URLCredential(trust: serverTrust))
        } else {
            completionHandler(URLSession.AuthChallengeDisposition.useCredential, nil);
        }
    }
    
    public func webView(_ webView: WKWebView, decidePolicyFor navigationAction: WKNavigationAction, decisionHandler: @escaping (WKNavigationActionPolicy) -> Void) {
        
        decisionHandler(.allow)

        /* TEST NOT GOOD DON'T WORKS
        guard let url = navigationAction.request.url else {
            decisionHandler(.allow)
            return
        }
        
        if String(describing: url).hasPrefix(NCBrandOptions.shared.webLoginAutenticationProtocol) {
            decisionHandler(.allow)
            return
        } else if navigationAction.request.httpMethod != "GET" || navigationAction.request.value(forHTTPHeaderField: "OCS-APIRequest") != nil {
            decisionHandler(.allow)
            return
        }
        
        decisionHandler(.cancel)
        
        let language = NSLocale.preferredLanguages[0] as String
        var request = URLRequest(url: url)
        
        request.setValue(CCUtility.getUserAgent(), forHTTPHeaderField: "User-Agent")
        request.addValue("true", forHTTPHeaderField: "OCS-APIRequest")
        request.addValue(language, forHTTPHeaderField: "Accept-Language")
        
        webView.load(request)
        */
    }
    
    public func webView(_ webView: WKWebView, didStartProvisionalNavigation navigation: WKNavigation!) {
        print("didStartProvisionalNavigation");
    }
    
    public func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
        activityIndicator.stopAnimating()
        print("didFinishProvisionalNavigation");
        
        if loginFlowV2Available {
            DispatchQueue.main.asyncAfter(deadline: .now() + 1) {
                NCCommunication.shared.getLoginFlowV2Poll(token: self.loginFlowV2Token, endpoint: self.loginFlowV2Endpoint) { (server, loginName, appPassword, errorCode, errorDescription) in
                    if errorCode == 0 && server != nil && loginName != nil && appPassword != nil {
                        self.createAccount(server: server!, username: loginName!, password: appPassword!)
                    }
                }
            }
        }
    }
    
    //MARK: -

    func createAccount(server: String, username: String, password: String) {
        
        var urlBase = server
        
        // NO account found, clear all
        if NCManageDatabase.shared.getAccounts() == nil { NCUtility.shared.removeAllSettings() }
            
        // Normalized
        if (urlBase.last == "/") {
            urlBase = String(urlBase.dropLast())
        }
        
        // Create account
        let account: String = "\(username) \(urlBase)"

        // Add new account
        NCManageDatabase.shared.deleteAccount(account)
        NCManageDatabase.shared.addAccount(account, urlBase: urlBase, user: username, password: password)
            
        guard let tableAccount = NCManageDatabase.shared.setAccountActive(account) else {
            self.dismiss(animated: true, completion: nil)
            return
        }
            
        appDelegate.settingAccount(account, urlBase: urlBase, user: username, userId: tableAccount.userId, password: password)
            
        if (CCUtility.getIntro()) {
            
            NotificationCenter.default.postOnMainThread(name: NCGlobal.shared.notificationCenterInitializeMain)
            self.dismiss(animated: true)
                
        } else {
            
            CCUtility.setIntro(true)
            if (self.presentingViewController == nil) {
                if let viewController = UIStoryboard(name: "Main", bundle: nil).instantiateInitialViewController() {
                    viewController.modalPresentationStyle = .fullScreen
                    NotificationCenter.default.postOnMainThread(name: NCGlobal.shared.notificationCenterInitializeMain)
                    viewController.view.alpha = 0
                    appDelegate.window?.rootViewController = viewController
                    appDelegate.window?.makeKeyAndVisible()
                    UIView.animate(withDuration: 0.5) {
                        viewController.view.alpha = 1
                    }
                }
            } else {
                NotificationCenter.default.postOnMainThread(name: NCGlobal.shared.notificationCenterInitializeMain)
                self.dismiss(animated: true)
            }
        }
    }
}