//
//  InAppBrowserWebViewController.swift
//  flutter_inappwebview
//
//  Created by Lorenzo on 17/09/18.
//

import Flutter
import UIKit
import WebKit
import Foundation

public class InAppBrowserWebViewController: UIViewController, InAppBrowserDelegate, UIScrollViewDelegate, UISearchBarDelegate, Disposable {
    static var METHOD_CHANNEL_NAME_PREFIX = "com.pichillilorenzo/flutter_inappbrowser_";
    
    var closeButton: UIBarButtonItem!
    var reloadButton: UIBarButtonItem!
    var backButton: UIBarButtonItem!
    var forwardButton: UIBarButtonItem!
    var shareButton: UIBarButtonItem!
    var searchBar: UISearchBar!
    var progressBar: UIProgressView!
    
    var tmpWindow: UIWindow?
    var id: String = ""
    var windowId: Int64?
    var webView: InAppWebView?
    var channelDelegate: InAppBrowserChannelDelegate?
    var initialUrlRequest: URLRequest?
    var initialFile: String?
    var contextMenu: [String: Any]?
    var browserSettings: InAppBrowserSettings?
    var webViewSettings: InAppWebViewSettings?
    var initialData: String?
    var initialMimeType: String?
    var initialEncoding: String?
    var initialBaseUrl: String?
    var previousStatusBarStyle = -1
    var initialUserScripts: [[String: Any]] = []
    var pullToRefreshInitialSettings: [String: Any?] = [:]

    public override func loadView() {
        let channel = FlutterMethodChannel(name: InAppBrowserWebViewController.METHOD_CHANNEL_NAME_PREFIX + id, binaryMessenger: SwiftFlutterPlugin.instance!.registrar!.messenger())
        channelDelegate = InAppBrowserChannelDelegate(channel: channel)
        
        var userScripts: [UserScript] = []
        for intialUserScript in initialUserScripts {
            userScripts.append(UserScript.fromMap(map: intialUserScript, windowId: windowId)!)
        }
        
        let preWebviewConfiguration = InAppWebView.preWKWebViewConfiguration(settings: webViewSettings)
        if let wId = windowId, let webViewTransport = InAppWebView.windowWebViews[wId] {
            webView = webViewTransport.webView
            webView!.contextMenu = contextMenu
            webView!.initialUserScripts = userScripts
        } else {
            webView = InAppWebView(id: nil,
                                   registrar: nil,
                                   frame: .zero,
                                   configuration: preWebviewConfiguration,
                                   contextMenu: contextMenu,
                                   userScripts: userScripts)
        }
        
        guard let webView = webView else {
            return
        }
        
        webView.inAppBrowserDelegate = self
        webView.id = id
        webView.channelDelegate = WebViewChannelDelegate(webView: webView, channel: channel)
        
        let pullToRefreshSettings = PullToRefreshSettings()
        let _ = pullToRefreshSettings.parse(settings: pullToRefreshInitialSettings)
        let pullToRefreshControl = PullToRefreshControl(registrar: SwiftFlutterPlugin.instance!.registrar!, id: id, settings: pullToRefreshSettings)
        webView.pullToRefreshControl = pullToRefreshControl
        pullToRefreshControl.delegate = webView
        pullToRefreshControl.prepare()
        
        prepareWebView()
        webView.windowCreated = true
        
        progressBar = UIProgressView(progressViewStyle: .bar)
        
        view = UIView()
        view.addSubview(webView)
        view.insertSubview(progressBar, aboveSubview: webView)
    }
    
    public override func viewDidLoad() {
        super.viewDidLoad()
        
        webView?.translatesAutoresizingMaskIntoConstraints = false
        progressBar.translatesAutoresizingMaskIntoConstraints = false
        
        if #available(iOS 9.0, *) {
            webView?.topAnchor.constraint(equalTo: self.view.topAnchor, constant: 0.0).isActive = true
            webView?.bottomAnchor.constraint(equalTo: self.view.bottomAnchor, constant: 0.0).isActive = true
            webView?.leadingAnchor.constraint(equalTo: self.view.leadingAnchor, constant: 0.0).isActive = true
            webView?.trailingAnchor.constraint(equalTo: self.view.trailingAnchor, constant: 0.0).isActive = true

            progressBar.topAnchor.constraint(equalTo: self.view.topAnchor, constant: 0.0).isActive = true
            progressBar.leadingAnchor.constraint(equalTo: self.view.leadingAnchor, constant: 0.0).isActive = true
            progressBar.trailingAnchor.constraint(equalTo: self.view.trailingAnchor, constant: 0.0).isActive = true
        } else {
            if let webView = webView {
                view.addConstraints([
                    NSLayoutConstraint(item: webView, attribute: .top, relatedBy: .equal, toItem: view, attribute: .top, multiplier: 1, constant: 0),
                    NSLayoutConstraint(item: webView, attribute: .bottom, relatedBy: .equal, toItem: view, attribute: .bottom, multiplier: 1, constant: 0),
                    NSLayoutConstraint(item: webView, attribute: .left, relatedBy: .equal, toItem: view, attribute: .left, multiplier: 1, constant: 0),
                    NSLayoutConstraint(item: webView, attribute: .right, relatedBy: .equal, toItem: view, attribute: .right, multiplier: 1, constant: 0)
                ])
            }
            if let progressBar = progressBar {
                view.addConstraints([
                    NSLayoutConstraint(item: progressBar, attribute: .top, relatedBy: .equal, toItem: view, attribute: .top, multiplier: 1, constant: 0),
                    NSLayoutConstraint(item: progressBar, attribute: .left, relatedBy: .equal, toItem: view, attribute: .left, multiplier: 1, constant: 0),
                    NSLayoutConstraint(item: progressBar, attribute: .right, relatedBy: .equal, toItem: view, attribute: .right, multiplier: 1, constant: 0)
                ])
            }
        }
        
        if let wId = windowId, let webViewTransport = InAppWebView.windowWebViews[wId] {
            webView?.load(webViewTransport.request)
        } else {
            if #available(iOS 11.0, *) {
                if let contentBlockers = webView?.settings?.contentBlockers, contentBlockers.count > 0 {
                    do {
                        let jsonData = try JSONSerialization.data(withJSONObject: contentBlockers, options: [])
                        let blockRules = String(data: jsonData, encoding: String.Encoding.utf8)
                        WKContentRuleListStore.default().compileContentRuleList(
                            forIdentifier: "ContentBlockingRules",
                            encodedContentRuleList: blockRules) { (contentRuleList, error) in

                                if let error = error {
                                    print(error.localizedDescription)
                                    return
                                }

                                let configuration = self.webView!.configuration
                                configuration.userContentController.add(contentRuleList!)

                                self.initLoad()
                        }
                        return
                    } catch {
                        print(error.localizedDescription)
                    }
                }
            }
            
            initLoad()
        }
    }
    
    public func initLoad() {
        if let initialFile = initialFile {
            do {
                try webView?.loadFile(assetFilePath: initialFile)
            }
            catch let error as NSError {
                dump(error)
            }
        }
        else if let initialData = initialData {
            let baseUrl = URL(string: initialBaseUrl!)!
            var allowingReadAccessToURL: URL? = nil
            if let allowingReadAccessTo = webView?.settings?.allowingReadAccessTo, baseUrl.scheme == "file" {
                allowingReadAccessToURL = URL(string: allowingReadAccessTo)
                if allowingReadAccessToURL?.scheme != "file" {
                    allowingReadAccessToURL = nil
                }
            }
            webView?.loadData(data: initialData, mimeType: initialMimeType!, encoding: initialEncoding!, baseUrl: baseUrl, allowingReadAccessTo: allowingReadAccessToURL)
        }
        else if let initialUrlRequest = initialUrlRequest {
            var allowingReadAccessToURL: URL? = nil
            if let allowingReadAccessTo = webView?.settings?.allowingReadAccessTo, let url = initialUrlRequest.url, url.scheme == "file" {
                allowingReadAccessToURL = URL(string: allowingReadAccessTo)
                if allowingReadAccessToURL?.scheme != "file" {
                    allowingReadAccessToURL = nil
                }
            }
            webView?.loadUrl(urlRequest: initialUrlRequest, allowingReadAccessTo: allowingReadAccessToURL)
        }
        
        channelDelegate?.onBrowserCreated()
    }
    
    public override func viewDidDisappear(_ animated: Bool) {
        dispose()
        super.viewDidDisappear(animated)
    }
    
    public override func viewWillDisappear (_ animated: Bool) {
        super.viewWillDisappear(animated)
    }
    
    public func prepareNavigationControllerBeforeViewWillAppear() {
        if let browserOptions = browserSettings {
            navigationController?.modalPresentationStyle = UIModalPresentationStyle(rawValue: browserOptions.presentationStyle)!
            navigationController?.modalTransitionStyle = UIModalTransitionStyle(rawValue: browserOptions.transitionStyle)!
        }
    }
    
    public func prepareWebView() {
        webView?.settings = webViewSettings
        webView?.prepare()
              
        searchBar = UISearchBar()
        searchBar.keyboardType = .URL
        searchBar.sizeToFit()
        searchBar.delegate = self
        navigationItem.titleView = searchBar
        
        let spacer = UIBarButtonItem(barButtonSystemItem: .flexibleSpace, target: nil, action: nil)
        reloadButton = UIBarButtonItem(barButtonSystemItem: .refresh, target: self, action: #selector(reload))
        shareButton = UIBarButtonItem(barButtonSystemItem: .action, target: self, action: #selector(share))
        forwardButton = UIBarButtonItem(title: "\u{203A}", style: .plain, target: self, action: #selector(goForward))
        forwardButton.isEnabled = false
        backButton = UIBarButtonItem(title: "\u{2039}", style: .plain, target: self, action: #selector(goBack))
        backButton.isEnabled = false
        
        for state: UIControl.State in [.normal, .disabled, .highlighted, .selected] {
            forwardButton.setTitleTextAttributes([
                NSAttributedString.Key.font: UIFont.systemFont(ofSize: 50.0),
                NSAttributedString.Key.baselineOffset: 2.5
            ], for: state)
            backButton.setTitleTextAttributes([
                NSAttributedString.Key.font: UIFont.systemFont(ofSize: 50.0),
                NSAttributedString.Key.baselineOffset: 2.5
            ], for: state)
        }
        
        toolbarItems = [backButton, spacer, forwardButton, spacer, shareButton, spacer, reloadButton]
        
        if let browserOptions = browserSettings {
            if !browserOptions.hideToolbarTop {
                navigationController?.navigationBar.isHidden = false
                if browserOptions.hideUrlBar {
                    searchBar.isHidden = true
                }
                if let bgColor = browserOptions.toolbarTopBackgroundColor, !bgColor.isEmpty {
                    navigationController?.navigationBar.backgroundColor = UIColor(hexString: bgColor)
                }
                if let barTintColor = browserOptions.toolbarTopBarTintColor, !barTintColor.isEmpty {
                    navigationController?.navigationBar.barTintColor = UIColor(hexString: barTintColor)
                }
                if let tintColor = browserOptions.toolbarTopTintColor, !tintColor.isEmpty {
                    navigationController?.navigationBar.barTintColor = UIColor(hexString: tintColor)
                }
                navigationController?.navigationBar.isTranslucent = browserOptions.toolbarTopTranslucent
            }
            else {
                navigationController?.navigationBar.isHidden = true
            }
            
            if !browserOptions.hideToolbarBottom {
                navigationController?.isToolbarHidden = false
                if let bgColor = browserOptions.toolbarBottomBackgroundColor, !bgColor.isEmpty {
                    navigationController?.toolbar.barTintColor = UIColor(hexString: bgColor)
                }
                if let tintColor = browserOptions.toolbarBottomTintColor, !tintColor.isEmpty {
                    navigationController?.toolbar.tintColor = UIColor(hexString: tintColor)
                }
                navigationController?.toolbar.isTranslucent = false
            }
            else {
                navigationController?.isToolbarHidden = true
            }
            
            if let closeButtonCaption = browserOptions.closeButtonCaption, !closeButtonCaption.isEmpty {
                closeButton = UIBarButtonItem(title: closeButtonCaption, style: .plain, target: self, action: #selector(close))
            } else {
                setDefaultCloseButton()
            }
            
            if let closeButtonColor = browserOptions.closeButtonColor, !closeButtonColor.isEmpty {
                closeButton.tintColor = UIColor(hexString: closeButtonColor)
            }
            
            if browserOptions.hideProgressBar {
                progressBar.isHidden = true
            }
        }
        
        navigationItem.rightBarButtonItem = closeButton
    }
    
    func setDefaultCloseButton() {
        if closeButton != nil {
            closeButton.target = nil
            closeButton.action = nil
        }
        if #available(iOS 13.0, *) {
            closeButton = UIBarButtonItem(barButtonSystemItem: .close, target: self, action: #selector(close))
        } else {
            closeButton = UIBarButtonItem(barButtonSystemItem: .cancel, target: self, action: #selector(close))
        }
    }
    
    public func didChangeTitle(title: String?) {
        guard let _ = title else {
            return
        }
    }
    
    public func didStartNavigation(url: URL?) {
        forwardButton.isEnabled = webView?.canGoForward ?? false
        backButton.isEnabled = webView?.canGoBack ?? false
        progressBar.setProgress(0.0, animated: false)
        guard let url = url else {
            return
        }
        searchBar.text = url.absoluteString
    }
    
    public func didUpdateVisitedHistory(url: URL?) {
        forwardButton.isEnabled = webView?.canGoForward ?? false
        backButton.isEnabled = webView?.canGoBack ?? false
        guard let url = url else {
            return
        }
        searchBar.text = url.absoluteString
    }
    
    public func didFinishNavigation(url: URL?) {
        forwardButton.isEnabled = webView?.canGoForward ?? false
        backButton.isEnabled = webView?.canGoBack ?? false
        progressBar.setProgress(0.0, animated: false)
        guard let url = url else {
            return
        }
        searchBar.text = url.absoluteString
    }
    
    public func didFailNavigation(url: URL?, error: Error) {
        forwardButton.isEnabled = webView?.canGoForward ?? false
        backButton.isEnabled = webView?.canGoBack ?? false
        progressBar.setProgress(0.0, animated: false)
    }
    
    public func didChangeProgress(progress: Double) {
        progressBar.setProgress(Float(progress), animated: true)
    }
    
    public func searchBarSearchButtonClicked(_ searchBar: UISearchBar) {
        guard let text = searchBar.text,
              let urlEncoded = text.addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed),
              let url = URL(string: urlEncoded) else {
            return
        }
        let request = URLRequest(url: url)
        webView?.load(request)
    }
    
    public func show(completion: (() -> Void)? = nil) {
        if let navController = navigationController as? InAppBrowserNavigationController, let window = navController.tmpWindow {
            window.alpha = 0.0
            window.isHidden = false
            window.makeKeyAndVisible()
            UIView.animate(withDuration: 0.2) {
                window.alpha = 1.0
                completion?()
            }
        }
    }

    public func hide(completion: (() -> Void)? = nil) {
        if let navController = navigationController as? InAppBrowserNavigationController, let window = navController.tmpWindow {
            window.alpha = 1.0
            UIView.animate(withDuration: 0.2) {
                window.alpha = 0.0
            } completion: { (finished) in
                if finished {
                    window.isHidden = true
                    UIApplication.shared.delegate?.window??.makeKeyAndVisible()
                    completion?()
                }
            }
        }
    }
    
    @objc public func reload() {
        webView?.reload()
        didUpdateVisitedHistory(url: webView?.url)
    }
    
    @objc public func share() {
        let vc = UIActivityViewController(activityItems: [webView?.url?.absoluteString ?? ""], applicationActivities: [])
        present(vc, animated: true, completion: nil)
    }
    
    public func close(completion: (() -> Void)? = nil) {
        if (navigationController?.responds(to: #selector(getter: navigationController?.presentingViewController)))! {
            navigationController?.presentingViewController?.dismiss(animated: true, completion: {() -> Void in
                completion?()
            })
        }
        else {
            navigationController?.parent?.dismiss(animated: true, completion: {() -> Void in
                completion?()
            })
        }
    }
    
    @objc public func close() {
        if (navigationController?.responds(to: #selector(getter: navigationController?.presentingViewController)))! {
            navigationController?.presentingViewController?.dismiss(animated: true, completion: nil)
        }
        else {
            navigationController?.parent?.dismiss(animated: true, completion: nil)
        }
    }
    
    @objc public func goBack() {
        if let webView = webView, webView.canGoBack {
            webView.goBack()
        }
    }
    
    @objc public func goForward() {
        if let webView = webView, webView.canGoForward {
            webView.goForward()
        }
    }
    
    @objc public func goBackOrForward(steps: Int) {
        webView?.goBackOrForward(steps: steps)
    }

    public func setSettings(newSettings: InAppBrowserSettings, newSettingsMap: [String: Any]) {
        let newInAppWebViewSettings = InAppWebViewSettings()
        let _ = newInAppWebViewSettings.parse(settings: newSettingsMap)
        webView?.setSettings(newSettings: newInAppWebViewSettings, newSettingsMap: newSettingsMap)
        
        if newSettingsMap["hidden"] != nil, browserSettings?.hidden != newSettings.hidden {
            if newSettings.hidden {
                hide()
            }
            else {
                show()
            }
        }

        if newSettingsMap["hideUrlBar"] != nil, browserSettings?.hideUrlBar != newSettings.hideUrlBar {
            searchBar.isHidden = newSettings.hideUrlBar
        }

        if newSettingsMap["hideToolbarTop"] != nil, browserSettings?.hideToolbarTop != newSettings.hideToolbarTop {
            navigationController?.navigationBar.isHidden = newSettings.hideToolbarTop
        }

        if newSettingsMap["toolbarTopBackgroundColor"] != nil, browserSettings?.toolbarTopBackgroundColor != newSettings.toolbarTopBackgroundColor {
            if let bgColor = newSettings.toolbarTopBackgroundColor, !bgColor.isEmpty {
                navigationController?.navigationBar.backgroundColor = UIColor(hexString: bgColor)
            } else {
                navigationController?.navigationBar.backgroundColor = nil
            }
        }
        
        if newSettingsMap["toolbarTopBarTintColor"] != nil, browserSettings?.toolbarTopBarTintColor != newSettings.toolbarTopBarTintColor {
            if let barTintColor = newSettings.toolbarTopBarTintColor, !barTintColor.isEmpty {
                navigationController?.navigationBar.barTintColor = UIColor(hexString: barTintColor)
            } else {
                navigationController?.navigationBar.barTintColor = nil
            }
        }
        
        if newSettingsMap["toolbarTopTintColor"] != nil, browserSettings?.toolbarTopTintColor != newSettings.toolbarTopTintColor {
            if let tintColor = newSettings.toolbarTopTintColor, !tintColor.isEmpty {
                navigationController?.navigationBar.tintColor = UIColor(hexString: tintColor)
            } else {
                navigationController?.navigationBar.tintColor = nil
            }
        }

        if newSettingsMap["hideToolbarBottom"] != nil, browserSettings?.hideToolbarBottom != newSettings.hideToolbarBottom {
            navigationController?.isToolbarHidden = !newSettings.hideToolbarBottom
        }

        if newSettingsMap["toolbarBottomBackgroundColor"] != nil, browserSettings?.toolbarBottomBackgroundColor != newSettings.toolbarBottomBackgroundColor {
            if let bgColor = newSettings.toolbarBottomBackgroundColor, !bgColor.isEmpty {
                navigationController?.toolbar.barTintColor = UIColor(hexString: bgColor)
            } else {
                navigationController?.toolbar.barTintColor = nil
            }
        }
        
        if newSettingsMap["toolbarBottomTintColor"] != nil, browserSettings?.toolbarBottomTintColor != newSettings.toolbarBottomTintColor {
            if let tintColor = newSettings.toolbarBottomTintColor, !tintColor.isEmpty {
                navigationController?.toolbar.tintColor = UIColor(hexString: tintColor)
            } else {
                navigationController?.toolbar.tintColor = nil
            }
        }

        if newSettingsMap["toolbarTopTranslucent"] != nil, browserSettings?.toolbarTopTranslucent != newSettings.toolbarTopTranslucent {
            navigationController?.navigationBar.isTranslucent = newSettings.toolbarTopTranslucent
        }
        
        if newSettingsMap["toolbarBottomTranslucent"] != nil, browserSettings?.toolbarBottomTranslucent != newSettings.toolbarBottomTranslucent {
            navigationController?.toolbar.isTranslucent = newSettings.toolbarBottomTranslucent
        }

        if newSettingsMap["closeButtonCaption"] != nil, browserSettings?.closeButtonCaption != newSettings.closeButtonCaption {
            if let closeButtonCaption = newSettings.closeButtonCaption, !closeButtonCaption.isEmpty {
                if let oldTitle = closeButton.title, !oldTitle.isEmpty {
                    closeButton.title = closeButtonCaption
                } else {
                    closeButton.target = nil
                    closeButton.action = nil
                    closeButton = UIBarButtonItem(title: closeButtonCaption, style: .plain, target: self, action: #selector(close))
                }
            } else {
                setDefaultCloseButton()
            }
        }

        if newSettingsMap["closeButtonColor"] != nil, browserSettings?.closeButtonColor != newSettings.closeButtonColor {
            if let tintColor = newSettings.closeButtonColor, !tintColor.isEmpty {
                closeButton.tintColor = UIColor(hexString: tintColor)
            } else {
                closeButton.tintColor = nil
            }
        }
        
        if newSettingsMap["presentationStyle"] != nil, browserSettings?.presentationStyle != newSettings.presentationStyle {
            navigationController?.modalPresentationStyle = UIModalPresentationStyle(rawValue: newSettings.presentationStyle)!
        }
        
        if newSettingsMap["transitionStyle"] != nil, browserSettings?.transitionStyle != newSettings.transitionStyle {
            navigationController?.modalTransitionStyle = UIModalTransitionStyle(rawValue: newSettings.transitionStyle)!
        }
        
        if newSettingsMap["hideProgressBar"] != nil, browserSettings?.hideProgressBar != newSettings.hideProgressBar {
            progressBar.isHidden = newSettings.hideProgressBar
        }
        
        browserSettings = newSettings
        webViewSettings = newInAppWebViewSettings
    }
    
    public func getSettings() -> [String: Any?]? {
        let webViewSettingsMap = webView?.getSettings()
        if (self.browserSettings == nil || webViewSettingsMap == nil) {
            return nil
        }
        var settingsMap = self.browserSettings!.getRealSettings(obj: self)
        settingsMap.merge(webViewSettingsMap!, uniquingKeysWith: { (current, _) in current })
        return settingsMap
    }
    
    public func dispose() {
        channelDelegate?.onExit()
        channelDelegate?.dispose()
        channelDelegate = nil
        webView?.dispose()
        webView = nil
        view = nil
        if previousStatusBarStyle != -1 {
            UIApplication.shared.statusBarStyle = UIStatusBarStyle(rawValue: previousStatusBarStyle)!
        }
        transitioningDelegate = nil
        searchBar.delegate = nil
        closeButton.target = nil
        forwardButton.target = nil
        backButton.target = nil
        reloadButton.target = nil
        shareButton.target = nil
    }
    
    deinit {
        debugPrint("InAppBrowserWebViewController - dealloc")
        dispose()
    }
}