//  _____ _
// |_   _| |_  _ _ ___ ___ _ __  __ _
//   | | | ' \| '_/ -_) -_) '  \/ _` |_
//   |_| |_||_|_| \___\___|_|_|_\__,_(_)
//
// Threema iOS Client
// Copyright (c) 2019-2020 Threema GmbH
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License, version 3,
// as published by the Free Software Foundation.
//
// 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 Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.

import Foundation

@objc class CompanyDirectoryViewController: ThemedViewController {
    
    @IBOutlet weak var tableView: UITableView!
    @IBOutlet weak var searchBar: SearchBarWithoutCancelButton!
    @IBOutlet weak var noEntriesFoundView: UIView!
    @IBOutlet weak var noEntriesFoundTitleLabel: UILabel!
    @IBOutlet weak var noEntriesFoundDescriptionLabel: UILabel!
    @IBOutlet weak var activeFiltersView: UIStackView!
    @IBOutlet weak var scrollView: UIScrollView!
    
    @objc var addContactActive: Bool = true
    var filterArray: [String] = [String]()

    private var contactsWithSections: [[CompanyDirectoryContact]] = [[CompanyDirectoryContact]]()
    private var sectionTitles: [String] = [String]()
    private var allSectionTitles: [String] = [String]()
    private var nextPage: Int = 0
    private var showLoadMore: Bool = false
    private var searchString: String = ""
    private var resultArray: [CompanyDirectoryContact] = [CompanyDirectoryContact]()    
    
    private let collation = UILocalizedIndexedCollation.current()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        searchBar.sizeToFit()
        searchBar.placeholder = BundleUtil.localizedString(forKey: "companydirectory_placeholder")
        
        tableView.setupAutoAdjust()
        
        noEntriesFoundTitleLabel.text = BundleUtil.localizedString(forKey: "companydirectory_noentries_title")
        noEntriesFoundDescriptionLabel.text = BundleUtil.localizedString(forKey: "companydirectory_noentries_description")
        
        self.title = MyIdentityStore.shared()?.companyName
    }
    
    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        
        if addContactActive == false {
            navigationItem.leftBarButtonItem = UIBarButtonItem.init(barButtonSystemItem: .cancel, target: self, action: #selector(cancel))
        }
        navigationItem.rightBarButtonItem = UIBarButtonItem.init(image: BundleUtil.imageNamed("Filter"), style: .plain, target: self, action: #selector(filter))
        
        self.searchBar.becomeFirstResponder()
        performSearch()
    }
    
    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        
        NSObject.cancelPreviousPerformRequests(withTarget: self, selector: #selector(performSearch), object: nil)
    }
    
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        if segue.identifier == "ShowFilterSegue" {
            if let destinationVC = segue.destination as? CompanyDirectoryCategoryViewController {
                destinationVC.companyDirectoryViewController = self
            }
        }
    }

    
    override func refresh() {
        super.refresh()
        
        setupColors()
        updateNoEntriesFound()
        setupFiltersView()
        tableView.reloadData()
    }
    
    func setupColors() {
        Colors.update(searchBar)
        Colors.update(tableView)
        
        noEntriesFoundTitleLabel.textColor = Colors.fontNormal()
        noEntriesFoundDescriptionLabel.textColor = Colors.fontLight()
    }
    
    func updateNoEntriesFound() {
        if contactsWithSections.count > 0 {
            tableView.tableFooterView = nil
        } else {
            tableView.tableFooterView = noEntriesFoundView
            showLoadMore = false
        }
    }
    
    @objc private func performSearch() {
        guard let query = searchBar.text, query.trimmingCharacters(in: .whitespaces) != "" else {
            contactsWithSections.removeAll()
            sectionTitles.removeAll()
            resultArray.removeAll()
            refresh()
            return
        }
        searchBar.isLoading = true
        
        // call api to get the results
        contactsWithSections.removeAll()
        sectionTitles.removeAll()
        resultArray.removeAll()
        nextPage = 0
        searchString = query
        
        ServerAPIConnector().search(inDirectory: query, categories: filterArray, page: Int32(nextPage), for: LicenseStore.shared(), for: MyIdentityStore.shared(), onCompletion: { (contacts, paging) in
            self.showLoadMore = false
            if contacts != nil {
                if contacts!.count > 0 {
                    for dict in contacts! {
                        let contact = CompanyDirectoryContact.init(dictionary: dict as! [AnyHashable : Any?])
                        self.resultArray.append(contact)
                    }
                    if UserSettings.shared().sortOrderFirstName == true {
                        let (arrayContacts, arrayTitles, allSectionTitles) = self.collation.partitionObjects(array: self.resultArray, collationStringSelector: #selector(getter: CompanyDirectoryContact.first))
                        self.contactsWithSections = arrayContacts as! [[CompanyDirectoryContact]]
                        self.sectionTitles = arrayTitles
                        self.allSectionTitles = allSectionTitles
                    } else {
                        let (arrayContacts, arrayTitles, allSectionTitles) = self.collation.partitionObjects(array: self.resultArray, collationStringSelector: #selector(getter: CompanyDirectoryContact.last))
                        self.contactsWithSections = arrayContacts as! [[CompanyDirectoryContact]]
                        self.sectionTitles = arrayTitles
                        self.allSectionTitles = allSectionTitles
                    }
                    if let next = paging?["next"] as? Int {
                        if let total = paging?["total"] as? Int {
                            if total != self.resultArray.count {
                                self.nextPage = next
                                self.showLoadMore = true
                            }
                        }
                    }
                }
            }
            
            self.refresh()
            self.searchBar.isLoading = false
        }) { (error) in
            if let theError = (error as NSError?) {
                if theError.code == 100 {
                    UIAlertTemplate.showAlert(owner: self, title: BundleUtil.localizedString(forKey: "cannot_connect_title"), message: BundleUtil.localizedString(forKey: "cannot_connect_message"))
                }
            }
            
            self.refresh()
            self.searchBar.isLoading = false
        }
    }
    
    private func loadMore(cell: UITableViewCell) {
        let activityView = UIActivityIndicatorView.init(style: .gray)
        switch Colors.getTheme() {
        case ColorThemeDark, ColorThemeDarkWork:
            activityView.style = .white
            break
        case ColorThemeUndefined, ColorThemeLight, ColorThemeLightWork:
            activityView.style = .gray
            break
        default:
            activityView.style = .gray
            break
        }
        activityView.startAnimating()
        cell.accessoryView = activityView
        ServerAPIConnector().search(inDirectory: searchString, categories: filterArray, page: Int32(nextPage), for: LicenseStore.shared(), for: MyIdentityStore.shared(), onCompletion: { (contacts, paging) in
            self.showLoadMore = false
            if contacts != nil {
                if contacts!.count > 0 {
                    for dict in contacts! {
                        let contact = CompanyDirectoryContact.init(dictionary: dict as! [AnyHashable : Any?])
                        self.resultArray.append(contact)
                    }
                    if UserSettings.shared().sortOrderFirstName == true {
                        let (arrayContacts, arrayTitles, allSectionTitles) = self.collation.partitionObjects(array: self.resultArray, collationStringSelector: #selector(getter: CompanyDirectoryContact.first))
                        self.contactsWithSections = arrayContacts as! [[CompanyDirectoryContact]]
                        self.sectionTitles = arrayTitles
                        self.allSectionTitles = allSectionTitles
                    } else {
                        let (arrayContacts, arrayTitles, allSectionTitles) = self.collation.partitionObjects(array: self.resultArray, collationStringSelector: #selector(getter: CompanyDirectoryContact.last))
                        self.contactsWithSections = arrayContacts as! [[CompanyDirectoryContact]]
                        self.sectionTitles = arrayTitles
                        self.allSectionTitles = allSectionTitles
                    }
                    if let next = paging?["next"] as? Int {
                        if let total = paging?["total"] as? Int {
                            if total != self.resultArray.count {
                                self.nextPage = next
                                self.showLoadMore = true
                            }
                        }
                    }
                }
            }
            activityView.stopAnimating()
            cell.accessoryView = nil
            self.refresh()
            self.searchBar.isLoading = false
        }) { (error) in
            activityView.stopAnimating()
            cell.accessoryView = nil
            self.searchBar.isLoading = false
        }
    }
    
    private func setupFiltersView() {
        if filterArray.count > 0 {
            self.scrollView.frame = CGRect.init(x: self.scrollView.frame.origin.x, y: self.scrollView.frame.origin.y, width: self.scrollView.frame.size.width, height: 44.0)
            self.scrollView.setNeedsLayout()
            self.scrollView.layoutIfNeeded()
        } else {
            self.scrollView.frame = CGRect.init(x: self.scrollView.frame.origin.x, y: self.scrollView.frame.origin.y, width: self.scrollView.frame.size.width, height: 0)
            self.scrollView.setNeedsLayout()
            self.scrollView.layoutIfNeeded()
        }
        
        for tempView in activeFiltersView.subviews {
            tempView.removeFromSuperview()
        }
        activeFiltersView.layoutIfNeeded()
        
        var i = 0
        let catDict = MyIdentityStore.shared().directoryCategories as! Dictionary<String, String>
        for category in filterArray {
            let filterLabel = createFilterLabel(text: catDict[category]!, index: i)
            activeFiltersView.addArrangedSubview(filterLabel)
            i += 1
        }
    }
    
    private func createFilterLabel(text: String, index: Int) -> UIStackView {
        let textWidth = text.widthOfString(usingFont: UIFont.preferredFont(forTextStyle: UIFont.TextStyle.footnote))
        let buttonWidth: CGFloat = 23.0
        let padding: CGFloat = 2.0
        
        let stackView = UIStackView.init(frame: CGRect.init(x: 0.0, y: 0.0, width: textWidth + buttonWidth + (padding * 2), height: activeFiltersView.frame.size.height))
        stackView.axis = .horizontal
        stackView.distribution = .equalSpacing
        stackView.spacing = 0
        
        let textlabel = UILabel.init(frame: CGRect.init(x: 0.0, y: 0.0, width: textWidth, height: 20.0))
        textlabel.textColor = Colors.fontInverted()
        textlabel.font = UIFont.preferredFont(forTextStyle: UIFont.TextStyle.footnote)
        textlabel.text = text
        stackView.addArrangedSubview(textlabel)
        
        let button = UIButton(type: .custom)
        button.frame = CGRect(x: 0.0, y: 0.0, width: buttonWidth, height: buttonWidth)
        button.backgroundColor = .clear
        button.layer.cornerRadius = CGFloat(button.frame.size.width)/CGFloat(2.0)
        button.setImage(UIImage(named: "CloseCategory", in: .white), for: .normal)
        button.tag = index
        button.imageView?.contentMode = .scaleAspectFit
        button.addTarget(self, action: #selector(removeTag(_:)), for: .touchUpInside)
        stackView.addArrangedSubview(button)
        
        let widthContraints =  NSLayoutConstraint(item: button, attribute: NSLayoutConstraint.Attribute.width, relatedBy: NSLayoutConstraint.Relation.equal, toItem: nil, attribute: NSLayoutConstraint.Attribute.notAnAttribute, multiplier: 1, constant: buttonWidth)
        NSLayoutConstraint.activate([widthContraints])


        stackView.layoutIfNeeded()
        
        let size = CGSize(width: textWidth, height: 1000)
        let options = NSStringDrawingOptions.usesFontLeading.union(.usesLineFragmentOrigin)
        let attributes = [NSAttributedString.Key.font: textlabel.font]
        let rectangleHeight = String(text).boundingRect(with: size, options: options, attributes: attributes as [NSAttributedString.Key : Any], context: nil).height

        let backgroundFrame = CGRect.init(x: stackView.frame.origin.x - (padding * 3), y: ((stackView.frame.size.height - rectangleHeight) / 2) - padding, width: stackView.frame.size.width + (padding * 2), height: rectangleHeight + (padding * 2))
        let backgroundView = UIView.init(frame: backgroundFrame)
        backgroundView.layer.cornerRadius = 5
        backgroundView.backgroundColor = Colors.backgroundInverted()
        
        stackView.insertSubview(backgroundView, at: 0)
        
        return stackView
    }
    
    @objc private func cancel() {
        self.dismiss(animated: true, completion: nil)
    }
    
    @objc private func filter() {
        self.performSegue(withIdentifier: "ShowFilterSegue", sender: self)
    }
    
    @objc private func removeTag(_ sender: AnyObject) {
        filterArray.remove(at: (sender.tag))
        performSearch()
    }
}

extension CompanyDirectoryViewController: UITableViewDataSource {
    
    func numberOfSections(in tableView: UITableView) -> Int {
        if showLoadMore {
            return sectionTitles.count + 1
        }
        return sectionTitles.count
    }
    
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        if showLoadMore && section == sectionTitles.count {
            return 1
        }
        return contactsWithSections[section].count
    }
    
    func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
        if showLoadMore && indexPath.section == sectionTitles.count {
            return 50.0
        }
        return UITableView.automaticDimension
    }
    
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        if showLoadMore && indexPath.section == sectionTitles.count {
            let cell:UITableViewCell = tableView.dequeueReusableCell(withIdentifier: "LoadMoreCell", for: indexPath)
            cell.textLabel?.text = BundleUtil.localizedString(forKey: "loadMore")
            let image = UIImage.init(named: "ArrowDown", in: Colors.fontLight())
            cell.imageView?.image = image?.resizedImage(newSize: CGSize.init(width: 25.0, height: 25.0))
            cell.accessoryView = nil
            return cell
        } else {
            let cell:CompanyDirectoryContactCell = tableView.dequeueReusableCell(withIdentifier: "CompanyDirectoryContactCell", for: indexPath) as! CompanyDirectoryContactCell
            let contact = contactsWithSections[indexPath.section][indexPath.row]
            cell.addContactActive = addContactActive
            cell.contact = contact
            return cell
        }
    }
    
    func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath) {
        Colors.update(cell)
        if cell.isKind(of: CompanyDirectoryContactCell.self) {
            (cell as! CompanyDirectoryContactCell).setupColors()
        }
    }
    
    func sectionIndexTitles(for tableView: UITableView) -> [String]? {
        return UILocalizedIndexedCollation.current().sectionIndexTitles
    }
    
    func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
        if showLoadMore && section == sectionTitles.count {
            return ""
        }
        return sectionTitles[section]
    }
    
    func tableView(_ tableView: UITableView, sectionForSectionIndexTitle title: String, at index: Int) -> Int {
        if title == "*" {
            return sectionTitles.count
        }
        
        if sectionTitles.contains(title) == true {
            return sectionTitles.firstIndex(of: title) ?? 0
        } else {
            var tempIndex:Int = 0
            for str in allSectionTitles {
                if sectionTitles.contains(str) == true {
                    tempIndex += 1
                }
                if str == title {
                    return tempIndex - 1
                }
            }
            return 0
        }
    }
}

extension CompanyDirectoryViewController: UITableViewDelegate {
    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        if nextPage > 0 && indexPath.section == sectionTitles.count {
            let cell = tableView.cellForRow(at: indexPath)
            let activityIndicator = UIActivityIndicatorView.init(style: .white)
            switch Colors.getTheme() {
            case ColorThemeDark, ColorThemeDarkWork:
                activityIndicator.style = .white
                break
            case ColorThemeUndefined, ColorThemeLight, ColorThemeLightWork:
                activityIndicator.style = .gray
                break
            default:
                activityIndicator.style = .gray
                break
            }
            activityIndicator.startAnimating()
            cell?.accessoryView = activityIndicator
            loadMore(cell: cell!)
        } else {
            let directoryContact = contactsWithSections[indexPath.section][indexPath.row]
            let contact = ContactStore.shared()?.addWorkContact(withIdentity: directoryContact.id, publicKey: directoryContact.pk, firstname: directoryContact.first, lastname: directoryContact.last)
            // show chat
            if contact != nil {
                navigationController?.dismiss(animated: true, completion: {
                    let info = [kKeyContact: contact!, kKeyForceCompose: true] as [String : Any]
                    NotificationCenter.default.post(name: NSNotification.Name(rawValue: kNotificationShowConversation), object: nil, userInfo: info)
                })
            }
        }
    }
}

extension CompanyDirectoryViewController: UISearchBarDelegate {
    func searchBarSearchButtonClicked(_ searchBar: UISearchBar) {
        //here you should call the function which will update your data source and reload table view (or other UI that you have)
        performSearch()
    }
    
    func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) {
        NSObject.cancelPreviousPerformRequests(withTarget: self, selector: #selector(performSearch), object: nil)
        if searchText.count >= 3 {
            perform(#selector(performSearch), with: nil, afterDelay: 0.75)
        } else {
            contactsWithSections.removeAll()
            sectionTitles.removeAll()
            resultArray.removeAll()
            refresh()
        }
    }
    
    func searchBarCancelButtonClicked(_ searchBar: UISearchBar) {
        NSObject.cancelPreviousPerformRequests(withTarget: self, selector: #selector(performSearch), object: nil)
    }
}

class SearchBarWithoutCancelButton:UISearchBar {
    override func layoutSubviews() {
        super.layoutSubviews()
        self.setShowsCancelButton(false, animated: false)
    }
    
    public var textField: UITextField? {
        let subViews = subviews.flatMap { $0.subviews }
        guard let textField = (subViews.filter { $0 is UITextField }).first as? UITextField else {
            return nil
        }
        return textField
    }
    
    public var activityIndicator: UIActivityIndicatorView? {
        return textField?.leftView?.subviews.compactMap{ $0 as? UIActivityIndicatorView }.first
    }
    
    var isLoading: Bool {
        get {
            return activityIndicator != nil
        } set {
            if newValue {
                if activityIndicator == nil {
                    let newActivityIndicator: UIActivityIndicatorView
                    switch Colors.getTheme() {
                    case ColorThemeDark, ColorThemeDarkWork:
                        newActivityIndicator = UIActivityIndicatorView(style: .white)
                        newActivityIndicator.backgroundColor = UIColor.init(red: 32.0/255.0, green: 32.0/255.0, blue: 29.0/255.0, alpha: 1.0)
                        break
                    case ColorThemeUndefined, ColorThemeLight, ColorThemeLightWork:
                        newActivityIndicator = UIActivityIndicatorView(style: .gray)
                        newActivityIndicator.backgroundColor = .white
                        break
                    default:
                        newActivityIndicator = UIActivityIndicatorView(style: .gray)
                        newActivityIndicator.backgroundColor = .white
                        break
                    }
                    
                    newActivityIndicator.startAnimating()
                    textField?.leftView?.addSubview(newActivityIndicator)
                    let leftViewSize = textField?.leftView?.frame.size ?? CGSize.zero
                    newActivityIndicator.center = CGPoint(x: leftViewSize.width/2, y: leftViewSize.height/2)
                }
            } else {
                activityIndicator?.removeFromSuperview()
            }
        }
    }
}

extension UITableView {
    func setupAutoAdjust() {
        NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardshown), name: UIResponder.keyboardWillShowNotification, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardhide), name: UIResponder.keyboardWillHideNotification, object: nil)
    }
    @objc func keyboardshown(_ notification:Notification) {
        if let keyboardSize = (notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
            self.fitContentInset(inset: UIEdgeInsets(top: 0, left: 0, bottom: keyboardSize.height, right: 0))
        }
    }
    @objc func keyboardhide(_ notification:Notification) {
        if ((notification.userInfo?[UIResponder.keyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue) != nil {
            self.fitContentInset(inset: .zero)
        }
        
    }
    func fitContentInset(inset:UIEdgeInsets!) {
        self.contentInset = inset
        self.scrollIndicatorInsets = inset
    }
}

extension UILocalizedIndexedCollation {
    //func for partition array in sections
    func partitionObjects(array:[AnyObject], collationStringSelector:Selector) -> ([AnyObject], [String], [String]) {
        var unsortedSections = [[AnyObject]]()
        //1. Create a array to hold the data for each section
        for _ in self.sectionTitles {
            unsortedSections.append([]) //appending an empty array
        }
        //2. Put each objects into a section
        for item in array {
            let index:Int = self.section(for: item, collationStringSelector:collationStringSelector)
            unsortedSections[index].append(item)
        }
        //3. sorting the array of each section
        var activeSectionTitles = [String]()
        var sections = [AnyObject]()
        for index in 0 ..< unsortedSections.count { if unsortedSections[index].count > 0 {
            activeSectionTitles.append(self.sectionTitles[index])
            sections.append(self.sortedArray(from: unsortedSections[index], collationStringSelector: collationStringSelector) as AnyObject)
            }
        }
        return (sections, activeSectionTitles, sectionTitles)

    }
}

extension String {
    
    func widthOfString(usingFont font: UIFont) -> CGFloat {
        let fontAttributes = [NSAttributedString.Key.font: font]
        let size = self.size(withAttributes: fontAttributes)
        return size.width
    }
}