//
//  TableView.swift
//  CapFinder
//
//  Created by User on 22.04.18.
//  Copyright © 2018 User. All rights reserved.
//

import UIKit

class TableView: UIViewController {

    @IBOutlet weak var table: UITableView!
    
    @IBOutlet weak var searchBar: UISearchBar!
    
    @IBOutlet weak var searchBarConstraint: NSLayoutConstraint!
    
    @IBOutlet weak var imageButtonConstraint: NSLayoutConstraint!
    
    private let imageViewDistance: CGFloat = 90

    override var preferredStatusBarStyle: UIStatusBarStyle {
        return .lightContent
    }

    // MARK: - Life cycle

    override func viewDidLoad() {
        super.viewDidLoad()

        Classifier.shared.delegate = self
        Cap.delegate = self
        tableViewSetup()
        imageButtonSetup()
        searchBar.delegate = self
        searchBarSetup()
        self.imageViewContraint.constant = imageViewDistance
        DropboxController.shared.initializeDatabase()
    }

    
    private var caps = [Cap]()

    private var shownCaps = [Cap]()
    
    private var sortType: SortCriteria = .id
    
    private var sortAscending: Bool = false

    /// This will be set to a cap id when adding a cap to it
    private var capToAddImageTo: Cap?
    
    // MARK: - Sort

    /**
     Resets the cap list to its original state, discarding any
     previous sorting.
     */
    private func showAllCapsByDescendingId() {
        sortType = .id
        sortAscending = false
        showAllCapsAndScrollToTop()
    }

    /**
     Display all caps in the table, and scrolls to the top
     */
    private func showAllCapsAndScrollToTop() {
        caps = Cap.capList(sortedBy: sortType, ascending: sortAscending)
        shownCaps = caps
        table.reloadData()
        tableViewScrollToTop()
    }
    
    // MARK: - TableView

     private func tableViewSetup() {
        table.dataSource = self
        table.delegate = self
        table.rowHeight = 100
    }

    /**
     Scroll the table view to the top
     */
    private func tableViewScrollToTop() {
        guard shownCaps.count > 0 else { return }
        let path = IndexPath(row: 0, section: 0)
        table.scrollToRow(at: path, at: .top, animated: true)
    }

    private func rename(cap: Cap, at indexPath: IndexPath) {

        let alertController = UIAlertController(
            title: "Enter name",
            message: "Choose a name for the image",
            preferredStyle: .alert,
            blurStyle: .dark)

        alertController.addTextField { textField in
            textField.text = cap.name
            textField.placeholder = "Cap name"
            textField.keyboardType = .default
        }

        let action = UIAlertAction(title: "Save", style: .default) { _ in
            guard let name = alertController.textFields?.first?.text else {
                return
            }
            cap.name = name
            self.table.reloadRows(at: [indexPath], with: .none)
        }
        alertController.addAction(action)
        
        let cancel = UIAlertAction(title: "Cancel", style: .cancel)
        alertController.addAction(cancel)
        
        self.present(alertController, animated: true)
        alertController.view.tintColor = AppDelegate.tintColor
    }
    
    // MARK: - Search bar

    private func searchBarSetup() {
        searchBar.text = nil
        searchBar.setShowsCancelButton(false, animated: false)
        registerKeyboardNotifications()
    }

    private func setSearchBarTextColor() {
        for subView in searchBar.subviews {
            for view in subView.subviews {
                if let textView = view as? UITextField {
                    textView.textColor = AppDelegate.tintColor
                    return
                }
            }
        }
    }

    private func registerKeyboardNotifications() {
        NotificationCenter.default.addObserver(
            self, selector: #selector(TableView.animateWithKeyboard),
            name: UIResponder.keyboardWillShowNotification, object: nil)

        NotificationCenter.default.addObserver(
            self, selector: #selector(TableView.animateWithKeyboard),
            name: UIResponder.keyboardWillHideNotification, object: nil)
    }

    @objc func animateWithKeyboard(notification: NSNotification) {
        let userInfo = notification.userInfo!
        let keyboardHeight = (userInfo[UIResponder.keyboardFrameEndUserInfoKey] as! NSValue).cgRectValue.height
        let duration = userInfo[UIResponder.keyboardAnimationDurationUserInfoKey] as! Double
        let curve = userInfo[UIResponder.keyboardAnimationCurveUserInfoKey] as! UInt
        let moveUp = (notification.name == UIResponder.keyboardWillShowNotification)

        searchBarConstraint.constant = moveUp ? keyboardHeight + 1 : 0
        searchBar.setShowsCancelButton(moveUp, animated: false)
        imageButtonConstraint.constant = moveUp ? -56 : 0

        let options = UIView.AnimationOptions(rawValue: curve << 16)

        UIView.animate(withDuration: duration, delay: 0, options: options,
                       animations: { self.view.layoutIfNeeded() })
    }

    // MARK: - Image/clear button

    @IBOutlet weak var imageClearButton: UIButton!

    private func imageButtonSetup() {
        let tint = AppDelegate.tintColor
        imageClearButton.setImage(UIImage.templateImage(named: "camera_square"), for: .normal)
        imageClearButton.tintColor = tint
    }

    @IBAction func imageClearButtonPressed() {
        discardImage()
    }

    // MARK: - Image view

    @IBOutlet weak var imageView: UIView!

    @IBOutlet weak var imageViewContraint: NSLayoutConstraint!

    private func discardImage() {
        searchBar.resignFirstResponder()
        searchBar.text = nil
        Cap.hasMatches = false
        showAllCapsByDescendingId()
        imageView(shouldBeVisible: false)
    }

    private func showImageView(with image: UIImage) {
        newImage.image = image
        showImageView()
    }

    private func imageView(shouldBeVisible: Bool) {
        shouldBeVisible ? showImageView() : dismissImageView()
    }

    private func showImageView() {
        UIView.animate(withDuration: 0.5) {
            self.imageViewContraint.constant = 0
        }
    }

    private func dismissImageView() {
        UIView.animate(withDuration: 0.5, animations: {
            self.imageViewContraint.constant = self.imageViewDistance
        }) { _ in self.newImage.image = nil }
    }

    @IBOutlet weak var newImage: RoundedImageView!

    @IBOutlet weak var saveButton: RoundedButton!

    @IBAction func saveButtonPressed() {
        if let image = newImage.image {
            saveNewCap(for: image)
        }
    }

    private func saveNewCap(for image: UIImage) {

        let alertController = UIAlertController(
            title: "Enter name",
            message: "Choose a name for the image",
            preferredStyle: .alert,
            blurStyle: .dark)

        alertController.addTextField { textField in
            //textField.backgroundColor = UIColor.darkGray
            textField.textColor = AppDelegate.tintColor
            textField.placeholder = "Cap name"
            textField.keyboardType = .default
        }

        let action = UIAlertAction(title: "Save", style: .default) { _ in
            guard let name = alertController.textFields?.first?.text else {
                self.showAlert("No name for cap")
                return
            }
            
            let _ = Cap(image: image, name: name)
            self.discardImage()
        }

        let cancel = UIAlertAction(title: "Cancel", style: .cancel)

        alertController.addAction(action)
        alertController.addAction(cancel)
        self.present(alertController, animated: true)
        alertController.view.tintColor = AppDelegate.tintColor
    }

    @IBOutlet weak var deleteButton: RoundedButton!

    @IBAction func deleteButtonPressed() {
        discardImage()
    }
    
    // MARK: - Navigation
    
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        self.giveFeedback(.medium)
        guard let id = segue.identifier else {
            error("No identifier for segue")
            return
        }
        switch id {
        case "showCamera":
            (segue.destination as! CameraController).delegate = self
        case "showSettings":
            break
        default:
            error("Invalid segue identifier \(id)")
        }
    }
    
    @IBAction func showSortOptions(_ sender: UIBarButtonItem) {
        let storyboard = UIStoryboard(name: "Main", bundle: nil)
        let controller = storyboard.instantiateViewController(withIdentifier: "SortController") as! SortController
        controller.selected = sortType
        controller.ascending = sortAscending
        controller.delegate = self
        
        let presentationController = AlwaysPresentAsPopover.configurePresentation(forController: controller)
        
        presentationController.barButtonItem = sender
        presentationController.permittedArrowDirections = [.up]
        self.present(controller, animated: true)
    }
}

// MARK: - SortControllerDelegate

extension TableView: SortControllerDelegate {
    
    func sortController(didSelect sortType: SortCriteria, ascending: Bool) {
        self.sortType = sortType
        self.sortAscending = ascending
        if sortType != .match {
            Cap.hasMatches = false
        }
        showAllCapsAndScrollToTop()
    }
}

// MARK: - CameraControllerDelegate

extension TableView: CameraControllerDelegate {
    
    func didCapture(image: UIImage) {
        if let cap = capToAddImageTo {
            cap.add(image: image) { success in
                guard success else {
                    self.error("Could not save image")
                    return
                }
                self.capToAddImageTo = nil
            }
        } else {
            // Hand image to classifier, delegate is ListViewController
            Classifier.shared.recognise(image: image)
        }
    }
    
    func didCancel() {
        capToAddImageTo = nil
    }
}

// MARK: - UITableViewDataSource

extension TableView: UITableViewDataSource {

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "cap") as! CapCell
        let cap = shownCaps[indexPath.row]
        cell.cap = cap
        return cell
    }

    func numberOfSections(in tableView: UITableView) -> Int {
        return 1
    }

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return shownCaps.count
    }
}

// MARK: - UITableViewDelegate

extension TableView: UITableViewDelegate {
    
    private func takeImage(for cap: Cap) {
        self.capToAddImageTo = cap
        self.performSegue(withIdentifier: "showCamera", sender: nil)
    }

    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        let cap = shownCaps[indexPath.row]
        if let image = newImage.image {
            cap.add(image: image) { success in
                guard success else {
                    self.error("Could not save image")
                    return
                }
                self.giveFeedback(.medium)
                self.updateCell(for: cap.id)
                self.discardImage()
            }
        } else {
            self.giveFeedback(.medium)
            takeImage(for: cap)
        }
        table.deselectRow(at: indexPath, animated: true)
    }
    
    private func updateCell(for capId: Int) {
        let cell = table.visibleCells.first { cell in
            let item = cell as! CapCell
            return item.cap.id == capId
        }
        (cell as! CapCell).updateCell()
    }
    
    private func giveFeedback(_ style: UIImpactFeedbackGenerator.FeedbackStyle) {
        let generator = UIImpactFeedbackGenerator(style: style)
        generator.impactOccurred()
    }
    
    func tableView(_ tableView: UITableView, trailingSwipeActionsConfigurationForRowAt indexPath: IndexPath) -> UISwipeActionsConfiguration? {
        let cap = shownCaps[indexPath.row]
        
        let rename = UIContextualAction(style: .normal, title: "Rename\ncap") { (_, _, success) in
            success(true)
            self.rename(cap: cap, at: indexPath)
            self.giveFeedback(.medium)
        }
        rename.backgroundColor = .blue

        let image = UIContextualAction(style: .normal, title: "Change\nimage") { (_, _, success) in
            self.giveFeedback(.medium)
            let storyboard = UIStoryboard(name: "Main", bundle: nil)
            let controller = storyboard.instantiateViewController(withIdentifier: "ImageSelector") as! ImageSelector
            controller.cap = cap
            self.navigationController?.pushViewController(controller, animated: true)
            success(true)
        }
        image.backgroundColor = .red
        
        return UISwipeActionsConfiguration(actions: [rename, image])
    }
    
    func tableView(_ tableView: UITableView, leadingSwipeActionsConfigurationForRowAt indexPath: IndexPath) -> UISwipeActionsConfiguration? {
        let cap = shownCaps[indexPath.row]
        
        let count = UIContextualAction(style: .normal, title: "Update\ncount") { (_, _, success) in
            self.giveFeedback(.medium)
            cap.updateCount { result in
                self.updateCell(for: cap.id)
                success(result)
            }
        }
        count.backgroundColor = .orange
        
        let similar = UIContextualAction(style: .normal, title: "Similar\ncaps") { (_, _, success) in
            self.giveFeedback(.medium)
            self.imageView(shouldBeVisible: false)
            if let image = cap.image {
                Classifier.shared.recognise(image: image, reportingImage: false)
            }
            success(true)
        }
        similar.backgroundColor = .blue
        
        return UISwipeActionsConfiguration(actions: [similar, count])
    }
}

// MARK: - ClassifierDelegate

extension TableView: ClassifierDelegate {

    func classifier(finished image: UIImage?) {
        if let img = image {
            showImageView(with: img)
        }
        sortType = .match
        sortAscending = false
        Cap.hasMatches = true
        showAllCapsAndScrollToTop()
    }

    func classifier(error: String) {
        self.showAlert(error)
    }
}

// MARK: - UISearchBarDelegate

extension TableView: UISearchBarDelegate {

    func searchBarCancelButtonClicked(_ searchBar: UISearchBar) {
        searchBar.resignFirstResponder()
        searchBar.text = nil
        showAllCapsAndScrollToTop()
    }

    func searchBarSearchButtonClicked(_ searchBar: UISearchBar) {
        searchBar.resignFirstResponder()
    }

    func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) {
        guard searchText != "" else {
            showAllCapsAndScrollToTop()
            return
        }
        DispatchQueue.global(qos: .userInteractive).async {
            let cleaned = searchText.clean
            let filteredCaps = self.caps.filter { cap in
                let name = cap.cleanName
                // For each part of text, check if name contains it
                for textItem in cleaned.components(separatedBy: " ") {
                    if textItem != "" && !name.contains(textItem) { return false }
                }
                return true
            }
            DispatchQueue.main.async {
                self.shownCaps = filteredCaps
                self.table.reloadData()
                self.tableViewScrollToTop()
            }
        }
    }
}

// MARK: - Logging

extension TableView: Logger {

    static let logToken = "[TableView]"
}

// MARK: - Protocol CapsDelegate

extension TableView: CapsDelegate {
    
    func capHasUpdates(_ cap: Cap) {
        if let cell = table.visibleCells.first(where: { ($0 as! CapCell).cap == cap }) {
            (cell as! CapCell).updateCell()
        } else if !caps.contains(cap) {
            // Reload the table when new cap is added
            showAllCapsAndScrollToTop()
        }
    }
    
    func capsLoaded() {
        showAllCapsByDescendingId()
    }
}