//
//  ImportedHostsViewController.swift
//  Passepartout-iOS
//
//  Created by Davide De Rosa on 10/27/18.
//  Copyright (c) 2019 Davide De Rosa. All rights reserved.
//
//  https://github.com/passepartoutvpn
//
//  This file is part of Passepartout.
//
//  Passepartout 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.
//
//  Passepartout 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 Passepartout.  If not, see <http://www.gnu.org/licenses/>.
//

import UIKit
import TunnelKit
import SwiftyBeaver
import PassepartoutCore

private let log = SwiftyBeaver.self

class ImportedHostsViewController: UITableViewController {
    private lazy var pendingConfigurationURLs = TransientStore.shared.service.pendingConfigurationURLs().sortedCaseInsensitive()
    
    private var importer: HostImporter?

    private var parsingResult: OpenVPN.ConfigurationParser.Result?
    
    override func viewDidLoad() {
        super.viewDidLoad()

        title = L10n.App.ImportedHosts.title
    }

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        
        parsingResult = nil
    }
    
    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)

//        guard !pendingConfigurationURLs.isEmpty else {
//            let alert = UIAlertController.asAlert(
//                title,
//                L10n.Core.Organizer.Alerts.AddHost.message
//            )
//            alert.addCancelAction(L10n.Core.Global.ok) {
//                self.close()
//            }
//            present(alert, animated: true, completion: nil)
//            return
//        }
        if let selectedIP = tableView.indexPathForSelectedRow {
            tableView.deselectRow(at: selectedIP, animated: true)
        }
    }
    
    // MARK: Actions
    
    @IBAction private func openConfigurationFile() {
        let picker = UIDocumentPickerViewController(documentTypes: AppConstants.URLs.filetypes, in: .import)
        picker.allowsMultipleSelection = false
        picker.delegate = self
        present(picker, animated: true, completion: nil)
    }
    
    override func shouldPerformSegue(withIdentifier identifier: String, sender: Any?) -> Bool {

        // segue parses configuration file if not yet
        if parsingResult == nil {
            guard let cell = sender as? UITableViewCell, let indexPath = tableView.indexPath(for: cell) else {
                return false
            }
            let url = pendingConfigurationURLs[indexPath.row]
            return tryParseURL(url, cell: cell)
        }
        return true
    }
    
    private func tryParseURL(_ url: URL, cell: UITableViewCell?) -> Bool {
        deselectSelectedRow()

        importer = HostImporter(withConfigurationURL: url, parentViewController: self)
        importer?.importHost(withPassphrase: nil, removeOnError: false, removeOnCancel: false) {
            self.parsingResult = $0
            self.perform(segue: StoryboardSegue.Organizer.importHostSegueIdentifier)
        }
        return true
    }
    
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        guard let wizard = segue.destination as? WizardHostViewController else {
            return
        }
        wizard.parsingResult = parsingResult

        // retain back button
        wizard.navigationItem.leftBarButtonItem = nil
    }
    
    @IBAction private func close() {
        dismiss(animated: true, completion: nil)
    }
    
    private func deselectSelectedRow() {
        if let selectedIP = tableView.indexPathForSelectedRow {
            tableView.deselectRow(at: selectedIP, animated: true)
        }
    }
}

extension ImportedHostsViewController {
    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return pendingConfigurationURLs.count
    }
    
    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let url = pendingConfigurationURLs[indexPath.row]
        let cell = Cells.setting.dequeue(from: tableView, for: indexPath)
        cell.leftText = url.normalizedFilename
        return cell
    }

    override func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
        return true
    }
    
    override func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
        let url = pendingConfigurationURLs[indexPath.row]
        try? FileManager.default.removeItem(at: url)
        pendingConfigurationURLs.remove(at: indexPath.row)
        tableView.deleteRows(at: [indexPath], with: .top)
    }
}

extension ImportedHostsViewController: UIDocumentPickerDelegate {
    func documentPickerWasCancelled(_ controller: UIDocumentPickerViewController) {
    }
    
    func documentPicker(_ controller: UIDocumentPickerViewController, didPickDocumentsAt urls: [URL]) {
        guard let url = urls.first else {
            return
        }
        _ = tryParseURL(url, cell: nil)
    }
}