//
//  PasswordEditorTableViewController.swift
//  pass
//
//  Created by Mingshen Sun on 12/2/2017.
//  Copyright © 2017 Bob Sun. All rights reserved.
//

import UIKit
import SwiftyUserDefaults
import OneTimePassword

enum PasswordEditorCellType {
    case textFieldCell, textViewCell, fillPasswordCell, passwordLengthCell, deletePasswordCell, scanQRCodeCell
}

enum PasswordEditorCellKey {
    case type, title, content, placeholders
}

class PasswordEditorTableViewController: UITableViewController, FillPasswordTableViewCellDelegate, PasswordSettingSliderTableViewCellDelegate, QRScannerControllerDelegate {
    
    var tableData = [
        [Dictionary<PasswordEditorCellKey, Any>]
        ]()
    var password: Password?
    
    private var navigationItemTitle: String?
    
    private var sectionHeaderTitles = ["name", "password", "additions",""].map {$0.uppercased()}
    private var sectionFooterTitles = ["", "", "Use \"key: value\" format for additional fields.", ""]
    private let passwordSection = 1
    private let additionsSection = 2
    private var hidePasswordSettings = true
    
    private var fillPasswordCell: FillPasswordTableViewCell?
    private var passwordLengthCell: SliderTableViewCell?
    private var deletePasswordCell: UITableViewCell?
    private var scanQRCodeCell: UITableViewCell?
    
    override func loadView() {
        super.loadView()
        
        deletePasswordCell = UITableViewCell(style: .default, reuseIdentifier: "default")
        deletePasswordCell!.textLabel?.text = "Delete Password"
        deletePasswordCell!.textLabel?.textColor = Globals.red
        deletePasswordCell?.selectionStyle = .default
        
        scanQRCodeCell = UITableViewCell(style: .default, reuseIdentifier: "default")
        scanQRCodeCell?.textLabel?.text = "Add One-Time Password"
        scanQRCodeCell?.textLabel?.textColor = Globals.blue
        scanQRCodeCell?.selectionStyle = .default
        scanQRCodeCell?.accessoryType = .disclosureIndicator
//        scanQRCodeCell?.imageView?.image = #imageLiteral(resourceName: "Camera").withRenderingMode(.alwaysTemplate)
//        scanQRCodeCell?.imageView?.tintColor = Globals.blue
//        scanQRCodeCell?.imageView?.contentMode = .scaleAspectFit
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()
        if navigationItemTitle != nil {
            navigationItem.title = navigationItemTitle
        }
        
        tableView.register(UINib(nibName: "TextFieldTableViewCell", bundle: nil), forCellReuseIdentifier: "textFieldCell")
        tableView.register(UINib(nibName: "TextViewTableViewCell", bundle: nil), forCellReuseIdentifier: "textViewCell")
        tableView.register(UINib(nibName: "FillPasswordTableViewCell", bundle: nil), forCellReuseIdentifier: "fillPasswordCell")
        tableView.register(UINib(nibName: "SliderTableViewCell", bundle: nil), forCellReuseIdentifier: "passwordLengthCell")
        
        tableView.rowHeight = UITableViewAutomaticDimension
        tableView.estimatedRowHeight = 48
        self.tableView.sectionFooterHeight = UITableViewAutomaticDimension;
        self.tableView.estimatedSectionFooterHeight = 0;
    }
    
    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cellData = tableData[indexPath.section][indexPath.row]
        
        switch cellData[PasswordEditorCellKey.type] as! PasswordEditorCellType {
        case .textViewCell:
            let cell = tableView.dequeueReusableCell(withIdentifier: "textViewCell", for: indexPath) as! ContentTableViewCell
            cell.setContent(content: cellData[PasswordEditorCellKey.content] as? String)
            return cell
        case .fillPasswordCell:
            fillPasswordCell = tableView.dequeueReusableCell(withIdentifier: "fillPasswordCell", for: indexPath) as? FillPasswordTableViewCell
            fillPasswordCell?.delegate = self
            fillPasswordCell?.setContent(content: cellData[PasswordEditorCellKey.content] as? String)
            return fillPasswordCell!
        case .passwordLengthCell:
            passwordLengthCell = tableView.dequeueReusableCell(withIdentifier: "passwordLengthCell", for: indexPath) as? SliderTableViewCell
            let lengthSetting = Globals.passwordDefaultLength[Defaults[.passwordGeneratorFlavor]] ??
                Globals.passwordDefaultLength["Random"]
            passwordLengthCell?.reset(title: "Length",
                                      minimumValue: lengthSetting?.min ?? 0,
                                      maximumValue: lengthSetting?.max ?? 0,
                                      defaultValue: lengthSetting?.def ?? 0)
            passwordLengthCell?.delegate = self
            return passwordLengthCell!
        case .deletePasswordCell:
            return deletePasswordCell!
        case .scanQRCodeCell:
            return scanQRCodeCell!
        default:
            let cell = tableView.dequeueReusableCell(withIdentifier: "textFieldCell", for: indexPath) as! ContentTableViewCell
            cell.setContent(content: cellData[PasswordEditorCellKey.content] as? String)
            return cell
        }
    }
    
    override func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
        return 44
    }

    override func numberOfSections(in tableView: UITableView) -> Int {
        return tableData.count
    }

    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        if section == passwordSection, hidePasswordSettings {
            // hide the password section, only the password should be shown
            return 1
        } else {
            return tableData[section].count
        }
    }

    override func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
        return sectionHeaderTitles[section]
    }
    
    override func tableView(_ tableView: UITableView, titleForFooterInSection section: Int) -> String? {
        return sectionFooterTitles[section]
    }
    
    override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        let selectedCell = tableView.cellForRow(at: indexPath)
        if selectedCell == deletePasswordCell {
            let alert = UIAlertController(title: "Delete Password?", message: nil, preferredStyle: UIAlertControllerStyle.alert)
            alert.addAction(UIAlertAction(title: "Delete", style: UIAlertActionStyle.destructive, handler: {[unowned self] (action) -> Void in
                self.performSegue(withIdentifier: "deletePasswordSegue", sender: self)
            }))
            alert.addAction(UIAlertAction(title: "Cancel", style: UIAlertActionStyle.cancel, handler:nil))
            self.present(alert, animated: true, completion: nil)
        } else if selectedCell == scanQRCodeCell {
            self.performSegue(withIdentifier: "showQRScannerSegue", sender: self)
        }
        tableView.deselectRow(at: indexPath, animated: true)
    }
    
    // generate password, copy to pasteboard, and set the cell
    // check whether the current password looks like an OTP field
    func generateAndCopyPassword() {
        if let currentPassword = fillPasswordCell?.getContent(),
            Password.LooksLikeOTP(line: currentPassword) {
            let alert = UIAlertController(title: "Overwrite?", message: "Overwrite the one-time password configuration?", preferredStyle: UIAlertControllerStyle.alert)
            alert.addAction(UIAlertAction(title: "Yes", style: UIAlertActionStyle.destructive, handler: {_ in
                self.generateAndCopyPasswordNoOtpCheck()
            }))
            alert.addAction(UIAlertAction(title: "Cancel", style: UIAlertActionStyle.cancel, handler: nil))
            self.present(alert, animated: true, completion: nil)
        } else {
            self.generateAndCopyPasswordNoOtpCheck()
        }
    }
    
    // generate the password, don't care whether the original line is otp
    func generateAndCopyPasswordNoOtpCheck() {
        // show password settings (e.g., the length slider)
        if hidePasswordSettings == true {
            hidePasswordSettings = false
            tableView.reloadSections([passwordSection], with: .fade)
        }
        let length = passwordLengthCell?.roundedValue ?? 0
        let plainPassword = Utils.generatePassword(length: length)
        Utils.copyToPasteboard(textToCopy: plainPassword)
        
        // update tableData so to make sure reloadData() works correctly
        tableData[passwordSection][0][PasswordEditorCellKey.content] = plainPassword
        
        // update cell manually, no need to call reloadData()
        fillPasswordCell?.setContent(content: plainPassword)
    }
    
    func showHidePasswordSettings() {
        hidePasswordSettings = !hidePasswordSettings
        tableView.reloadSections([passwordSection], with: .fade)
    }
    
    func insertScannedOTPFields(_ otpauth: String) {
        // update tableData
        if let additionsPlainText = (tableData[additionsSection][0][PasswordEditorCellKey.content] as? String)?.trimmingCharacters(in: .whitespacesAndNewlines), additionsPlainText != "" {
            tableData[additionsSection][0][PasswordEditorCellKey.content] = additionsPlainText + "\n" + otpauth
        } else {
            tableData[additionsSection][0][PasswordEditorCellKey.content] = otpauth
        }
        // reload
        tableView.reloadSections([additionsSection], with: .none)
    }
    
    // MARK: - QRScannerControllerDelegate Methods
    func checkScannedOutput(line: String) -> (accept: Bool, message: String) {
        if let url = URL(string: line), let _ = Token(url: url) {
            return (accept: true, message: "Valid token URL")
        } else {
            return (accept: false, message: "Invalid token URL")
        }
    }
    
    // MARK: - QRScannerControllerDelegate Methods
    func handleScannedOutput(line: String) {
        insertScannedOTPFields(line)
    }
    
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        if segue.identifier == "showQRScannerSegue" {
            if let navController = segue.destination as? UINavigationController {
                if let viewController = navController.topViewController as? QRScannerController {
                    viewController.delegate = self
                }
            } else if let viewController = segue.destination as? QRScannerController {
                viewController.delegate = self
            }
        }
    }
    
    @IBAction private func cancelOTPScanner(segue: UIStoryboardSegue) {
        
    }
}