ICTextField.swift

//
//  ICTextField.swift
// 
//
//  Created by Mahabaleshwar Hegde on 26/04/18.
//  Copyright © 2018 Mahabaleshwar. All rights reserved.
//

import UIKit

@objc
protocol UIDatePickerDelegate: UITextFieldDelegate {
    @objc optional func datePickerValueChanged(date: Date, textField: ICTextField)
}

@objc
protocol UIDropDownDelegate: UITextFieldDelegate {
    @objc optional func datePickerDidSelect(row: Int)
}

@IBDesignable
final class ICTextField: UITextField {

    private var pickerView: UIPickerView?

    public var textFieldIdentifier: TextFieldIdentifier = .default

    /// Textfield leftView or rightViewMode
    ///
    /// - left: leftView Mode enabled
    /// - right: rightView Mode enabled
    public enum ViewModePostion {
        case left
        case right
    }

    /// Date picker content dispaly type.
    ///
    /// - time: Displays hour, minute, and optionally AM/PM designation depending on the locale setting (e.g. 6 | 53 | PM)
    /// - `date`: Displays month, day, and year depending on the locale setting (e.g. November | 15 | 2007)
    /// - dateAndTime:  Displays date, hour, minute, and optionally AM/PM designation depending on the locale setting (e.g. Wed Nov 15 | 6 | 53 | PM)
    /// - countDownTimer: Displays hour and minute (e.g. 1 | 53)
    public enum DatePickerMode: Int {
        case time = 1
        case date
        case dateAndTime
        case countDownTimer
    }

    /// To show the date or time input from textfield set this value to true
    /// Default is false.
    @IBInspectable open var isDatePicker: Bool = false {
        didSet {
            if self.isDatePicker {
                self.inputView = self.datePicker
                self.inputAccessoryView = self.configureToolBar()
            }

            self.reloadInputViews()
        }
    }

    /// Legtview image name
    @IBInspectable open var leftDrawable: UIImage? {
        didSet {
            guard let _ = self.leftDrawable else {
                self.rightViewMode = .never
                return
            }
            self.updateDrwableViewMode(forPostion: .left)
        }
    }

    /// Right view image name
    @IBInspectable open var rightDrawable: UIImage? {
        didSet {
            guard let _ = self.rightDrawable else {
                self.rightViewMode = .never
                return
            }
            self.updateDrwableViewMode(forPostion: .right)
        }
    }

    /// Textfield placeholder color
    @IBInspectable open var placeholderColor: UIColor? = UIColor.white.withAlphaComponent(0.5) {
        didSet {
            guard let placeholder = self.placeholder, let color = self.placeholderColor else { return }
            let attributes = [NSAttributedStringKey.foregroundColor: color]
            self.attributedPlaceholder = NSAttributedString(string: placeholder, attributes: attributes)
        }
    }

    /// Shows the inputview as UITableView. able to select multiple option, default is false
    @IBInspectable open var isDropDown: Bool = false {
        didSet {
            if isDropDown {
                self.pickerView = UIPickerView()
                self.pickerView?.dataSource = self
                self.pickerView?.delegate = self
                self.inputAccessoryView = self.configureToolBar()
                self.inputView = self.pickerView
                self.reloadInputViews()
            } else {
                self.inputView = nil
                self.reloadInputViews()
            }
        }
    }

    // MARK: - Public Properties

    let datePicker: UIDatePicker = {
        let dateDropDown = UIDatePicker()
        dateDropDown.datePickerMode = .date
        dateDropDown.locale = Locale(identifier: "en_US_POSIX")
        dateDropDown.addTarget(self, action: #selector(ICTextField.datePickerValueChanged(sender:)), for: .valueChanged)
        return dateDropDown
    }()

    /// Datepicker mode
    var datePickerMode: DatePickerMode = .date {
        didSet {
            var mode: UIDatePickerMode = .date
            switch self.datePickerMode {
            case .date:
                mode = .date
            case .countDownTimer:
                mode = .countDownTimer
            case .dateAndTime:
                mode = .dateAndTime
            case .time:
                mode = .time
            }
            self.datePicker.datePickerMode = mode
        }
    }

    var dropDownSource: [String] = [] {
        didSet {
            self.pickerView?.reloadAllComponents()
        }
    }

    /// Tool bar to show cancel and done on top of textfield.
    open var accessoryToolBar: UIToolbar? {
        didSet {
            self.inputAccessoryView = accessoryToolBar
            self.reloadInputViews()
        }
    }

    override var keyboardType: UIKeyboardType {
        didSet {
            if self.keyboardType == .numberPad || self.keyboardType == .decimalPad {
                self.inputAccessoryView = self.configureToolBar()
                self.reloadInputViews()
            }
        }
    }

    private(set) var selectedDropDownItem: (row: Int, item: String)!

    // MARK: - private Properties

    private var datePickerDelegate: UIDatePickerDelegate? {
        return self.delegate as? UIDatePickerDelegate
    }

    private var dropDownDelegate: UIDropDownDelegate? {
        return self.delegate as? UIDropDownDelegate
    }

    private var selectedDate: Date = Date()

    // MARK: - override Methods

    override func awakeFromNib() {
        super.awakeFromNib()
    }

    @objc private func datePickerValueChanged(sender: UIDatePicker) {
        self.selectedDate = sender.date
        self.datePickerDelegate?.datePickerValueChanged?(date: sender.date, textField: self)
    }

    private func configureToolBar() -> UIToolbar {
        let frame = CGRect(x: 0, y: 0, width: self.frame.width, height: 40.0)
        let toolBar = UIToolbar(frame: frame)
        toolBar.barStyle = .default
        toolBar.barTintColor = UIColor(hex: "4db8ff")
        let doneButton = UIBarButtonItem(title: "Done", style: .done, target: self, action: #selector(donePressed))
        let cancelButton = UIBarButtonItem(title: "Cancel", style: .plain, target: self, action: #selector(cancelPressed))
        let spaceButton = UIBarButtonItem(barButtonSystemItem: .flexibleSpace, target: nil, action: nil)
        toolBar.setItems([cancelButton, spaceButton, doneButton], animated: false)

        toolBar.isUserInteractionEnabled = true
        toolBar.sizeToFit()
        return toolBar
    }

    @objc fileprivate func donePressed() {

        if self.isDatePicker {
            self.datePickerDelegate?.datePickerValueChanged?(date: self.selectedDate, textField: self)
        } else if self.isDropDown {
            guard let row = self.pickerView?.selectedRow(inComponent: 0) else {
                self.resignFirstResponder()
                return
            }
            self.setSelectedItem(row: row)
        }

        self.resignFirstResponder()
    }

    @objc private func cancelPressed() {

        if self.isDatePicker {
            self.text = nil
        }
        self.text = ""
        self.selectedDropDownItem = nil
        self.resignFirstResponder()
    }

    // MARK: - Private Functions
    private func updateDrwableViewMode(forPostion postion: ViewModePostion) {
        switch postion {
        case .left:
            guard let image = self.leftDrawable else { return }
            self.leftViewMode = .always
            let leftView = UIImageView(frame: CGRect(x: 0.0, y: 0.0, width: self.bounds.height - 8.0, height: self.bounds.height - 16.0))
            leftView.image = image
            leftView.contentMode = .scaleAspectFill
            leftView.clipsToBounds = true
            self.leftView = leftView
            self.layoutIfNeeded()
        case .right:
            guard let image = self.rightDrawable else { return }
            self.rightViewMode = .always
            let rightView = UIImageView(frame: CGRect(x: 0.0, y: 8.0, width: 12.0, height: 12.0))
            rightView.image = image
            rightView.contentMode = .scaleAspectFill
            rightView.clipsToBounds = true
            self.rightView = rightView
            self.layoutIfNeeded()
        }
    }
}

// MARK: - UIPickerViewDataSource

extension ICTextField: UIPickerViewDataSource {

    func numberOfComponents(in _: UIPickerView) -> Int {
        return 1
    }

    func pickerView(_: UIPickerView, numberOfRowsInComponent _: Int) -> Int {
        return self.dropDownSource.count
    }
}

// MARK: - UIPickerViewDelegate

extension ICTextField: UIPickerViewDelegate {

    func pickerView(_: UIPickerView, titleForRow row: Int, forComponent _: Int) -> String? {
        guard self.dropDownSource.indices.contains(row) else {
            return nil
        }
        return self.dropDownSource[row]
    }

    func pickerView(_: UIPickerView, didSelectRow row: Int, inComponent _: Int) {

        self.setSelectedItem(row: row)
        self.dropDownDelegate?.datePickerDidSelect?(row: row)
    }

    private func setSelectedItem(row: Int) {

        guard self.dropDownSource.indices.contains(row) else {
            self.text = nil
            self.selectedDropDownItem = nil
            return
        }

        let item = self.dropDownSource[row]
        self.text = item
        self.selectedDropDownItem = (row: row, item: item)
    }
}