//
//  IQKeyboardReturnKeyHandler.swift
// https://github.com/hackiftekhar/IQKeyboardManager
// Copyright (c) 2013-16 Iftekhar Qurashi.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

import Foundation
import UIKit

private class IQTextFieldViewInfoModal: NSObject {

    fileprivate weak var textFieldDelegate: UITextFieldDelegate?
    fileprivate weak var textViewDelegate: UITextViewDelegate?
    fileprivate weak var textFieldView: UIView?
    fileprivate var originalReturnKeyType = UIReturnKeyType.default

    init(textFieldView: UIView?, textFieldDelegate: UITextFieldDelegate?, textViewDelegate: UITextViewDelegate?, originalReturnKeyType: UIReturnKeyType = .default) {
        self.textFieldView = textFieldView
        self.textFieldDelegate = textFieldDelegate
        self.textViewDelegate = textViewDelegate
        self.originalReturnKeyType = originalReturnKeyType
    }
}

/**
Manages the return key to work like next/done in a view hierarchy.
*/
public class IQKeyboardReturnKeyHandler: NSObject, UITextFieldDelegate, UITextViewDelegate {

    ///---------------
    // MARK: Settings
    ///---------------

    /**
    Delegate of textField/textView.
    */
    @objc public weak var delegate: (UITextFieldDelegate & UITextViewDelegate)?

    /**
    Set the last textfield return key type. Default is UIReturnKeyDefault.
    */
    @objc public var lastTextFieldReturnKeyType: UIReturnKeyType = UIReturnKeyType.default {

        didSet {

            for modal in textFieldInfoCache {

                if let view = modal.textFieldView {
                    updateReturnKeyTypeOnTextField(view)
                }
            }
        }
    }

    ///--------------------------------------
    // MARK: Initialization/Deinitialization
    ///--------------------------------------

    @objc public override init() {
        super.init()
    }

    /**
    Add all the textFields available in UIViewController's view.
    */
    @objc public init(controller: UIViewController) {
        super.init()

        addResponderFromView(controller.view)
    }

    deinit {

        for modal in textFieldInfoCache {

            if let textField = modal.textFieldView as? UITextField {
                textField.returnKeyType = modal.originalReturnKeyType

                textField.delegate = modal.textFieldDelegate

            } else if let textView = modal.textFieldView as? UITextView {

                textView.returnKeyType = modal.originalReturnKeyType

                textView.delegate = modal.textViewDelegate
            }
        }

        textFieldInfoCache.removeAll()
    }

    ///------------------------
    // MARK: Private variables
    ///------------------------
    private var textFieldInfoCache          =   [IQTextFieldViewInfoModal]()

    ///------------------------
    // MARK: Private Functions
    ///------------------------
    private func textFieldViewCachedInfo(_ textField: UIView) -> IQTextFieldViewInfoModal? {

        for modal in textFieldInfoCache {

            if let view = modal.textFieldView {

                if view == textField {
                    return modal
                }
            }
        }

        return nil
    }

    private func updateReturnKeyTypeOnTextField(_ view: UIView) {
        var superConsideredView: UIView?

        //If find any consider responderView in it's upper hierarchy then will get deepResponderView. (Bug ID: #347)
        for disabledClass in IQKeyboardManager.shared.toolbarPreviousNextAllowedClasses {

            superConsideredView = view.superviewOfClassType(disabledClass)

            if superConsideredView != nil {
                break
            }
        }

        var textFields = [UIView]()

        //If there is a tableView in view's hierarchy, then fetching all it's subview that responds.
        if let unwrappedTableView = superConsideredView {     //   (Enhancement ID: #22)
            textFields = unwrappedTableView.deepResponderViews()
        } else {  //Otherwise fetching all the siblings

            textFields = view.responderSiblings()

            //Sorting textFields according to behaviour
            switch IQKeyboardManager.shared.toolbarManageBehaviour {
                //If needs to sort it by tag
            case .byTag:        textFields = textFields.sortedArrayByTag()
                //If needs to sort it by Position
            case .byPosition:   textFields = textFields.sortedArrayByPosition()
            default:    break
            }
        }

        if let lastView = textFields.last {

            if let textField = view as? UITextField {

                //If it's the last textField in responder view, else next
                textField.returnKeyType = (view == lastView)    ?   lastTextFieldReturnKeyType: UIReturnKeyType.next
            } else if let textView = view as? UITextView {

                //If it's the last textField in responder view, else next
                textView.returnKeyType = (view == lastView)    ?   lastTextFieldReturnKeyType: UIReturnKeyType.next
            }
        }
    }

    ///----------------------------------------------
    // MARK: Registering/Unregistering textFieldView
    ///----------------------------------------------

    /**
    Should pass UITextField/UITextView intance. Assign textFieldView delegate to self, change it's returnKeyType.
    
    @param view UITextField/UITextView object to register.
    */
    @objc public func addTextFieldView(_ view: UIView) {

        let modal = IQTextFieldViewInfoModal(textFieldView: view, textFieldDelegate: nil, textViewDelegate: nil)

        if let textField = view as? UITextField {

            modal.originalReturnKeyType = textField.returnKeyType
            modal.textFieldDelegate = textField.delegate
            textField.delegate = self

        } else if let textView = view as? UITextView {

            modal.originalReturnKeyType = textView.returnKeyType
            modal.textViewDelegate = textView.delegate
            textView.delegate = self
        }

        textFieldInfoCache.append(modal)
    }

    /**
    Should pass UITextField/UITextView intance. Restore it's textFieldView delegate and it's returnKeyType.
    
    @param view UITextField/UITextView object to unregister.
    */
    @objc public func removeTextFieldView(_ view: UIView) {

        if let modal = textFieldViewCachedInfo(view) {

            if let textField = view as? UITextField {

                textField.returnKeyType = modal.originalReturnKeyType
                textField.delegate = modal.textFieldDelegate
            } else if let textView = view as? UITextView {

                textView.returnKeyType = modal.originalReturnKeyType
                textView.delegate = modal.textViewDelegate
            }

            if let index = textFieldInfoCache.firstIndex(where: { $0.textFieldView == view}) {

                textFieldInfoCache.remove(at: index)
            }
        }
    }

    /**
    Add all the UITextField/UITextView responderView's.
    
    @param view UIView object to register all it's responder subviews.
    */
    @objc public func addResponderFromView(_ view: UIView) {

        let textFields = view.deepResponderViews()

        for textField in textFields {

            addTextFieldView(textField)
        }
    }

    /**
    Remove all the UITextField/UITextView responderView's.
    
    @param view UIView object to unregister all it's responder subviews.
    */
    @objc public func removeResponderFromView(_ view: UIView) {

        let textFields = view.deepResponderViews()

        for textField in textFields {

            removeTextFieldView(textField)
        }
    }

    @discardableResult private func goToNextResponderOrResign(_ view: UIView) -> Bool {

        var superConsideredView: UIView?

        //If find any consider responderView in it's upper hierarchy then will get deepResponderView. (Bug ID: #347)
        for disabledClass in IQKeyboardManager.shared.toolbarPreviousNextAllowedClasses {

            superConsideredView = view.superviewOfClassType(disabledClass)

            if superConsideredView != nil {
                break
            }
        }

        var textFields = [UIView]()

        //If there is a tableView in view's hierarchy, then fetching all it's subview that responds.
        if let unwrappedTableView = superConsideredView {     //   (Enhancement ID: #22)
            textFields = unwrappedTableView.deepResponderViews()
        } else {  //Otherwise fetching all the siblings

            textFields = view.responderSiblings()

            //Sorting textFields according to behaviour
            switch IQKeyboardManager.shared.toolbarManageBehaviour {
                //If needs to sort it by tag
            case .byTag:        textFields = textFields.sortedArrayByTag()
                //If needs to sort it by Position
            case .byPosition:   textFields = textFields.sortedArrayByPosition()
            default:
                break
            }
        }

        //Getting index of current textField.
        if let index = textFields.firstIndex(of: view) {
            //If it is not last textField. then it's next object becomeFirstResponder.
            if index < (textFields.count - 1) {

                let nextTextField = textFields[index+1]
                nextTextField.becomeFirstResponder()
                return false
            } else {

                view.resignFirstResponder()
                return true
            }
        } else {
            return true
        }
    }

    ///---------------------------------------
    // MARK: UITextField/UITextView delegates
    ///---------------------------------------

    @objc public func textFieldShouldBeginEditing(_ textField: UITextField) -> Bool {

        if delegate == nil {

            if let unwrapDelegate = textFieldViewCachedInfo(textField)?.textFieldDelegate {
                if unwrapDelegate.responds(to: #selector(UITextFieldDelegate.textFieldShouldBeginEditing(_:))) {
                    return unwrapDelegate.textFieldShouldBeginEditing?(textField) == true
                }
            }
        }

        return true
    }

    @objc public func textFieldShouldEndEditing(_ textField: UITextField) -> Bool {

        if delegate == nil {

            if let unwrapDelegate = textFieldViewCachedInfo(textField)?.textFieldDelegate {
                if unwrapDelegate.responds(to: #selector(UITextFieldDelegate.textFieldShouldEndEditing(_:))) {
                    return unwrapDelegate.textFieldShouldEndEditing?(textField) == true
                }
            }
        }

        return true
    }

    @objc public func textFieldDidBeginEditing(_ textField: UITextField) {
        updateReturnKeyTypeOnTextField(textField)

        var aDelegate: UITextFieldDelegate? = delegate

        if aDelegate == nil {

            if let modal = textFieldViewCachedInfo(textField) {
                aDelegate = modal.textFieldDelegate
            }
        }

        aDelegate?.textFieldDidBeginEditing?(textField)
    }

    @objc public func textFieldDidEndEditing(_ textField: UITextField) {

        var aDelegate: UITextFieldDelegate? = delegate

        if aDelegate == nil {

            if let modal = textFieldViewCachedInfo(textField) {
                aDelegate = modal.textFieldDelegate
            }
        }

        aDelegate?.textFieldDidEndEditing?(textField)
    }

    #if swift(>=4.2)
    @available(iOS 10.0, *)
    @objc public func textFieldDidEndEditing(_ textField: UITextField, reason: UITextField.DidEndEditingReason) {

        var aDelegate: UITextFieldDelegate? = delegate

        if aDelegate == nil {

            if let modal = textFieldViewCachedInfo(textField) {
                aDelegate = modal.textFieldDelegate
            }
        }

        aDelegate?.textFieldDidEndEditing?(textField, reason: reason)
    }
    #else
    @available(iOS 10.0, *)
    @objc public func textFieldDidEndEditing(_ textField: UITextField, reason: UITextFieldDidEndEditingReason) {

        var aDelegate: UITextFieldDelegate? = delegate

        if aDelegate == nil {

            if let modal = textFieldViewCachedInfo(textField) {
                aDelegate = modal.textFieldDelegate
            }
        }

        aDelegate?.textFieldDidEndEditing?(textField, reason: reason)
    }
    #endif

    @objc public func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {

        if delegate == nil {

            if let unwrapDelegate = textFieldViewCachedInfo(textField)?.textFieldDelegate {
                if unwrapDelegate.responds(to: #selector(UITextFieldDelegate.textField(_:shouldChangeCharactersIn:replacementString:))) {
                    return unwrapDelegate.textField?(textField, shouldChangeCharactersIn: range, replacementString: string) == true
                }
            }
        }
        return true
    }

    @objc public func textFieldShouldClear(_ textField: UITextField) -> Bool {

        if delegate == nil {

            if let unwrapDelegate = textFieldViewCachedInfo(textField)?.textFieldDelegate {
                if unwrapDelegate.responds(to: #selector(UITextFieldDelegate.textFieldShouldClear(_:))) {
                    return unwrapDelegate.textFieldShouldClear?(textField) == true
                }
            }
        }

        return true
    }

    @objc public func textFieldShouldReturn(_ textField: UITextField) -> Bool {

        var shouldReturn = true

        if delegate == nil {

            if let unwrapDelegate = textFieldViewCachedInfo(textField)?.textFieldDelegate {
                if unwrapDelegate.responds(to: #selector(UITextFieldDelegate.textFieldShouldReturn(_:))) {
                    shouldReturn = unwrapDelegate.textFieldShouldReturn?(textField) == true
                }
            }
        }

        if shouldReturn == true {
            goToNextResponderOrResign(textField)
            return true
        } else {
            return goToNextResponderOrResign(textField)
        }
    }

    @objc public func textViewShouldBeginEditing(_ textView: UITextView) -> Bool {

        if delegate == nil {

            if let unwrapDelegate = textFieldViewCachedInfo(textView)?.textViewDelegate {
                if unwrapDelegate.responds(to: #selector(UITextViewDelegate.textViewShouldBeginEditing(_:))) {
                    return unwrapDelegate.textViewShouldBeginEditing?(textView) == true
                }
            }
        }

        return true
    }

    @objc public func textViewShouldEndEditing(_ textView: UITextView) -> Bool {

        if delegate == nil {

            if let unwrapDelegate = textFieldViewCachedInfo(textView)?.textViewDelegate {
                if unwrapDelegate.responds(to: #selector(UITextViewDelegate.textViewShouldEndEditing(_:))) {
                    return unwrapDelegate.textViewShouldEndEditing?(textView) == true
                }
            }
        }

        return true
    }

    @objc public func textViewDidBeginEditing(_ textView: UITextView) {
        updateReturnKeyTypeOnTextField(textView)

        var aDelegate: UITextViewDelegate? = delegate

        if aDelegate == nil {

            if let modal = textFieldViewCachedInfo(textView) {
                aDelegate = modal.textViewDelegate
            }
        }

        aDelegate?.textViewDidBeginEditing?(textView)
    }

    @objc public func textViewDidEndEditing(_ textView: UITextView) {

        var aDelegate: UITextViewDelegate? = delegate

        if aDelegate == nil {

            if let modal = textFieldViewCachedInfo(textView) {
                aDelegate = modal.textViewDelegate
            }
        }

        aDelegate?.textViewDidEndEditing?(textView)
    }

    @objc public func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool {

        var shouldReturn = true

        if delegate == nil {

            if let unwrapDelegate = textFieldViewCachedInfo(textView)?.textViewDelegate {
                if unwrapDelegate.responds(to: #selector(UITextViewDelegate.textView(_:shouldChangeTextIn:replacementText:))) {
                    shouldReturn = (unwrapDelegate.textView?(textView, shouldChangeTextIn: range, replacementText: text)) == true
                }
            }
        }

        if shouldReturn == true && text == "\n" {
            shouldReturn = goToNextResponderOrResign(textView)
        }

        return shouldReturn
    }

    @objc public func textViewDidChange(_ textView: UITextView) {

        var aDelegate: UITextViewDelegate? = delegate

        if aDelegate == nil {

            if let modal = textFieldViewCachedInfo(textView) {
                aDelegate = modal.textViewDelegate
            }
        }

        aDelegate?.textViewDidChange?(textView)
    }

    @objc public func textViewDidChangeSelection(_ textView: UITextView) {

        var aDelegate: UITextViewDelegate? = delegate

        if aDelegate == nil {

            if let modal = textFieldViewCachedInfo(textView) {
                aDelegate = modal.textViewDelegate
            }
        }

        aDelegate?.textViewDidChangeSelection?(textView)
    }

    @available(iOS 10.0, *)
    @objc public func textView(_ aTextView: UITextView, shouldInteractWith URL: URL, in characterRange: NSRange, interaction: UITextItemInteraction) -> Bool {

        if delegate == nil {

            if let unwrapDelegate = textFieldViewCachedInfo(aTextView)?.textViewDelegate {
                if unwrapDelegate.responds(to: #selector(textView as (UITextView, URL, NSRange, UITextItemInteraction) -> Bool)) {
                    return unwrapDelegate.textView?(aTextView, shouldInteractWith: URL, in: characterRange, interaction: interaction) == true
                }
            }
        }

        return true
    }

    @available(iOS 10.0, *)
    @objc public func textView(_ aTextView: UITextView, shouldInteractWith textAttachment: NSTextAttachment, in characterRange: NSRange, interaction: UITextItemInteraction) -> Bool {

        if delegate == nil {

            if let unwrapDelegate = textFieldViewCachedInfo(aTextView)?.textViewDelegate {
                if unwrapDelegate.responds(to: #selector(textView as (UITextView, NSTextAttachment, NSRange, UITextItemInteraction) -> Bool)) {
                    return unwrapDelegate.textView?(aTextView, shouldInteractWith: textAttachment, in: characterRange, interaction: interaction) == true
                }
            }
        }

        return true
    }

    @available(iOS, deprecated: 10.0)
    @objc public func textView(_ aTextView: UITextView, shouldInteractWith URL: URL, in characterRange: NSRange) -> Bool {

        if delegate == nil {

            if let unwrapDelegate = textFieldViewCachedInfo(aTextView)?.textViewDelegate {
                if unwrapDelegate.responds(to: #selector(textView as (UITextView, URL, NSRange) -> Bool)) {
                    return unwrapDelegate.textView?(aTextView, shouldInteractWith: URL, in: characterRange) == true
                }
            }
        }

        return true
    }

    @available(iOS, deprecated: 10.0)
    @objc public func textView(_ aTextView: UITextView, shouldInteractWith textAttachment: NSTextAttachment, in characterRange: NSRange) -> Bool {

        if delegate == nil {

            if let unwrapDelegate = textFieldViewCachedInfo(aTextView)?.textViewDelegate {
                if unwrapDelegate.responds(to: #selector(textView as (UITextView, NSTextAttachment, NSRange) -> Bool)) {
                    return unwrapDelegate.textView?(aTextView, shouldInteractWith: textAttachment, in: characterRange) == true
                }
            }
        }

        return true
    }
}