//
//  CustomExtensions.swift
//  Pods-AARxSwiftExtensions
//
//  Created by Arlind on 8/12/18.
//

import UIKit
import RxSwift
import CoreLocation
import RxCocoa

extension Reactive where Base: NotificationCenter {
    public func notification(_ name: Notification.Name, object: AnyObject? = nil) -> Observable<Notification> {
        return Observable.create { notificationObserver in
            let observer = self.base.addObserver(forName: name, object: object, queue: nil) { notification in
                notificationObserver.onNext(notification)
            }
            return Disposables.create {
                self.base.removeObserver(observer)
            }
        }
    }
}

class RxUIScrollViewDelegateProxy: DelegateProxy<UIScrollView,
    UIScrollViewDelegate>, DelegateProxyType, UIScrollViewDelegate
{
    static func registerKnownImplementations() {
        self.register { RxUIScrollViewDelegateProxy(scollView: $0) }
    }

    public weak private(set) var scollView: UIScrollView?
    public init(scollView: ParentObject) {
        self.scollView = scollView
        super.init(parentObject: scollView, delegateProxy:
            RxUIScrollViewDelegateProxy.self)
    }
}

extension Reactive where Base: UIScrollView {
    public var delegate: DelegateProxy<UIScrollView,
        UIScrollViewDelegate> {
        return RxUIScrollViewDelegateProxy.proxy(for: base)
    }

    var contentOffset: Observable<CGPoint> {
        return
            delegate.methodInvoked(#selector(UIScrollViewDelegate.scrollViewDidScroll(_:)))
                .map { obcjects in
                    let scrollView = obcjects[0] as! UIScrollView
                    return scrollView.contentOffset
        }
    }
}

extension UIScrollView {
    func bindKeyboardEvents() -> Disposable {
        let observable =
            Observable.from([
                NotificationCenter.default.rx.notification(Notification.Name.UIKeyboardWillShow) .map { notification in
                    let keyboardFrame = notification.userInfo![UIKeyboardFrameEndUserInfoKey] as! CGRect
                    let keyboardHeight: CGFloat = keyboardFrame.height
                    return keyboardHeight
                },
                NotificationCenter.default.rx.notification(Notification.Name.UIKeyboardWillHide) .map { _ in CGFloat(0) }])
                .merge()
                .observeOn(MainScheduler.instance)

        return observable.subscribe(onNext: { [weak self] keyboardHeight in
            self?.contentInset.bottom = keyboardHeight
            self?.scrollIndicatorInsets.bottom = keyboardHeight
        })
    }

    func loadNextPageObservable() -> Observable<Void> {
        return rx.contentOffset
            .skipWhile {
                $0.y < self.frame.size.height
            }.map { contentOffset -> Bool in
                let padding = CGFloat(20.0)
                return contentOffset.y + self.frame.size.height + padding > self.contentSize.height
            }.distinctUntilChanged().map { shouldLoad in
                if shouldLoad {
                    Void()
                }
        }
    }
}

extension Date {
    func formattedForView() -> String {
        let formatter = DateFormatter()
        formatter.dateFormat = "MM/dd/yyyy"
        return formatter.string(from: self)
    }
}