//
//  PhotoPreviewViewController.swift
//  PaiAi
//
//  Created by zhengjianfei on 16/4/9.
//  Copyright © 2016年 FFIB. All rights reserved.
//

import UIKit
import PaiaiDataKit
import PaiaiUIKit
import RxCocoa
import RxSwift
import RxDataSources

final class PhotoPreviewViewController: UIViewController {

    /// MARK: Storyboard property
    @IBOutlet weak var collectionView: UICollectionView!
    var viewModel: PhotoDetailListViewModel!
    var disposeBag = DisposeBag()
    
    override var prefersStatusBarHidden: Bool {
        return true
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()
        binding()
        scrollToSpecifiedImage()
        navigationController?.setNavigationBarHidden(true, animated: true)
        
    }
    
    func scrollToSpecifiedImage() {
        collectionView.layoutIfNeeded()
        collectionView.scrollToItem(at: IndexPath(item: viewModel.currIndex, section: 0), at: .right, animated: false)
    }
    
    override func viewDidAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        bindCollectionViewToViewModel()
    }
    
    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        navigationController?.setNavigationBarHidden(false, animated: true)
    }
    
    @objc func image(_ image: UIImage?, didFinishSavingWithError error: NSError?, contextInfo info: UnsafeMutableRawPointer) {
        if error != nil {
            Toast.show(message: "保存照片失败")
        } else {
            Toast.show(message: "已保存照片到相册中", image: UIImage(named: "icon-success"))
        }
    }
    var angle: CGFloat = 0
}

/// binding
extension PhotoPreviewViewController {
    
    var dataSource: RxCollectionViewSectionedAnimatedDataSource<AnimatableSectionModel<Int, PhotoItem>> {
        return RxCollectionViewSectionedAnimatedDataSource<AnimatableSectionModel<Int, PhotoItem>>(configureCell: { (dataSource, collectionView, indexPath, item) in
            let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "imageCell", for: indexPath) as! ImageCell
            cell.setModel(url: item.murl.isEmpty ? item.photo_url : item.murl)
            return cell
        })
    }
    
    func binding() {
        bindViewModelToCollectionView()
        bindCollectionViewDelegate()
    }
    
    func bindViewModelToCollectionView() {
        viewModel.content
            .bind(to: collectionView.rx.items(dataSource: dataSource))
            .disposed(by: disposeBag)
    }
    
    func bindCollectionViewDelegate() {
        collectionView.rx.setDelegate(self).disposed(by: disposeBag)
    }
    
    func bindCollectionViewToViewModel() {
        collectionView.rx.willDisplayCell
            .asDriver()
            .drive(onNext: { [unowned self] in self.viewModel.willShow(index: $0.at.row) })
            .disposed(by: disposeBag)
    }
}

/// storyboard button action
extension PhotoPreviewViewController {
    @IBAction  func back() {
        dismissController()
    }
    
    @IBAction func rotateTheImage(_ sender: UIButton) {
        guard let cell = collectionView.cellForItem(at: IndexPath(item: viewModel.currIndex, section: 0)) as? ImageCell else {
            return
        }
        cell.rotate()
    }
    
    @IBAction func download(_ sender: UIButton) {
        Toast.showActivity(message: "正在保存照片到相册")
        guard let cell = collectionView.cellForItem(at: IndexPath(item: viewModel.currIndex, section: 0)) as? ImageCell,
            let image = cell.photoImage.image else {
                Toast.show(message: "未检测到照片")
                return
        }
        
        UIImageWriteToSavedPhotosAlbum(image, self, #selector(image(_:didFinishSavingWithError:contextInfo:)), nil)
    }
}

// MARK: UICollectionView delegate
extension PhotoPreviewViewController: UICollectionViewDelegateFlowLayout {

    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        return CGSize(width: collectionView.width, height: collectionView.height - 20)
    }
}