//
//  GroupViewModel.swift
//  PaiAi
//
//  Created by zhengjianfei on 2017/1/4.
//  Copyright © 2017年 FFIB. All rights reserved.
//

import UIKit
import RxSwift
import RxCocoa
import RxDataSources

public protocol GroupViewModelDelegate: class {
    func didSelect(_ item: PhotoItem)
    func navigateToGroupDetail()
}

public class GroupViewModel {
    
    private let disposeBag = DisposeBag()
    
    private var respository: GroupPhotoRepository
    
    private var _isLoading = PublishSubject<Void>()
    private let items = BehaviorRelay<[PhotoItem]>(value: [])
    
    
    public var isLoading: Observable<Void> {
        return _isLoading.asObservable()
    }

    public var contents: Observable<[AnimatableSectionModel<Int, PhotoItem>]> {
        return items.map({ model in
            return [AnimatableSectionModel(model: 0, items: model)]
        })
    }
    
    public weak var delegate: GroupViewModelDelegate?
    
    public init(groupItem: GroupItem) {
        self.respository = GroupPhotoRepository(groupId: groupItem.group_id)
    }
    
    public func reload() {
        respository.load()
            .subscribe(onSuccess: {[weak self] (result) in
                guard let `self` = self else { return }
                self._isLoading.onNext(())
                self.items.accept(result)
                }, onError: {[weak self] (error) in
                    guard let `self` = self else { return }
                    self._isLoading.onNext(())
            }).disposed(by: disposeBag)
    }

    public func submit(data: Data) {
        respository.upload(data: data).subscribe(onSuccess: { [weak self] result in
            guard let `self` = self else { return }
            self.items.accept(result)
            self._isLoading.onNext(())
        }) {[weak self] (error) in
            guard let  `self` = self else { return }
            self._isLoading.onNext(())
        }.disposed(by: disposeBag)
    }
    
    public func layoutSizeForIndexPath(_ indexPath: IndexPath) -> CGSize {
        let item = items.value[indexPath.row]
        let w = item.photo_thumbnail_w
        let h = item.photo_thumbnail_h

        //        header 42, footer: 32
        return CGSize(width: w, height: h + 74)
    }
}

/// GroupViewModelDelegate
public extension GroupViewModel {
    func didSelect(_ item: PhotoItem) {
        delegate?.didSelect(item)
    }
    
    @objc func navigateToGroupDetail() {
        delegate?.navigateToGroupDetail()
    }
}