//
//  MineOrderViewModel.swift
//  PaiAi
//
//  Created by LISA on 2017/5/8.
//  Copyright © 2017年 yb. All rights reserved.
//

import UIKit
import RxSwift
import RxCocoa
import RxDataSources

public protocol MineOrderViewModelDelegate: class {
    func didSelect(_ item: OrderItem)
}

public class MineOrderViewModel {
    
    private var repository: OrderRepository
    private var disposeBag = DisposeBag()
    private var page = 1
    
    private var _isLoading = PublishSubject<Bool>()
    private var _isEmpty = BehaviorRelay<Bool>(value: false)
    private var _hasMoreData = PublishSubject<Bool>()
    private var _showMessage = PublishSubject<String>()
    private let items = BehaviorRelay<[OrderItem]>(value: [])
    
    public weak var delegate: MineOrderViewModelDelegate?
    
    public var isEmpty: Observable<Bool> {
        return _isEmpty.asObservable()
    }
    
    public var hasMoreData: Observable<Bool> {
        return _hasMoreData.asObservable()
    }
    
    public var isLoading: Observable<Bool> {
        return _isLoading.asObserver()
    }
    
    public init() {
        self.repository = OrderRepository()
    }
    
    public var contents: Observable<[AnimatableSectionModel<Int, OrderItem>]> {
        return items.map({ model in
            return [AnimatableSectionModel(model: 0, items: model)]
        })
    }
    
    public func reload() {
        page = 1
        repository.load(page: page)
            .asDriver(onErrorJustReturn: NetworkArrayData<OrderItem>.empty())
            .drive(onNext: {[weak self] (model) in
                guard let `self` = self else { return }
                self._hasMoreData.onNext(model.hasMore)
                self._isEmpty.accept(!model.data.isEmpty)
                
                self.items.accept(model.data)
                }, onDisposed: {[weak self] in
                    guard let `self` = self else { return }
                    self._isLoading.onNext(true)
            }).disposed(by: disposeBag)
    }
    
    public func preload() {
        page += 1
        
        repository.load(page: page)
            .asDriver(onErrorJustReturn: NetworkArrayData<OrderItem>.empty())
            .drive(onNext: {[weak self] (model) in
                guard let `self` = self else { return }
                self._hasMoreData.onNext(model.hasMore)
                self.items.accept(self.items.value + model.data)
                }, onDisposed: {[weak self] in
                    guard let `self` = self else { return }
                    self._isLoading.onNext(false)
            }).disposed(by: disposeBag)
    }
    
    public func didSelect(_ item: OrderItem) {
        delegate?.didSelect(item)
    }
}