//
//  PhotoDetailListViewModel.swift
//  PaiaiDataKit
//
//  Created by FFIB on 2019/3/19.
//  Copyright © 2019 FFIB. All rights reserved.
//

import Foundation
import RxSwift
import RxCocoa
import RxDataSources

public protocol PhotoDetailViewModelDelegate: class {
    func didSelected()
    func navigateToGroup(_ item: GroupItem, photoItems: [PhotoItem])
}

public final class PhotoDetailViewModel {
    private var _items: BehaviorRelay<[PhotoItem]>
    private var itemViewModel: PhotoDetailItemViewModel
    private var purchaseViewModel: PhotoPurchaseViewModel
    private var _hasGetPrice = BehaviorRelay<Bool>(value: false)

    private var disposeBag = DisposeBag()

    public var currIndex: Int

    public var thumbupItems: Observable<[PhotoThumbupUserItem]> {
        return itemViewModel.thumbupItems.asObservable()
    }

    public var commentItems: Observable<[AnimatableSectionModel<Int, PhotoCommentItem>]> {
        return itemViewModel.commentItems.map ({ model in
            return [AnimatableSectionModel(model: 0, items: model)]
        })
    }

    public var group_name: Observable<String> {
        return itemViewModel.item.map({ val in
            return val.group_name
        })
    }

    public var group_avatar: Observable<Int> {
        return itemViewModel.item.map({ val in
            return val.group_default_avatar
        })
    }

    public var userName: Observable<String> {
        return itemViewModel.item.map({ val in
            return val.nickname
        })
    }

    public var userAvatar: Observable<String> {
        return itemViewModel.item.map({ val in
            return val.avatar
        })
    }

    public var photoTime: Observable<String> {
        return itemViewModel.item.map({ val in
            return val.create_at_time_interval
        })
    }

    public var thumbupCount: Observable<String> {
        return itemViewModel.thumbupItems.map({ val in
            return "(\(val.count))"
        })
    }

    public var commentCount: Observable<String> {
        return itemViewModel.commentItems.map({ val in
            return "(\(val.count))"
        })
    }

    public var canBuy: Observable<Bool> {
        return itemViewModel.item.map({ val in
            return val.display_payment_btn > 0
        })
    }

    public var watermarkImage: Observable<Bool> {
        return _hasGetPrice.asObservable()
    }

    public var watermarkText: Observable<String> {
        return _hasGetPrice.map ({ hasGetPrice in
            return hasGetPrice ? "￥\(CGFloat(self.itemViewModel.item.value.nomark) / 100)" : "去除水印"
        })
    }

    public var watermarkTextWithBought: Observable<String> {
        return itemViewModel.item.map({ val in
            return val.murl.isEmpty ? "去除水印" : "查看无水印照片"
        })
    }

    public var watermarkImageWithBought: Observable<Bool> {
        return itemViewModel.item.map({ val in
            return !val.murl.isEmpty
        })
    }

    public var isHiddenEnterGroupBtn = BehaviorRelay<Bool>(value: false)

    public var viewWillAppear = BehaviorRelay<Void>(value: ())
    public weak var delegate: PhotoDetailViewModelDelegate?

    public var content: Observable<[AnimatableSectionModel<Int, PhotoItem>]> {
        return _items.map({ model in
            return [AnimatableSectionModel(model: 0, items: model)]
        })
    }

    public init(items: [PhotoItem], currIndex: Int) {
        self._items = BehaviorRelay<[PhotoItem]>(value: items)
        self.currIndex = currIndex
        self.itemViewModel = PhotoDetailItemViewModel(item: items[currIndex])
        self.purchaseViewModel = PhotoPurchaseViewModel(item: items[currIndex])

        setNotification()
    }

    public func willShow(index: Int) {
        currIndex = index
        _hasGetPrice.accept(false)
        itemViewModel.item.accept(_items.value[index])
        purchaseViewModel.switchItem(item: _items.value[index])

        purchaseViewModel.notifyPhotoChanged.subscribe(onNext: payDidFinish(item:)).disposed(by: disposeBag)
    }

    public func submitThumbup() {
        itemViewModel.submitThumbup()
    }

    public func submitComment(text: String) {
        itemViewModel.submitComment(text: text)
    }

    public func purchase() {
        if !itemViewModel.item.value.murl.isEmpty {
            delegate?.didSelected()
            return
        }
        if !_hasGetPrice.value {
            _hasGetPrice.accept(true)
        } else {
            Toast.showActivity(message: "正在支付")
            purchaseViewModel.purchase()
        }
    }

    public func payDidFinish(item: PhotoItem) {
        var originItems = _items.value
        originItems[currIndex] = item
        _items.accept(originItems)
        itemViewModel.item.accept(item)
    }

    private func setNotification() {
        NotificationCenter.default.rx.notification(.PhotoItemsChanged).subscribe(onNext: { (notification) in
            guard let itemOperator = notification.userInfo?[PhotoItemsOperator.key] as? PhotoItemsOperator,
                case let .update(id, val) = itemOperator,
                let index = self._items.value.firstIndex(where: { $0.photo_id == id }) else { return }
            var items = self._items.value
            items[index] = val
            self._items.accept(items)
        }).disposed(by: disposeBag)
    }

}

extension PhotoDetailViewModel {
    public func navigateToGroup() {
        let currItem = _items.value[currIndex]
        delegate?.navigateToGroup(GroupItem(json: currItem.toJSON() as [String : AnyObject]),
                                  photoItems: _items.value.filter { $0.photo_id == currItem.photo_id })
    }

    public func didSelected() {
        delegate?.didSelected()
    }
}