//
//  GroupDetailViewModel.swift
//  PaiaiDataKit
//
//  Created by FFIB on 2017/1/3.
//  Copyright © 2017年 FFIB. All rights reserved.
//

import Foundation
import RxSwift
import RxCocoa

public protocol GroupDetailViewModelDelegate: class {
    func navigateToGroupMember(_ item: GroupDetailItem)
    func navigateToGroupNameModification(_ item: GroupDetailItem)
    func navigateToRootViewController()
    func navigationBackToGroupDetail()
}

public class GroupDetailViewModel {
    
    private let repository: GroupDetailRepository
    private var disposeBag = DisposeBag()
    
    public weak var delegate: GroupDetailViewModelDelegate?
    
    public let didQuit = PublishSubject<Void>()
    public let item: BehaviorRelay<GroupDetailItem>
    
    public var groupName: Observable<String> {
        return item.asObservable().flatMapLatest({ (item) -> Observable<String> in
            return Observable.just(item.group.group_name)
        })
    }
    
    public var groupMembers: Observable<[GroupMemberItem]> {
        return item.asObservable().flatMapLatest({ (item) -> Observable<[GroupMemberItem]> in
            return Observable.just(item.users)
        })
    }
    
    public var groupMemberCount: Observable<String> {
        return item.asObservable().flatMapLatest({ (item) -> Observable<String> in
            return Observable.just("\(item.users.count)")
        })
    }
    
    public var isAdmin: Observable<Bool> {
        return item.asObservable().flatMapLatest({ (item) -> Observable<Bool> in
            return Observable.just(item.group.admin_id == ShareUserId)
        })
    }
    
    public var groupLock: Observable<Bool> {
        return item.asObservable().flatMapLatest({ (item) -> Observable<Bool> in
            return Observable.just(item.group.group_lock)
        })
    }
    
    public init(item: GroupItem) {
        self.repository = PhotoGroupDetailRepository(groupId: item.group_id)
        
        var groupDetailItem = GroupDetailItem(json: [:])
        groupDetailItem.group = item
        self.item = BehaviorRelay<GroupDetailItem>(value: groupDetailItem)
    }
    
    public func toggle(isLock: Bool) {
        if isLock {
            repository.lock().subscribe(onCompleted: {
                var v = self.item.value
                v.group.group_lock = true
                self.item.accept(v)
                Toast.show(message: "群已锁定")
            }).disposed(by: disposeBag)
        } else {
            repository.unlock().subscribe(onCompleted: {
                var v = self.item.value
                v.group.group_lock = false
                Toast.show(message: "群未锁定")
            }).disposed(by: disposeBag)
        }
    }
    
    public func reload() {
        repository.load().subscribe(onSuccess: {[unowned self] (v) in
            self.item.accept(v)
        }, onError: nil).disposed(by: disposeBag)
    }
    
    public func quit() {
        guard item.value.group.admin_id != ShareUserId else {
            Toast.show(message: "群主不能退出群")
            return
        }
        Toast.showActivity(message: "正在退出群")
        repository.quit()
            .subscribe(onCompleted: {[unowned self] in
                Toast.show(message: "退出群成功")
                self.didQuit.onNext(())
                NotificationCenter.default.post(name: .GroupItemsChanged, object: nil, userInfo: [GroupItemsOperator.key: GroupItemsOperator.remove(self.item.value.group_id)])
                self.delegate?.navigateToRootViewController()
            }).disposed(by: disposeBag)
    }
    
    public func changeName(name: String) {
        repository.update(name: name)
            .subscribe(onCompleted: {[unowned self] in
                Toast.show(message: "群名称已修改")
                var v = self.item.value
                v.group.group_name = name
                self.item.accept(v)
                NotificationCenter.default.post(name: .GroupItemsChanged, object: nil, userInfo: [GroupItemsOperator.key: GroupItemsOperator.update(v.group_id, v.group)])
                self.delegate?.navigationBackToGroupDetail()
        }).disposed(by: disposeBag)
    }
}

public extension GroupDetailViewModel {
    func navigateToGroupMember() {
        delegate?.navigateToGroupMember(item.value)
    }
    
    func navigateToGroupNameModification() {
        delegate?.navigateToGroupNameModification(item.value)
    }
}