//
//  SelectorGroupHandlerable.swift
//  VDS
//
//  Created by Matt Bruce on 8/23/22.
//

import Foundation
import UIKit

///MARK:  Groups that allow anything selected
public protocol SelectorGroupModelHandlerable: ModelHandlerable, Disabling, Surfaceable where ModelType: SelectorGroupModelable {
    associatedtype ModelHandlerType: ModelHandlerable where ModelType.SelectorModelType == ModelHandlerType.ModelType, ModelHandlerType: UIControl
    var selectorViews: [ModelHandlerType] { get set }
    func createModelHandler(selector: ModelHandlerType.ModelType) -> ModelHandlerType
}

extension SelectorGroupModelHandlerable {
    
    public func findSelectorView(id: UUID) -> ModelHandlerType? {
        return selectorViews.first(where: { existingSelectorView in
            return existingSelectorView.model.id == id
        })
    }
    
    public func createModelHandler(selector: ModelHandlerType.ModelType) -> ModelHandlerType {
        //create view
        let newSelectorView = ModelHandlerType(with: selector)
        
        //add model update to the subscribers
        newSelectorView.handlerPublisher()
            .sink { [weak self] model in
                if let cached = self?.getCachedSelector(viewModel: model), newSelectorView.shouldUpdateView(viewModel: cached) {
                    self?.replace(viewModel: model)
                }
            }
            .store(in: &subscribers)
        
        return newSelectorView
    }
    
    public func updateSelectors(){
        let selectors = model.selectors.compactMap { existing in
            return existing.copyWith {
                $0.disabled = disabled
                $0.surface = surface
            }
        }
        model.selectors = selectors
    }

    public func getCachedSelector(viewModel: ModelHandlerType.ModelType) -> ModelHandlerType.ModelType? {
        if let  index = model.selectors.firstIndex(where: { element in
            return element.id == viewModel.id
        }) {
            return model.selectors[index]
        } else {
            return nil
        }
    }
    
    public func replace(viewModel: ModelHandlerType.ModelType){
        if let  index = model.selectors.firstIndex(where: { element in
            return element.id == viewModel.id
        }) {
            model.selectors[index] = viewModel
        }
    }
}

///MARK:  Groups that allow single selections
public protocol SelectorGroupSelectedModelHandlerable: SelectorGroupModelHandlerable {
    var selectedModel: ModelHandlerType.ModelType? { get set }
    func didSelect(selector: ModelHandlerType.ModelType)
}

extension SelectorGroupSelectedModelHandlerable {
    
    public func createModelHandler(selector: ModelHandlerType.ModelType) -> ModelHandlerType {
        //create view
        let newSelectorView = ModelHandlerType(with: selector)
        
        //add the selectedPublisher for the change
        newSelectorView.publisher(for: .valueChanged)
            .sink(receiveValue: { [weak self] control in
                guard self?.model.selectors.count ?? 0 > 0 else { return }
                self?.didSelect(selector: control.model)
            })
            .store(in: &subscribers)
        
        //add model update to the subscribers
        newSelectorView.handlerPublisher()
            .sink { [weak self] model in
                if let cached = self?.getCachedSelector(viewModel: model), newSelectorView.shouldUpdateView(viewModel: cached) {
                    self?.replace(viewModel: model)
                }
            }
            .store(in: &subscribers)
        
        return newSelectorView
    }
    
    public func didSelect(selector: ModelHandlerType.ModelType) {
        if var oldSelectedModel = selectedModel {
            oldSelectedModel.selected = false
            replace(viewModel: oldSelectedModel)
        }
        
        //only select is selected
        if selector.selected {
            var newSelectedModel = selector
            newSelectedModel.selected = true
            replace(viewModel: newSelectedModel)
            selectedModel = newSelectedModel
        } else {
            //ensure current value is removed
            selectedModel = nil
        }
    }
}