/*
 * Copyright (c) 2010-2020 Belledonne Communications SARL.
 *
 * This file is part of linphone-iphone
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

import UIKit
import Foundation
import linphonesw

final class SheetViewController: UIViewController {
    
    private let collectionHeader = UICollectionView(frame: .zero, collectionViewLayout: UICollectionViewFlowLayout.init())
    private let collectionPage = UICollectionView(frame: .zero, collectionViewLayout: UICollectionViewFlowLayout.init())
    private let collectionHeaderIdentifier = "COLLECTION_HEADER_IDENTIFIER"
    private let collectionPageIdentifier = "COLLECTION_PAGE_IDENTIFIER"
    private var items = [UIViewController]()
    private var titles = [String]()
    private var colorHeaderActive = UIColor.blue
    private var colorHeaderInActive = UIColor.gray
    private var colorHeaderBackground = UIColor.white
    private var currentPosition = 0
    private var tabStyle = SlidingTabStyle.fixed
    private let heightHeader = 40
	var chatMessage : ChatMessage
	var chatMessageDelegate: ChatMessageDelegate? = nil

	/// Put your custom argument labels here, not inside the `required init?`
	init(chatMessageInit: ChatMessage) {
		self.chatMessage = chatMessageInit
		super.init(nibName: nil, bundle: nil)
	}
	
	/// This is in case the View Controller is loaded from the Storyboard
	required init?(coder: NSCoder) {
		fatalError("init(coder:) has not been implemented")
	}
	
	override func viewDidDisappear(_ animated: Bool) {
		super.viewDidDisappear(animated)
		if chatMessageDelegate != nil {
			chatMessage.removeDelegate(delegate: chatMessageDelegate!)
		}
	}
	
    override func viewDidLoad() {
        super.viewDidLoad()
        setupUI()
		addMessageDelegate()
    }
    
	func reloadUI() {
		items.removeAll()
		titles.removeAll()
		setupUI()
	}
	
	func addMessageDelegate(){
		chatMessageDelegate = ChatMessageDelegateStub(
			onNewMessageReaction: { (message: ChatMessage, messageReaction: ChatMessageReaction) -> Void in
				self.reloadUI()
			},
			onReactionRemoved: { (message: ChatMessage, address: Address) -> Void in
				self.reloadUI()
			}
		)
		chatMessage.addDelegate(delegate: chatMessageDelegate!)
	}
	
    private func setupUI(){
        // view
        view.backgroundColor = VoipTheme.voipBackgroundBWColor.get()
        
        navigationController?.navigationBar.barTintColor = .orange
        navigationController?.navigationBar.isTranslucent = false
        navigationController?.navigationBar.shadowImage = UIImage()
        navigationController?.navigationBar.titleTextAttributes = [NSAttributedString.Key.foregroundColor: UIColor.white]
        navigationController?.navigationBar.barStyle = .black
				
		if chatMessage.reactions.count <= 1 {
			addItem(item: SimpleItemViewController(chatMessageReactionsListInit: chatMessage.reactions), title: "\(chatMessage.reactions.count) REACTION")
		} else {
			addItem(item: SimpleItemViewController(chatMessageReactionsListInit: chatMessage.reactions), title: "\(chatMessage.reactions.count) REACTIONS")
		}
		
		let reaction1Count = chatMessage.reactions.filter({$0.body == "❤️"}).count
		let reaction2Count = chatMessage.reactions.filter({$0.body == "👍"}).count
		let reaction3Count = chatMessage.reactions.filter({$0.body == "😂"}).count
		let reaction4Count = chatMessage.reactions.filter({$0.body == "😮"}).count
		let reaction5Count = chatMessage.reactions.filter({$0.body == "😢"}).count
		
		if reaction1Count > 0 {
			addItem(item: SimpleItemViewController(chatMessageReactionsListInit: chatMessage.reactions.filter({$0.body == "❤️"})), title: "❤️ \(reaction1Count)")
		}
		if reaction2Count > 0 {
			addItem(item: SimpleItemViewController(chatMessageReactionsListInit: chatMessage.reactions.filter({$0.body == "👍"})), title: "👍 \(reaction2Count)")
		}
		if reaction3Count > 0 {
			addItem(item: SimpleItemViewController(chatMessageReactionsListInit: chatMessage.reactions.filter({$0.body == "😂"})), title: "😂 \(reaction3Count)")
		}
		if reaction4Count > 0 {
			addItem(item: SimpleItemViewController(chatMessageReactionsListInit: chatMessage.reactions.filter({$0.body == "😮"})), title: "😮 \(reaction4Count)")
		}
		if reaction5Count > 0 {
			addItem(item: SimpleItemViewController(chatMessageReactionsListInit: chatMessage.reactions.filter({$0.body == "😢"})), title: "😢 \(reaction5Count)")
		}
		
		setHeaderActiveColor(color: .orange) // default blue
		setStyle(style: .fixed) // default fixed
		build()
    }
    
    func addItem(item: UIViewController, title: String){
        items.append(item)
        titles.append(title)
    }
    
    func setHeaderBackgroundColor(color: UIColor){
        colorHeaderBackground = color
    }
    
    func setHeaderActiveColor(color: UIColor){
        colorHeaderActive = color
    }
    
    func setHeaderInActiveColor(color: UIColor){
        colorHeaderInActive = color
    }
	
	func setCurrentPosition(position: Int){
		currentPosition = position
		let path = IndexPath(item: currentPosition, section: 0)
		
		DispatchQueue.main.async {
			if self.tabStyle == .flexible {
				self.collectionHeader.scrollToItem(at: path, at: .centeredHorizontally, animated: true)
			}
			
			self.collectionHeader.reloadData()
		}
		
		DispatchQueue.main.async {
			self.collectionPage.isPagingEnabled = false
			self.collectionPage.scrollToItem(
				at: path,
				at: .centeredHorizontally,
				animated: true
			)
			self.collectionPage.isPagingEnabled = true
		}
	}
    
    func setStyle(style: SlidingTabStyle){
        tabStyle = style
    }
    
    func build(){
        // view
        view.addSubview(collectionHeader)
        view.addSubview(collectionPage)
        
        // collectionHeader
        collectionHeader.translatesAutoresizingMaskIntoConstraints = false
        collectionHeader.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor, constant: 20).isActive = true
        collectionHeader.leadingAnchor.constraint(equalTo: view.leadingAnchor).isActive = true
        collectionHeader.trailingAnchor.constraint(equalTo: view.trailingAnchor).isActive = true
        collectionHeader.heightAnchor.constraint(equalToConstant: CGFloat(heightHeader)).isActive = true
        (collectionHeader.collectionViewLayout as? UICollectionViewFlowLayout)?.scrollDirection = .horizontal
        collectionHeader.showsHorizontalScrollIndicator = false
        collectionHeader.backgroundColor = VoipTheme.voipBackgroundBWColor.get()
        collectionHeader.register(HeaderCell.self, forCellWithReuseIdentifier: collectionHeaderIdentifier)
        collectionHeader.delegate = self
        collectionHeader.dataSource = self
        collectionHeader.reloadData()
        
        // collectionPage
        collectionPage.translatesAutoresizingMaskIntoConstraints = false
        collectionPage.topAnchor.constraint(equalTo: collectionHeader.bottomAnchor).isActive = true
        collectionPage.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
        collectionPage.leadingAnchor.constraint(equalTo: view.leadingAnchor).isActive = true
        collectionPage.trailingAnchor.constraint(equalTo: view.trailingAnchor).isActive = true
        collectionPage.backgroundColor = VoipTheme.voipBackgroundBWColor.get()
        collectionPage.showsHorizontalScrollIndicator = false
        (collectionPage.collectionViewLayout as? UICollectionViewFlowLayout)?.scrollDirection = .horizontal
        collectionPage.isPagingEnabled = true
        collectionPage.register(UICollectionViewCell.self, forCellWithReuseIdentifier: collectionPageIdentifier)
        collectionPage.delegate = self
        collectionPage.dataSource = self
        collectionPage.reloadData()
    }
    
    private class HeaderCell: UICollectionViewCell {
        
        private let label = UILabel()
        private let indicator = UIView()
    
        var text: String! {
            didSet {
                label.text = text
				if label.text!.contains("REACTIONS") {
					label.font = UIFont.boldSystemFont(ofSize: 8)
				} else {
					label.font = UIFont.boldSystemFont(ofSize: 14)
				}
            }
        }
        
        override init(frame: CGRect) {
            super.init(frame: frame)
            setupUI()
        }
        
        required init?(coder aDecoder: NSCoder) {
            fatalError("init(coder:) has not been implemented")
        }
        
        func select(didSelect: Bool, activeColor: UIColor, inActiveColor: UIColor){
            indicator.backgroundColor = activeColor
            
            if didSelect {
                label.textColor = activeColor
                indicator.isHidden = false
            }else{
                label.textColor = inActiveColor
                indicator.isHidden = true
            }
        }
        
        private func setupUI(){
            // view
            self.addSubview(label)
            self.addSubview(indicator)
            
            // label
            label.translatesAutoresizingMaskIntoConstraints = false
            label.centerXAnchor.constraint(equalTo: self.centerXAnchor).isActive = true
            label.centerYAnchor.constraint(equalTo: self.centerYAnchor).isActive = true
            label.font = UIFont.boldSystemFont(ofSize: 14)
            
            // indicator
            indicator.translatesAutoresizingMaskIntoConstraints = false
            indicator.bottomAnchor.constraint(equalTo: self.bottomAnchor).isActive = true
            indicator.leadingAnchor.constraint(equalTo: self.leadingAnchor).isActive = true
            indicator.trailingAnchor.constraint(equalTo: self.trailingAnchor).isActive = true
            indicator.heightAnchor.constraint(equalToConstant: 2).isActive = true
        }
        
    }
    
}

extension SheetViewController: UICollectionViewDelegate{
    func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
        setCurrentPosition(position: indexPath.row)
    }
    
    func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {
        if scrollView == collectionPage{
            let currentIndex = Int(self.collectionPage.contentOffset.x / collectionPage.frame.size.width)
            setCurrentPosition(position: currentIndex)
        }
    }
}

extension SheetViewController: UICollectionViewDataSource{
    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        if collectionView == collectionHeader {
            return titles.count
        }
        
        return items.count
    }
    
    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        if collectionView == collectionHeader {
            let cell = collectionView.dequeueReusableCell(withReuseIdentifier: collectionHeaderIdentifier, for: indexPath) as! HeaderCell
            cell.text = titles[indexPath.row]
            
            var didSelect = false
            
            if currentPosition == indexPath.row {
                didSelect = true
            }
            
            cell.select(didSelect: didSelect, activeColor: colorHeaderActive, inActiveColor: colorHeaderInActive)
            
            return cell
        }
        
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: collectionPageIdentifier, for: indexPath)
        let vc = items[indexPath.row]
        
        cell.addSubview(vc.view)
        
        vc.view.translatesAutoresizingMaskIntoConstraints = false
        vc.view.topAnchor.constraint(equalTo: cell.topAnchor, constant: 28).isActive = true
        vc.view.leadingAnchor.constraint(equalTo: cell.leadingAnchor).isActive = true
        vc.view.trailingAnchor.constraint(equalTo: cell.trailingAnchor).isActive = true
        vc.view.bottomAnchor.constraint(equalTo: cell.bottomAnchor).isActive = true
        
        return cell
    }
}

extension SheetViewController: UICollectionViewDelegateFlowLayout{
    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        if collectionView == collectionHeader {
            if tabStyle == .fixed {
                let spacer = CGFloat(titles.count)
                return CGSize(width: view.frame.width / spacer, height: CGFloat(heightHeader))
            }else{
                return CGSize(width: view.frame.width * 20 / 100, height: CGFloat(heightHeader))
            }
        }
        
        return CGSize(width: view.frame.width, height: view.frame.height)
    }
    
    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
        if collectionView == collectionHeader {
            return 0
        }
        
        return 0
    }
}

enum SlidingTabStyle: String {
    case fixed
    case flexible
}

class SimpleItemViewController: UIViewController, UITableViewDataSource {
	
	let reactionsListTableView =  UITableView()
	var chatMessageReactionsList : [ChatMessageReaction] = []
	
	init(chatMessageReactionsListInit: [ChatMessageReaction]) {
		self.chatMessageReactionsList = chatMessageReactionsListInit
		super.init(nibName: nil, bundle: nil)
	}
	
	/// This is in case the View Controller is loaded from the Storyboard
	required init?(coder: NSCoder) {
		fatalError("init(coder:) has not been implemented")
	}
	
	
    override func viewDidLoad() {
        super.viewDidLoad()
        setupUI()
    }
    
    private func setupUI(){
        // view
        view.backgroundColor = VoipTheme.voipBackgroundBWColor.get()
		
		// ParticipantsList
		view.addSubview(reactionsListTableView)
		reactionsListTableView.alignParentTop(withMargin: 10).alignParentBottom().alignParentLeft().alignParentRight().done()
		reactionsListTableView.dataSource = self
		reactionsListTableView.register(ReactionCell.self, forCellReuseIdentifier: "ReactionCell")
		reactionsListTableView.allowsSelection = false
		if #available(iOS 15.0, *) {
			reactionsListTableView.allowsFocus = false
		}
		reactionsListTableView.separatorStyle = .singleLine
		reactionsListTableView.separatorColor = .white
    }
	
	func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
		return chatMessageReactionsList.count
	}
	
	func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
		let cell:ReactionCell = tableView.dequeueReusableCell(withIdentifier: "ReactionCell") as! ReactionCell
		cell.selectionStyle = .none
		cell.reactionData = chatMessageReactionsList[indexPath.row]
		return cell
	}
}