import Foundation
import UIKit
import AsyncDisplayKit
import Display
import TelegramCore
import SyncCore
import Postbox
import SwiftSignalKit
import TelegramPresentationData
import AlertUI
import PresentationDataUtils
import PeerInfoUI
import UndoUI

private enum SubscriberAction: Equatable {
    case join
    case kicked
    case muteNotifications
    case unmuteNotifications
    case unpinMessages(Int)
    case hidePinnedMessages
}

private func titleAndColorForAction(_ action: SubscriberAction, theme: PresentationTheme, strings: PresentationStrings) -> (String, UIColor) {
    switch action {
        case .join:
            return (strings.Channel_JoinChannel, theme.chat.inputPanel.panelControlAccentColor)
        case .kicked:
            return (strings.Channel_JoinChannel, theme.chat.inputPanel.panelControlDisabledColor)
        case .muteNotifications:
            return (strings.Conversation_Mute, theme.chat.inputPanel.panelControlAccentColor)
        case .unmuteNotifications:
            return (strings.Conversation_Unmute, theme.chat.inputPanel.panelControlAccentColor)
        case .unpinMessages:
            return (strings.Chat_PanelUnpinAllMessages, theme.chat.inputPanel.panelControlAccentColor)
        case .hidePinnedMessages:
            return (strings.Chat_PanelHidePinnedMessages, theme.chat.inputPanel.panelControlAccentColor)
    }
}

private func actionForPeer(peer: Peer, interfaceState: ChatPresentationInterfaceState, isMuted: Bool) -> SubscriberAction? {
    if case .pinnedMessages = interfaceState.subject {
        var canManagePin = false
        if let channel = peer as? TelegramChannel {
            canManagePin = channel.hasPermission(.pinMessages)
        } else if let group = peer as? TelegramGroup {
            switch group.role {
                case .creator, .admin:
                    canManagePin = true
                default:
                    if let defaultBannedRights = group.defaultBannedRights {
                        canManagePin = !defaultBannedRights.flags.contains(.banPinMessages)
                    } else {
                        canManagePin = true
                    }
            }
        } else if let _ = peer as? TelegramUser, interfaceState.explicitelyCanPinMessages {
            canManagePin = true
        }
        if canManagePin {
            return .unpinMessages(max(1, interfaceState.pinnedMessage?.totalCount ?? 1))
        } else {
            return .hidePinnedMessages
        }
    } else {
        if let channel = peer as? TelegramChannel {
            switch channel.participationStatus {
                case .kicked:
                    return .kicked
                case .left:
                    return .join
                case .member:
                    if isMuted {
                        return .unmuteNotifications
                    } else {
                        return .muteNotifications
                    }
            }
        } else {
            if isMuted {
                return .unmuteNotifications
            } else {
                return .muteNotifications
            }
        }
    }
}

private let badgeFont = Font.regular(14.0)

final class ChatChannelSubscriberInputPanelNode: ChatInputPanelNode {
    private let button: HighlightableButtonNode
    private let discussButton: HighlightableButtonNode
    private let discussButtonText: ImmediateTextNode
    private let badgeBackground: ASImageNode
    private let badgeText: ImmediateTextNode
    private let activityIndicator: UIActivityIndicatorView
    
    private let helpButton: HighlightableButtonNode
    
    private var action: SubscriberAction?
    
    private let actionDisposable = MetaDisposable()
    private let badgeDisposable = MetaDisposable()
    
    private var presentationInterfaceState: ChatPresentationInterfaceState?
    
    private var layoutData: (CGFloat, CGFloat, CGFloat)?
    
    override init() {
        self.button = HighlightableButtonNode()
        self.discussButton = HighlightableButtonNode()
        self.activityIndicator = UIActivityIndicatorView(style: .gray)
        self.activityIndicator.isHidden = true
        
        self.discussButtonText = ImmediateTextNode()
        self.discussButtonText.displaysAsynchronously = false
        
        self.badgeBackground = ASImageNode()
        self.badgeBackground.displaysAsynchronously = false
        self.badgeBackground.displayWithoutProcessing = true
        self.badgeBackground.isHidden = true
        
        self.badgeText = ImmediateTextNode()
        self.badgeText.displaysAsynchronously = false
        self.badgeText.isHidden = true
        
        self.helpButton = HighlightableButtonNode()
        
        self.discussButton.addSubnode(self.discussButtonText)
        self.discussButton.addSubnode(self.badgeBackground)
        self.discussButton.addSubnode(self.badgeText)
        
        super.init()
        
        self.addSubnode(self.button)
        self.addSubnode(self.discussButton)
        self.view.addSubview(self.activityIndicator)
        self.addSubnode(self.helpButton)
        
        self.button.addTarget(self, action: #selector(self.buttonPressed), forControlEvents: .touchUpInside)
        self.discussButton.addTarget(self, action: #selector(self.discussPressed), forControlEvents: .touchUpInside)
        self.helpButton.addTarget(self, action: #selector(self.helpPressed), forControlEvents: .touchUpInside)
    }
    
    deinit {
        self.actionDisposable.dispose()
        self.badgeDisposable.dispose()
    }
    
    override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
        if !self.bounds.contains(point) {
            return nil
        }
        return super.hitTest(point, with: event)
    }
    
    @objc func helpPressed() {
        self.interfaceInteraction?.presentGigagroupHelp()
    }
    
    @objc func buttonPressed() {
        guard let context = self.context, let action = self.action, let presentationInterfaceState = self.presentationInterfaceState, let peer = presentationInterfaceState.renderedPeer?.peer else {
            return
        }
        
        switch action {
        case .join:
            self.activityIndicator.isHidden = false
            self.activityIndicator.startAnimating()
            self.actionDisposable.set((context.peerChannelMemberCategoriesContextsManager.join(account: context.account, peerId: peer.id)
            |> afterDisposed { [weak self] in
                Queue.mainQueue().async {
                    if let strongSelf = self {
                        strongSelf.activityIndicator.isHidden = true
                        strongSelf.activityIndicator.stopAnimating()
                    }
                }
            }).start(error: { [weak self] error in
                guard let strongSelf = self, let presentationInterfaceState = strongSelf.presentationInterfaceState, let peer = presentationInterfaceState.renderedPeer?.peer else {
                    return
                }
                let text: String
                switch error {
                case .tooMuchJoined:
                    strongSelf.interfaceInteraction?.getNavigationController()?.pushViewController(oldChannelsController(context: context, intent: .join, completed: { value in
                        if value {
                            self?.buttonPressed()
                        }
                    }))
                    return
                default:
                    if let channel = peer as? TelegramChannel, case .broadcast = channel.info {
                        text = presentationInterfaceState.strings.Channel_ErrorAccessDenied
                    } else {
                        text = presentationInterfaceState.strings.Group_ErrorAccessDenied
                    }
                }
                strongSelf.interfaceInteraction?.presentController(textAlertController(context: context, title: nil, text: text, actions: [TextAlertAction(type: .defaultAction, title: presentationInterfaceState.strings.Common_OK, action: {})]), nil)
            }))
        case .kicked:
            break
        case .muteNotifications, .unmuteNotifications:
            if let context = self.context, let presentationInterfaceState = self.presentationInterfaceState, let peer = presentationInterfaceState.renderedPeer?.peer {
                self.actionDisposable.set(togglePeerMuted(account: context.account, peerId: peer.id).start())
            }
        case .hidePinnedMessages, .unpinMessages:
            self.interfaceInteraction?.unpinAllMessages()
        }
    }
    
    @objc private func discussPressed() {
        if let presentationInterfaceState = self.presentationInterfaceState, let peerDiscussionId = presentationInterfaceState.peerDiscussionId {
            self.interfaceInteraction?.navigateToChat(peerDiscussionId)
        }
    }
    
    override func updateLayout(width: CGFloat, leftInset: CGFloat, rightInset: CGFloat, additionalSideInsets: UIEdgeInsets, maxHeight: CGFloat, isSecondary: Bool, transition: ContainedViewLayoutTransition, interfaceState: ChatPresentationInterfaceState, metrics: LayoutMetrics) -> CGFloat {
        self.layoutData = (width, leftInset, rightInset)
        
        if self.presentationInterfaceState != interfaceState {
            let previousState = self.presentationInterfaceState
            self.presentationInterfaceState = interfaceState
            
            if previousState?.theme !== interfaceState.theme {
                self.badgeBackground.image = PresentationResourcesChatList.badgeBackgroundActive(interfaceState.theme, diameter: 20.0)
                self.helpButton.setImage(generateTintedImage(image: UIImage(bundleImageName: "Chat/Input/Accessory Panels/Help"), color: interfaceState.theme.chat.inputPanel.panelControlAccentColor), for: .normal)
            }
            
            if let peer = interfaceState.renderedPeer?.peer, previousState?.renderedPeer?.peer == nil || !peer.isEqual(previousState!.renderedPeer!.peer!) || previousState?.theme !== interfaceState.theme || previousState?.strings !== interfaceState.strings || previousState?.peerIsMuted != interfaceState.peerIsMuted || previousState?.pinnedMessage != interfaceState.pinnedMessage {
                if let action = actionForPeer(peer: peer, interfaceState: interfaceState, isMuted: interfaceState.peerIsMuted) {
                    self.action = action
                    let (title, color) = titleAndColorForAction(action, theme: interfaceState.theme, strings: interfaceState.strings)
                    self.button.setTitle(title, with: Font.regular(17.0), with: color, for: [])
                } else {
                    self.action = nil
                }
                
                self.discussButton.isHidden = true
            }
        }
        
        let panelHeight = defaultHeight(metrics: metrics)
        
        if self.discussButton.isHidden {
            if let action = self.action, action == .muteNotifications || action == .unmuteNotifications {
                let buttonWidth = self.button.titleNode.calculateSizeThatFits(CGSize(width: width, height: panelHeight)).width + 24.0
                self.button.frame = CGRect(origin: CGPoint(x: floor((width - buttonWidth) / 2.0), y: 0.0), size: CGSize(width: buttonWidth, height: panelHeight))
                
                if let peer = interfaceState.renderedPeer?.peer as? TelegramChannel, peer.flags.contains(.isGigagroup) {
                    self.helpButton.isHidden = false
                } else {
                    self.helpButton.isHidden = true
                }
            } else {
                self.button.frame = CGRect(origin: CGPoint(x: leftInset, y: 0.0), size: CGSize(width: width - leftInset - rightInset, height: panelHeight))
                self.helpButton.isHidden = true
            }
            self.helpButton.frame = CGRect(x: width - rightInset - panelHeight, y: 0.0, width: panelHeight, height: panelHeight)
        } else {
            self.helpButton.isHidden = true
            
            let availableWidth = min(600.0, width - leftInset - rightInset)
            let leftOffset = floor((width - availableWidth) / 2.0)
            self.button.frame = CGRect(origin: CGPoint(x: leftOffset, y: 0.0), size: CGSize(width: floor(availableWidth / 2.0), height: panelHeight))
            self.discussButton.frame = CGRect(origin: CGPoint(x: leftOffset + floor(availableWidth / 2.0), y: 0.0), size: CGSize(width: floor(availableWidth / 2.0), height: panelHeight))
            
            let discussButtonSize = self.discussButton.bounds.size
            let discussTextSize = self.discussButtonText.updateLayout(discussButtonSize)
            self.discussButtonText.frame = CGRect(origin: CGPoint(x: floor((discussButtonSize.width - discussTextSize.width) / 2.0), y: floor((discussButtonSize.height - discussTextSize.height) / 2.0)), size: discussTextSize)
            
            let badgeOffset = self.discussButtonText.frame.maxX + 5.0 - self.badgeBackground.frame.minX
            self.badgeBackground.frame = self.badgeBackground.frame.offsetBy(dx: badgeOffset, dy: 0.0)
            self.badgeText.frame = self.badgeText.frame.offsetBy(dx: badgeOffset, dy: 0.0)
        }
        
        let indicatorSize = self.activityIndicator.bounds.size
        self.activityIndicator.frame = CGRect(origin: CGPoint(x: width - rightInset - indicatorSize.width - 12.0, y: floor((panelHeight - indicatorSize.height) / 2.0)), size: indicatorSize)
        
        return panelHeight
    }
    
    override func minimalHeight(interfaceState: ChatPresentationInterfaceState, metrics: LayoutMetrics) -> CGFloat {
        return defaultHeight(metrics: metrics)
    }
}