import Foundation
import UIKit
import Display
import AsyncDisplayKit
import TelegramPresentationData
import Postbox
import AccountContext
import AvatarNode
import TelegramCore

private let timezoneOffset: Int32 = {
    let nowTimestamp = Int32(CFAbsoluteTimeGetCurrent() + NSTimeIntervalSince1970)
    var now: time_t = time_t(nowTimestamp)
    var timeinfoNow: tm = tm()
    localtime_r(&now, &timeinfoNow)
    return Int32(timeinfoNow.tm_gmtoff)
}()

private let granularity: Int32 = 60 * 60 * 24

final class ChatMessageDateHeader: ListViewItemHeader {
    private let timestamp: Int32
    private let roundedTimestamp: Int32
    private let scheduled: Bool
    
    let id: ListViewItemNode.HeaderId
    let presentationData: ChatPresentationData
    let context: AccountContext
    let action: ((Int32, Bool) -> Void)?
    
    init(timestamp: Int32, scheduled: Bool, presentationData: ChatPresentationData, context: AccountContext, action: ((Int32, Bool) -> Void)? = nil) {
        self.timestamp = timestamp
        self.scheduled = scheduled
        self.presentationData = presentationData
        self.context = context
        self.action = action
        self.roundedTimestamp = dateHeaderTimestampId(timestamp: timestamp)
        self.id = ListViewItemNode.HeaderId(space: 0, id: Int64(self.roundedTimestamp))
    }
    
    let stickDirection: ListViewItemHeaderStickDirection = .bottom
    let stickOverInsets: Bool = true
    
    let height: CGFloat = 34.0

    public func combinesWith(other: ListViewItemHeader) -> Bool {
        if let other = other as? ChatMessageDateHeader, other.id == self.id {
            return true
        } else {
            return false
        }
    }
    
    func node(synchronousLoad: Bool) -> ListViewItemHeaderNode {
        return ChatMessageDateHeaderNode(localTimestamp: self.roundedTimestamp, scheduled: self.scheduled, presentationData: self.presentationData, context: self.context, action: self.action)
    }
    
    func updateNode(_ node: ListViewItemHeaderNode, previous: ListViewItemHeader?, next: ListViewItemHeader?) {
        guard let node = node as? ChatMessageDateHeaderNode, let next = next as? ChatMessageDateHeader else {
            return
        }
        node.updatePresentationData(next.presentationData, context: next.context)
    }
}

private func monthAtIndex(_ index: Int, strings: PresentationStrings) -> String {
    switch index {
        case 0:
            return strings.Month_GenJanuary
        case 1:
            return strings.Month_GenFebruary
        case 2:
            return strings.Month_GenMarch
        case 3:
            return strings.Month_GenApril
        case 4:
            return strings.Month_GenMay
        case 5:
            return strings.Month_GenJune
        case 6:
            return strings.Month_GenJuly
        case 7:
            return strings.Month_GenAugust
        case 8:
            return strings.Month_GenSeptember
        case 9:
            return strings.Month_GenOctober
        case 10:
            return strings.Month_GenNovember
        case 11:
            return strings.Month_GenDecember
        default:
            return ""
    }
}

private func dateHeaderTimestampId(timestamp: Int32) -> Int32 {
    if timestamp == scheduleWhenOnlineTimestamp {
        return timestamp
    } else if timestamp == Int32.max {
        return timestamp / (granularity) * (granularity)
    } else {
        return ((timestamp + timezoneOffset) / (granularity)) * (granularity)
    }
}

final class ChatMessageDateHeaderNode: ListViewItemHeaderNode {
    let labelNode: TextNode
    let backgroundNode: NavigationBackgroundNode
    let stickBackgroundNode: ASImageNode
    let activateArea: AccessibilityAreaNode
    
    private let localTimestamp: Int32
    private var presentationData: ChatPresentationData
    private let context: AccountContext
    private let text: String
    
    private var flashingOnScrolling = false
    private var stickDistanceFactor: CGFloat = 0.0
    private var action: ((Int32, Bool) -> Void)? = nil
    
    init(localTimestamp: Int32, scheduled: Bool, presentationData: ChatPresentationData, context: AccountContext, action: ((Int32, Bool) -> Void)? = nil) {
        self.presentationData = presentationData
        self.context = context
        
        self.localTimestamp = localTimestamp
        self.action = action
        
        self.labelNode = TextNode()
        self.labelNode.isUserInteractionEnabled = false
        self.labelNode.displaysAsynchronously = !presentationData.isPreview
        
        self.backgroundNode = NavigationBackgroundNode(color: .clear)
        self.backgroundNode.isUserInteractionEnabled = false
        
        self.stickBackgroundNode = ASImageNode()
        self.stickBackgroundNode.isLayerBacked = true
        self.stickBackgroundNode.displayWithoutProcessing = true
        self.stickBackgroundNode.displaysAsynchronously = false
        
        let nowTimestamp = Int32(CFAbsoluteTimeGetCurrent() + NSTimeIntervalSince1970)
        
        var t: time_t = time_t(localTimestamp)
        var timeinfo: tm = tm()
        gmtime_r(&t, &timeinfo)
        
        var now: time_t = time_t(nowTimestamp)
        var timeinfoNow: tm = tm()
        localtime_r(&now, &timeinfoNow)
        
        var text: String
        if timeinfo.tm_year == timeinfoNow.tm_year {
            if timeinfo.tm_yday == timeinfoNow.tm_yday {
                text = presentationData.strings.Weekday_Today
            } else {
                text = presentationData.strings.Date_ChatDateHeader(monthAtIndex(Int(timeinfo.tm_mon), strings: presentationData.strings), "\(timeinfo.tm_mday)").string
            }
        } else {
            text = presentationData.strings.Date_ChatDateHeaderYear(monthAtIndex(Int(timeinfo.tm_mon), strings: presentationData.strings), "\(timeinfo.tm_mday)", "\(1900 + timeinfo.tm_year)").string
        }
        
        if scheduled {
            if localTimestamp == scheduleWhenOnlineTimestamp {
                text = presentationData.strings.ScheduledMessages_ScheduledOnline
            } else if timeinfo.tm_year == timeinfoNow.tm_year && timeinfo.tm_yday == timeinfoNow.tm_yday {
                text = presentationData.strings.ScheduledMessages_ScheduledToday
            } else {
                text = presentationData.strings.ScheduledMessages_ScheduledDate(text).string
            }
        }
        self.text = text
        
        self.activateArea = AccessibilityAreaNode()
        self.activateArea.accessibilityTraits = .staticText
        
        super.init(layerBacked: false, dynamicBounce: true, isRotated: true, seeThrough: false)
        
        self.transform = CATransform3DMakeRotation(CGFloat.pi, 0.0, 0.0, 1.0)
        
        let graphics = PresentationResourcesChat.principalGraphics(theme: presentationData.theme.theme, wallpaper: presentationData.theme.wallpaper, bubbleCorners: presentationData.chatBubbleCorners)

        self.backgroundNode.updateColor(color: selectDateFillStaticColor(theme: presentationData.theme.theme, wallpaper: presentationData.theme.wallpaper), enableBlur: dateFillNeedsBlur(theme: presentationData.theme.theme, wallpaper: presentationData.theme.wallpaper), transition: .immediate)
        self.stickBackgroundNode.image = graphics.dateFloatingBackground
        self.stickBackgroundNode.alpha = 0.0

        self.addSubnode(self.backgroundNode)
        self.addSubnode(self.labelNode)
        
        self.addSubnode(self.activateArea)
        
        let titleFont = Font.medium(min(18.0, floor(presentationData.fontSize.baseDisplaySize * 13.0 / 17.0)))
        
        let attributedString = NSAttributedString(string: text, font: titleFont, textColor: bubbleVariableColor(variableColor: presentationData.theme.theme.chat.serviceMessage.dateTextColor, wallpaper: presentationData.theme.wallpaper))
        let labelLayout = TextNode.asyncLayout(self.labelNode)
        
        self.activateArea.accessibilityLabel = text
        
        let (size, apply) = labelLayout(TextNodeLayoutArguments(attributedString: attributedString, backgroundColor: nil, maximumNumberOfLines: 1, truncationType: .end, constrainedSize: CGSize(width: 320.0, height: CGFloat.greatestFiniteMagnitude), alignment: .natural, cutout: nil, insets: UIEdgeInsets()))
        let _ = apply()
        self.labelNode.frame = CGRect(origin: CGPoint(), size: size.size)
    }

    override func didLoad() {
        super.didLoad()
        
        self.view.addGestureRecognizer(ListViewTapGestureRecognizer(target: self, action: #selector(self.tapGesture(_:))))
    }
    
    func updatePresentationData(_ presentationData: ChatPresentationData, context: AccountContext) {
        let previousPresentationData = self.presentationData
        self.presentationData = presentationData
        
        let graphics = PresentationResourcesChat.principalGraphics(theme: presentationData.theme.theme, wallpaper: presentationData.theme.wallpaper, bubbleCorners: presentationData.chatBubbleCorners)

        self.backgroundNode.updateColor(color: selectDateFillStaticColor(theme: presentationData.theme.theme, wallpaper: presentationData.theme.wallpaper), enableBlur: dateFillNeedsBlur(theme: presentationData.theme.theme, wallpaper: presentationData.theme.wallpaper), transition: .immediate)
        self.stickBackgroundNode.image = graphics.dateFloatingBackground
        
        let titleFont = Font.medium(min(18.0, floor(presentationData.fontSize.baseDisplaySize * 13.0 / 17.0)))
        
        let attributedString = NSAttributedString(string: self.text, font: titleFont, textColor: bubbleVariableColor(variableColor: presentationData.theme.theme.chat.serviceMessage.dateTextColor, wallpaper: presentationData.theme.wallpaper))
        let labelLayout = TextNode.asyncLayout(self.labelNode)
        
        let (size, apply) = labelLayout(TextNodeLayoutArguments(attributedString: attributedString, backgroundColor: nil, maximumNumberOfLines: 1, truncationType: .end, constrainedSize: CGSize(width: 320.0, height: CGFloat.greatestFiniteMagnitude), alignment: .natural, cutout: nil, insets: UIEdgeInsets()))
        let _ = apply()
        
        if presentationData.fontSize != previousPresentationData.fontSize {
            self.labelNode.bounds = CGRect(origin: CGPoint(), size: size.size)
        }

        self.setNeedsLayout()
    }
    
    func updateBackgroundColor(color: UIColor, enableBlur: Bool) {
        self.backgroundNode.updateColor(color: color, enableBlur: enableBlur, transition: .immediate)
    }
    
    override func updateLayout(size: CGSize, leftInset: CGFloat, rightInset: CGFloat) {
        let chatDateSize: CGFloat = 20.0
        let chatDateInset: CGFloat = 6.0
        
        let labelSize = self.labelNode.bounds.size
        let backgroundSize = CGSize(width: labelSize.width + chatDateInset * 2.0, height: chatDateSize)
        
        let backgroundFrame = CGRect(origin: CGPoint(x: floorToScreenPixels((size.width - backgroundSize.width) / 2.0), y: (34.0 - chatDateSize) / 2.0), size: backgroundSize)
        self.stickBackgroundNode.frame = CGRect(origin: CGPoint(), size: backgroundFrame.size)
        self.backgroundNode.frame = backgroundFrame
        self.backgroundNode.update(size: backgroundFrame.size, cornerRadius: backgroundFrame.size.height / 2.0, transition: .immediate)
        self.labelNode.frame = CGRect(origin: CGPoint(x: backgroundFrame.origin.x + chatDateInset, y: backgroundFrame.origin.y + floorToScreenPixels((backgroundSize.height - labelSize.height) / 2.0)), size: labelSize)
        
        self.activateArea.frame = backgroundFrame
    }
    
    override func updateStickDistanceFactor(_ factor: CGFloat, transition: ContainedViewLayoutTransition) {
        if !self.stickDistanceFactor.isEqual(to: factor) {
            self.stickBackgroundNode.alpha = factor
            
            let wasZero = self.stickDistanceFactor < 0.5
            let isZero = factor < 0.5
            self.stickDistanceFactor = factor
            
            if wasZero != isZero {
                var animated = true
                if case .immediate = transition {
                    animated = false
                }
                self.updateFlashing(animated: animated)
            }
        }
    }
    
    override func updateFlashingOnScrolling(_ isFlashingOnScrolling: Bool, animated: Bool) {
        self.flashingOnScrolling = isFlashingOnScrolling
        self.updateFlashing(animated: animated)
    }
    
    private func updateFlashing(animated: Bool) {
        let flashing = self.flashingOnScrolling || self.stickDistanceFactor < 0.5
        
        let alpha: CGFloat = flashing ? 1.0 : 0.0
        let previousAlpha = self.backgroundNode.alpha
        
        if !previousAlpha.isEqual(to: alpha) {
            self.backgroundNode.alpha = alpha
            self.labelNode.alpha = alpha
            if animated {
                let duration: Double = flashing ? 0.3 : 0.4
                self.backgroundNode.layer.animateAlpha(from: previousAlpha, to: alpha, duration: duration)
                self.labelNode.layer.animateAlpha(from: previousAlpha, to: alpha, duration: duration)
            }
        }
    }

    override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
        if !self.bounds.contains(point) {
            return nil
        }
        if self.labelNode.alpha.isZero {
            return nil
        }
        if self.backgroundNode.frame.contains(point) {
            return self.view
        }
        return nil
    }
    
    override func touchesCancelled(_ touches: Set<UITouch>?, with event: UIEvent?) {
        super.touchesCancelled(touches, with: event)
    }
    
    @objc func tapGesture(_ recognizer: ListViewTapGestureRecognizer) {
        if case .ended = recognizer.state {
            self.action?(self.localTimestamp, self.stickDistanceFactor < 0.5)
        }
    }
}

final class ChatMessageAvatarHeader: ListViewItemHeader {
    struct Id: Hashable {
        var peerId: PeerId
        var timestampId: Int32
    }

    let id: ListViewItemNode.HeaderId
    let peerId: PeerId
    let peer: Peer?
    let messageReference: MessageReference?
    let effectiveTimestamp: Int32
    let presentationData: ChatPresentationData
    let context: AccountContext
    let controllerInteraction: ChatControllerInteraction

    init(timestamp: Int32, peerId: PeerId, peer: Peer?, messageReference: MessageReference?, message: Message, presentationData: ChatPresentationData, context: AccountContext, controllerInteraction: ChatControllerInteraction) {
        self.peerId = peerId
        self.peer = peer
        self.messageReference = messageReference

        var effectiveTimestamp = message.timestamp
        if let forwardInfo = message.forwardInfo, forwardInfo.flags.contains(.isImported) {
            effectiveTimestamp = forwardInfo.date
        }
        self.effectiveTimestamp = effectiveTimestamp

        self.presentationData = presentationData
        self.context = context
        self.controllerInteraction = controllerInteraction
        self.id = ListViewItemNode.HeaderId(space: 1, id: Id(peerId: peerId, timestampId: dateHeaderTimestampId(timestamp: timestamp)))
    }

    let stickDirection: ListViewItemHeaderStickDirection = .top
    let stickOverInsets: Bool = false

    let height: CGFloat = 38.0

    public func combinesWith(other: ListViewItemHeader) -> Bool {
        if let other = other as? ChatMessageAvatarHeader, other.id == self.id {
            if abs(self.effectiveTimestamp - other.effectiveTimestamp) >= 10 * 60 {
                return false
            }
            return true
        } else {
            return false
        }
    }

    func node(synchronousLoad: Bool) -> ListViewItemHeaderNode {
        return ChatMessageAvatarHeaderNode(peerId: self.peerId, peer: self.peer, messageReference: self.messageReference, presentationData: self.presentationData, context: self.context, controllerInteraction: self.controllerInteraction, synchronousLoad: synchronousLoad)
    }

    func updateNode(_ node: ListViewItemHeaderNode, previous: ListViewItemHeader?, next: ListViewItemHeader?) {
        guard let node = node as? ChatMessageAvatarHeaderNode, let next = next as? ChatMessageAvatarHeader else {
            return
        }
        node.updatePresentationData(next.presentationData, context: next.context)
    }
}

private let avatarFont = avatarPlaceholderFont(size: 16.0)

final class ChatMessageAvatarHeaderNode: ListViewItemHeaderNode {
    private let peerId: PeerId
    private let messageReference: MessageReference?
    private let peer: Peer?

    private let containerNode: ContextControllerSourceNode
    private let avatarNode: AvatarNode
    private var presentationData: ChatPresentationData
    private let context: AccountContext
    private let controllerInteraction: ChatControllerInteraction

    init(peerId: PeerId, peer: Peer?, messageReference: MessageReference?, presentationData: ChatPresentationData, context: AccountContext, controllerInteraction: ChatControllerInteraction, synchronousLoad: Bool) {
        self.peerId = peerId
        self.peer = peer
        self.messageReference = messageReference
        self.presentationData = presentationData
        self.context = context
        self.controllerInteraction = controllerInteraction

        self.containerNode = ContextControllerSourceNode()

        self.avatarNode = AvatarNode(font: avatarFont)

        super.init(layerBacked: false, dynamicBounce: true, isRotated: true, seeThrough: false)

        self.transform = CATransform3DMakeRotation(CGFloat.pi, 0.0, 0.0, 1.0)

        self.addSubnode(self.containerNode)
        self.containerNode.addSubnode(self.avatarNode)

        if let peer = peer {
            self.setPeer(context: context, theme: presentationData.theme.theme, synchronousLoad: synchronousLoad, peer: peer, authorOfMessage: messageReference, emptyColor: .black)
        }

        self.containerNode.activated = { [weak self] gesture, _ in
            guard let strongSelf = self, let peer = strongSelf.peer else {
                return
            }
            var messageId: MessageId?
            if let messageReference = messageReference, case let .message(_, id, _, _, _) = messageReference.content {
                messageId = id
            }
            strongSelf.controllerInteraction.openPeerContextMenu(peer, messageId, strongSelf.containerNode, strongSelf.containerNode.bounds, gesture)
        }

        self.updateSelectionState(animated: false)
    }

    func setCustomLetters(context: AccountContext, theme: PresentationTheme, synchronousLoad: Bool, letters: [String], emptyColor: UIColor) {
        self.containerNode.isGestureEnabled = false

        self.avatarNode.setCustomLetters(letters, icon: !letters.isEmpty ? nil : .phone)
    }

    func setPeer(context: AccountContext, theme: PresentationTheme, synchronousLoad: Bool, peer: Peer, authorOfMessage: MessageReference?, emptyColor: UIColor) {
        self.containerNode.isGestureEnabled = peer.smallProfileImage != nil

        var overrideImage: AvatarNodeImageOverride?
        if peer.isDeleted {
            overrideImage = .deletedIcon
        }
        self.avatarNode.setPeer(context: context, theme: theme, peer: EnginePeer(peer), authorOfMessage: authorOfMessage, overrideImage: overrideImage, emptyColor: emptyColor, synchronousLoad: synchronousLoad, displayDimensions: CGSize(width: 38.0, height: 38.0))
    }

    override func didLoad() {
        super.didLoad()

        self.avatarNode.view.addGestureRecognizer(ListViewTapGestureRecognizer(target: self, action: #selector(self.tapGesture(_:))))
    }

    func updatePresentationData(_ presentationData: ChatPresentationData, context: AccountContext) {
        self.presentationData = presentationData

        self.setNeedsLayout()
    }

    override func updateLayout(size: CGSize, leftInset: CGFloat, rightInset: CGFloat) {
        self.containerNode.frame = CGRect(origin: CGPoint(x: leftInset + 3.0, y: 0.0), size: CGSize(width: 38.0, height: 38.0))
        self.avatarNode.frame = CGRect(origin: CGPoint(), size: CGSize(width: 38.0, height: 38.0))
    }

    override func animateRemoved(duration: Double) {
        self.alpha = 0.0
        self.layer.animateAlpha(from: 1.0, to: 0.0, duration: duration, removeOnCompletion: false)
        self.avatarNode.layer.animateScale(from: 1.0, to: 0.2, duration: duration, removeOnCompletion: false)
    }

    override func animateAdded(duration: Double) {
        self.layer.animateAlpha(from: 0.0, to: self.alpha, duration: 0.2)
        self.avatarNode.layer.animateScale(from: 0.2, to: 1.0, duration: 0.2)
    }

    override func updateStickDistanceFactor(_ factor: CGFloat, transition: ContainedViewLayoutTransition) {
    }

    override func updateFlashingOnScrolling(_ isFlashingOnScrolling: Bool, animated: Bool) {
    }

    func updateSelectionState(animated: Bool) {
        let offset: CGFloat = self.controllerInteraction.selectionState != nil ? 42.0 : 0.0

        let previousSubnodeTransform = self.subnodeTransform
        self.subnodeTransform = CATransform3DMakeTranslation(offset, 0.0, 0.0);
        if animated {
            self.layer.animate(from: NSValue(caTransform3D: previousSubnodeTransform), to: NSValue(caTransform3D: self.subnodeTransform), keyPath: "sublayerTransform", timingFunction: CAMediaTimingFunctionName.easeOut.rawValue, duration: 0.2)
        }
    }

    override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
        if !self.bounds.contains(point) {
            return nil
        }
        let result = self.containerNode.view.hitTest(self.view.convert(point, to: self.containerNode.view), with: event)
        return result
    }

    override func touchesCancelled(_ touches: Set<UITouch>?, with event: UIEvent?) {
        super.touchesCancelled(touches, with: event)
    }

    @objc func tapGesture(_ recognizer: ListViewTapGestureRecognizer) {
        if case .ended = recognizer.state {
            if self.peerId.namespace == Namespaces.Peer.Empty, case let .message(_, id, _, _, _) = self.messageReference?.content {
                self.controllerInteraction.displayMessageTooltip(id, self.presentationData.strings.Conversation_ForwardAuthorHiddenTooltip, self, self.avatarNode.frame)
            } else {
                if let channel = self.peer as? TelegramChannel, case .broadcast = channel.info {
                    self.controllerInteraction.openPeer(self.peerId, .chat(textInputState: nil, subject: nil, peekData: nil), self.messageReference, nil)
                } else {
                    self.controllerInteraction.openPeer(self.peerId, .info, self.messageReference, nil)
                }
            }
        }
    }
}