import Foundation
import UIKit
import AsyncDisplayKit
import Display
import Postbox
import TelegramCore
import SwiftSignalKit
import TelegramPresentationData
import AccountContext
import RadialStatusNode
import PhotoResources
import MediaResources
import LiveLocationPositionNode

private struct FetchControls {
    let fetch: (Bool) -> Void
    let cancel: () -> Void
}

final class InstantPageImageNode: ASDisplayNode, InstantPageNode {
    private let context: AccountContext
    private let webPage: TelegramMediaWebpage
    private var theme: InstantPageTheme
    let media: InstantPageMedia
    let attributes: [InstantPageImageAttribute]
    private let interactive: Bool
    private let roundCorners: Bool
    private let fit: Bool
    private let openMedia: (InstantPageMedia) -> Void
    private let longPressMedia: (InstantPageMedia) -> Void
    
    private var fetchControls: FetchControls?
    
    private let imageNode: TransformImageNode
    private let statusNode: RadialStatusNode
    private let linkIconNode: ASImageNode
    private let pinNode: ChatMessageLiveLocationPositionNode
    
    private var currentSize: CGSize?
    
    private var fetchStatus: MediaResourceStatus?
    private var fetchedDisposable = MetaDisposable()
    private var statusDisposable = MetaDisposable()
    
    private var themeUpdated: Bool = false
    
    init(context: AccountContext, theme: InstantPageTheme, webPage: TelegramMediaWebpage, media: InstantPageMedia, attributes: [InstantPageImageAttribute], interactive: Bool, roundCorners: Bool, fit: Bool, openMedia: @escaping (InstantPageMedia) -> Void, longPressMedia: @escaping (InstantPageMedia) -> Void) {
        self.context = context
        self.theme = theme
        self.webPage = webPage
        self.media = media
        self.attributes = attributes
        self.interactive = interactive
        self.roundCorners = roundCorners
        self.fit = fit
        self.openMedia = openMedia
        self.longPressMedia = longPressMedia
        
        self.imageNode = TransformImageNode()
        self.statusNode = RadialStatusNode(backgroundNodeColor: UIColor(white: 0.0, alpha: 0.6))
        self.linkIconNode = ASImageNode()
        self.pinNode = ChatMessageLiveLocationPositionNode()
        
        super.init()
        
        self.addSubnode(self.imageNode)
        
        if let image = media.media as? TelegramMediaImage, let largest = largestImageRepresentation(image.representations) {
            let imageReference = ImageMediaReference.webPage(webPage: WebpageReference(webPage), media: image)
            self.imageNode.setSignal(chatMessagePhoto(postbox: context.account.postbox, photoReference: imageReference))
            
            self.fetchedDisposable.set(chatMessagePhotoInteractiveFetched(context: context, photoReference: imageReference, storeToDownloadsPeerType: nil).start())
            
            self.fetchControls = FetchControls(fetch: { [weak self] manual in
                if let strongSelf = self {
                    strongSelf.fetchedDisposable.set(chatMessagePhotoInteractiveFetched(context: context, photoReference: imageReference, storeToDownloadsPeerType: nil).start())
                }
            }, cancel: {
                chatMessagePhotoCancelInteractiveFetch(account: context.account, photoReference: imageReference)
            })
            
            if interactive {
                self.statusDisposable.set((context.account.postbox.mediaBox.resourceStatus(largest.resource) |> deliverOnMainQueue).start(next: { [weak self] status in
                    displayLinkDispatcher.dispatch {
                        if let strongSelf = self {
                            strongSelf.fetchStatus = status
                            strongSelf.updateFetchStatus()
                        }
                    }
                }))
                
                if media.url != nil {
                    self.linkIconNode.image = UIImage(bundleImageName: "Instant View/ImageLink")
                    self.addSubnode(self.linkIconNode)
                }

                self.addSubnode(self.statusNode)
            }
        } else if let file = media.media as? TelegramMediaFile {
            let fileReference = FileMediaReference.webPage(webPage: WebpageReference(webPage), media: file)
            if file.mimeType.hasPrefix("image/") {
                _ = freeMediaFileInteractiveFetched(account: context.account, fileReference: fileReference).start()
                self.imageNode.setSignal(instantPageImageFile(account: context.account, fileReference: fileReference, fetched: true))
            } else {
                self.imageNode.setSignal(chatMessageVideo(postbox: context.account.postbox, videoReference: fileReference))
            }
            if file.isVideo {
                self.statusNode.transitionToState(.play(.white), animated: false, completion: {})
                self.addSubnode(self.statusNode)
            }
        } else if let map = media.media as? TelegramMediaMap {
            self.addSubnode(self.pinNode)
            
            var zoom: Int32 = 12
            var dimensions = CGSize(width: 200.0, height: 100.0)
            for attribute in self.attributes {
                if let mapAttribute = attribute as? InstantPageMapAttribute {
                    zoom = mapAttribute.zoom
                    dimensions = mapAttribute.dimensions
                    break
                }
            }
            let resource = MapSnapshotMediaResource(latitude: map.latitude, longitude: map.longitude, width: Int32(dimensions.width), height: Int32(dimensions.height))
            self.imageNode.setSignal(chatMapSnapshotImage(account: context.account, resource: resource))
        } else if let webPage = media.media as? TelegramMediaWebpage, case let .Loaded(content) = webPage.content, let image = content.image {
            let imageReference = ImageMediaReference.webPage(webPage: WebpageReference(webPage), media: image)
            self.imageNode.setSignal(chatMessagePhoto(postbox: context.account.postbox, photoReference: imageReference))
            self.fetchedDisposable.set(chatMessagePhotoInteractiveFetched(context: context, photoReference: imageReference, storeToDownloadsPeerType: nil).start())
            self.statusNode.transitionToState(.play(.white), animated: false, completion: {})
            self.addSubnode(self.statusNode)
        }
    }
    
    deinit {
        self.fetchedDisposable.dispose()
        self.statusDisposable.dispose()
    }
    
    override func didLoad() {
        super.didLoad()
        
        if self.interactive {
            let recognizer = TapLongTapOrDoubleTapGestureRecognizer(target: self, action: #selector(self.tapGesture(_:)))
            recognizer.delaysTouchesBegan = false
            self.view.addGestureRecognizer(recognizer)
        } else {
            self.view.isUserInteractionEnabled = false
        }
    }
    
    func updateIsVisible(_ isVisible: Bool) {    
    }
    
    func updateLayout(size: CGSize, transition: ContainedViewLayoutTransition) {
    }
    
    func update(strings: PresentationStrings, theme: InstantPageTheme) {
        if self.theme.imageTintColor != theme.imageTintColor {
            self.theme = theme
            self.themeUpdated = true
            self.setNeedsLayout()
        }
    }
    
    private func updateFetchStatus() {
        var state: RadialStatusNodeState = .none
        if let fetchStatus = self.fetchStatus {
            switch fetchStatus {
                case let .Fetching(_, progress):
                    let adjustedProgress = max(progress, 0.027)
                    state = .progress(color: .white, lineWidth: nil, value: CGFloat(adjustedProgress), cancelEnabled: true)
                case .Remote:
                    state = .download(.white)
                default:
                    break
            }
        }
        self.statusNode.transitionToState(state, completion: { [weak statusNode] in
            if state == .none {
                statusNode?.removeFromSupernode()
            }
        })
    }
    
    override func layout() {
        super.layout()
        
        let size = self.bounds.size
        
        if self.currentSize != size || self.themeUpdated {
            self.currentSize = size
            self.themeUpdated = false
            
            self.imageNode.frame = CGRect(origin: CGPoint(), size: size)
            
            let radialStatusSize: CGFloat = 50.0
            self.statusNode.frame = CGRect(x: floorToScreenPixels((size.width - radialStatusSize) / 2.0), y: floorToScreenPixels((size.height - radialStatusSize) / 2.0), width: radialStatusSize, height: radialStatusSize)
            
            if let image = self.media.media as? TelegramMediaImage, let largest = largestImageRepresentation(image.representations) {
                let imageSize = largest.dimensions.aspectFilled(size)
                let boundingSize = size
                let radius: CGFloat = self.roundCorners ? floor(min(imageSize.width, imageSize.height) / 2.0) : 0.0
                let makeLayout = self.imageNode.asyncLayout()
                let apply = makeLayout(TransformImageArguments(corners: ImageCorners(radius: radius), imageSize: imageSize, boundingSize: boundingSize, intrinsicInsets: UIEdgeInsets(), emptyColor: self.theme.panelBackgroundColor))
                apply()
                
                self.linkIconNode.frame = CGRect(x: size.width - 38.0, y: 14.0, width: 24.0, height: 24.0)
            } else if let file = self.media.media as? TelegramMediaFile, let dimensions = file.dimensions {
                let emptyColor = file.mimeType.hasPrefix("image/") ? self.theme.imageTintColor : nil

                let imageSize = dimensions.aspectFilled(size)
                let boundingSize = size
                let makeLayout = self.imageNode.asyncLayout()
                let apply = makeLayout(TransformImageArguments(corners: ImageCorners(), imageSize: imageSize, boundingSize: boundingSize, intrinsicInsets: UIEdgeInsets(), emptyColor: emptyColor))
                apply()
            } else if self.media.media is TelegramMediaMap {
                for attribute in self.attributes {
                    if let mapAttribute = attribute as? InstantPageMapAttribute {
                        let imageSize = mapAttribute.dimensions.aspectFilled(size)
                        let boundingSize = size
                        let radius: CGFloat = self.roundCorners ? floor(min(imageSize.width, imageSize.height) / 2.0) : 0.0
                        let makeLayout = self.imageNode.asyncLayout()
                        let apply = makeLayout(TransformImageArguments(corners: ImageCorners(radius: radius), imageSize: imageSize, boundingSize: boundingSize, intrinsicInsets: UIEdgeInsets()))
                        apply()
                        break
                    }
                }
                
                let makePinLayout = self.pinNode.asyncLayout()
                let theme = self.context.sharedContext.currentPresentationData.with { $0 }.theme
                let (pinSize, pinApply) = makePinLayout(self.context.account, theme, nil, false)
                self.pinNode.frame = CGRect(origin: CGPoint(x: floor((size.width - pinSize.width) / 2.0), y: floor(size.height * 0.5 - 10.0 - pinSize.height / 2.0)), size: pinSize)
                pinApply()
            } else if let webPage = media.media as? TelegramMediaWebpage, case let .Loaded(content) = webPage.content, let image = content.image, let largest = largestImageRepresentation(image.representations) {
                let imageSize = largest.dimensions.aspectFilled(size)
                let boundingSize = size
                let radius: CGFloat = self.roundCorners ? floor(min(imageSize.width, imageSize.height) / 2.0) : 0.0
                let makeLayout = self.imageNode.asyncLayout()
                let apply = makeLayout(TransformImageArguments(corners: ImageCorners(radius: radius), imageSize: imageSize, boundingSize: boundingSize, intrinsicInsets: UIEdgeInsets(), emptyColor: self.theme.pageBackgroundColor))
                apply()
            }
        }
    }
    
    func transitionNode(media: InstantPageMedia) -> (ASDisplayNode, () -> (UIView?, UIView?))? {
        if media == self.media {
            let imageNode = self.imageNode
            return (self.imageNode, { [weak imageNode] in
                return (imageNode?.view.snapshotContentTree(unhide: true), nil)
            })
        } else {
            return nil
        }
    }
    
    func updateHiddenMedia(media: InstantPageMedia?) {
        self.imageNode.isHidden = self.media == media
        self.statusNode.isHidden = self.imageNode.isHidden
    }
    
    @objc private func tapGesture(_ recognizer: TapLongTapOrDoubleTapGestureRecognizer) {
        switch recognizer.state {
            case .ended:
                if let (gesture, _) = recognizer.lastRecognizedGestureAndLocation {
                    if let fetchStatus = self.fetchStatus {
                        switch fetchStatus {
                            case .Local:
                                switch gesture {
                                    case .tap:
                                        if self.media.media is TelegramMediaImage && self.media.index == -1 {
                                            return
                                        }
                                        self.openMedia(self.media)
                                    case .longTap:
                                        self.longPressMedia(self.media)
                                    default:
                                        break
                                }
                            case .Remote:
                                if case .tap = gesture {
                                    self.fetchControls?.fetch(true)
                                }
                            case .Fetching:
                                if case .tap = gesture {
                                    self.fetchControls?.cancel()
                                }
                        }
                    } else {
                        switch gesture {
                            case .tap:
                                if self.media.media is TelegramMediaImage && self.media.index == -1 {
                                    return
                                }
                                self.openMedia(self.media)
                            case .longTap:
                                self.longPressMedia(self.media)
                            default:
                                break
                        }
                    }
                }
            default:
                break
        }
    }
}