//
//  KMPDFThumbnailView.swift
//  PDF Master
//
//  Created by lxy on 2022/12/15.
//

import Cocoa

@objc protocol KMPDFThumbnailViewDelegate: NSObjectProtocol {
    @objc optional func thumbnailView(thumbanView: KMPDFThumbnailView, didSelectPageAtIndex index: UInt, event: NSEvent)
    @objc optional func thumbnailView(thumbanView: KMPDFThumbnailView, item: KMPDFThumbnailItem, rightMouseDidSelect index: UInt, event: NSEvent)
    @objc optional func thumbnailView(thumbanView: KMPDFThumbnailView, didDragAddFiles files: [URL], indexpath: IndexPath)
    @objc optional func thumbnailView(thumbanView: KMPDFThumbnailView, didDragPages pages: [Int], indexpath: IndexPath)
    
    @objc optional func thumbnailView(thumbanView: KMPDFThumbnailView, minimumLineSpacingForSectionAt section: Int) -> CGFloat
    @objc optional func thumbnailView(thumbanView: KMPDFThumbnailView, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat
    @objc optional func thumbnailView(thumbanView: KMPDFThumbnailView, insetForSectionAt section: Int) -> NSEdgeInsets
    
    @objc optional func thumbnailView(thumbanView: KMPDFThumbnailView, sizeForItemAt indexpath: IndexPath) -> NSSize
    @objc optional func thumbnailView(thumbanView: KMPDFThumbnailView, itemForRepresentedObjectAt indexpath: IndexPath) -> NSCollectionViewItem
}

class KMPDFThumbnailView: NSView {
    open weak var delegate: KMPDFThumbnailViewDelegate?
    
    var document : CPDFDocument = CPDFDocument()
    var isShowPageSize : Bool = false
    var backgroundColor : NSColor = NSColor.white
    var highlightColor : NSColor = NSColor.blue
    var pageSelectionColor : NSColor = NSColor()
    var textSelectionColor : NSColor = NSColor()
    var thumbnailSzie : CGSize = CGSize()
    var scrollView : NSScrollView = NSScrollView()
    var collectionView : NSCollectionView = NSCollectionView()
    
    var doublePageMode : Bool! = false
    
    private let thumbnailDraggedTypes = NSPasteboard.PasteboardType(rawValue: "localForDraggedTypes")
    
    private var dragedIndexPaths: [IndexPath] = []
    
    //标记线
    var isNeedMarkerLine: Bool = false
    var markerLineView: NSView = NSView()
    var markBeginIndexes: IndexSet = IndexSet()
    //注释状态
    var annotationShowState: KMAnnotationViewShowType = .none {
        didSet {
            self.collectionView.reloadData()
        }
    }
    //悬浮
    var hoverIndex: Int = -1
    
    override func draw(_ dirtyRect: NSRect) {
        super.draw(dirtyRect)
    }
    
    required init?(coder: NSCoder) {
        super.init(coder: coder)
        self.initUI()
    }
    
    override init(frame frameRect: NSRect) {
        super.init(frame: frameRect)
        self.initUI()
    }
    
    private func initUI() {
        self.wantsLayer = true
        self.layer?.backgroundColor = NSColor(hex: "#F7F8FA").cgColor
        
        self.thumbnailSzie = CGSize(width: 120, height: 155)
  
        let layout = NSCollectionViewFlowLayout()
        layout.sectionInset = NSEdgeInsetsMake(8, 15, 8, 15)
        layout.minimumLineSpacing = 0
        layout.minimumInteritemSpacing = 0
        
        self.collectionView.autoresizingMask = NSView.AutoresizingMask(rawValue: 18)
        self.collectionView.collectionViewLayout = layout
        self.collectionView.dataSource = self
        self.collectionView.delegate = self
        self.collectionView.register(KMPDFThumbnailItem.self, forItemWithIdentifier: NSUserInterfaceItemIdentifier(rawValue: "KMPDFThumbnailItem"))
        self.collectionView.registerForDraggedTypes([thumbnailDraggedTypes])
        self.collectionView.isSelectable = true
        
        self.collectionView.wantsLayer = true
        self.collectionView.layer?.backgroundColor = NSColor(hex: "#F7F8FA").cgColor
        
        
        self.scrollView.hasHorizontalScroller = true
        self.scrollView.hasVerticalScroller = true
        self.scrollView.autohidesScrollers = true
        self.scrollView.minMagnification = 1.0
        self.scrollView.scrollerStyle = NSScroller.Style.overlay
        self.scrollView.documentView = self.collectionView
        
        self.scrollView.wantsLayer = true
        self.scrollView.layer?.backgroundColor = NSColor.clear.cgColor
        
        self.scrollView.contentView.layer?.backgroundColor = NSColor(hex: "#FFFFFF").cgColor
        self.scrollView.contentView.wantsLayer = true
        
        self.addSubview(self.scrollView)
        
        
        markerLineView.wantsLayer = true
        markerLineView.layer?.backgroundColor = NSColor(hex: "#1770F4").cgColor
        markerLineView.frame = CGRectMake(0, 0, 100, 2)
        self.collectionView.addSubview(markerLineView)
        markerLineView.isHidden = true
    }
    
    override func setFrameSize(_ newSize: NSSize) {
        super.setFrameSize(newSize)
        self.scrollView.frame = self.bounds
    }
    
    public func reloadData(indexs: Set<IndexPath> = NSSet() as! Set<IndexPath>) {
        if indexs.count == 0 {
            self.collectionView.reloadData()
        } else {
            var indexpaths: Set<IndexPath> = []
            for index in indexs {
                if (index.section >= self.collectionView.numberOfSections) {
                    continue
                }
                if (index.item >= self.collectionView.numberOfItems(inSection: index.section)) {
                    continue
                }
                
                indexpaths.insert(index)
            }
            if (indexpaths.count == 0) {
                return
            }
            
            if (Thread.isMainThread) {
                self.collectionView.reloadItems(at: indexpaths)
            } else {
                DispatchQueue.main.async {
                    self.collectionView.reloadItems(at: indexpaths)
                }
            }
        }
    }
}

extension KMPDFThumbnailView : NSCollectionViewDataSource {
    
    func numberOfSections(in collectionView: NSCollectionView) -> Int {
        return 1
    }
    
    func collectionView(_ collectionView: NSCollectionView, numberOfItemsInSection section: Int) -> Int {
        if self.document.isLocked {
            return 0
        }
        return Int(self.document.pageCount)
    }
        
    func collectionView(_ collectionView: NSCollectionView, itemForRepresentedObjectAt indexPath: IndexPath) -> NSCollectionViewItem {
        let view = self.delegate?.thumbnailView?(thumbanView: self, itemForRepresentedObjectAt: indexPath)
        if (view != nil) {
            return view!
        }
        
        let cellView: KMPDFThumbnailItem = collectionView.makeItem(withIdentifier: NSUserInterfaceItemIdentifier(rawValue: "KMPDFThumbnailItem"), for: indexPath) as! KMPDFThumbnailItem
        cellView.thumbnailView = self
        cellView.page = self.document.page(at: UInt(indexPath.item))
        cellView.annotationShowState = self.annotationShowState
        if indexPath.item == hoverIndex {
            cellView.hover = true
        } else {
            cellView.hover = false
        }
        
        cellView.mouseDownAction = { [unowned self] (view, event) in
            self.delegate?.thumbnailView?(thumbanView: self, didSelectPageAtIndex: UInt(indexPath.item), event: event)
        }
        
        cellView.rightMouseDownAction = { [unowned self] (view, event) in
            self.delegate?.thumbnailView?(thumbanView: self, item: view, rightMouseDidSelect: UInt(indexPath.item), event: event)
        }
        
        cellView.hoverCallBack = { [unowned self] view, mouseEntered in
            if self.collectionView.item(at: hoverIndex)?.view != nil {
                let tempCell = self.collectionView.item(at: hoverIndex) as? KMPDFThumbnailItem
                tempCell!.hover = false
            }
            
            if mouseEntered {
                hoverIndex = indexPath.item
                if self.collectionView.item(at: hoverIndex)?.view != nil {
                    let tempCell = self.collectionView.item(at: hoverIndex) as? KMPDFThumbnailItem
                    tempCell!.hover = true
                }
            } else {
                hoverIndex = -1
            }
        }
        
        return cellView
    }
}

extension KMPDFThumbnailView: NSCollectionViewDelegateFlowLayout {
    /**
     * MARK: item大小
     */
    func collectionView(_ collectionView: NSCollectionView, layout collectionViewLayout: NSCollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> NSSize {
        if (self.delegate != nil) {
            let size = self.delegate!.thumbnailView?(thumbanView: self, sizeForItemAt: indexPath)
            if (size != nil) {
//                self.thumbnailSzie = size!
                return size!
            }
        }
        
        let page = self.document.page(at: UInt(indexPath.item))
        let height = KMPDFThumbnailItem.sizeToFit(size: self.thumbnailSzie, page: page!, isShow: self.isShowPageSize)
        
        return NSMakeSize(collectionView.frame.size.width - 20, CGFloat(height))
    }
    
    func collectionView(_ collectionView: NSCollectionView, layout collectionViewLayout: NSCollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
        if (self.delegate != nil) {
            let minimumLineSpacing = self.delegate!.thumbnailView?(thumbanView: self, minimumLineSpacingForSectionAt: section)
            if (minimumLineSpacing != nil) {
                return minimumLineSpacing!
            }
        }
        
        return 8
    }
    
    func collectionView(_ collectionView: NSCollectionView, layout collectionViewLayout: NSCollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat {
        if (self.delegate != nil) {
            let minimumInteritemSpacing = self.delegate!.thumbnailView?(thumbanView: self, minimumInteritemSpacingForSectionAt: section)
            if (minimumInteritemSpacing != nil) {
                return minimumInteritemSpacing!
            }
        }
        
        return 0.01
    }
    
    func collectionView(_ collectionView: NSCollectionView, layout collectionViewLayout: NSCollectionViewLayout, insetForSectionAt section: Int) -> NSEdgeInsets {
        let inset = self.delegate?.thumbnailView?(thumbanView: self, insetForSectionAt: section)
        if (inset != nil) {
            return inset!
        }
        return NSEdgeInsetsZero
    }
}

extension KMPDFThumbnailView: NSCollectionViewDelegate {
    func collectionView(_ collectionView: NSCollectionView, shouldSelectItemsAt indexPaths: Set<IndexPath>) -> Set<IndexPath> {
        return indexPaths
    }
    
    func collectionView(_ collectionView: NSCollectionView, didSelectItemsAt indexPaths: Set<IndexPath>) {
//        let index: IndexPath = indexPaths.first!
//        self.delegate?.thumbnailView?(thumbanView: self, didSelectPageAtIndex: UInt(index.item))
    }
    
    func collectionView(_ collectionView: NSCollectionView, shouldDeselectItemsAt indexPaths: Set<IndexPath>) -> Set<IndexPath> {
        return indexPaths
    }
    
    func collectionView(_ collectionView: NSCollectionView, didDeselectItemsAt indexPaths: Set<IndexPath>) {
    }
    
    func collectionView(_ collectionView: NSCollectionView, canDragItemsAt indexPaths: Set<IndexPath>, with event: NSEvent) -> Bool {

        return true
    }

    func collectionView(_ collectionView: NSCollectionView, writeItemsAt indexPaths: Set<IndexPath>, to pasteboard: NSPasteboard) -> Bool {
        let data: Data = try! NSKeyedArchiver.archivedData(withRootObject: indexPaths, requiringSecureCoding: true)
        pasteboard.declareTypes([self.thumbnailDraggedTypes], owner: self)
        pasteboard.setData(data, forType: self.thumbnailDraggedTypes)
        
        self.dragedIndexPaths.removeAll()
        for indexPath in indexPaths {
            self.dragedIndexPaths.append(indexPath)
        }
        return true
    }
    
    func collectionView(_ collectionView: NSCollectionView, draggingSession session: NSDraggingSession, willBeginAt screenPoint: NSPoint, forItemsAt indexes: IndexSet) {
        if self.isNeedMarkerLine {
            self.markBeginIndexes = self.collectionView.selectionIndexes
        }
    }
    
    func collectionView(_ collectionView: NSCollectionView, validateDrop draggingInfo: NSDraggingInfo, proposedIndexPath proposedDropIndexPath: AutoreleasingUnsafeMutablePointer<NSIndexPath>, dropOperation proposedDropOperation: UnsafeMutablePointer<NSCollectionView.DropOperation>) -> NSDragOperation {
        if self.isNeedMarkerLine {
            if self.markBeginIndexes.count != 0 {
                if !self.markBeginIndexes.contains(proposedDropIndexPath.pointee.item) {
                    //标记线
                    var rect = self.collectionView.frameForItem(at: proposedDropIndexPath.pointee.item)
                    rect.size.height = 2
                    self.markerLineView.frame = rect
                    self.markerLineView.isHidden = false
                }
            }
        }
        
        let pboard = draggingInfo.draggingPasteboard
        if (pboard.availableType(from: [thumbnailDraggedTypes]) != nil) {
            return .move
        }

        return NSDragOperation(rawValue: 0)
    }
    
    func collectionView(_ collectionView: NSCollectionView, acceptDrop draggingInfo: NSDraggingInfo, indexPath: IndexPath, dropOperation: NSCollectionView.DropOperation) -> Bool {
        markerLineView.isHidden = true
        self.markBeginIndexes = IndexSet()
        
        let pboard = draggingInfo.draggingPasteboard
        if (pboard.availableType(from: [NSPasteboard.PasteboardType(rawValue: "localForDraggedTypes")]) != nil) {
            let dragIndexPath = self.dragedIndexPaths.first
            if (dragIndexPath == nil) {
                return false
            }
            let dragIndex = dragIndexPath!.item
            let toIndex = max(0, indexPath.item)
            if dragIndex < 0 || dragIndex > self.document.pageCount {
                return false
            }
            if (toIndex >= self.document.pageCount) {
                return false
            }
            
            if dragIndex == toIndex {
                return false
            }
            
            var dragPages: [Int] = []
            for indexpath in dragedIndexPaths {
                dragPages.append(indexpath.item)
            }
            self.dragedIndexPaths.removeAll()
            
            self.delegate?.thumbnailView?(thumbanView: self, didDragPages: dragPages, indexpath: indexPath)
            return true
        } else if ((pboard.availableType(from: [.fileURL])) != nil) {
            //获取url
            var array: [URL] = []
            for item: NSPasteboardItem in pboard.pasteboardItems! {
                let string: String = item.string(forType: NSPasteboard.PasteboardType.fileURL)!
                let url = NSURL(string: string)
                ///  MARK: 暂时支持PDF格式
                if (url?.pathExtension?.lowercased() == "pdf") {
                    array.append(url! as URL)
                }
            }
            
            self.delegate?.thumbnailView?(thumbanView: self, didDragAddFiles: array, indexpath: indexPath)
        }

        return false
    }
}

class MyLayoutAttributes: NSCollectionViewLayoutAttributes {
    var markerLocation = CGPoint.zero
}