//
//  KMNThumbnailManager.swift
//  PDF Reader Pro
//
//  Created by 丁林圭 on 2024/10/21.
//

import Cocoa

let kmnThumbnailFolder: String = {
    let documentDirectory = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true).first!
    return (documentDirectory as NSString).appendingPathComponent("ThumbnailFolder")
}()

public class KMNThumbnail: NSObject {
    var thumbnailDocument:CPDFDocument = CPDFDocument()
    
   typealias KMNThumbnailCompletion = (_ image: NSImage?) -> Void

    var thumbnaiPage:CPDFPage?
    var pageSize:CGSize = CGSizeZero
    var pageIndex:Int = 0
    
    var isHoveBookMark:Bool = false

    public var pageRotate:CGFloat = 0.0 {
        didSet {
            
        }
    }
    
    public init(document: CPDFDocument,currentPageIndex:Int) {
        thumbnailDocument = document
        pageIndex = currentPageIndex
        let page = document.page(at: UInt(currentPageIndex))
        let size =  page?.bounds.size ?? CGSizeZero
        pageSize = size

        thumbnaiPage = page
        pageRotate = 0
        
        isHoveBookMark = document.bookmark(forPageIndex: UInt(pageIndex)) != nil
        
        super.init()
    }
    
    public override init() {
        super.init()
    }
    
    func generateThumImage(completion: KMNThumbnailCompletion?) {
        let filePathID = KMNThumbnailManager.filePathId(for: thumbnailDocument.documentURL.path)
        let docsFilePath = kmnThumbnailFolder + "/" + filePathID
        let fileManager = FileManager.default

        if !fileManager.fileExists(atPath: docsFilePath) {
            try? FileManager.default.createDirectory(atPath: docsFilePath, withIntermediateDirectories: true, attributes: nil)
        }
        
        let pageObjNum = thumbnaiPage?.getObjNum() ?? -1 //获取Page的唯一标识码
        var imageFilePath = ""

        if(pageObjNum == -1) {
            imageFilePath = ""
        } else {
            imageFilePath =  docsFilePath + "/" + String(pageObjNum) + ".png"
        }
        var thumSize = pageSize
        
        if(imageFilePath.isEmpty == true) {
            
            let maxOrg = max(thumSize.width, thumSize.height)
            let minOrg = min(thumSize.width, thumSize.height)

            let maxWidth = 300.0
            let maxHeight = 500.0
            
            let scanW = maxWidth / minOrg
            let scanH = maxHeight / maxOrg
            let minScanl = min(scanW, scanH)
            
            if (thumbnaiPage?.rotation ?? 0) % 180 != 0 {
                thumSize.width = pageSize.height * minScanl
                thumSize.height = pageSize.width * minScanl
            } else {
                thumSize.width = pageSize.width * minScanl
                thumSize.height = pageSize.height * minScanl
            }
            
            thumbnaiPage?.thumbnail(of: thumSize, needReset: true,completion: { pageImage in
                if completion != nil {
                    completion!(pageImage)
                }
                // 将 NSImage 转换为 PNG 数据
                guard let tiffData = pageImage?.tiffRepresentation,
                         let bitmapImage = NSBitmapImageRep(data: tiffData),
                         let pngData = bitmapImage.representation(using: .png, properties: [:]) else {
                       return
                   }

                   do {
                       try pngData.write(to: URL(fileURLWithPath: imageFilePath))
                   } catch {
                   }
                
            });
        } else {
            if fileManager.fileExists(atPath: imageFilePath) {
               let image = NSImage.init(contentsOfFile: imageFilePath) ?? NSImage()
                if completion != nil {
                    completion!(image)
                }
            } else {
                let maxOrg = max(thumSize.width, thumSize.height)
                let minOrg = min(thumSize.width, thumSize.height)

                let maxWidth = 300.0
                let maxHeight = 500.0
                
                let scanW = maxWidth / minOrg
                let scanH = maxHeight / maxOrg
                let minScanl = min(scanW, scanH)
                
                if (thumbnaiPage?.rotation ?? 0) % 180 != 0 {
                    thumSize.width = pageSize.height * minScanl
                    thumSize.height = pageSize.width * minScanl
                } else {
                    thumSize.width = pageSize.width * minScanl
                    thumSize.height = pageSize.height * minScanl
                }
                
                thumbnaiPage?.thumbnail(of: thumSize, needReset: true,completion: { pageImage in
                    if completion != nil {
                        completion!(pageImage)
                    }
                    // 将 NSImage 转换为 PNG 数据
                    guard let tiffData = pageImage?.tiffRepresentation,
                             let bitmapImage = NSBitmapImageRep(data: tiffData),
                             let pngData = bitmapImage.representation(using: .png, properties: [:]) else {
                           return
                       }

                       do {
                           try pngData.write(to: URL(fileURLWithPath: imageFilePath))
                       } catch {
                       }
                    
                });
            }
        }
    }
    
    func removeCacheImage() {
        let filePathID = KMNThumbnailManager.filePathId(for: thumbnailDocument.documentURL.path)
        let docsFilePath = kmnThumbnailFolder + "/" + filePathID
        let fileManager = FileManager.default

        let pageObjNum = thumbnaiPage?.getObjNum() ?? -1
        var imageFilePath = ""

        if(pageObjNum == -1) {
            imageFilePath = ""
        } else {
            imageFilePath =  docsFilePath + "/" + String(pageObjNum) + ".png"
        }
                
        if fileManager.fileExists(atPath: imageFilePath) {
           try? fileManager.removeItem(atPath: imageFilePath)
        }
    }

}

class KMNThumbnailManager: NSObject {
    
    static let manager = KMNThumbnailManager()
    
    var copyPages: [CPDFPage] = []
    
    var copyDocument: [CPDFDocument] = []
    
    class func filePathId(for filePath: String) -> String {
        return "\(filePath.hash)"
    }
    
    class func clearCacheFilePath(filePath:String) {
        let filePathID = KMNThumbnailManager.filePathId(for: filePath)
        let docsFilePath = kmnThumbnailFolder + "/" + filePathID
        let fileManager = FileManager.default
        
        if fileManager.fileExists(atPath: docsFilePath) {
           try? fileManager.removeItem(atPath: docsFilePath)
        }
    }

    class func clearCacheThumImage() {
        if FileManager.default.fileExists(atPath: kmnThumbnailFolder) {
            try?FileManager.default.removeItem(atPath: kmnThumbnailFolder)
        }
    }
    
}