//
//  KMURLToPDF.swift
//  PDF Reader Pro
//
//  Created by Niehaoyu on 2024/10/16.
//

import Cocoa
import WebKit
import PDFKit

class KMURLToPDF: NSObject, WKNavigationDelegate {
    
    @objc public static let shareInstance = KMURLToPDF()
    
    var webView: WKWebView!
    var completion: ((URL?, Error?) -> Void)?
    
    var savePath: String = ""
    var saveName: String = ""
    
    func convertHtmlFileToPDF(fromPath: String, toPath: String, completion: @escaping (URL?, Error?) -> Void) {
        
        self.completion = completion
        savePath = toPath
        
        webView = WKWebView(frame: CGRectMake(0, 0, 1920, 1080))
        webView.navigationDelegate = self
        
        let fileURL: URL = URL(fileURLWithPath: fromPath)
        let readAccessURL = fileURL.deletingLastPathComponent()
        webView.loadFileURL(fileURL, allowingReadAccessTo: readAccessURL)
        
        saveName = fromPath.deletingPathExtension.lastPathComponent + ".pdf"
        
    }
    
    func convertLinkString(string: String, toPath: String, completion: @escaping (URL?, Error?) -> Void) {
        
        self.completion = completion
        savePath = toPath
        
        webView = WKWebView(frame: CGRectMake(0, 0, 1920, 1080))
        webView.navigationDelegate = self
        
        if let url = URL(string: string) {
            webView.load(URLRequest(url: url))
        }
    }
    
    func stopLoading() {
        webView?.stopLoading()
    }
    
    
    //MARK: - WKNavigationDelegate
    func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
        webView.stopLoading()
        
        let configuration: WKPDFConfiguration = WKPDFConfiguration()
        
        var contentWidth: CGFloat = 0
        var contentHeight: CGFloat = 0
        webView.evaluateJavaScript("document.title") { (result, error) in
            if let name = result as? String {
                self.saveName = name + ".pdf"
            }
            webView.evaluateJavaScript("document.body.scrollWidth") { (width, error) in
                if let width = width as? CGFloat {
                    contentWidth = width
                }
                // 获取内容高度
                webView.evaluateJavaScript("document.body.scrollHeight") { (height, error) in
                    if let height = height as? CGFloat {
                        contentHeight = height
                    }
                    if contentWidth > 0 && contentHeight > 0 {
                        configuration.rect = CGRectMake(0, 0, contentWidth, contentHeight)
                        webView.createPDF(configuration: configuration) { result in
                            switch result {
                            case .success(let pdfData):
                                // PDF successfully created, handle the PDF data
                                
                                let filePath = URL(fileURLWithPath: self.savePath.stringByAppendingPathComponent(self.saveName))
                                if FileManager.default.fileExists(atPath: filePath.path) {
                                    try?FileManager.default.removeItem(atPath: filePath.path)
                                }
                                
                                do {
                                    try pdfData.write(to: filePath)
                                    print("PDF saved to: \(filePath)")
                                } catch {
                                    print("Failed to save PDF: \(error)")
                                }
                                
                                guard let callBack = self.completion else {
                                    return
                                }
                                callBack(filePath, nil)
                                
                            case .failure(let error):
                                guard let callBack = self.completion else {
                                    return
                                }
                                callBack(nil, error)
                            }
                        }
                    } else {
                        guard let callBack = self.completion else {
                            return
                        }
                        callBack(nil, NSError(domain: "create error", code: 0))
                    }
                }
            }
        }
    }
    
    func webView(_ webView: WKWebView, didFail navigation: WKNavigation!, withError error: Error) {
        webView.stopLoading()
        
        guard let callBack = self.completion else {
            return
        }
        callBack(nil, error)
    }
    
    func webView(_ webView: WKWebView, didFailProvisionalNavigation navigation: WKNavigation!, withError error: Error) {
        webView.stopLoading()
        
        guard let callBack = self.completion else {
            return
        }
        callBack(nil, error)
        
    }
}