import PDFKit

// 创建PDFView
let pdfView = PDFView(frame: view.bounds)
pdfView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
view.addSubview(pdfView)

// 加载PDF文档
if let url = Bundle.main.url(forResource: "sample", withExtension: "pdf") {
    pdfView.document = PDFDocument(url: url)
}

// 添加高亮注释
func addHighlightAnnotation(to page: PDFPage, text: String, color: UIColor) {
    // 查找文本范围
    let selections = page.selectionForRange(pdfView.document!.findString(text, withOptions: .caseInsensitive))
    
    // 创建高亮注释
    let highlight = PDFAnnotation(bounds: selections.bounds(for: page), forType: .highlight, withProperties: nil)
    highlight.color = color.withAlphaComponent(0.5)
    
    // 添加注释到页面
    page.addAnnotation(highlight)
}

// 添加自由文本注释
func addTextAnnotation(to page: PDFPage, text: String, at point: CGPoint) {
    let textAnnotation = PDFAnnotation(bounds: CGRect(x: point.x, y: point.y, width: 200, height: 50), 
                                      forType: .freeText, 
                                      withProperties: nil)
    textAnnotation.contents = text
    textAnnotation.font = UIFont.systemFont(ofSize: 14)
    textAnnotation.color = .blue
    page.addAnnotation(textAnnotation)
}

// 保存带注释的PDF
func saveAnnotatedPDF() {
    if let document = pdfView.document {
        let data = document.dataRepresentation()
        try? data?.write(to: URL(fileURLWithPath: "/path/to/save.pdf"))
    }
}

// 确保使用document的dataRepresentation()方法保存
if let document = pdfView.document {
    let data = document.dataRepresentation()
    // 保存data到文件
}

// 使用正确的坐标系转换
let pageBounds = page.bounds(for: .cropBox)
let annotationBounds = selections.bounds(for: page).applying(CGAffineTransform(translationX: 0, y: -pageBounds.height))