import SwiftUI
import SVGKit

struct SVGImage: UIViewRepresentable {
    let svgName: String
    var contentMode: ContentMode = .fit
    var tintColor: Color?
    
    private var svgPath: String {
        return svgName
    }
    
    private func createImageView() -> SVGKFastImageView {
        let emptySVGString = """
        <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1 1" preserveAspectRatio="xMidYMid meet">
            <rect width="1" height="1" fill="transparent"/>
        </svg>
        """
        
        if let data = emptySVGString.data(using: .utf8),
           let svgImage = SVGKImage(data: data) {
            let imageView = SVGKFastImageView(svgkImage: svgImage) ?? SVGKFastImageView()
            imageView.contentMode = .scaleAspectFit
            imageView.backgroundColor = .clear
            return imageView
        }
        
        let fallbackView = SVGKFastImageView()
        fallbackView.backgroundColor = .clear
        return fallbackView
    }
    
    func makeUIView(context: Context) -> SVGKFastImageView {
        print("🔄 开始加载SVG: \(svgName)")
        let imageView = createImageView()
        loadSVG(into: imageView)
        configureView(imageView)
        return imageView
    }
    
    private func loadSVG(into imageView: SVGKFastImageView) {
        guard let path = Bundle.main.path(forResource: svgPath, ofType: "svg") else {
            print("⚠️ 在main bundle中找不到文件: \(svgPath).svg")
            return
        }
        
        let url = URL(fileURLWithPath: path)
        guard let svgImage = SVGKImage(contentsOf: url) else {
            print("❌ 无法从URL创建SVG: \(path)")
            return
        }
        
        // 设置SVG的尺寸为容器大小
        let containerSize = imageView.bounds.size
        if containerSize != .zero {
            svgImage.size = containerSize
        } else {
            // 如果容器大小未知，设置一个默认大小
            svgImage.size = CGSize(width: 100, height: 100)
        }
        
        print("✅ 成功加载SVG: \(svgName), 尺寸: \(svgImage.size)")
        
        DispatchQueue.main.async {
            imageView.image = svgImage
            imageView.setNeedsLayout()
            imageView.layoutIfNeeded()
        }
    }
    
    private func configureView(_ imageView: SVGKFastImageView) {
        imageView.contentMode = contentMode == .fit ? .scaleAspectFit : .scaleAspectFill
        imageView.clipsToBounds = true
        imageView.translatesAutoresizingMaskIntoConstraints = false
        imageView.backgroundColor = .clear
        
        // 确保图片视图可以正确缩放
        imageView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
        
        if let tintColor = tintColor?.uiColor {
            imageView.tintColor = tintColor
            DispatchQueue.main.async {
                self.applyTintColor(tintColor, to: imageView.layer)
            }
        }
    }
    
    private func applyTintColor(_ color: UIColor, to layer: CALayer) {
        if let shapeLayer = layer as? CAShapeLayer {
            shapeLayer.fillColor = color.cgColor
        }
        
        layer.sublayers?.forEach { sublayer in
            applyTintColor(color, to: sublayer)
        }
    }
    
    func updateUIView(_ uiView: SVGKFastImageView, context: Context) {
        loadSVG(into: uiView)
        
        if let tintColor = tintColor?.uiColor {
            uiView.tintColor = tintColor
            DispatchQueue.main.async {
                self.applyTintColor(tintColor, to: uiView.layer)
            }
        }
        
        uiView.contentMode = contentMode == .fit ? .scaleAspectFit : .scaleAspectFill
    }
    
    func sizeThatFits(_ proposal: ProposedViewSize, uiView: SVGKFastImageView, context: Context) -> CGSize? {
        return nil
    }
}

// MARK: - ContentMode
extension SVGImage {
    enum ContentMode {
        case fit   // 保持宽高比，适应容器
        case fill  // 保持宽高比，填充容器（可能被裁剪）
    }
}

// MARK: - Preview
#Preview {
    VStack(spacing: 20) {
        Text("IP SVG")
        SVGImage(svgName: "IP")
            .frame(width: 100, height: 100)
            .background(Color.gray.opacity(0.2))
            .border(Color.red, width: 1)
        
        Text("Pioneer SVG")
        SVGImage(svgName: "Pioneer", contentMode: .fill)
            .frame(width: 100, height: 50)
            .background(Color.gray.opacity(0.2))
            .border(Color.blue, width: 1)
            .clipped()
    }
    .padding()
}

// MARK: - Color Extension
private extension Color {
    var uiColor: UIColor {
        return UIColor(self)
    }
}