package com.bonus.sdk;

import java.awt.image.BufferedImage;
import java.awt.image.DataBufferByte;
import java.io.*;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.StandardCopyOption;
import java.util.HashSet;
import java.util.Set;

public class YoloSdk implements AutoCloseable {

    private long nativeHandle; // 指向 C++ YoloDetector 实例的指针
    private static final Set<String> loadedLibraries = new HashSet<>();
    private static Path tempDir; // 用于存放所有本地库的唯一临时目录

    /**
     * 静态初始化块，用于加载本地库。
     */
    static {
        try {
            // 1. 创建一个唯一的临时目录，用于存放所有DLL/SO文件
            tempDir = Files.createTempDirectory("yolo_sdk_native_libs_");
            // 2. 确保在JVM退出时删除此目录
            tempDir.toFile().deleteOnExit();
            
            // 3. 将所有库解压并加载到此目录
            loadSdkLibrary(tempDir);

        } catch (IOException e) {
            throw new RuntimeException("CRITICAL: Failed to create temp directory for native libraries", e);
        }
    }

    /**
     * 负责解压和加载所有本地库。
     * @param tempDir 
     */
    private static void loadSdkLibrary(Path tempDir) throws IOException {
        String osName = System.getProperty("os.name").toLowerCase();
        String osArch = System.getProperty("os.arch").toLowerCase();
        String libPathInJar;
        String sdkLibName;
        String[] dependencyLibs = {};

        if (osName.contains("win") && osArch.contains("64")) {
            libPathInJar = "/lib/win-x64/";
            // 依赖项必须按加载顺序列出
            dependencyLibs = new String[]{
                    "onnxruntime.dll",
                    "abseil_dll.dll",
                    "libprotobuf.dll",
                    "zlib1.dll",
                    "opencv_core4.dll",
                    "opencv_imgproc4.dll",
                    "opencv_dnn4.dll"
            };
            sdkLibName = "my_yolo_sdk.dll";

        } else if ((osName.contains("nix") || osName.contains("nux")) && osArch.contains("64")) {
            libPathInJar = "/lib/linux-x86_64/";
            // 确保这些是您Linux构建所需的 .so 依赖项
            dependencyLibs = new String[]{
                    "libonnxruntime.so.1.23.2", // 示例，请使用您确切的文件名
                    "libopencv_core.so.4.6.0",
                    "libopencv_imgproc.so.4.6.0",
                    "libopencv_dnn.so.4.6.0"
            };
            sdkLibName = "libmy_yolo_sdk.so";

        } else {
            throw new UnsupportedOperationException("Unsupported OS/Arch: " + osName + "/" + osArch);
        }

        // --- 关键的修复逻辑 ---

        // 步骤 1: 首先，将所有库文件从JAR解压到同一个临时目录，保持原始文件名
        for (String lib : dependencyLibs) {
            extractLibraryFromJar(libPathInJar + lib, tempDir);
        }
        // 解压主SDK库
        extractLibraryFromJar(libPathInJar + sdkLibName, tempDir);

        // 步骤 2: 然后，按顺序从该临时目录加载库
        // 这样，Windows/Linux加载器可以在同一目录中找到所有依赖项
        try {
            for (String lib : dependencyLibs) {
                if (!loadedLibraries.contains(lib)) {
                    System.load(tempDir.resolve(lib).toAbsolutePath().toString());
                    loadedLibraries.add(lib);
                }
            }
            if (!loadedLibraries.contains(sdkLibName)) {
                System.load(tempDir.resolve(sdkLibName).toAbsolutePath().toString());
                loadedLibraries.add(sdkLibName);
            }
        } catch (UnsatisfiedLinkError e) {
            // 提供更详细的错误信息
            System.err.println("--- NATIVE LIBRARY LOAD FAILED ---");
            System.err.println("Failed to load native library. This often means a dependency is missing on the host system.");
            System.err.println("For Windows: Ensure 'Visual C++ Redistributable for Visual Studio (x64)' is installed.");
            System.err.println("Libraries were extracted to: " + tempDir.toAbsolutePath());
            System.err.println("-----------------------------------");
            throw e; // 重新抛出原始错误
        }
    }

    /**
     * * @param pathInJar 
     * @param tempDir 
     */
    private static void extractLibraryFromJar(String pathInJar, Path tempDir) throws IOException {
        String libName = new File(pathInJar).getName();
        
        try (InputStream in = YoloSdk.class.getResourceAsStream(pathInJar)) {
            if (in == null) {
                throw new FileNotFoundException("Library " + pathInJar + " not found in JAR.");
            }

            // 目标文件路径，保持原始文件名
            Path targetFile = tempDir.resolve(libName);
            
            // 将文件从JAR复制到临时目录
            Files.copy(in, targetFile, StandardCopyOption.REPLACE_EXISTING);
            
            // 为解压的目录/文件设置退出时删除（双重保险）
            targetFile.toFile().deleteOnExit();
        }
    }

    // --- Native JNI 方法 ---
    private native long nativeInit(String modelPath, int inputWidth, int inputHeight);
    private native void nativeRelease(long handle);
    private native Detection[] nativePredict(
            long handle, byte[] bgrBytes, int imageWidth, int imageHeight,
            float confThreshold, float iouThreshold
    );

    // --- 公共 Java API ---

    /**
     * 初始化YOLO SDK。
     * @param modelPath 
     * @param inputWidth 
     * @param inputHeight 
     */
    public YoloSdk(String modelPath, int inputWidth, int inputHeight) {
        this.nativeHandle = nativeInit(modelPath, inputWidth, inputHeight);
        if (this.nativeHandle == 0) {
            throw new RuntimeException("Failed to initialize native YOLO SDK. Check logs for details.");
        }
    }

    /**
     * @param image
     * @param confThreshold
     * @param iouThreshold
     * @return 
     */
    public Detection[] predict(BufferedImage image, float confThreshold, float iouThreshold) {
        if (this.nativeHandle == 0) {
            throw new IllegalStateException("SDK already closed or failed to initialize.");
        }
        byte[] bgrBytes = getBgrBytes(image);
        return nativePredict(
                this.nativeHandle, bgrBytes, image.getWidth(), image.getHeight(),
                confThreshold, iouThreshold
        );
    }

    /**
     * 释放本地资源。
     */
    @Override
    public void close() {
        if (this.nativeHandle != 0) {
            nativeRelease(this.nativeHandle);
            this.nativeHandle = 0;
        }
    }

    /**
     * * @param image 
     * @return 
     */
    private byte[] getBgrBytes(BufferedImage image) {
        // 如果图像已经是 3-byte BGR，直接返回
        if (image.getType() == BufferedImage.TYPE_3BYTE_BGR) {
            return ((DataBufferByte) image.getRaster().getDataBuffer()).getData();
        }
        
        // 否则，创建一个 BGR 副本
        BufferedImage bgrImage = new BufferedImage(image.getWidth(), image.getHeight(), BufferedImage.TYPE_3BYTE_BGR);
        bgrImage.getGraphics().drawImage(image, 0, 0, null);
        return ((DataBufferByte) bgrImage.getRaster().getDataBuffer()).getData();
    }
}