package com.safeluck.floatwindow.util;

import android.content.Context;
import android.os.StatFs;
import android.os.storage.StorageManager;

import java.io.File;
import java.lang.reflect.Array;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.Date;
import java.util.List;
import java.util.Locale;

import timber.log.Timber;

public class FileUtil {
    //获取插入的TFCard目录路径
    public static String getStoragePath(Context mContext, boolean is_removale) {
        if (mContext != null) {
            StorageManager mStorageManager = (StorageManager) mContext.getSystemService(Context.STORAGE_SERVICE);
            Class<?> storageVolumeClazz = null;
            try {
                storageVolumeClazz = Class.forName("android.os.storage.StorageVolume");
                Method getVolumeList = mStorageManager.getClass().getMethod("getVolumeList");
                Method getPath = storageVolumeClazz.getMethod("getPath");
                Method isRemovable = storageVolumeClazz.getMethod("isRemovable");
                Object result = getVolumeList.invoke(mStorageManager);
                final int length = Array.getLength(result);
                for (int i = 0; i < length; i++) {
                    Object storageVolumeElement = Array.get(result, i);
                    String path = (String) getPath.invoke(storageVolumeElement);
                    boolean removable = (Boolean) isRemovable.invoke(storageVolumeElement);
                    if (is_removale == removable) {
                        return path;
                    }
                }
            } catch (ClassNotFoundException e) {
                e.printStackTrace();
            } catch (InvocationTargetException e) {
                e.printStackTrace();
            } catch (NoSuchMethodException e) {
                e.printStackTrace();
            } catch (IllegalAccessException e) {
                e.printStackTrace();
            }
            return  null;
        } else {

            return null;
        }

    }

    /**
     * 清理 TF 卡上的 h264 文件
     * 当 h264 文件总大小超过指定阈值或 TF 卡剩余空间小于指定值时，删除日期最早的文件夹
     * 
     * @param context Context 对象，用于获取 TF 卡路径和剩余空间
     * @param h264RootDir h264 根目录路径，例如 "/sdcard/h264"
     * @param maxTotalSizeGB 最大总大小（GB），默认 5GB
     * @param minFreeSpaceGB 最小剩余空间（GB），默认 1GB
     */
    public static void cleanupH264Files(Context context, String h264RootDir, long maxTotalSizeGB, long minFreeSpaceGB) {
        if (context == null || h264RootDir == null || h264RootDir.trim().isEmpty()) {
            Timber.w("Context or h264 root directory is null, skip cleanup");
            return;
        }

        File h264Root = new File(h264RootDir);
        if (!h264Root.exists() || !h264Root.isDirectory()) {
            Timber.d("H264 root directory does not exist: %s, skip cleanup", h264RootDir);
            return;
        }

        try {
            // 获取 TF 卡路径
            String tfCardPath = getStoragePath(context, true);
            if (tfCardPath == null || tfCardPath.trim().isEmpty()) {
                Timber.w("TF card path not available, skip cleanup");
                return;
            }

            // 获取 TF 卡剩余空间（GB）
            long freeSpaceGB = getFreeSpaceGB(tfCardPath);
            Timber.d("TF card free space: %d GB", freeSpaceGB);

            // 扫描所有日期文件夹
            File[] dateDirs = h264Root.listFiles(File::isDirectory);
            if (dateDirs == null || dateDirs.length == 0) {
                Timber.d("No date directories found in h264 root: %s", h264RootDir);
                return;
            }

            // 按日期排序（最早的在前）
            List<DateDirInfo> dateDirList = new ArrayList<>();
            SimpleDateFormat dateFormat = new SimpleDateFormat("yyyyMMdd", Locale.CHINA);
            
            for (File dateDir : dateDirs) {
                String dirName = dateDir.getName();
                // 只处理符合日期格式的文件夹（yyyyMMdd）
                if (dirName.length() == 8 && dirName.matches("\\d{8}")) {
                    try {
                        Date date = dateFormat.parse(dirName);
                        long totalSize = calculateH264FilesSize(dateDir);
                        dateDirList.add(new DateDirInfo(dateDir, date, totalSize));
                    } catch (ParseException e) {
                        Timber.w("Invalid date directory name: %s", dirName);
                    }
                }
            }

            // 按日期排序（最早的在前）
            Collections.sort(dateDirList, new Comparator<DateDirInfo>() {
                @Override
                public int compare(DateDirInfo o1, DateDirInfo o2) {
                    return o1.date.compareTo(o2.date);
                }
            });

            // 计算所有 h264 文件的总大小（GB）
            long totalSizeGB = 0;
            for (DateDirInfo info : dateDirList) {
                totalSizeGB += info.totalSize / (1024L * 1024L * 1024L);
            }
            Timber.d("Total h264 files size: %d GB, Max allowed: %d GB", totalSizeGB, maxTotalSizeGB);
            Timber.d("TF card free space: %d GB, Min required: %d GB", freeSpaceGB, minFreeSpaceGB);

            // 检查是否需要清理
            boolean needCleanup = (totalSizeGB > maxTotalSizeGB) || (freeSpaceGB < minFreeSpaceGB);

            if (!needCleanup) {
                Timber.d("No cleanup needed");
                return;
            }

            // 删除最早的日期文件夹，直到满足条件
            int deletedCount = 0;
            while (!dateDirList.isEmpty() && ((totalSizeGB > maxTotalSizeGB) || (freeSpaceGB < minFreeSpaceGB))) {
                DateDirInfo oldestDir = dateDirList.remove(0);
                
                Timber.d("Deleting oldest date directory: %s (size: %d GB, date: %s)", 
                        oldestDir.dir.getName(), oldestDir.totalSize / (1024L * 1024L * 1024L), 
                        dateFormat.format(oldestDir.date));

                // 删除文件夹及其所有内容
                if (deleteDirectory(oldestDir.dir)) {
                    deletedCount++;
                    totalSizeGB -= oldestDir.totalSize / (1024L * 1024L * 1024L);
                    
                    // 重新获取剩余空间
                    freeSpaceGB = getFreeSpaceGB(tfCardPath);
                    Timber.d("After deletion - Total size: %d GB, Free space: %d GB", 
                            totalSizeGB, freeSpaceGB);
                } else {
                    Timber.e("Failed to delete directory: %s", oldestDir.dir.getAbsolutePath());
                    break; // 删除失败，停止清理
                }
            }

            Timber.i("Cleanup completed. Deleted %d date directories. Final total size: %d GB, Free space: %d GB",
                    deletedCount, totalSizeGB, freeSpaceGB);

        } catch (Exception e) {
            Timber.e(e, "Error during h264 files cleanup");
        }
    }

    /**
     * 清理 TF 卡上的 h264 文件（使用默认参数：最大5GB，最小剩余空间1GB）
     */
    public static void cleanupH264Files(Context context, String h264RootDir) {
        cleanupH264Files(context, h264RootDir, 5, 1);
    }

    /**
     * 检查内部 Flash（非 TF 卡）剩余空间，如果小于 800MB，则按时间顺序删除 h264_*.h264 文件
     * 目录：context.getExternalFilesDir(null).getAbsolutePath()
     * 文件名格式示例：h264_1735023032000.h264、h264_camera2_1735023032000.h264
     *
     * 删除规则：
     * - 按文件名中的时间戳从小到大（越早越先删）依次删除
     * - 每删除一次后重新计算剩余空间，直到 ≥ 800MB 或文件删完
     *
     * 返回值：
     * - 0：最终剩余空间 ≥ 800MB 或无需删除
     * - -1：删除完所有符合规则的文件后，剩余空间仍然 < 800MB
     */
    public static int ensureInternalFlashSpaceForH264(Context context) {
        if (context == null) {
            Timber.w("ensureInternalFlashSpaceForH264: context is null");
            return 0;
        }

        File externalDir = context.getExternalFilesDir(null);
        if (externalDir == null) {
            Timber.w("ensureInternalFlashSpaceForH264: external files dir is null");
            return 0;
        }

        String basePath = externalDir.getAbsolutePath();
        long minFreeBytes = 800L * 1024L * 1024L; // 800MB

        long freeBytes = getFreeSpaceBytes(basePath);
        Timber.d("ensureInternalFlashSpaceForH264: freeBytes=%d, minRequired=%d", freeBytes, minFreeBytes);

        if (freeBytes >= minFreeBytes) {
            // 空间充足，无需处理
            return 0;
        }

        // 收集符合命名规则的 h264 文件
        File[] files = externalDir.listFiles();
        if (files == null || files.length == 0) {
            Timber.w("ensureInternalFlashSpaceForH264: no files in dir -> %s", basePath);
            // 已经没有可删的文件，如果仍小于 800MB，则直接返回 -1
            return freeBytes >= minFreeBytes ? 0 : -1;
        }

        class H264FileInfo {
            File file;
            long timestamp;

            H264FileInfo(File file, long timestamp) {
                this.file = file;
                this.timestamp = timestamp;
            }
        }

        List<H264FileInfo> h264Files = new ArrayList<>();
        for (File file : files) {
            if (!file.isFile()) {
                continue;
            }

            String name = file.getName();
            // 只处理 .h264 结尾，且以 h264_ 开头的文件
            if (!name.toLowerCase(Locale.CHINA).endsWith(".h264")) {
                continue;
            }
            if (!name.startsWith("h264_") && !name.startsWith("h264_camera2_")) {
                continue;
            }

            // 提取时间戳部分
            String timePart = null;
            if (name.startsWith("h264_camera2_")) {
                // 前缀长度 13："h264_camera2_"
                timePart = name.substring("h264_camera2_".length(), name.length() - ".h264".length());
            } else if (name.startsWith("h264_")) {
                // 前缀长度 5："h264_"
                timePart = name.substring("h264_".length(), name.length() - ".h264".length());
            }

            if (timePart == null || timePart.isEmpty()) {
                continue;
            }

            try {
                long ts = Long.parseLong(timePart);
                h264Files.add(new H264FileInfo(file, ts));
            } catch (NumberFormatException e) {
                // 文件名不符合时间戳格式，跳过
                Timber.w("ensureInternalFlashSpaceForH264: invalid timestamp in file name -> %s", name);
            }
        }

        if (h264Files.isEmpty()) {
            Timber.w("ensureInternalFlashSpaceForH264: no matched h264 files in -> %s", basePath);
            return freeBytes >= minFreeBytes ? 0 : -1;
        }

        // 按时间戳升序排列（越早的越先删）
        Collections.sort(h264Files, new Comparator<H264FileInfo>() {
            @Override
            public int compare(H264FileInfo o1, H264FileInfo o2) {
                return Long.compare(o1.timestamp, o2.timestamp);
            }
        });

        int deletedCount = 0;
        for (H264FileInfo info : h264Files) {
            if (freeBytes >= minFreeBytes) {
                break;
            }

            File f = info.file;
            long size = f.length();
            Timber.d("ensureInternalFlashSpaceForH264: deleting file -> %s, size=%d, ts=%d",
                    f.getAbsolutePath(), size, info.timestamp);

            if (f.delete()) {
                deletedCount++;
                // 删除后重新获取剩余空间，更准确
                freeBytes = getFreeSpaceBytes(basePath);
                Timber.d("ensureInternalFlashSpaceForH264: after delete, freeBytes=%d", freeBytes);
            } else {
                Timber.e("ensureInternalFlashSpaceForH264: failed to delete file -> %s", f.getAbsolutePath());
            }
        }

        Timber.i("ensureInternalFlashSpaceForH264: deleted %d files, final freeBytes=%d", deletedCount, freeBytes);

        return freeBytes >= minFreeBytes ? 0 : -1;
    }

    /**
     * 计算目录下所有 .h264 文件的总大小（字节）
     */
    private static long calculateH264FilesSize(File dir) {
        long totalSize = 0;
        File[] files = dir.listFiles();
        if (files != null) {
            for (File file : files) {
                if (file.isFile() && file.getName().toLowerCase().endsWith(".h264")) {
                    totalSize += file.length();
                }
            }
        }
        return totalSize;
    }

    /**
     * 获取指定路径的剩余空间（GB）
     */
    private static long getFreeSpaceGB(String path) {
        try {
            StatFs statFs = new StatFs(path);
            long blockSize = statFs.getBlockSizeLong();
            long availableBlocks = statFs.getAvailableBlocksLong();
            long freeBytes = availableBlocks * blockSize;
            return freeBytes / (1024L * 1024L * 1024L); // 转换为 GB
        } catch (Exception e) {
            Timber.e(e, "Error getting free space for path: %s", path);
            return 0;
        }
    }

    /**
     * 获取指定路径的剩余空间（字节）
     */
    private static long getFreeSpaceBytes(String path) {
        try {
            StatFs statFs = new StatFs(path);
            long blockSize = statFs.getBlockSizeLong();
            long availableBlocks = statFs.getAvailableBlocksLong();
            return availableBlocks * blockSize;
        } catch (Exception e) {
            Timber.e(e, "Error getting free space (bytes) for path: %s", path);
            return 0;
        }
    }

    /**
     * 递归删除目录及其所有内容
     */
    private static boolean deleteDirectory(File dir) {
        if (dir == null || !dir.exists()) {
            return true;
        }

        if (dir.isDirectory()) {
            File[] children = dir.listFiles();
            if (children != null) {
                for (File child : children) {
                    if (!deleteDirectory(child)) {
                        return false;
                    }
                }
            }
        }

        return dir.delete();
    }

    /**
     * 日期文件夹信息
     */
    private static class DateDirInfo {
        File dir;
        Date date;
        long totalSize; // 字节

        DateDirInfo(File dir, Date date, long totalSize) {
            this.dir = dir;
            this.date = date;
            this.totalSize = totalSize;
        }
    }
}