Aria/PublicComponent/src/main/java/com/arialyy/aria/util/UriFileUtil.java

/*
 * Copyright (C) 2016 AriaLyy(https://github.com/AriaLyy/Aria)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.arialyy.aria.util;

import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.net.Uri;
import android.os.ParcelFileDescriptor;
import android.provider.OpenableColumns;
import android.text.TextUtils;

/**
 * 分区存储（Scoped Storage）相关 Uri 工具类，提供文件名解析、可写性探测和权限持久化能力。
 */
public class UriFileUtil {
    private static final String TAG = "UriFileUtil";

    /**
     * 从 Uri 中获取文件名
     *
     * @param context 上下文，可为 null（仅用 lastPathSegment 兜底）
     * @param uri     文档 Uri
     * @return 文件名，无法获取时返回空串
     */
    public static String getFileName(Context context, Uri uri) {
        if (uri == null) {
            return "";
        }
        String name = queryDisplayName(context, uri);
        if (!TextUtils.isEmpty(name)) {
            return name;
        }
        String last = uri.getLastPathSegment();
        if (!TextUtils.isEmpty(last)) {
            int idx = last.lastIndexOf('/');
            return idx >= 0 ? last.substring(idx + 1) : last;
        }
        return "";
    }

    private static String queryDisplayName(Context context, Uri uri) {
        if (!"content".equalsIgnoreCase(uri.getScheme()) || context == null) {
            return null;
        }
        Cursor cursor = null;
        try {
            cursor = context.getContentResolver()
                    .query(uri, new String[]{OpenableColumns.DISPLAY_NAME}, null, null, null);
            if (cursor != null && cursor.moveToFirst()) {
                int idx = cursor.getColumnIndex(OpenableColumns.DISPLAY_NAME);
                if (idx >= 0) {
                    return cursor.getString(idx);
                }
            }
        } catch (Exception e) {
            ALog.w(TAG, "query display name error: " + e.getMessage());
        } finally {
            if (cursor != null) {
                cursor.close();
            }
        }
        return null;
    }

    /**
     * 测试 Uri 是否可写（以读写方式打开）
     */
    public static boolean canWrite(Context context, Uri uri) {
        if (context == null || uri == null) {
            return false;
        }
        ParcelFileDescriptor pfd = null;
        try {
            pfd = context.getContentResolver().openFileDescriptor(uri, "rw");
            return pfd != null;
        } catch (Exception e) {
            ALog.w(TAG, "uri canWrite test failed: " + e.getMessage());
            return false;
        } finally {
            if (pfd != null) {
                try {
                    pfd.close();
                } catch (Exception ignored) {
                    // ignore
                }
            }
        }
    }

    /**
     * 获取 Uri 对应文件的长度
     *
     * @return 文件长度；无法获取（Uri 不存在、无权限、流式内容等）时返回 -1
     */
    public static long getFileLength(Context context, Uri uri) {
        if (context == null || uri == null) {
            return -1;
        }
        ParcelFileDescriptor pfd = null;
        try {
            pfd = context.getContentResolver().openFileDescriptor(uri, "r");
            return pfd == null ? -1 : pfd.getStatSize();
        } catch (Exception e) {
            ALog.w(TAG, "get uri file length failed: " + e.getMessage());
            return -1;
        } finally {
            if (pfd != null) {
                try {
                    pfd.close();
                } catch (Exception ignored) {
                    // ignore
                }
            }
        }
    }

    /**
     * 尝试持久化 Uri 权限，以便应用重启后仍能访问（SAF 文档树/文件）。
     * 若 Uri 不支持持久化权限则静默忽略。
     */
    public static void tryTakePersistablePermission(Context context, Uri uri) {
        if (context == null || uri == null) {
            return;
        }
        try {
            context.getContentResolver()
                    .takePersistableUriPermission(uri,
                            Intent.FLAG_GRANT_READ_URI_PERMISSION | Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
        } catch (SecurityException | IllegalArgumentException ignored) {
            // 部分 Uri（如 MediaStore 插入项）不支持持久化权限，忽略即可
        }
    }
}