In order to understand how all things working, You have to look at classes and files where all logic resides in the helper folders.

Below data is just to learn about how things work, You can not get things like, how data passed to the query and from where the data is coming.

Database Schema:

Files Table Schema:

{
    "fileId": string,
    "folderId": string,
    "name": string,
    "size": number,
    "dim": {
        "h": number,
        "w": number
    },
    "type": string,
    "src": urlString,
    "date": utcTimeString
}

Folders Table Schema:

{   
    "folderId": string,
    "path": string,
    "name": string,
    "size": number,
    "files": array<string>,
    "folders": array<string>,
    "parentFolderId": string,
    "date": utcTimeString
}

Queries:

a. Insert a new folder or file at any level (root or inside a folder)

Create Folder

db.collection("Folders").insertOne({
    folderId: mFolderId,
    path: mPath,
    name: mName,
    size: mSize,
    files: mFiles,
    folders: mFolders,
    parentFolderId: mParentFolderId,
    date: new Date().toISOString()
})

Create File

db.collection("Files").insertOne({
    fileId: mFileId,
    folderId: mFolderId,
    name: mName,
    size: mSize,
    dim: mDimObj,
    type: mType,
    src: mSrc,
    date: new Date().toISOString(),
})

b. Get list of all files reverse sorted by date

db.collection("Files")
    .find({})
    .sort({ date: -1 })
    .toArray()

c. Find the total size of a folder (like total size of files contained in Folder2 which would include size of files File3.jpg and File4.txt)

db.collection("Folders").findOne(
    { folderId: folderId },
    { size: 1 , _id: 1},
)

d. Delete a folder

db.collection("Folders").deleteMany({
    folderId: { $in: [...folders] },
});

where folder is list of folder to delete and its child and grand child folders.

e. Search by filename and

f. Search for files with name “File1” and format = PNG

db.collection("Files").find({
    $and: [
    {
        name: { $regex: fileName ?? `.*`},
    },
    {
        type: { $regex: fileType ?? `.*` },
    },
    ]
}).toArray()

You can search by FileName("File_0", "File_1", or starting/ending with "File_1") and/or FileType ("PNG", "JPEG" or any sub-chars.)

g. Rename SubFolder2 to NestedFolder2

db.collection("Folders").updateOne(
    { folderId: mFolderId },
    { $set: { name: mNewName } },
)

Thank you. Dharmendra Jagodana