Feature request: offline recursive EPUB optimization for folder trees (preserve subdirectories)

[alrudimgn]

Hi! First of all, thank you for this project — the optimizer looks very useful for Xteink X4 / CrossPoint-style constrained devices.

I’m using it for a local/offline workflow to prepare a copy of my EPUB library for reading on Xteink X4. The source library is already organized in a deep folder tree (authors/series/books), and I want to preserve that structure in the optimized copy.

Current use case

Source: large EPUB library (generated offline from FB2)

Goal: optimize only the copy of the library for better performance (CSS cleanup, image optimization, grayscale, font stripping, etc.)

Requirement: offline, batch, recursive, preserve folder structure

What works now

Web optimizer is available and useful

CLI convert exists (init, convert) for EPUB → XTC/XTCH

What is missing (for EPUB optimizer workflow)

A CLI/offline way to optimize EPUB files recursively in a directory tree.

Requested features (priority order)

1. CLI command for EPUB optimization

Something like:

node index.js optimize -o -c settings.json

Where:

can be a file or folder

is target file/folder

uses the same optimization options as the web Optimizer tab

2. Recursive folder processing

Support recursive processing of subfolders, e.g.:

node index.js optimize ./library-epub -o ./library-epub-x4 --recursive
3) Preserve directory structure

When optimizing a folder tree, preserve relative paths:

library-epub/Author/Series/Book.epub
→
library-epub-x4/Author/Series/Book.epub

This is extremely important for existing libraries.

4. In-place mode (optional)

Useful for optimized copy maintenance:

node index.js optimize ./library-epub-x4 --recursive --in-place
5) Dry-run and report/log output (optional but very useful)

For large libraries, it would help to have:

--dry-run

--report <file.json/csv>

summary of:

processed files

failed files

size before/after

applied optimizations

6. Filter options (optional)

Examples:

--include "*.epub"

--exclude "*_original.epub"

--skip-existing

--overwrite

Thanks again!

[bigbag]

@alrudimgn Added in 0.6.0