use std::io::Write;

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let filename: String = std::env::args()
        .collect::<Vec<_>>()
        .get(1)
        .expect("missing filename")
        .to_owned();
    let document = mupdf::document::Document::open(&filename)?;

    let mut image_num: u32 = 0;

    for page in document.pages()? {
        let text_page = page?.to_text_page(mupdf::text_page::TextPageOptions::PRESERVE_IMAGES)?;

        for block in text_page.blocks() {
            if let Some(image) = block.image() {
                let pixmap = image.to_pixmap()?;
                let mut bytes: Vec<u8> = vec![];
                pixmap.write_to(&mut bytes, mupdf::pixmap::ImageFormat::PNG)?;

                let mut output_file = std::fs::File::create(format!("output_{}.png", image_num))?;
                output_file.write_all(&bytes)?;

                image_num += 1;
            }
        }
    }

    Ok(())
}