improve #342

[RicterZ]

1. change option from --regenerate-cbz to --regenerate, to indicate program regenerate pdf or cbz file
2. by default, if a pdf or a cbz file exists, skip following download and generation process
3. furthermore, if a pdf file exists, but someone still want to generate a cbz file, he can use --cbz --regenerate (under now program logic)

[RicterZ]

In fact, this code will never be reached, will be removed in the future

[normalizedwater546]

I was able to reach this code with the following commands:

nhentai --id 530833 --download --format '%t [%i]' --threads=4 --pdf --meta --output="test-out"
nhentai --id 530833 --download --format '%t [%i]' --threads=4 --cbz --meta --output="test-out"

[RicterZ]

@normalizedwater546 Does the current program logic meet your needs?

[normalizedwater546]

furthermore, if a pdf file exists, but someone still want to generate a cbz file, he can use --cbz --regenerate (under now program logic)

I think that this is unintuitive. --regenerate should be used when you want to regenerate the same file extension.

This is how I think expected actions to be.

command	expected action
nhentai --pdf	ok (first time)
nhentai --cbz	ok (first time)
nhentai --pdf	duplicate
nhentai --cbz	duplicate
nhentai --pdf --cbz	duplicate
nhentai --pdf --regenerate	ok
nhentai --cbz --regenerate	ok
nhentai --pdf --cbz --regenerate	ok

[normalizedwater546]

Does the current program logic meet your needs?

I actually don't need to create both pdf and cbz, my main goal was to fix the metadata crash when attempting to download duplicated doujins in cbz format. I just encountered other issues while debugging. So yes, the current logic is fine for me.

[normalizedwater546]

Thanks for the improvements!

Is the change to auto-generate HTML file intentional? Should I be adding --no-html to all my commands if I don't want them?

[RicterZ]

Yes, the html file is auto-generate, you can add --no-html to avoid it