Use pkg-config to find dependencies

[Youw]

• completely rework setup.py to use pkg-config for dependencies and build options (similar way how HIDAPI does it) when building HIDAPI from sources;
• use pkg-config when searching for HIDAPI package with --use-system-hidapi;
• switch to hidraw(-only) backend as a default on Linux;

Fixes: #54 Closes: #55 Closes: #131 Fixes: #133

[Youw]

I've only properly tested this on Linux. ~Will check it on Windows/macOS later.~ UPD: checked Windows and macOS as well. Don't have any BSD to check it for now.

[Youw]

Just noticed #131 - I'll include that change in this PR as well as otherwise if would make a huge conflict in the code.

[Youw]

Just noticed https://github.com/trezor/cython-hidapi/pull/131 - I'll include that change in this PR as well as otherwise if would make a huge conflict in the code.

After going over #131 carefully, and taking into account that HIDAPI/libusb backend has a lot (even though very specific uses) and probably going to be available on Windows and macOS, I'm opting into keeping the behavior of --with-libusb as a complete fallback to "legacy" behavior (when both hid package is available for libusb and hidraw package for hidraw backend of HIDAPI).

As for future plans/default behavior - I'd consider explicitly providing a separate package (e.g. hid.libusb) on platforms that support it in addition to hid package, which should be considered as best/default backend for those who don't care explicitly.

[Youw]

Still haven't checked BSD-like systems, but I'm confident this is ready to be checked/reviewed.

NOTE: there is no special handling of BSD-like on HIDAPI/CMake build scripts (except NETBSD - recently there is a separate backend, but that's a separate story), so probably shouldn't be anything specific in cython-hidapi either.

[Youw]

~BTW: I also had to include (partially unrelated) fix, to be able to run it locally.~ ~It appears it fixes the "known" issue (https://github.com/trezor/cython-hidapi/actions/runs/6552643885/job/17796388898) and would unblock #160 as well.~ ~Surely can be contributed to master as a separate commit if requested by code owner.~ ~A separate PR just for that: #163 will rebase once merged.~ UPD: in master.

[Youw]

One more thing: if there're any code-style/indentation guides I should follow or a a tool to apply formatting - please do let me know. Python is not my primary language, I've formatted the code based on the existing code and my personal preferences.

[prusnak]

I merged all your work into the rework branch. Thank you for all your effort.

I will try to build the wheels via your new method and if everything works just fine I'll merge this branch into master.

Thanks again!

[prusnak]

The CI successfully built the rework branch here: https://github.com/trezor/cython-hidapi/actions/runs/6842485940

So I merged rework into master. Thanks again!

[bearsh]

As this PR changes the default backend on linux, wouldn't it make sense to adjust the wheels action to pass --with-libusb to be backwards compatible? otherwise it would make sense to raise the version to 1.x as this is kind of a breaking change as e.g. the users udev rules may not work anymore.

[prusnak]

As this PR changes the default backend on linux, wouldn't it make sense to adjust the wheels action to pass --with-libusb to be backwards compatible? otherwise it would make sense to raise the version to 1.x as this is kind of a breaking change as e.g. the users udev rules may not work anymore.

I want to keep the version number the same as hidapi version, so no bump to 1.x

@Youw what do you think about the broken udev rules? Should we keep using libusb as the default backend on Linux?

[Youw]

Totally agree on the version thing.

As for the backward compatibility - I completely get the potential frustration of users who would accidentally (during the upgrade) would get their environment broken without even possible workaround on the code level (only (re-)installing of the python package is an option as of now. Until we have a migration plan - it makes sense to keep libusb as a default for now.

I think it does makes sense to have hidraw as a default for setup.py but still have libusb as a default for wheels. Lets continue this conversation in #166.

[prusnak]

wouldn't it make sense to adjust the wheels action to pass --with-libusb to be backwards compatible?

Done in https://github.com/trezor/cython-hidapi/commit/690824080c360c60276e4da0f873bd3df223a502