Blockstream jade integration

[Saleciani]

We need the option to connect blockstream jade, import xpub and sign transactions via bluetooth.

[i5hi]

This would be a good starting point: https://github.com/Blockstream/lwk/blob/master/lwk_jade/tests/emulator.rs

[i5hi]

More resources:

https://docs.rs/lwk_jade/latest/lwk_jade/
https://github.com/Blockstream/Jade/blob/master/docs/index.rst

[i5hi]

We should make a new file in lwk-dart called jade.rs

Next would be to figure out what the top level struct would hold; my first thought would be the Jade struct inside a mutex; similar to Wollet :

https://docs.rs/lwk_jade/latest/lwk_jade/struct.Jade.html

So something liek:

pub struct JadeHardware {
    pub inner: RustOpaque<Mutex<lwk_jade::Jade>>,
}

[i5hi]

We will also need this helper method to handle the locked JadeHardware which will be called in all the other methods that need to use the object:

    fn get_jade(&self) -> Result<MutexGuard<lwk_jade::Jade>, LwkError> {
        {
            match self.inner.lock() {
                Ok(result) => Ok(result),
                Err(_) => Err(LwkError {
                    msg: "Could not aquire lock on jade".to_string(),
                }),
            }
        }
    }

Edit:

The purpose of the mutex guard is to make sure that multiple concurrent calls have to wait for the first caller to complete before performing any operations on the object. The error Could not aquire lock on jade will be thrown if someone has already locked it and is currently using it.

[i5hi]

Then the remaining should just be wrappers around the existing methods.

ping would be a perfect method to add first and test: https://docs.rs/lwk_jade/latest/lwk_jade/struct.Jade.html#method.ping

[i5hi]

Note: When we add lwk-jade to the dependencies we need to add the sync feature in Cargo.toml to access the Jade struct