Add initializing wallet configuration with bdk-cli wallet init

[tvpeter]

Description

This PR adds bdk-cli wallet init command to save wallet configuration information to config.toml file in the data directory.

Fixes #192

Notes to the reviewers

• Reusing the exported serde crate from bdk_wallet did not offer the derive feature
• CLI parameters have higher precedence over saved config values

Changelog notice

• Add wallet subcommand init to save wallet configs
• Add an optional flag --use-config to use saved configs for a wallet

Checklists

All Submissions:

• I've signed all my commits
• I followed the contribution guidelines
• I ran cargo fmt and cargo clippy before committing

New Features:

• I've added tests for the new feature
• I've added docs for the new feature
• I've updated CHANGELOG.md

[coveralls]

Pull Request Test Coverage Report for Build 17438777973

Details

• 0 of 331 (0.0%) changed or added relevant lines in 5 files are covered.
• 2 unchanged lines in 2 files lost coverage.
• Overall coverage decreased (-0.5%) to 1.702%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/utils.rs	0	9	0.0%
src/commands.rs	0	28	0.0%
src/config.rs	0	67	0.0%
src/handlers.rs	0	97	0.0%
src/main.rs	0	130	0.0%

Files with Coverage Reduction	New Missed Lines	%
src/handlers.rs	1	2.49%
src/utils.rs	1	0.0%

Totals
Change from base Build 17324807959:	-0.5%
Covered Lines:	25
Relevant Lines:	1469

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💛 - Coveralls

[notmandatory]

I like the approach for loading the config file parameters if the file exists, but is there a reason you didn't add a CLI bdk-cli wallet init ... command in rust to create the config file rather than using just ?

Creating the config file in rust should be easier to maintain/keep in sync than your just approach and shouldn't take too much more than adding the Serialize trait to WalletConfigInner. You should be able to reuse the WalletOpts to capture the values with clap that you need to put in the config file too.

[tvpeter]

I like the approach for loading the config file parameters if the file exists, but is there a reason you didn't add a CLI bdk-cli wallet init ... command in rust to create the config file rather than using just ?

Creating the config file in rust should be easier to maintain/keep in sync than your just approach and shouldn't take too much more than adding the Serialize trait to WalletConfigInner. You should be able to reuse the WalletOpts to capture the values with clap that you need to put in the config file too.

Alright, I will update.

[tvpeter]

Alright, I will update.

@notmandatory I have updated the PR

[thunderbiscuit]

I need to start keeping track of all these awesome new features I honestly see the PRs come in and can't keep up. This is super cool.

[tvpeter]

I need to start keeping track of all these awesome new features I honestly see the PRs come in and can't keep up. This is super cool.

Thank you @thunderbiscuit

[notmandatory]

I spent some time today reviewing and even though this looks like a workable way to do it and is based on my suggestion I'm afraid it's going to be a hassle to maintain. I've been experimenting with somehow using the different clap parsing functions (https://docs.rs/clap/latest/clap/trait.Parser.html) but so far haven't figured out a better way. I'd like to keep thinking about it. We might have to simplify the problem somehow such as by not trying to merge loaded and CLI args.

[tvpeter]

I'm afraid it's going to be a hassle to maintain. I've been experimenting with somehow using the different clap parsing functions (https://docs.rs/clap/latest/clap/trait.Parser.html) but so far haven't figured out a better way. I'd like to keep thinking about it. We might have to simplify the problem somehow such as by not trying to merge loaded and CLI args.

Thank you @notmandatory.
Yes, I agree that it will be challenging to maintain, as it involves two steps (pre clap parsing and after parsing) and even more difficult as they are in different locations in the codebase. I thought about moving everything to pre clap parsing based on the wallet sub-command the user has entered but that will clog the entry point as there will be lots of if...else checks.

Also, for the Parser trait, I read that it does not allow interacting with an external resource such as reading a file as I would want it.

I will also be trying out other approaches in case there is a cleaner way to handle it.

[notmandatory]

How about something like:

1. One command to save a wallet config, give wallet name or a default name is used, clap enforces required options; optional -f to override existing config:
   wallet [-f] [-w <name>] config <wallet opts>
2. All other wallet commands require that a config exists, use wallet name or the default is used. Give error if config is missing:
   wallet [-w <name>] sync | balance | new_address | etc...
3. Repl uses the same wallet configs:
   repl [-w <name>]
4. Add a command to list all available config names with summary of configured options:
   wallet list
5. Should throw warnings if using mainnet and saving a private descriptor in a config.