# Contributing to pret/pokeplatinum

Welcome! If you're reading this guide, then you probably want to contribute
revisions, documentation, or tooling to the project. We value any and all
contributions, however small or large. Before getting started, please take a
look through this document for some important tips on how to smooth out the
experience of your first contribution.

Thanks again, and we look forward to hearing from you! 🎉

## Table of Contents

<!--toc:start-->
- [What work is there to be done?](#what-work-is-there-to-be-done)
- [How do I set up a development environment?](#how-do-i-set-up-a-development-environment)
  - [Auto-Completion and Language Server Setup](#auto-completion-and-language-server-setup)
  - [Editor Configuration](#editor-configuration)
  - [Code Formatting](#code-formatting)
- [How should I name things?](#how-should-i-name-things)
- [I can't find a file that's `include`d; where is it?](#i-cant-find-a-file-thats-included-where-is-it)
- [Your First Contribution](#your-first-contribution)
  - [What must I do before submitting a pull request?](#what-must-i-do-before-submitting-a-pull-request)
  - [How do I submit a pull request?](#how-do-i-submit-a-pull-request)
  - [What to Expect](#what-to-expect)
<!--toc:end-->

## What work is there to be done?

At this stage of its life-cycle, the repository is almost 100% C code, although
much of it is obfuscated. Some straggler-routines still linger in ARM assembly,
and some small utility libraries also need to be decompiled. As a result, much
of the work for this repository at present comes down to **documentation** and
**tooling**.

If you are looking for a bite-sized work-item to pick out for your first
contribution, we maintain [a living issue][first-efforts] to document files or
functions which we have identified as being smaller in scope. Take a look
through and see if something strikes your interest! Alternatively, if there is a
particular piece of functionality that you want to explore, please reach out to
us [on Discord][pret-github-io] for pointers in the right direction.

[first-efforts]: https://github.com/pret/pokeplatinum/issues/325
[pret-github-io]: https://pret.github.io/

## How do I set up a development environment?

If you haven't already, take the time to read through [`INSTALL.md`](INSTALL.md)
and ensure that you can successfully build a matching version of the binary
target:

```bash
make check
```

We provide some tooling within the repository to integrate with common developer
enhancements.

### Auto-Completion and Language Server Setup

We provide some instructions for setting up a variety of popular editors; refer
to the documentation snippets in `docs/editor_setup` to see if your editor has
specific instructions. If it is not, you may be able to adapt an existing guide
for your preferred editor; if so, feel free to file a pull request with a new
guide tailored to that editor!

### Editor Configuration

An `.editorconfig` file exists at the root of the repository, which helps
alleviate configuring individual editors to present code identically. Many
popular editors will provide support for this integration out-of-the-box with no
installation required; others may require a plugin or extension. For details on
which is which, refer to [this documentation](https://editorconfig.org).

### Code Formatting

We make use of [`clang-format`][clang-format] for our automated code formatting.
Some additional tooling is built into the repository to keep our code-style
consistent and alleviate the need for manual upkeep from maintainers via pull
requests reviews. To ensure that this style is _always_ upheld, a rule is
enabled on the repository that will check that every pull request matches the
style guidelines.

The caveat to this is that a contributor must remember to format their code. To
smooth out this experience, we:

1. Expose the `clang-format` build option generated by Meson via a `Makefile`
   entry-point. If we are ever unsure if the repository is incorrectly
   formatted, we can run `make format` as a manual check to ensure correctness.
2. Integrate `clang-format` into our commit workflows. We manage this via
   [`pre-commit`][pre-commit], which allows us to pin the version of
   `clang-format` used within the repository and ensure that end-users can
   easily install it.

> [!WARNING]
> To ensure that a pull request passes our CI checks, it is recommended that you
> install a version of `clang-format` which is the same version or more recent
> as is used in the CI checks. You can verify what version is expected by
> checking the field `version` in the file `.github/workflows/pr-lint.yml`.

> [!TIP]
> It is heavily recommended that you make use of `pre-commit` as a contributor.
> Doing so will ensure that you are using the same version of any on-commit
> tools as all other contributors.

To install `pre-commit` via a project-local Python virtual environment, run the
following commands in sequence:

```bash
python -m venv .venv
source .venv/bin/activate.sh
pip install pre-commit
```

Once the installation completes, you can tell `pre-commit` to install the
configured hooks into your project:

```bash
pre-commit install
```

[clang-format]: https://clang.llvm.org/docs/ClangFormat.html
[pre-commit]: https://pre-commit.com/

## How should I name things?

The eternal question. Some elements of development cannot be automated via
tooling, and we leave these to our best judgment. In general, the following
rules apply throughout the repository:

```c
// Use PascalCase for structure names. Include both a structure tag ("struct
// MyStruct") and a typedef ("MyStruct").
typedef struct MyStruct {
    u32 myField; // Use camelCase for member variables.
} MyStruct;

// Use PascalCase for enum names. Unlike structs, do NOT typedef enums.
enum MyEnum {
    // Use UPPER_SNAKE_CASE for enum members. Explicitly label the first member
    // with a direct assignment.
    MY_ENUM_MEMBER = 0,
    MY_ENUM_MEMBER, // Successive members should not have a direct assignment.
};

// Use PascalCase for function names and camelCase for parameters.
static int MyFunction(int myParameter)
{
    int myLocalVariable; // Use camelCase for local variables.
}

// Due to the breadth of the repository and its general structure tending
// towards OOP paradigms, modules tend to prefix their public functions with
// their own name followed by an underscore.
int Module_MyExternalFunction(int myParameter)
{
    //
}
```

## I can't find a file that's `include`d; where is it?

We generate a lot of files through meta-programming utilities. For example, a
large number of our named-constants are constructed as part of the build; these
live in the source-tree as plain text files in the `generated` subdirectory. A
program picks up these files, e.g., `generated/days_of_week.txt`:

```text
DAY_OF_WEEK_SUNDAY
DAY_OF_WEEK_MONDAY
DAY_OF_WEEK_TUESDAY
DAY_OF_WEEK_WEDNESDAY
DAY_OF_WEEK_THURSDAY
DAY_OF_WEEK_FRIDAY
DAY_OF_WEEK_SATURDAY
```

...and transforms them into C headers in the build-tree, e.g., from
`build/generated/days_of_week.txt`:

```c
#ifdef POKEPLATINUM_GENERATED_ENUM

enum DayOfWeek {
    DAY_OF_WEEK_SUNDAY    = 0,
    DAY_OF_WEEK_MONDAY    = 1,
    DAY_OF_WEEK_TUESDAY   = 2,
    DAY_OF_WEEK_WEDNESDAY = 3,
    DAY_OF_WEEK_THURSDAY  = 4,
    DAY_OF_WEEK_FRIDAY    = 5,
    DAY_OF_WEEK_SATURDAY  = 6,
}; /* enum DayOfWeek */

#else

#define DAY_OF_WEEK_SUNDAY    0
#define DAY_OF_WEEK_MONDAY    1
#define DAY_OF_WEEK_TUESDAY   2
#define DAY_OF_WEEK_WEDNESDAY 3
#define DAY_OF_WEEK_THURSDAY  4
#define DAY_OF_WEEK_FRIDAY    5
#define DAY_OF_WEEK_SATURDAY  6

#endif /* POKEPLATINUM_GENERATED_ENUM */
```

This allows us to make use of a single source of truth for values which should
be shared between the compiled C code and the assembly files used to build the
game's custom scripting implementation. For example, if included from a C file,
the above header-snippet would be treated as `enum DayOfWeek` with all of the
appropriate symbols and `enum` benefits, whereas an assembler will read the
pre-processor definitions instead.

## Your First Contribution

You've picked out a feature, documented it, and have maybe even made some
commits. Congratulations! You're on the way to your first contribution.

If you are new to `git` and/or GitHub, take some time to read through [The
Basics of Git and GitHub][taar-git] from Team Aqua's Asset Repo. While
originally written with the target audience of `pokeemerald` modders in mind,
the concepts are still very applicable, and it provides a great overview of the
topics and terminology that is often thrown around among more seasoned `git`
users.

[taar-git]: https://github.com/Pawkkie/Team-Aquas-Asset-Repo/wiki/The-Basics-of-GitHub

### What must I do before submitting a pull request?

1. Ensure that a local build of `make check` returns `OK`, which signals that
   your code builds a matching ROM.
2. Format your code such that it matches the repository's style guide. Refer to
   [Code Formatting](#code-formatting) for instructions on how to do this as an
   automatic part of your commit workflow or manually before you commit your
   changes.

We run automated checks via GitHub Actions to ensure that all pull requests meet
these requirements. If any of these are not done, then their respective checks
will fail, and your pull request will not be accepted.

### How do I submit a pull request?

We follow a basic fork-model for pull requests, since it provides the simplest
GitHub integration. If you haven't done so already, create a fork for your
repository [via GitHub][github-fork-docs], then set it up as your `origin`:

```bash
git remote add pret https://github.com/pret/pokeplatinum.git
git remote set-url origin https://github.com/<YOUR_USER>/pokeplatinum.git
```

Now that you have a fork, checkout your changes to a clean branch, giving it a
name that reflects your work:

```bash
git checkout -b <branch_name>
```

Finally, push to your new fork:

```bash
git push -u origin <branch_name>
```

...and submit your changes for review! 🚀

[github-fork-docs]: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/working-with-forks/fork-a-repo

### What to Expect

A maintainer of the repository will respond to your Pull Request at their
earliest convenience. If you'd like to communicate with the maintainers more
directly, feel free to reach out to us in the `#pokeplatinum` channel of the
pret Discord.

Your pull request will be labeled with `new-contributor`; this is _not_ a
target, we promise! It is just your first welcome aboard the team.

Maintainers are encouraged to follow [Conventional Comments][conv-comments],
which helps to more clearly convey tone of speech and clarify the goal of a
particular piece of feedback. In general, these prefixes can be read as:

1. **suggestion**: A proposed improvement to the subject.
2. **polish**: A variant of suggestion where quality can immediately be
   improved. Applicable to cases where there is nothing wrong with the subject.
3. **quibble**: A trivial, often preference-based request. Inherently
   non-blocking.
4. **issue**: A highlight for a specific problem with the subject. For our
   use-case, these typically are framed around minimizing wires for users of the
   repository to trip over.
5. **todo**: A small, trivial, necessary change.
6. **question**: A curiosity from the author, often seeking understanding of why
   the code behaves in the way that it does.
7. **thought**: An idea that popped up during review. Often left so that we do
   not lose access to past ideas. Inherently non-blocking.
8. **chore**: A simple task that must be completed before the subject can be
   officially accepted. Tends to refer to process (and may indicate
   opportunities to improve developer tooling).
9. **note**: A highlight that the reader should notice. Inherently non-blocking.

You may receive a lot of feedback on your first request, and it may feel
intimidating. Rest assured that it is not targeted, nor is a newcomer's review
more-heavily scrutinized than a long-time contributor's. We all have room to
improve. 🙏

[conv-comments]: https://conventionalcomments.org/