[wpilib] Pregenerate PWM motor controllers

[pjreiniger]

Fixes #6739

[TheTripleV]

Consider using pathlib instead of wrangling names manually. The trailing backslash vs no trailing backslash can bite someone who tries to update it in the future.

Do explicitly set utf-8 as the encoding on file operations in case someone tries to run this on Windows. Python on Windows will switch to utf-8 by default (ignoring locale) in 2026.

gpt conversion doing both for example

#!/usr/bin/env python3

# Copyright (c) FIRST and other WPILib contributors.
# Open Source Software; you can modify and/or share it under the terms of
# the WPILib BSD license file in the root directory of this project.
import argparse
import json
import sys
from pathlib import Path

from jinja2 import Environment, FileSystemLoader


def render_template(template, output_dir, filename, controller):
    output_dir_path = Path(output_dir)
    output_dir_path.mkdir(parents=True, exist_ok=True)

    (output_dir_path / filename).write_text(template.render(controller), encoding="utf-8")


def generate_pwm_motor_controllers(output_root, template_root):
    template_root_path = Path(template_root)
    with (template_root_path / "pwm_motor_controllers.json").open(encoding="utf-8") as f:
        controllers = json.load(f)

    env = Environment(
        loader=FileSystemLoader(str(template_root_path)),
        autoescape=False,
        keep_trailing_newline=True,
    )

    root_path = Path(output_root) / "main/java/edu/wpi/first/wpilibj/motorcontrol"
    template = env.get_template("pwm_motor_controller.java.jinja")

    for controller in controllers:
        controller_name = f"{controller['name']}.java"
        render_template(template, root_path, controller_name, controller)


def main(argv):
    script_path = Path(__file__).resolve()
    dirname = script_path.parent

    parser = argparse.ArgumentParser()
    parser.add_argument(
        "--output_directory",
        help="Optional. If set, will output the generated files to this directory, otherwise it will use a path relative to the script",
        default=dirname / "src/generated",
    )
    parser.add_argument(
        "--template_root",
        help="Optional. If set, will use this directory as the root for the jinja templates",
        default=dirname / "src/generate",
    )
    args = parser.parse_args(argv)

    generate_pwm_motor_controllers(args.output_directory, args.template_root)


if __name__ == "__main__":
    main(sys.argv[1:])