load("//:project_config.bzl", "version")
load("@rules_cc//cc:find_cc_toolchain.bzl", "find_cc_toolchain", "use_cc_toolchain")

def configure_file(**kwargs):
    _configure_file(
        source_file = "{name}.h".format(**kwargs),
        **kwargs
    )

def _configure_file_impl(ctx):
    cc_toolchain = find_cc_toolchain(ctx)

    ctx.actions.expand_template(
        template = ctx.file.template,
        output = ctx.outputs.source_file,
        substitutions = {
            "{VERSION}": '"{}"'.format(version()),
            "{CC}": '"{} " __VERSION__'.format(cc_toolchain.compiler),
        },
    )

_configure_file = rule(
    attrs = {
        "template": attr.label(allow_single_file = True),
        "source_file": attr.output(mandatory = True),
    },
    toolchains = use_cc_toolchain(),
    implementation = _configure_file_impl,
)