# Copyright (c) 2021 Digital Asset (Switzerland) GmbH and/or its affiliates. All rights reserved.
# SPDX-License-Identifier: Apache-2.0

def _impl(ctx):
    # Generates an empty BUILD file, because we do not need to build anything.
    ctx.file(
        "BUILD",
        content = """exports_files(["index.bzl"])""",
        executable = False,
    )

    version = ctx.os.environ.get("DAML_SCALA_VERSION", default = "2.12.12")
    suffix = version.replace(".", "_")

    major = version[:version.rfind(".")]
    major_suffix = major.replace(".", "_")
    ctx.file(
        "index.bzl",
        content =
            """
scala_version = "{version}"
scala_major_version = "{major}"
scala_version_suffix = "{suffix}"
scala_major_version_suffix = "{major_suffix}"
""".format(
                version = version,
                major = major,
                suffix = suffix,
                major_suffix = major_suffix,
            ),
        executable = False,
    )

scala_version = repository_rule(
    environ = ["DAML_SCALA_VERSION"],
    implementation = _impl,
    attrs = {},
)