"""Repository rule for Android SDK and NDK autoconfiguration.

`android_configure` depends on the following environment variables:

  * `ANDROID_NDK_HOME`: Location of Android NDK root.
  * `ANDROID_SDK_HOME`: Location of Android SDK root.
  * `ANDROID_SDK_API_LEVEL`: Desired Android SDK API version.
  * `ANDROID_NDK_API_LEVEL`: Desired Android NDK API version.
  * `ANDROID_BUILD_TOOLS_VERSION`: Desired Android build tools version.
"""

# TODO(mikecase): Move logic for getting default values for the env variables
# from configure.py script into this rule.

_ANDROID_NDK_HOME = "ANDROID_NDK_HOME"
_ANDROID_SDK_HOME = "ANDROID_SDK_HOME"
_ANDROID_NDK_API_VERSION = "ANDROID_NDK_API_LEVEL"
_ANDROID_SDK_API_VERSION = "ANDROID_SDK_API_LEVEL"
_ANDROID_BUILD_TOOLS_VERSION = "ANDROID_BUILD_TOOLS_VERSION"

_ANDROID_SDK_REPO_TEMPLATE = """
  native.android_sdk_repository(
      name="androidsdk",
      path="%s",
      api_level=%s,
      build_tools_version="%s",
  )
"""

_ANDROID_NDK_REPO_TEMPLATE = """
  native.android_ndk_repository(
      name="androidndk",
      path="%s",
      api_level=%s,
  )
"""

def _android_autoconf_impl(repository_ctx):
  """Implementation of the android_autoconf repository rule."""
  sdk_home = repository_ctx.os.environ.get(_ANDROID_SDK_HOME)
  sdk_api_level = repository_ctx.os.environ.get(_ANDROID_SDK_API_VERSION)
  build_tools_version = repository_ctx.os.environ.get(
      _ANDROID_BUILD_TOOLS_VERSION)
  ndk_home = repository_ctx.os.environ.get(_ANDROID_NDK_HOME)
  ndk_api_level = repository_ctx.os.environ.get(_ANDROID_NDK_API_VERSION)

  sdk_rule = "pass"
  if all([sdk_home, sdk_api_level, build_tools_version]):
    sdk_rule = _ANDROID_SDK_REPO_TEMPLATE % (
        sdk_home, sdk_api_level, build_tools_version)

  ndk_rule = "pass"
  if all([ndk_home, ndk_api_level]):
    ndk_rule = _ANDROID_NDK_REPO_TEMPLATE % (ndk_home, ndk_api_level)

  repository_ctx.template(
      "BUILD",
      Label("//third_party/android:android_configure.BUILD.tpl"))
  repository_ctx.template(
      "android.bzl",
      Label("//third_party/android:android.bzl.tpl"),
      substitutions={
          "MAYBE_ANDROID_SDK_REPOSITORY": sdk_rule,
          "MAYBE_ANDROID_NDK_REPOSITORY": ndk_rule,
      })

android_configure = repository_rule(
    implementation = _android_autoconf_impl,
    environ = [
        _ANDROID_SDK_API_VERSION,
        _ANDROID_NDK_API_VERSION,
        _ANDROID_BUILD_TOOLS_VERSION,
        _ANDROID_NDK_HOME,
        _ANDROID_SDK_HOME,
    ],
)
"""Writes Android SDK and NDK rules.

Add the following to your WORKSPACE FILE:

```python
android_configure(name = "local_config_android")
```

Args:
  name: A unique name for this workspace rule.
"""