#!/usr/bin/python3
#
# Copyright (C) 2022 The Android Open Source Project
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

from functools import lru_cache
import os

from build_file_generator import AndroidBpFile, AndroidBpModule, BuildFileGenerator, ConfigAxis
from utils import ASSEMBLE_PHONY_TARGET, Context


class JavaApiAssemblyContext(object):
    """Context object for managing global state of Java API Assembly."""

    def get_java_api_assembler(self):
        """Return a callback to assemble Java APIs.

        The callback is a member of the context object,
        and therefore has access to its state."""
        return self.assemble_java_api_library

    @lru_cache(maxsize=None)
    def _java_api_library_module(self, context: Context,
                                 build_file_generator: BuildFileGenerator,
                                 surface_name: str,
                                 surface_version: str) -> AndroidBpModule:
        """Initializes the java_api_library AndroidBpModule for an API surface stub

        Args:
            context: Container for global state.
            build_file_generator: Container for registering Android.bp files.
            surface_name: API surface name (e.g. publicapi).
            surface_version: API surface version (e.g. 29, 30, current).

        Returns:
            AndroidBpModule object
        """
        # Create Android.bp module.
        # There should be one stub library per (api_surface, version).
        name = f"{surface_name}_{surface_version}"
        api_library_module = AndroidBpModule(name=name,
                                             module_type="java_api_library")
        staging_dir = context.out.api_library_dir(surface_name,
                                                  surface_version, "")
        # Create Android.bp file
        bp_file = AndroidBpFile(directory=staging_dir)
        bp_file.add_comment_string("WARNING: THIS IS AN AUTOGENERATED FILE.")
        bp_file.add_module(api_library_module)
        build_file_generator.add_android_bp_file(bp_file)

        return api_library_module

    def assemble_java_api_library(self, context: Context, ninja,
                                  build_file_generator: BuildFileGenerator,
                                  stub_library) -> None:
        """Assembles the API .txt files in the output directory.

        Args:
            context: Container for global state.
            ninja: Ninja writer object. ninja_tools.Ninja instance.
            build_file_generator: Container for registering Android.bp files.
            stub_library: Container for APIs provided by a library an API surface
                at a specific version. api_assembly.StubLibrary instance.
        Returns:
            None
        """
        staging_dir = context.out.api_library_dir(
            stub_library.api_surface,
            stub_library.api_surface_version,
            "",
        )
        # Create one java_api_library for the api surface. This should be
        # idempotent.
        api_library_module = self._java_api_library_module(
            context, build_file_generator, stub_library.api_surface,
            stub_library.api_surface_version)

        api_deps = []
        for c in stub_library.contributions:
            # (A single API domain can provide multiple java libraries)
            # Proposed layout
            # out/api_surfaces/
            #   publicapi/current/
            #     <contribution1>/current.txt
            #     <contribution2>/current.txt
            #     ...
            #   systemapi/current/
            #     <contribution1>/current.txt
            #     <contribution1>/system-current.txt
            #     <contribution2>/current.txt
            #     <contribution2>/system-current.txt
            #   ...
            name = c.library_contribution["name"]
            api = c.library_contribution["api"]
            api_out = os.path.join(staging_dir, name, os.path.basename(api))
            ninja.add_copy_file(api_out, os.path.join(
                c.inner_tree.root,
                api,
            ))

            # TODO: Short term hack to make the files in outer tree available to files
            # in inner tree. This is needed because chdir'd trees cannot reach
            # into outer tree's scope.
            # The list of inner trees is hardcoded for now.
            for inner_tree in ["system", "vendor", "apexes"]:
                path_in_inner_tree = api_out.replace(
                    context.out.api_surfaces_dir(),
                    os.path.join(inner_tree, context.out.root(),
                                 "api_surfaces"))
                ninja.add_phony(path_in_inner_tree, api_out)

            # Add the api file to java_api_library
            api_library_module.extend_property(
                prop="api_files",
                val=[os.path.join(name, os.path.basename(api))])
            api_deps.append(api_out)

        # Add the api files as deps of the phony assembly target
        ninja.add_global_phony(ASSEMBLE_PHONY_TARGET, api_deps)