#!/usr/bin/env python3
# Copyright (C) 2020 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.

# Exports AppSearch Androidx code to Framework
#
# NOTE: This will remove and replace all files in the
# frameworks/base/apex/appsearch path.
#
# Example usage (from root dir of androidx workspace):
# $ ./frameworks/support/appsearch/exportToFramework.py "$HOME/android/master" "<jetpack changeid>"

# Special directives supported by this script:
#
# Causes the file where it appears to not be copied at all:
#   @exportToFramework:skipFile()
#
# Causes the text appearing between startStrip() and endStrip() to be removed during export:
#   // @exportToFramework:startStrip() ... // @exportToFramework:endStrip()
#
# Replaced with @hide:
#   <!--@exportToFramework:hide-->
#
# Replaced with @CurrentTimeMillisLong:
#   /*@exportToFramework:CurrentTimeMillisLong*/
#
# Removes the text appearing between ifJetpack() and else(), and causes the text appearing between
# else() and --> to become uncommented, to support framework-only Javadocs:
#   <!--@exportToFramework:ifJetpack()-->
#   Jetpack-only Javadoc
#   <!--@exportToFramework:else()
#   Framework-only Javadoc
#   -->
# Note: Using the above pattern, you can hide a method in Jetpack but unhide it in Framework like
# this:
#   <!--@exportToFramework:ifJetpack()-->@hide<!--@exportToFramework:else()-->

import os
import re
import subprocess
import sys

# Jetpack paths relative to frameworks/support/appsearch
JETPACK_API_ROOT = 'appsearch/src/main/java/androidx/appsearch'
JETPACK_API_TEST_ROOT = 'appsearch/src/androidTest/java/androidx/appsearch'
JETPACK_IMPL_ROOT = 'local-storage/src/main/java/androidx/appsearch'
JETPACK_IMPL_TEST_ROOT = 'local-storage/src/androidTest/java/androidx/appsearch'

# Framework paths relative to frameworks/base/apex/appsearch
FRAMEWORK_API_ROOT = 'framework/java/external/android/app/appsearch'
FRAMEWORK_API_TEST_ROOT = '../../core/tests/coretests/src/android/app/appsearch/external'
FRAMEWORK_IMPL_ROOT = 'service/java/com/android/server/appsearch/external'
FRAMEWORK_IMPL_TEST_ROOT = (
        '../../services/tests/servicestests/src/com/android/server/appsearch/external')
FRAMEWORK_TEST_UTIL_ROOT = 'testing/java/com/android/server/appsearch/testing/external/'
FRAMEWORK_CTS_TEST_ROOT = '../../../../cts/tests/appsearch/src/com/android/cts/appsearch/external'
GOOGLE_JAVA_FORMAT = (
        '../../../../prebuilts/tools/common/google-java-format/google-java-format')

# Miscellaneous constants
CHANGEID_FILE_NAME = 'synced_jetpack_changeid.txt'


class ExportToFramework:
    def __init__(self, jetpack_appsearch_root, framework_appsearch_root):
        self._jetpack_appsearch_root = jetpack_appsearch_root
        self._framework_appsearch_root = framework_appsearch_root
        self._written_files = []

    def _PruneDir(self, dir_to_prune):
        for walk_path, walk_folders, walk_files in os.walk(dir_to_prune):
            for walk_filename in walk_files:
                abs_path = os.path.join(walk_path, walk_filename)
                print('Prune: remove "%s"' % abs_path)
                os.remove(abs_path)

    def _TransformAndCopyFile(
            self, source_path, dest_path, transform_func=None, ignore_skips=False):
        with open(source_path, 'r') as fh:
            contents = fh.read()

        if not ignore_skips and '@exportToFramework:skipFile()' in contents:
            print('Skipping: "%s" -> "%s"' % (source_path, dest_path), file=sys.stderr)
            return

        print('Copy: "%s" -> "%s"' % (source_path, dest_path), file=sys.stderr)
        if transform_func:
            contents = transform_func(contents)
        os.makedirs(os.path.dirname(dest_path), exist_ok=True)
        with open(dest_path, 'w') as fh:
            fh.write(contents)

        # Save file for future formatting
        self._written_files.append(dest_path)

    def _TransformCommonCode(self, contents):
        # Apply stripping
        contents = re.sub(
            r'\/\/ @exportToFramework:startStrip\(\).*?\/\/ @exportToFramework:endStrip\(\)',
            '',
            contents,
            flags=re.DOTALL)

        # Apply if/elses in javadocs
        contents = re.sub(
            r'<!--@exportToFramework:ifJetpack\(\)-->.*?<!--@exportToFramework:else\(\)(.*?)-->',
            r'\1',
            contents,
            flags=re.DOTALL)

        # Add additional imports if required
        imports_to_add = []
        if '@exportToFramework:CurrentTimeMillisLong' in contents:
            imports_to_add.append('android.annotation.CurrentTimeMillisLong')
        if '@exportToFramework:UnsupportedAppUsage' in contents:
            imports_to_add.append('android.compat.annotation.UnsupportedAppUsage')
        for import_to_add in imports_to_add:
            contents = re.sub(
                    r'^(\s*package [^;]+;\s*)$', r'\1\nimport %s;\n' % import_to_add, contents,
                    flags=re.MULTILINE)

        # Apply in-place replacements
        return (contents
            .replace('androidx.appsearch.app', 'android.app.appsearch')
            .replace(
                    'androidx.appsearch.localstorage.',
                    'com.android.server.appsearch.external.localstorage.')
            .replace('androidx.appsearch', 'android.app.appsearch')
            .replace(
                    'androidx.annotation.GuardedBy',
                    'com.android.internal.annotations.GuardedBy')
            .replace(
                    'androidx.annotation.VisibleForTesting',
                    'com.android.internal.annotations.VisibleForTesting')
            .replace('androidx.annotation.', 'android.annotation.')
            .replace('androidx.collection.ArrayMap', 'android.util.ArrayMap')
            .replace('androidx.collection.ArraySet', 'android.util.ArraySet')
            .replace(
                    'androidx.core.util.ObjectsCompat',
                    'java.util.Objects')
            # Preconditions.checkNotNull is replaced with Objects.requireNonNull. We add both
            # imports and let google-java-format sort out which one is unused.
            .replace(
                    'import androidx.core.util.Preconditions;',
                    'import java.util.Objects; import com.android.internal.util.Preconditions;')
            .replace('import androidx.annotation.RestrictTo;', '')
            .replace('@RestrictTo(RestrictTo.Scope.LIBRARY)', '')
            .replace('@RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)', '')
            .replace('Preconditions.checkNotNull(', 'Objects.requireNonNull(')
            .replace('ObjectsCompat.', 'Objects.')
            .replace('/*@exportToFramework:CurrentTimeMillisLong*/', '@CurrentTimeMillisLong')
            .replace('/*@exportToFramework:UnsupportedAppUsage*/', '@UnsupportedAppUsage')
            .replace('<!--@exportToFramework:hide-->', '@hide')
            .replace('// @exportToFramework:skipFile()', '')
        )

    def _TransformTestCode(self, contents):
        contents = (contents
            .replace('androidx.appsearch.app.util.', 'com.android.server.appsearch.testing.')
            .replace(
                    'package androidx.appsearch.app.util;',
                    'package com.android.server.appsearch.testing;')
            .replace(
                    'androidx.appsearch.localstorage.LocalStorage',
                    'android.app.appsearch.AppSearchManager')
            .replace('LocalStorage.', 'AppSearchManager.')
        )
        for shim in ['AppSearchSession', 'GlobalSearchSession', 'SearchResults']:
            contents = re.sub(r"([^a-zA-Z])(%s)([^a-zA-Z0-9])" % shim, r'\1\2Shim\3', contents)
        return self._TransformCommonCode(contents)

    def _TransformCtsTestCode(self, contents):
        contents = self._TransformTestCode(contents)
        return (contents
                .replace('android.app.appsearch.test', 'com.android.cts.appsearch')
        )

    def _TransformAndCopyFolder(self, source_dir, dest_dir, transform_func=None):
        for currentpath, folders, files in os.walk(source_dir):
            dir_rel_to_root = os.path.relpath(currentpath, source_dir)
            for filename in files:
                source_abs_path = os.path.join(currentpath, filename)
                dest_path = os.path.join(dest_dir, dir_rel_to_root, filename)
                self._TransformAndCopyFile(source_abs_path, dest_path, transform_func)

    def _ExportApiCode(self):
        # Prod source
        api_source_dir = os.path.join(self._jetpack_appsearch_root, JETPACK_API_ROOT)
        api_dest_dir = os.path.join(self._framework_appsearch_root, FRAMEWORK_API_ROOT)

        # Unit tests
        api_test_source_dir = os.path.join(self._jetpack_appsearch_root, JETPACK_API_TEST_ROOT)
        api_test_dest_dir = os.path.join(self._framework_appsearch_root, FRAMEWORK_API_TEST_ROOT)

        # CTS tests
        cts_test_source_dir = os.path.join(api_test_source_dir, 'cts')
        cts_test_dest_dir = os.path.join(self._framework_appsearch_root, FRAMEWORK_CTS_TEST_ROOT)

        # Test utils
        test_util_source_dir = os.path.join(api_test_source_dir, 'app/util')
        test_util_dest_dir = os.path.join(self._framework_appsearch_root, FRAMEWORK_TEST_UTIL_ROOT)

        # Prune existing files
        self._PruneDir(api_dest_dir)
        self._PruneDir(api_test_dest_dir)
        self._PruneDir(cts_test_dest_dir)
        self._PruneDir(test_util_dest_dir)

        # Copy api classes. We can't use _TransformAndCopyFolder here because we
        # need to specially handle the 'app' package.
        print('~~~ Copying API classes ~~~')
        def _TransformApiCode(contents):
            contents = contents.replace(
                    'package androidx.appsearch.app;',
                    'package android.app.appsearch;')
            return self._TransformCommonCode(contents)
        for currentpath, folders, files in os.walk(api_source_dir):
            dir_rel_to_root = os.path.relpath(currentpath, api_source_dir)
            for filename in files:
                # Figure out what folder to place them into
                source_abs_path = os.path.join(currentpath, filename)
                if dir_rel_to_root == 'app':
                    # Files in the 'app' folder live in the root of the platform tree
                    dest_path = os.path.join(api_dest_dir, filename)
                else:
                    dest_path = os.path.join(api_dest_dir, dir_rel_to_root, filename)
                self._TransformAndCopyFile(source_abs_path, dest_path, _TransformApiCode)

        # Copy api unit tests. We can't use _TransformAndCopyFolder here because we need to skip the
        # 'util' and 'cts' subfolders.
        print('~~~ Copying API unit tests ~~~')
        for currentpath, folders, files in os.walk(api_test_source_dir):
            if (currentpath.startswith(cts_test_source_dir) or
                    currentpath.startswith(test_util_source_dir)):
                continue
            dir_rel_to_root = os.path.relpath(currentpath, api_test_source_dir)
            for filename in files:
                source_abs_path = os.path.join(currentpath, filename)
                dest_path = os.path.join(api_test_dest_dir, dir_rel_to_root, filename)
                self._TransformAndCopyFile(source_abs_path, dest_path, self._TransformTestCode)

        # Copy CTS tests
        print('~~~ Copying CTS tests ~~~')
        self._TransformAndCopyFolder(
                cts_test_source_dir, cts_test_dest_dir, transform_func=self._TransformCtsTestCode)

        # Copy test utils
        print('~~~ Copying test utils ~~~')
        self._TransformAndCopyFolder(
                test_util_source_dir, test_util_dest_dir, transform_func=self._TransformTestCode)
        for iface_file in (
                'AppSearchSession.java', 'GlobalSearchSession.java', 'SearchResults.java'):
            dest_file_name = os.path.splitext(iface_file)[0] + 'Shim.java'
            self._TransformAndCopyFile(
                    os.path.join(api_source_dir, 'app/' + iface_file),
                    os.path.join(test_util_dest_dir, dest_file_name),
                    transform_func=self._TransformTestCode,
                    ignore_skips=True)

    def _ExportImplCode(self):
        impl_source_dir = os.path.join(self._jetpack_appsearch_root, JETPACK_IMPL_ROOT)
        impl_test_source_dir = os.path.join(self._jetpack_appsearch_root, JETPACK_IMPL_TEST_ROOT)
        impl_dest_dir = os.path.join(self._framework_appsearch_root, FRAMEWORK_IMPL_ROOT)
        impl_test_dest_dir = os.path.join(self._framework_appsearch_root, FRAMEWORK_IMPL_TEST_ROOT)

        # Prune
        self._PruneDir(impl_dest_dir)
        self._PruneDir(impl_test_dest_dir)

        # Copy impl classes
        def _TransformImplCode(contents):
            contents = (contents
                    .replace('package androidx.appsearch',
                            'package com.android.server.appsearch.external')
                    .replace('com.google.android.icing.protobuf.', 'com.google.protobuf.')
            )
            return self._TransformCommonCode(contents)
        self._TransformAndCopyFolder(
                impl_source_dir, impl_dest_dir, transform_func=_TransformImplCode)

        # Copy servicestests
        def _TransformImplTestCode(contents):
            contents = (contents
                    .replace('package androidx.appsearch',
                            'package com.android.server.appsearch.external')
                    .replace('com.google.android.icing.proto.',
                            'com.android.server.appsearch.icing.proto.')
                    .replace('com.google.android.icing.protobuf.',
                            'com.android.server.appsearch.protobuf.')
            )
            return self._TransformTestCode(contents)
        self._TransformAndCopyFolder(
                impl_test_source_dir, impl_test_dest_dir, transform_func=_TransformImplTestCode)

    def _FormatWrittenFiles(self):
        google_java_format_cmd = [GOOGLE_JAVA_FORMAT, '--aosp', '-i'] + self._written_files
        print('$ ' + ' '.join(google_java_format_cmd))
        subprocess.check_call(google_java_format_cmd, cwd=self._framework_appsearch_root)

    def ExportCode(self):
        self._ExportApiCode()
        self._ExportImplCode()
        self._FormatWrittenFiles()

    def WriteChangeIdFile(self, changeid):
        """Copies the changeid of the most recent public CL into a file on the framework side.

        This file is used for tracking, to determine what framework is synced to.

        You must always provide a changeid of an exported, preferably even submitted CL. If you
        abandon the CL pointed to by this changeid, the next person syncing framework will be unable
        to find what CL it is synced to.
        """
        file_path = os.path.join(self._framework_appsearch_root, CHANGEID_FILE_NAME)
        with open(file_path, 'w') as fh:
            print(changeid, file=fh)
        print('Wrote "%s"' % file_path)


if __name__ == '__main__':
    if len(sys.argv) != 3:
        print('Usage: %s <path/to/frameworks/base> <changeId of head jetpack commit>' % sys.argv[0],
              file=sys.stderr)
        sys.exit(1)
    source_dir = os.path.normpath(os.path.dirname(sys.argv[0]))
    dest_dir = os.path.normpath(sys.argv[1])
    if os.path.basename(dest_dir) == 'appsearch':
        pass
    elif os.path.basename(dest_dir) == 'base':
        dest_dir = os.path.join(dest_dir, 'apex/appsearch')
    else:
        dest_dir = os.path.join(dest_dir, 'frameworks/base/apex/appsearch')
    if not os.path.isdir(dest_dir):
        print('Destination path "%s" does not exist or is not a directory' % (
                dest_dir),
              file=sys.stderr)
        sys.exit(1)
    exporter = ExportToFramework(source_dir, dest_dir)
    exporter.ExportCode()
    exporter.WriteChangeIdFile(sys.argv[2])