1 /*
2  * Copyright (C) 2024 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.android.tools.metalava.model.testing.transformer
18 
19 import com.android.tools.metalava.model.Codebase
20 import java.util.ServiceLoader
21 
22 interface CodebaseTransformer {
23 
24     /** Transform the [codebase] into a different [Codebase] */
transformnull25     fun transform(codebase: Codebase): Codebase
26 
27     companion object {
28 
29         /**
30          * Find all the [CodebaseTransformer]s and apply as follows:
31          * 1. If none are available return [codebase].
32          * 2. If more than one are available fail.
33          * 3. Load the available one and apply to [codebase] returning the result.
34          */
35         fun transformIfAvailable(codebase: Codebase): Codebase {
36             // Try and load CodebaseTransformers.
37             val loader = ServiceLoader.load(CodebaseTransformer::class.java)
38 
39             // If there are none then return the codebase unchanged.
40             if (loader.none()) return codebase
41 
42             // Get the sole transformer.
43             val transformer = loader.toList().single()
44 
45             // Apply it.
46             return transformer.transform(codebase)
47         }
48     }
49 }
50