/*
 * Copyright (C) 2024 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.
 */

package com.android.settingslib.ipc

import android.app.Application
import android.content.pm.PackageManager
import android.os.Process
import androidx.collection.mutableIntIntMapOf

/** Checker for permission. */
fun interface PermissionChecker {
    /**
     * Checks permission.
     *
     * @param application application context
     * @param callingPid uid of peer process
     * @param callingUid uid of peer process
     */
    fun check(application: Application, callingPid: Int, callingUid: Int): Boolean
}

/** Verifies apk signatures as permission check. */
class SignatureChecker : PermissionChecker {
    private val cache = mutableIntIntMapOf()

    override fun check(application: Application, callingPid: Int, callingUid: Int): Boolean =
        cache.getOrPut(callingUid) {
            application.packageManager.checkSignatures(Process.myUid(), callingUid)
        } == PackageManager.SIGNATURE_MATCH
}