/*
 * Copyright 2020 the original author or authors.
 *
 * 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 org.gradle.configurationcache

import org.gradle.api.file.FileCollection
import org.gradle.configurationcache.initialization.ConfigurationCacheProblemsListener
import org.gradle.configurationcache.serialization.Workarounds
import org.gradle.configurationcache.services.EnvironmentChangeTracker
import org.gradle.internal.classpath.Instrumented
import org.gradle.internal.event.ListenerManager
import org.gradle.internal.service.scopes.Scopes
import org.gradle.internal.service.scopes.ServiceScope
import java.io.File


private
val allowedProperties = setOf(
    "os.name",
    "os.version",
    "os.arch",
    // TODO(https://github.com/gradle/gradle/issues/18432) Remove this from the list when a proper support for the modifications is in place.
    "java.awt.headless", // Some popular plugins modify this property at runtime.
    "java.version",
    "java.version.date",
    "java.vendor",
    "java.vendor.url",
    "java.vendor.version",
    "java.specification.version",
    "java.specification.vendor",
    "java.specification.name",
    "java.vm.version",
    "java.vm.specification.version",
    "java.vm.specification.vendor",
    "java.vm.specification.name",
    "java.vm.version",
    "java.vm.vendor",
    "java.vm.name",
    "java.class.version",
    "java.home",
    "java.class.path",
    "java.library.path",
    "java.compiler",
    "file.separator",
    "path.separator",
    "line.separator",
    "user.name",
    "user.home",
    "java.runtime.version"
    // Not java.io.tmpdir and user.dir at this stage
)


@ServiceScope(Scopes.BuildTree::class)
class InstrumentedInputAccessListener(
    listenerManager: ListenerManager,
    configurationCacheProblemsListener: ConfigurationCacheProblemsListener,
    private val environmentChangeTracker: EnvironmentChangeTracker,
) : Instrumented.Listener {

    private
    val undeclaredInputBroadcast = listenerManager.getBroadcaster(UndeclaredBuildInputListener::class.java)

    private
    val externalProcessListener = configurationCacheProblemsListener

    override fun systemPropertyQueried(key: String, value: Any?, consumer: String) {
        if (allowedProperties.contains(key) || Workarounds.canReadSystemProperty(consumer)) {
            return
        }
        undeclaredInputBroadcast.systemPropertyRead(key, value, consumer)
    }

    override fun systemPropertyChanged(key: Any, value: Any?, consumer: String) {
        environmentChangeTracker.systemPropertyChanged(key, value, consumer)
    }

    override fun systemPropertyRemoved(key: Any, consumer: String) {
        environmentChangeTracker.systemPropertyRemoved(key)
    }

    override fun systemPropertiesCleared(consumer: String) {
        environmentChangeTracker.systemPropertiesCleared()
    }

    override fun envVariableQueried(key: String, value: String?, consumer: String) {
        if (Workarounds.canReadEnvironmentVariable(consumer)) {
            return
        }
        undeclaredInputBroadcast.envVariableRead(key, value, consumer)
    }

    override fun externalProcessStarted(command: String, consumer: String) {
        if (Workarounds.canStartExternalProcesses(consumer)) {
            return
        }
        externalProcessListener.onExternalProcessStarted(command, consumer)
    }

    override fun fileOpened(file: File, consumer: String) {
        if (Workarounds.canReadFiles(consumer)) {
            return
        }
        undeclaredInputBroadcast.fileOpened(file, consumer)
    }

    override fun fileObserved(file: File, consumer: String?) {
        undeclaredInputBroadcast.fileObserved(file, consumer)
    }

    override fun fileCollectionObserved(fileCollection: FileCollection, consumer: String) {
        undeclaredInputBroadcast.fileCollectionObserved(fileCollection, consumer)
    }
}
