/*
 * 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.
 */

package com.android.internal.systemui.lint

import com.android.SdkConstants.CLASS_CONTEXT
import com.android.tools.lint.detector.api.Category
import com.android.tools.lint.detector.api.Detector
import com.android.tools.lint.detector.api.Implementation
import com.android.tools.lint.detector.api.Issue
import com.android.tools.lint.detector.api.JavaContext
import com.android.tools.lint.detector.api.Scope
import com.android.tools.lint.detector.api.Severity
import com.android.tools.lint.detector.api.SourceCodeScanner
import com.intellij.psi.PsiMethod
import org.jetbrains.uast.UCallExpression

@Suppress("UnstableApiUsage")
class NonInjectedMainThreadDetector : Detector(), SourceCodeScanner {

    override fun getApplicableMethodNames(): List<String> {
        return listOf("getMainThreadHandler", "getMainLooper", "getMainExecutor")
    }

    override fun visitMethodCall(context: JavaContext, node: UCallExpression, method: PsiMethod) {
        if (context.evaluator.isMemberInSubClassOf(method, CLASS_CONTEXT)) {
            context.report(
                issue = ISSUE,
                location = context.getNameLocation(node),
                message = "Replace with injected `@Main Executor`."
            )
        }
    }

    companion object {
        @JvmField
        val ISSUE: Issue =
            Issue.create(
                id = "NonInjectedMainThread",
                briefDescription = "Main thread usage without dependency injection",
                explanation =
                    """
                                Main thread should be injected using the `@Main Executor` instead \
                                of using the accessors in `Context`. This is to make the \
                                dependencies explicit and increase testability. It's much easier \
                                to pass a `FakeExecutor` on test constructors than it is to deal \
                                with loopers in unit tests.""",
                category = Category.LINT,
                priority = 8,
                severity = Severity.WARNING,
                implementation =
                    Implementation(NonInjectedMainThreadDetector::class.java, Scope.JAVA_FILE_SCOPE)
            )
    }
}