/*
 * Copyright (C) 2023 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.tools.lint.client.api.UElementHandler
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 java.util.EnumSet
import java.util.regex.Pattern
import org.jetbrains.uast.UAnnotation
import org.jetbrains.uast.UElement

@Suppress("UnstableApiUsage") // For linter api
class DemotingTestWithoutBugDetector : Detector(), SourceCodeScanner {
    override fun getApplicableUastTypes(): List<Class<out UElement>> {
        return listOf(UAnnotation::class.java)
    }

    override fun createUastHandler(context: JavaContext): UElementHandler {
        return object : UElementHandler() {
            override fun visitAnnotation(node: UAnnotation) {
                // Annotations having int bugId field
                if (node.qualifiedName in DEMOTING_ANNOTATION_BUG_ID) {
                    if (!containsBugId(node)) {
                        val location = context.getLocation(node)
                        val message =
                            """Please attach a bug id to track demoted test, """ +
                                """e.g. @FlakyTest(bugId = 123)"""
                        context.report(ISSUE, node, location, message)
                    }
                }
                // @Ignore has a String field for specifying reasons
                if (node.qualifiedName == DEMOTING_ANNOTATION_IGNORE) {
                    if (!containsBugString(node)) {
                        val location = context.getLocation(node)
                        val message =
                            """Please attach a bug to track demoted test, e.g. @Ignore("b/123")"""
                        context.report(ISSUE, node, location, message)
                    }
                }
            }
        }
    }

    private fun containsBugId(node: UAnnotation): Boolean {
        val bugId = node.findAttributeValue("bugId")?.evaluate() as Int?
        return bugId != null && bugId > 0
    }

    private fun containsBugString(node: UAnnotation): Boolean {
        val reason = node.findAttributeValue("value")?.evaluate() as String?
        val bugPattern = Pattern.compile("b/\\d+")
        return reason != null && bugPattern.matcher(reason).find()
    }

    companion object {
        val DEMOTING_ANNOTATION_BUG_ID =
            listOf(
                "androidx.test.filters.FlakyTest",
                "android.platform.test.annotations.FlakyTest",
                "android.platform.test.rule.PlatinumRule.Platinum",
            )

        const val DEMOTING_ANNOTATION_IGNORE = "org.junit.Ignore"

        @JvmField
        val ISSUE: Issue =
            Issue.create(
                id = "DemotingTestWithoutBug",
                briefDescription = "Demoting a test without attaching a bug.",
                explanation =
                    """
                    Annotations (`@FlakyTest`) demote tests to an unmonitored \
                    test suite. Please set the `bugId` field in such annotations to track \
                    the test status.
                    """,
                category = Category.TESTING,
                priority = 8,
                severity = Severity.WARNING,
                implementation =
                    Implementation(
                        DemotingTestWithoutBugDetector::class.java,
                        EnumSet.of(Scope.JAVA_FILE, Scope.TEST_SOURCES)
                    )
            )
    }
}