/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 */

import org.apache.rat.Defaults
import org.apache.rat.document.impl.FileDocument
import org.apache.rat.api.MetaData

import javax.inject.Inject;
import org.gradle.internal.logging.progress.ProgressLoggerFactory
import org.gradle.internal.logging.progress.ProgressLogger

buildscript {
  repositories {
    mavenCentral()
  }

  dependencies {
    classpath "org.apache.rat:apache-rat:${scriptDepVersions['apache-rat']}"
  }
}

def extensions = [
    'adoc',
    'bat',
    'cmd',
    'css',
    'g4',
    'gradle',
    'groovy',
    'html',
    'java',
    'jflex',
    'jj',
    'js',
    'json',
    'md',
    'mdtext',
    'pl',
    'policy',
    'properties',
    'py',
    'sh',
    'template',
    'txt',
    'vm',
    'xml',
    'xsl',
]

// Create source validation task local to each project
allprojects {
  task validateSourcePatterns(type: ValidateSourcePatternsTask) { task ->
    group = 'Verification'
    description = 'Validate Source Patterns'

    sourceFiles = fileTree(projectDir) {
      extensions.each{
        include "**/*.${it}"
      }

      // Don't go into child projects (scanned separately).
      childProjects.keySet().each{
        exclude "${it}/**"
      }

      // default excludes.
      exclude '**/build/**'
      exclude '**/.idea/**'

      if (project == rootProject) {
        // ourselves :-)
        exclude 'gradle/validation/validate-source-patterns.gradle'

        // gradle and idea folders.
        exclude '.gradle/**'
        exclude '.idea/**'
      } else {
        // ignore txt files in source resources and tests.
        exclude 'src/**/*.txt'
      }
    }
  }

  // Add source validation to per-project checks as well.
  check.dependsOn validateSourcePatterns

  // Ensure validation runs prior to any compilation task. This also means
  // no executable code can leak out to other modules.
  tasks.withType(JavaCompile).configureEach {
    mustRunAfter validateSourcePatterns
  }
}

configure(project(':lucene:benchmark')) {
  project.tasks.withType(ValidateSourcePatternsTask) {
    sourceFiles.exclude 'data/**'

    // Known .txt offenders.
    sourceFiles.exclude '**/reuters.first20.lines.txt', '**/trecQRels.txt'
  }
}


@CacheableTask
class ValidateSourcePatternsTask extends DefaultTask {
  private ProgressLoggerFactory progressLoggerFactory

  @InputFiles
  @PathSensitive(PathSensitivity.RELATIVE)
  @IgnoreEmptyDirectories
  FileTree sourceFiles

  @Inject
  ValidateSourcePatternsTask(ProgressLoggerFactory progressLoggerFactory) {
    this.progressLoggerFactory = progressLoggerFactory
  }

  @TaskAction
  public void check() {
    def invalidPatterns = [
      (~$/@author\b/$) : '@author javadoc tag',
      (~$/(?i)\bno(n|)commit\b/$) : 'nocommit',
      (~$/\bTOOD:/$) : 'TOOD instead TODO',
      (~$/\t/$) : 'tabs instead spaces',
      (~$/[\u202A-\u202E\u2066-\u2069]/$) : 'misuse of RTL/LTR (https://trojansource.codes)',
      (~$/\Q/**\E((?:\s)|(?:\*))*\Q{@inheritDoc}\E((?:\s)|(?:\*))*\Q*/\E/$) : '{@inheritDoc} on its own is unnecessary',
      (~$/\$$(?:LastChanged)?Date\b/$) : 'svn keyword',
      (~$/\$$(?:(?:LastChanged)?Revision|Rev)\b/$) : 'svn keyword',
      (~$/\$$(?:LastChangedBy|Author)\b/$) : 'svn keyword',
      (~$/\$$(?:Head)?URL\b/$) : 'svn keyword',
      (~$/\$$Id\b/$) : 'svn keyword',
      (~$/\$$Header\b/$) : 'svn keyword',
      (~$/\$$Source\b/$) : 'svn keyword',
      (~$/^\uFEFF/$) : 'UTF-8 byte order mark',
      (~$/import java\.lang\.\w+;/$) : 'java.lang import is unnecessary'
    ]

    // Python and others merrily use var declarations, this is a problem _only_ in Java at least for 8x where we're forbidding var declarations
    def invalidJavaOnlyPatterns = [
      (~$/\n\s*var\s+.*=.*<>.*/$) : 'Diamond operators should not be used with var'
    ]

    def found = 0;
    def violations = new TreeSet();
    def reportViolation = { f, name ->
      logger.error('{}: {}', name, f);
      violations.add(name);
      found++;
    }

    def javadocsPattern = ~$/(?sm)^\Q/**\E(.*?)\Q*/\E/$;
    def javaCommentPattern = ~$/(?sm)^\Q/*\E(.*?)\Q*/\E/$;
    def xmlCommentPattern = ~$/(?sm)\Q<!--\E(.*?)\Q-->\E/$;
    def lineSplitter = ~$/[\r\n]+/$;
    def licenseMatcher = Defaults.createDefaultMatcher();
    def validLoggerPattern = ~$/(?s)\b(private\s|static\s|final\s){3}+\s*Logger\s+\p{javaJavaIdentifierStart}+\s+=\s+\QLoggerFactory.getLogger(MethodHandles.lookup().lookupClass());\E/$;
    def validLoggerNamePattern = ~$/(?s)\b(private\s|static\s|final\s){3}+\s*Logger\s+log+\s+=\s+\QLoggerFactory.getLogger(MethodHandles.lookup().lookupClass());\E/$;
    def packagePattern = ~$/(?m)^\s*package\s+org\.apache.*;/$;
    def xmlTagPattern = ~$/(?m)\s*<[a-zA-Z].*/$;
    def validSPINameJavadocTag = ~$/(?s)\s*\*\s*@lucene\.spi\s+\{@value #NAME\}/$;

    def isLicense = { matcher, ratDocument ->
      licenseMatcher.reset()
      return lineSplitter.split(matcher.group(1)).any { licenseMatcher.match(ratDocument, it) }
    }

    def checkLicenseHeaderPrecedes = { f, description, contentPattern, commentPattern, text, ratDocument ->
      def contentMatcher = contentPattern.matcher(text);
      if (contentMatcher.find()) {
        def contentStartPos = contentMatcher.start();
        def commentMatcher = commentPattern.matcher(text);
        while (commentMatcher.find()) {
          if (isLicense(commentMatcher, ratDocument)) {
            if (commentMatcher.start() < contentStartPos) {
              break; // This file is all good, so break loop: license header precedes 'description' definition
            } else {
              reportViolation(f, description+' declaration precedes license header');
            }
          }
        }
      }
    }

    def checkMockitoAssume = { f, text ->
      if (text.contains("mockito") && !text.contains("assumeWorkingMockito()")) {
        reportViolation(f, 'File uses Mockito but has no assumeWorkingMockito() call')
      }
    }

    ProgressLogger progress = progressLoggerFactory.newOperation(this.class)
    progress.start(this.name, this.name)

    sourceFiles.each{ f ->
      progress.progress("Scanning ${f.name}")
      logger.debug('Scanning source file: {}', f);

      def text = f.getText('UTF-8');
      invalidPatterns.each { pattern, name ->
        if (pattern.matcher(text).find()) {
          reportViolation(f, name);
        }
      }
      def javadocsMatcher = javadocsPattern.matcher(text);
      def ratDocument = new FileDocument(f);
      while (javadocsMatcher.find()) {
        if (isLicense(javadocsMatcher, ratDocument)) {
          reportViolation(f, String.format(Locale.ENGLISH, 'javadoc-style license header [%s]',
            ratDocument.getMetaData().value(MetaData.RAT_URL_LICENSE_FAMILY_NAME)));
        }
      }
      if (f.name.endsWith('.java')) {
        if (text.contains('org.slf4j.LoggerFactory')) {
          if (!validLoggerPattern.matcher(text).find()) {
            reportViolation(f, 'invalid logging pattern [not private static final, uses static class name]');
          }
          if (!validLoggerNamePattern.matcher(text).find()) {
            reportViolation(f, 'invalid logger name [log, uses static class name, not specialized logger]')
          }
        }
        // make sure that SPI names of all tokenizers/charfilters/tokenfilters are documented
        if (!f.name.contains("Test") && !f.name.contains("Mock") && !f.name.contains("Fake") && !text.contains("abstract class") &&
            !f.name.equals("TokenizerFactory.java") && !f.name.equals("CharFilterFactory.java") && !f.name.equals("TokenFilterFactory.java") &&
            (f.name.contains("TokenizerFactory") && text.contains("extends TokenizerFactory") ||
                f.name.contains("CharFilterFactory") && text.contains("extends CharFilterFactory") ||
                f.name.contains("FilterFactory") && text.contains("extends TokenFilterFactory"))) {
          if (!validSPINameJavadocTag.matcher(text).find()) {
            reportViolation(f, 'invalid spi name documentation')
          }
        }
        checkLicenseHeaderPrecedes(f, 'package', packagePattern, javaCommentPattern, text, ratDocument);
        if (f.name.contains("Test")) {
          checkMockitoAssume(f, text);
        }

        invalidJavaOnlyPatterns.each { pattern,name ->
          if (pattern.matcher(text).find()) {
            reportViolation(f, name);
          }
        }
      }
      if (f.name.endsWith('.xml')) {
        checkLicenseHeaderPrecedes(f, '<tag>', xmlTagPattern, xmlCommentPattern, text, ratDocument);
      }
    }
    progress.completed()

    if (found) {
      throw new GradleException(String.format(Locale.ENGLISH, 'Found %d violations in source files (%s).',
        found, violations.join(', ')));
    }
  }
}