/*
 * Copyright 2016 The Bazel Authors. All rights reserved.
 *
 * 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.google.idea.blaze.base.lang.buildfile.references;

import com.google.idea.blaze.base.lang.buildfile.BuildFileIntegrationTestCase;
import com.google.idea.blaze.base.lang.buildfile.psi.Argument;
import com.google.idea.blaze.base.lang.buildfile.psi.BuildFile;
import com.google.idea.blaze.base.lang.buildfile.psi.FuncallExpression;
import com.google.idea.blaze.base.lang.buildfile.psi.StringLiteral;
import com.google.idea.blaze.base.lang.buildfile.psi.util.PsiUtils;
import com.google.idea.blaze.base.lang.buildfile.search.FindUsages;
import com.intellij.psi.PsiElement;
import com.intellij.psi.PsiFile;
import com.intellij.psi.PsiReference;

import java.util.List;

import static com.google.common.truth.Truth.assertThat;

/**
 * Tests that string literal references are correctly resolved.
 */
public class LabelReferenceTest extends BuildFileIntegrationTestCase {

  public void testExternalFileReference() {
    BuildFile file = createBuildFile(
      "java/com/google/BUILD",
      "exports_files([\"test.txt\", \"//java/com/google:plugin.xml\"])");

    PsiFile txtFile = createPsiFile("java/com/google/test.txt");
    PsiFile xmlFile = createPsiFile("java/com/google/plugin.xml");

    List<StringLiteral> strings = PsiUtils.findAllChildrenOfClassRecursive(file, StringLiteral.class);
    assertThat(strings).hasSize(2);
    assertThat(strings.get(0).getReferencedElement())
      .isEqualTo(txtFile);
    assertThat(strings.get(1).getReferencedElement())
      .isEqualTo(xmlFile);
  }

  public void testLocalRuleReference() {
    BuildFile file = createBuildFile(
      "java/com/google/BUILD",
      "java_library(name = \"lib\")",
      "java_library(name = \"foo\", deps = [\":lib\"])",
      "java_library(name = \"bar\", deps = [\"//java/com/google:lib\"])");

    FuncallExpression lib = file.findRule("lib");
    FuncallExpression foo = file.findRule("foo");
    FuncallExpression bar = file.findRule("bar");

    assertThat(lib).isNotNull();

    StringLiteral label = PsiUtils.findFirstChildOfClassRecursive(foo.getKeywordArgument("deps"), StringLiteral.class);
    assertThat(label.getReferencedElement()).isEqualTo(lib);

    label = PsiUtils.findFirstChildOfClassRecursive(bar.getKeywordArgument("deps"), StringLiteral.class);
    assertThat(label.getReferencedElement()).isEqualTo(lib);
  }

  public void testTargetInAnotherPackageResolves() {
    BuildFile targetFile = createBuildFile(
      "java/com/google/foo/BUILD",
      "rule(name = \"target\")");

    BuildFile referencingFile = createBuildFile(
      "java/com/google/bar/BUILD",
      "rule(name = \"other\", dep = \"//java/com/google/foo:target\")");

    FuncallExpression target = targetFile.findRule("target");
    assertThat(target).isNotNull();

    Argument.Keyword depArgument = referencingFile
      .findRule("other")
      .getKeywordArgument("dep");

    assertThat(depArgument.getValue().getReferencedElement())
      .isEqualTo(target);
  }

  public void testRuleNameDoesntCrossPackageBoundaries() {
    BuildFile targetFile = createBuildFile(
      "java/com/google/pkg/subpkg/BUILD",
      "rule(name = \"target\")");

    BuildFile referencingFile = createBuildFile(
      "java/com/google/pkg/BUILD",
      "rule(name = \"other\", dep = \":subpkg/target\")");

    Argument.Keyword depArgument = referencingFile
      .findRule("other")
      .getKeywordArgument("dep");

    LabelReference ref = (LabelReference) depArgument.getValue().getReference();
    assertThat(ref.resolve()).isNull();

    replaceStringContents(ref.getElement(), "//java/com/google/pkg/subpkg:target");
    assertThat(ref.resolve()).isNotNull();
    assertThat(ref.resolve()).isEqualTo(targetFile.findRule("target"));
  }

  public void testLabelWithImplicitRuleName() {
    BuildFile targetFile = createBuildFile(
      "java/com/google/foo/BUILD",
      "rule(name = \"foo\")");

    BuildFile referencingFile = createBuildFile(
      "java/com/google/bar/BUILD",
      "rule(name = \"other\", dep = \"//java/com/google/foo\")");

    FuncallExpression target = targetFile.findRule("foo");
    assertThat(target).isNotNull();

    Argument.Keyword depArgument = referencingFile
      .findRule("other")
      .getKeywordArgument("dep");

    assertThat(depArgument.getValue().getReferencedElement())
      .isEqualTo(target);
  }

  public void testAbsoluteLabelInSkylarkExtension() {
    BuildFile targetFile = createBuildFile(
      "java/com/google/foo/BUILD",
      "rule(name = \"foo\")");

    BuildFile referencingFile = createBuildFile(
      "java/com/google/foo/skylark.bzl",
      "LIST = ['//java/com/google/foo:foo']");

    FuncallExpression target = targetFile.findRule("foo");
    assertThat(target).isNotNull();

    StringLiteral label = PsiUtils.findFirstChildOfClassRecursive(referencingFile, StringLiteral.class);
    assertThat(label.getReferencedElement()).isEqualTo(target);
  }

  public void testRulePreferredOverFile() {
    BuildFile targetFile = createBuildFile(
      "java/com/foo/BUILD",
      "java_library(name = 'lib')");

    createDirectory("java/com/foo/lib");

    BuildFile referencingFile = createBuildFile(
      "java/com/google/bar/BUILD",
      "java_library(",
      "    name = 'bar',",
      "    src = glob(['**/*.java'])," +
      "    deps = ['//java/com/foo:lib'],",
      ")");

    FuncallExpression target = targetFile.findRule("lib");
    assertThat(target).isNotNull();

    PsiReference[] references = FindUsages.findAllReferences(target);
    assertThat(references).hasLength(1);

    PsiElement element = references[0].getElement();
    FuncallExpression rule = PsiUtils.getParentOfType(element, FuncallExpression.class);
    assertThat(rule.getName()).isEqualTo("bar");
    assertThat(rule.getContainingFile()).isEqualTo(referencingFile);
  }
}