//===- unittest/Tooling/RefactoringTestActionRulesTest.cpp ----------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#include "ReplacementTest.h"
#include "RewriterTestContext.h"
#include "clang/Tooling/Refactoring.h"
#include "clang/Tooling/Refactoring/Extract/Extract.h"
#include "clang/Tooling/Refactoring/RefactoringAction.h"
#include "clang/Tooling/Refactoring/RefactoringDiagnostic.h"
#include "clang/Tooling/Refactoring/Rename/SymbolName.h"
#include "clang/Tooling/Tooling.h"
#include "llvm/Support/Errc.h"
#include "gtest/gtest.h"
#include <optional>

using namespace clang;
using namespace tooling;

namespace {

class RefactoringActionRulesTest : public ::testing::Test {
protected:
  void SetUp() override {
    Context.Sources.setMainFileID(
        Context.createInMemoryFile("input.cpp", DefaultCode));
  }

  RewriterTestContext Context;
  std::string DefaultCode = std::string(100, 'a');
};

Expected<AtomicChanges>
createReplacements(const std::unique_ptr<RefactoringActionRule> &Rule,
                   RefactoringRuleContext &Context) {
  class Consumer final : public RefactoringResultConsumer {
    void handleError(llvm::Error Err) override { Result = std::move(Err); }

    void handle(AtomicChanges SourceReplacements) override {
      Result = std::move(SourceReplacements);
    }
    void handle(SymbolOccurrences Occurrences) override {
      RefactoringResultConsumer::handle(std::move(Occurrences));
    }

  public:
    std::optional<Expected<AtomicChanges>> Result;
  };

  Consumer C;
  Rule->invoke(C, Context);
  return std::move(*C.Result);
}

TEST_F(RefactoringActionRulesTest, MyFirstRefactoringRule) {
  class ReplaceAWithB : public SourceChangeRefactoringRule {
    std::pair<SourceRange, int> Selection;

  public:
    ReplaceAWithB(std::pair<SourceRange, int> Selection)
        : Selection(Selection) {}

    static Expected<ReplaceAWithB>
    initiate(RefactoringRuleContext &Cotnext,
             std::pair<SourceRange, int> Selection) {
      return ReplaceAWithB(Selection);
    }

    Expected<AtomicChanges>
    createSourceReplacements(RefactoringRuleContext &Context) {
      const SourceManager &SM = Context.getSources();
      SourceLocation Loc =
          Selection.first.getBegin().getLocWithOffset(Selection.second);
      AtomicChange Change(SM, Loc);
      llvm::Error E = Change.replace(SM, Loc, 1, "b");
      if (E)
        return std::move(E);
      return AtomicChanges{Change};
    }
  };

  class SelectionRequirement : public SourceRangeSelectionRequirement {
  public:
    Expected<std::pair<SourceRange, int>>
    evaluate(RefactoringRuleContext &Context) const {
      Expected<SourceRange> R =
          SourceRangeSelectionRequirement::evaluate(Context);
      if (!R)
        return R.takeError();
      return std::make_pair(*R, 20);
    }
  };
  auto Rule =
      createRefactoringActionRule<ReplaceAWithB>(SelectionRequirement());

  // When the requirements are satisfied, the rule's function must be invoked.
  {
    RefactoringRuleContext RefContext(Context.Sources);
    SourceLocation Cursor =
        Context.Sources.getLocForStartOfFile(Context.Sources.getMainFileID())
            .getLocWithOffset(10);
    RefContext.setSelectionRange({Cursor, Cursor});

    Expected<AtomicChanges> ErrorOrResult =
        createReplacements(Rule, RefContext);
    ASSERT_FALSE(!ErrorOrResult);
    AtomicChanges Result = std::move(*ErrorOrResult);
    ASSERT_EQ(Result.size(), 1u);
    std::string YAMLString =
        const_cast<AtomicChange &>(Result[0]).toYAMLString();

    ASSERT_STREQ("---\n"
                 "Key:             'input.cpp:30'\n"
                 "FilePath:        input.cpp\n"
                 "Error:           ''\n"
                 "InsertedHeaders: []\n"
                 "RemovedHeaders:  []\n"
                 "Replacements:\n"
                 "  - FilePath:        input.cpp\n"
                 "    Offset:          30\n"
                 "    Length:          1\n"
                 "    ReplacementText: b\n"
                 "...\n",
                 YAMLString.c_str());
  }

  // When one of the requirements is not satisfied, invoke should return a
  // valid error.
  {
    RefactoringRuleContext RefContext(Context.Sources);
    Expected<AtomicChanges> ErrorOrResult =
        createReplacements(Rule, RefContext);

    ASSERT_TRUE(!ErrorOrResult);
    unsigned DiagID;
    llvm::handleAllErrors(ErrorOrResult.takeError(),
                          [&](DiagnosticError &Error) {
                            DiagID = Error.getDiagnostic().second.getDiagID();
                          });
    EXPECT_EQ(DiagID, diag::err_refactor_no_selection);
  }
}

TEST_F(RefactoringActionRulesTest, ReturnError) {
  class ErrorRule : public SourceChangeRefactoringRule {
  public:
    static Expected<ErrorRule> initiate(RefactoringRuleContext &,
                                        SourceRange R) {
      return ErrorRule(R);
    }

    ErrorRule(SourceRange R) {}
    Expected<AtomicChanges> createSourceReplacements(RefactoringRuleContext &) {
      return llvm::make_error<llvm::StringError>(
          "Error", llvm::make_error_code(llvm::errc::invalid_argument));
    }
  };

  auto Rule =
      createRefactoringActionRule<ErrorRule>(SourceRangeSelectionRequirement());
  RefactoringRuleContext RefContext(Context.Sources);
  SourceLocation Cursor =
      Context.Sources.getLocForStartOfFile(Context.Sources.getMainFileID());
  RefContext.setSelectionRange({Cursor, Cursor});
  Expected<AtomicChanges> Result = createReplacements(Rule, RefContext);

  ASSERT_TRUE(!Result);
  std::string Message;
  llvm::handleAllErrors(Result.takeError(), [&](llvm::StringError &Error) {
    Message = Error.getMessage();
  });
  EXPECT_EQ(Message, "Error");
}

std::optional<SymbolOccurrences>
findOccurrences(RefactoringActionRule &Rule, RefactoringRuleContext &Context) {
  class Consumer final : public RefactoringResultConsumer {
    void handleError(llvm::Error) override {}
    void handle(SymbolOccurrences Occurrences) override {
      Result = std::move(Occurrences);
    }
    void handle(AtomicChanges Changes) override {
      RefactoringResultConsumer::handle(std::move(Changes));
    }

  public:
    std::optional<SymbolOccurrences> Result;
  };

  Consumer C;
  Rule.invoke(C, Context);
  return std::move(C.Result);
}

TEST_F(RefactoringActionRulesTest, ReturnSymbolOccurrences) {
  class FindOccurrences : public FindSymbolOccurrencesRefactoringRule {
    SourceRange Selection;

  public:
    FindOccurrences(SourceRange Selection) : Selection(Selection) {}

    static Expected<FindOccurrences> initiate(RefactoringRuleContext &,
                                              SourceRange Selection) {
      return FindOccurrences(Selection);
    }

    Expected<SymbolOccurrences>
    findSymbolOccurrences(RefactoringRuleContext &) override {
      SymbolOccurrences Occurrences;
      Occurrences.push_back(SymbolOccurrence(SymbolName("test"),
                                             SymbolOccurrence::MatchingSymbol,
                                             Selection.getBegin()));
      return std::move(Occurrences);
    }
  };

  auto Rule = createRefactoringActionRule<FindOccurrences>(
      SourceRangeSelectionRequirement());

  RefactoringRuleContext RefContext(Context.Sources);
  SourceLocation Cursor =
      Context.Sources.getLocForStartOfFile(Context.Sources.getMainFileID());
  RefContext.setSelectionRange({Cursor, Cursor});
  std::optional<SymbolOccurrences> Result = findOccurrences(*Rule, RefContext);

  ASSERT_FALSE(!Result);
  SymbolOccurrences Occurrences = std::move(*Result);
  EXPECT_EQ(Occurrences.size(), 1u);
  EXPECT_EQ(Occurrences[0].getKind(), SymbolOccurrence::MatchingSymbol);
  EXPECT_EQ(Occurrences[0].getNameRanges().size(), 1u);
  EXPECT_EQ(Occurrences[0].getNameRanges()[0],
            SourceRange(Cursor, Cursor.getLocWithOffset(strlen("test"))));
}

TEST_F(RefactoringActionRulesTest, EditorCommandBinding) {
  const RefactoringDescriptor &Descriptor = ExtractFunction::describe();
  EXPECT_EQ(Descriptor.Name, "extract-function");
  EXPECT_EQ(
      Descriptor.Description,
      "(WIP action; use with caution!) Extracts code into a new function");
  EXPECT_EQ(Descriptor.Title, "Extract Function");
}

} // end anonymous namespace