//===-- RenameTests.cpp -----------------------------------------*- C++ -*-===//
//
// 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 "Annotations.h"
#include "TestFS.h"
#include "TestTU.h"
#include "index/Ref.h"
#include "refactor/Rename.h"
#include "clang/Tooling/Core/Replacement.h"
#include "llvm/Support/MemoryBuffer.h"
#include "gmock/gmock.h"
#include "gtest/gtest.h"

namespace clang {
namespace clangd {
namespace {

using testing::Eq;
using testing::Pair;
using testing::UnorderedElementsAre;

// Build a RefSlab from all marked ranges in the annotation. The ranges are
// assumed to associate with the given SymbolName.
std::unique_ptr<RefSlab> buildRefSlab(const Annotations &Code,
                                      llvm::StringRef SymbolName,
                                      llvm::StringRef Path) {
  RefSlab::Builder Builder;
  TestTU TU;
  TU.HeaderCode = Code.code();
  auto Symbols = TU.headerSymbols();
  const auto &SymbolID = findSymbol(Symbols, SymbolName).ID;
  for (const auto &Range : Code.ranges()) {
    Ref R;
    R.Kind = RefKind::Reference;
    R.Location.Start.setLine(Range.start.line);
    R.Location.Start.setColumn(Range.start.character);
    R.Location.End.setLine(Range.end.line);
    R.Location.End.setColumn(Range.end.character);
    auto U = URI::create(Path).toString();
    R.Location.FileURI = U.c_str();
    Builder.insert(SymbolID, R);
  }

  return std::make_unique<RefSlab>(std::move(Builder).build());
}

std::vector<
    std::pair</*InitialCode*/ std::string, /*CodeAfterRename*/ std::string>>
applyEdits(FileEdits FE) {
  std::vector<std::pair<std::string, std::string>> Results;
  for (auto &It : FE)
    Results.emplace_back(
        It.first().str(),
        llvm::cantFail(tooling::applyAllReplacements(
            It.getValue().InitialCode, It.getValue().Replacements)));
  return Results;
}

// Generates an expected rename result by replacing all ranges in the given
// annotation with the NewName.
std::string expectedResult(Annotations Test, llvm::StringRef NewName) {
  std::string Result;
  unsigned NextChar = 0;
  llvm::StringRef Code = Test.code();
  for (const auto &R : Test.llvm::Annotations::ranges()) {
    assert(R.Begin <= R.End && NextChar <= R.Begin);
    Result += Code.substr(NextChar, R.Begin - NextChar);
    Result += NewName;
    NextChar = R.End;
  }
  Result += Code.substr(NextChar);
  return Result;
}

TEST(RenameTest, WithinFileRename) {
  // rename is runnning on all "^" points, and "[[]]" ranges point to the
  // identifier that is being renamed.
  llvm::StringRef Tests[] = {
      // Function.
      R"cpp(
        void [[foo^]]() {
          [[fo^o]]();
        }
      )cpp",

      // Type.
      R"cpp(
        struct [[foo^]] {};
        [[foo]] test() {
           [[f^oo]] x;
           return x;
        }
      )cpp",

      // Local variable.
      R"cpp(
        void bar() {
          if (auto [[^foo]] = 5) {
            [[foo]] = 3;
          }
        }
      )cpp",

      // Rename class, including constructor/destructor.
      R"cpp(
        class [[F^oo]] {
          [[F^oo]]();
          ~[[Foo]]();
          void foo(int x);
        };
        [[Foo]]::[[Fo^o]]() {}
        void [[Foo]]::foo(int x) {}
      )cpp",

      // Class in template argument.
      R"cpp(
        class [[F^oo]] {};
        template <typename T> void func();
        template <typename T> class Baz {};
        int main() {
          func<[[F^oo]]>();
          Baz<[[F^oo]]> obj;
          return 0;
        }
      )cpp",

      // Forward class declaration without definition.
      R"cpp(
        class [[F^oo]];
        [[Foo]] *f();
      )cpp",

      // Class methods overrides.
      R"cpp(
        struct A {
         virtual void [[f^oo]]() {}
        };
        struct B : A {
          void [[f^oo]]() override {}
        };
        struct C : B {
          void [[f^oo]]() override {}
        };

        void func() {
          A().[[f^oo]]();
          B().[[f^oo]]();
          C().[[f^oo]]();
        }
      )cpp",

      // Template class (partial) specializations.
      R"cpp(
        template <typename T>
        class [[F^oo]] {};

        template<>
        class [[F^oo]]<bool> {};
        template <typename T>
        class [[F^oo]]<T*> {};

        void test() {
          [[Foo]]<int> x;
          [[Foo]]<bool> y;
          [[Foo]]<int*> z;
        }
      )cpp",

      // Template class instantiations.
      R"cpp(
        template <typename T>
        class [[F^oo]] {
        public:
          T foo(T arg, T& ref, T* ptr) {
            T value;
            int number = 42;
            value = (T)number;
            value = static_cast<T>(number);
            return value;
          }
          static void foo(T value) {}
          T member;
        };

        template <typename T>
        void func() {
          [[F^oo]]<T> obj;
          obj.member = T();
          [[Foo]]<T>::foo();
        }

        void test() {
          [[F^oo]]<int> i;
          i.member = 0;
          [[F^oo]]<int>::foo(0);

          [[F^oo]]<bool> b;
          b.member = false;
          [[Foo]]<bool>::foo(false);
        }
      )cpp",

      // Template class methods.
      R"cpp(
        template <typename T>
        class A {
        public:
          void [[f^oo]]() {}
        };

        void func() {
          A<int>().[[f^oo]]();
          A<double>().[[f^oo]]();
          A<float>().[[f^oo]]();
        }
      )cpp",

      // Complicated class type.
      R"cpp(
         // Forward declaration.
        class [[Fo^o]];
        class Baz {
          virtual int getValue() const = 0;
        };

        class [[F^oo]] : public Baz  {
        public:
          [[Foo]](int value = 0) : x(value) {}

          [[Foo]] &operator++(int);

          bool operator<([[Foo]] const &rhs);
          int getValue() const;
        private:
          int x;
        };

        void func() {
          [[Foo]] *Pointer = 0;
          [[Foo]] Variable = [[Foo]](10);
          for ([[Foo]] it; it < Variable; it++);
          const [[Foo]] *C = new [[Foo]]();
          const_cast<[[Foo]] *>(C)->getValue();
          [[Foo]] foo;
          const Baz &BazReference = foo;
          const Baz *BazPointer = &foo;
          reinterpret_cast<const [[^Foo]] *>(BazPointer)->getValue();
          static_cast<const [[^Foo]] &>(BazReference).getValue();
          static_cast<const [[^Foo]] *>(BazPointer)->getValue();
        }
      )cpp",

      // CXXConstructor initializer list.
      R"cpp(
        class Baz {};
        class Qux {
          Baz [[F^oo]];
        public:
          Qux();
        };
        Qux::Qux() : [[F^oo]]() {}
      )cpp",

      // DeclRefExpr.
      R"cpp(
        class C {
        public:
          static int [[F^oo]];
        };

        int foo(int x);
        #define MACRO(a) foo(a)

        void func() {
          C::[[F^oo]] = 1;
          MACRO(C::[[Foo]]);
          int y = C::[[F^oo]];
        }
      )cpp",

      // Macros.
      R"cpp(
        // no rename inside macro body.
        #define M1 foo
        #define M2(x) x
        int [[fo^o]]();
        void boo(int);

        void qoo() {
          [[foo]]();
          boo([[foo]]());
          M1();
          boo(M1());
          M2([[foo]]());
          M2(M1()); // foo is inside the nested macro body.
        }
      )cpp",

      // MemberExpr in macros
      R"cpp(
        class Baz {
        public:
          int [[F^oo]];
        };
        int qux(int x);
        #define MACRO(a) qux(a)

        int main() {
          Baz baz;
          baz.[[Foo]] = 1;
          MACRO(baz.[[Foo]]);
          int y = baz.[[Foo]];
        }
      )cpp",

      // Template parameters.
      R"cpp(
        template <typename [[^T]]>
        class Foo {
          [[T]] foo([[T]] arg, [[T]]& ref, [[^T]]* ptr) {
            [[T]] value;
            int number = 42;
            value = ([[T]])number;
            value = static_cast<[[^T]]>(number);
            return value;
          }
          static void foo([[T]] value) {}
          [[T]] member;
        };
      )cpp",

      // Typedef.
      R"cpp(
        namespace std {
        class basic_string {};
        typedef basic_string [[s^tring]];
        } // namespace std

        std::[[s^tring]] foo();
      )cpp",

      // Variable.
      R"cpp(
        namespace A {
        int [[F^oo]];
        }
        int Foo;
        int Qux = Foo;
        int Baz = A::[[^Foo]];
        void fun() {
          struct {
            int Foo;
          } b = {100};
          int Foo = 100;
          Baz = Foo;
          {
            extern int Foo;
            Baz = Foo;
            Foo = A::[[F^oo]] + Baz;
            A::[[Fo^o]] = b.Foo;
          }
          Foo = b.Foo;
        }
      )cpp",

      // Namespace alias.
      R"cpp(
        namespace a { namespace b { void foo(); } }
        namespace [[^x]] = a::b;
        void bar() {
          [[x]]::foo();
        }
      )cpp",

      // Scope enums.
      R"cpp(
        enum class [[K^ind]] { ABC };
        void ff() {
          [[K^ind]] s;
          s = [[Kind]]::ABC;
        }
      )cpp",

      // template class in template argument list.
      R"cpp(
        template<typename T>
        class [[Fo^o]] {};
        template <template<typename> class Z> struct Bar { };
        template <> struct Bar<[[Foo]]> {};
      )cpp",
  };
  for (const auto T : Tests) {
    Annotations Code(T);
    auto TU = TestTU::withCode(Code.code());
    TU.ExtraArgs.push_back("-fno-delayed-template-parsing");
    auto AST = TU.build();
    llvm::StringRef NewName = "abcde";
    for (const auto &RenamePos : Code.points()) {
      auto RenameResult =
          rename({RenamePos, NewName, AST, testPath(TU.Filename)});
      ASSERT_TRUE(bool(RenameResult)) << RenameResult.takeError();
      ASSERT_EQ(1u, RenameResult->size());
      EXPECT_EQ(applyEdits(std::move(*RenameResult)).front().second,
                expectedResult(Code, NewName));
    }
  }
}

TEST(RenameTest, Renameable) {
  struct Case {
    const char *Code;
    const char* ErrorMessage; // null if no error
    bool IsHeaderFile;
    const SymbolIndex *Index;
  };
  TestTU OtherFile = TestTU::withCode("Outside s; auto ss = &foo;");
  const char *CommonHeader = R"cpp(
    class Outside {};
    void foo();
  )cpp";
  OtherFile.HeaderCode = CommonHeader;
  OtherFile.Filename = "other.cc";
  // The index has a "Outside" reference and a "foo" reference.
  auto OtherFileIndex = OtherFile.index();
  const SymbolIndex *Index = OtherFileIndex.get();

  const bool HeaderFile = true;
  Case Cases[] = {
      {R"cpp(// allow -- function-local
        void f(int [[Lo^cal]]) {
          [[Local]] = 2;
        }
      )cpp",
       nullptr, HeaderFile, Index},

      {R"cpp(// allow -- symbol is indexable and has no refs in index.
        void [[On^lyInThisFile]]();
      )cpp",
       nullptr, HeaderFile, Index},

      {R"cpp(// disallow -- symbol is indexable and has other refs in index.
        void f() {
          Out^side s;
        }
      )cpp",
       "used outside main file", HeaderFile, Index},

      {R"cpp(// disallow -- symbol is not indexable.
        namespace {
        class Unin^dexable {};
        }
      )cpp",
       "not eligible for indexing", HeaderFile, Index},

      {R"cpp(// disallow -- namespace symbol isn't supported
        namespace n^s {}
      )cpp",
       "not a supported kind", HeaderFile, Index},

      {
          R"cpp(
         #define MACRO 1
         int s = MAC^RO;
       )cpp",
          "not a supported kind", HeaderFile, Index},

      {

          R"cpp(
        struct X { X operator++(int); };
        void f(X x) {x+^+;})cpp",
          "not a supported kind", HeaderFile, Index},

      {R"cpp(// foo is declared outside the file.
        void fo^o() {}
      )cpp",
       "used outside main file", !HeaderFile /*cc file*/, Index},

      {R"cpp(
         // We should detect the symbol is used outside the file from the AST.
         void fo^o() {})cpp",
       "used outside main file", !HeaderFile, nullptr /*no index*/},

      {R"cpp(
         void foo(int);
         void foo(char);
         template <typename T> void f(T t) {
           fo^o(t);
         })cpp",
       "multiple symbols", !HeaderFile, nullptr /*no index*/},

      {R"cpp(// disallow rename on unrelated token.
         cl^ass Foo {};
       )cpp",
       "no symbol", !HeaderFile, nullptr},

      {R"cpp(// disallow rename on unrelated token.
         temp^late<typename T>
         class Foo {};
       )cpp",
       "no symbol", !HeaderFile, nullptr},
  };

  for (const auto& Case : Cases) {
    Annotations T(Case.Code);
    TestTU TU = TestTU::withCode(T.code());
    TU.HeaderCode = CommonHeader;
    TU.ExtraArgs.push_back("-fno-delayed-template-parsing");
    if (Case.IsHeaderFile) {
      // We open the .h file as the main file.
      TU.Filename = "test.h";
      // Parsing the .h file as C++ include.
      TU.ExtraArgs.push_back("-xobjective-c++-header");
    }
    auto AST = TU.build();
    llvm::StringRef NewName = "dummyNewName";
    auto Results =
        rename({T.point(), NewName, AST, testPath(TU.Filename), Case.Index});
    bool WantRename = true;
    if (T.ranges().empty())
      WantRename = false;
    if (!WantRename) {
      assert(Case.ErrorMessage && "Error message must be set!");
      EXPECT_FALSE(Results)
          << "expected rename returned an error: " << T.code();
      auto ActualMessage = llvm::toString(Results.takeError());
      EXPECT_THAT(ActualMessage, testing::HasSubstr(Case.ErrorMessage));
    } else {
      EXPECT_TRUE(bool(Results)) << "rename returned an error: "
                                 << llvm::toString(Results.takeError());
      ASSERT_EQ(1u, Results->size());
      EXPECT_EQ(applyEdits(std::move(*Results)).front().second,
                expectedResult(T, NewName));
    }
  }
}

TEST(RenameTest, MainFileReferencesOnly) {
  // filter out references not from main file.
  llvm::StringRef Test =
      R"cpp(
        void test() {
          int [[fo^o]] = 1;
          // rename references not from main file are not included.
          #include "foo.inc"
        })cpp";

  Annotations Code(Test);
  auto TU = TestTU::withCode(Code.code());
  TU.AdditionalFiles["foo.inc"] = R"cpp(
      #define Macro(X) X
      &Macro(foo);
      &foo;
    )cpp";
  auto AST = TU.build();
  llvm::StringRef NewName = "abcde";

  auto RenameResult =
      rename({Code.point(), NewName, AST, testPath(TU.Filename)});
  ASSERT_TRUE(bool(RenameResult)) << RenameResult.takeError() << Code.point();
  ASSERT_EQ(1u, RenameResult->size());
  EXPECT_EQ(applyEdits(std::move(*RenameResult)).front().second,
            expectedResult(Code, NewName));
}

TEST(RenameTests, CrossFile) {
  Annotations FooCode("class [[Foo]] {};");
  std::string FooPath = testPath("foo.cc");
  Annotations FooDirtyBuffer("class [[Foo]] {};\n// this is dirty buffer");
  Annotations BarCode("void [[Bar]]() {}");
  std::string BarPath = testPath("bar.cc");
  // Build the index, the index has "Foo" references from foo.cc and "Bar"
  // references from bar.cc.
  FileSymbols FSymbols;
  FSymbols.update(FooPath, nullptr, buildRefSlab(FooCode, "Foo", FooPath),
                  nullptr, false);
  FSymbols.update(BarPath, nullptr, buildRefSlab(BarCode, "Bar", BarPath),
                  nullptr, false);
  auto Index = FSymbols.buildIndex(IndexType::Light);

  Annotations MainCode("class  [[Fo^o]] {};");
  auto MainFilePath = testPath("main.cc");
  // Dirty buffer for foo.cc.
  auto GetDirtyBuffer = [&](PathRef Path) -> llvm::Optional<std::string> {
    if (Path == FooPath)
      return FooDirtyBuffer.code().str();
    return llvm::None;
  };

  // Run rename on Foo, there is a dirty buffer for foo.cc, rename should
  // respect the dirty buffer.
  TestTU TU = TestTU::withCode(MainCode.code());
  auto AST = TU.build();
  llvm::StringRef NewName = "newName";
  auto Results = rename({MainCode.point(), NewName, AST, MainFilePath,
                         Index.get(), /*CrossFile=*/true, GetDirtyBuffer});
  ASSERT_TRUE(bool(Results)) << Results.takeError();
  EXPECT_THAT(
      applyEdits(std::move(*Results)),
      UnorderedElementsAre(
          Pair(Eq(FooPath), Eq(expectedResult(FooDirtyBuffer, NewName))),
          Pair(Eq(MainFilePath), Eq(expectedResult(MainCode, NewName)))));

  // Run rename on Bar, there is no dirty buffer for the affected file bar.cc,
  // so we should read file content from VFS.
  MainCode = Annotations("void [[Bar]]() { [[B^ar]](); }");
  TU = TestTU::withCode(MainCode.code());
  // Set a file "bar.cc" on disk.
  TU.AdditionalFiles["bar.cc"] = BarCode.code();
  AST = TU.build();
  Results = rename({MainCode.point(), NewName, AST, MainFilePath, Index.get(),
                    /*CrossFile=*/true, GetDirtyBuffer});
  ASSERT_TRUE(bool(Results)) << Results.takeError();
  EXPECT_THAT(
      applyEdits(std::move(*Results)),
      UnorderedElementsAre(
          Pair(Eq(BarPath), Eq(expectedResult(BarCode, NewName))),
          Pair(Eq(MainFilePath), Eq(expectedResult(MainCode, NewName)))));

  // Run rename on a pagination index which couldn't return all refs in one
  // request, we reject rename on this case.
  class PaginationIndex : public SymbolIndex {
    bool refs(const RefsRequest &Req,
              llvm::function_ref<void(const Ref &)> Callback) const override {
      return true; // has more references
    }

    bool fuzzyFind(
        const FuzzyFindRequest &Req,
        llvm::function_ref<void(const Symbol &)> Callback) const override {
      return false;
    }
    void
    lookup(const LookupRequest &Req,
           llvm::function_ref<void(const Symbol &)> Callback) const override {}

    void relations(const RelationsRequest &Req,
                   llvm::function_ref<void(const SymbolID &, const Symbol &)>
                       Callback) const override {}
    size_t estimateMemoryUsage() const override { return 0; }
  } PIndex;
  Results = rename({MainCode.point(), NewName, AST, MainFilePath, &PIndex,
                    /*CrossFile=*/true, GetDirtyBuffer});
  EXPECT_FALSE(Results);
  EXPECT_THAT(llvm::toString(Results.takeError()),
              testing::HasSubstr("too many occurrences"));
}

TEST(CrossFileRenameTests, CrossFileOnLocalSymbol) {
  // cross-file rename should work for function-local symbols, even there is no
  // index provided.
  Annotations Code("void f(int [[abc]]) { [[a^bc]] = 3; }");
  auto TU = TestTU::withCode(Code.code());
  auto Path = testPath(TU.Filename);
  auto AST = TU.build();
  llvm::StringRef NewName = "newName";
  auto Results = rename({Code.point(), NewName, AST, Path});
  ASSERT_TRUE(bool(Results)) << Results.takeError();
  EXPECT_THAT(
      applyEdits(std::move(*Results)),
      UnorderedElementsAre(Pair(Eq(Path), Eq(expectedResult(Code, NewName)))));
}

TEST(CrossFileRenameTests, BuildRenameEdits) {
  Annotations Code("[[😂]]");
  auto LSPRange = Code.range();
  llvm::StringRef FilePath = "/test/TestTU.cpp";
  auto Edit = buildRenameEdit(FilePath, Code.code(), {LSPRange}, "abc");
  ASSERT_TRUE(bool(Edit)) << Edit.takeError();
  ASSERT_EQ(1UL, Edit->Replacements.size());
  EXPECT_EQ(FilePath, Edit->Replacements.begin()->getFilePath());
  EXPECT_EQ(4UL, Edit->Replacements.begin()->getLength());

  // Test invalid range.
  LSPRange.end = {10, 0}; // out of range
  Edit = buildRenameEdit(FilePath, Code.code(), {LSPRange}, "abc");
  EXPECT_FALSE(Edit);
  EXPECT_THAT(llvm::toString(Edit.takeError()),
              testing::HasSubstr("fail to convert"));

  // Normal ascii characters.
  Annotations T(R"cpp(
    [[range]]
              [[range]]
      [[range]]
  )cpp");
  Edit = buildRenameEdit(FilePath, T.code(), T.ranges(), "abc");
  ASSERT_TRUE(bool(Edit)) << Edit.takeError();
  EXPECT_EQ(applyEdits(FileEdits{{T.code(), std::move(*Edit)}}).front().second,
            expectedResult(Code, expectedResult(T, "abc")));
}

} // namespace
} // namespace clangd
} // namespace clang