//===-- SourceCodeTests.cpp  ------------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Evaluating scoring functions isn't a great fit for assert-based tests.
// For interesting cases, both exact scores and "X beats Y" are too brittle to
// make good hard assertions.
//
// Here we test the signal extraction and sanity-check that signals point in
// the right direction. This should be supplemented by quality metrics which
// we can compute from a corpus of queries and preferred rankings.
//
//===----------------------------------------------------------------------===//

#include "FileDistance.h"
#include "Quality.h"
#include "TestFS.h"
#include "TestTU.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/Type.h"
#include "clang/Sema/CodeCompleteConsumer.h"
#include "llvm/Support/Casting.h"
#include "gmock/gmock.h"
#include "gtest/gtest.h"

namespace clang {
namespace clangd {

// Force the unittest URI scheme to be linked,
static int LLVM_ATTRIBUTE_UNUSED UnittestSchemeAnchorDest =
    UnittestSchemeAnchorSource;

namespace {

TEST(QualityTests, SymbolQualitySignalExtraction) {
  auto Header = TestTU::withHeaderCode(R"cpp(
    int _X;

    [[deprecated]]
    int _f() { return _X; }
  )cpp");
  auto Symbols = Header.headerSymbols();
  auto AST = Header.build();

  SymbolQualitySignals Quality;
  Quality.merge(findSymbol(Symbols, "_X"));
  EXPECT_FALSE(Quality.Deprecated);
  EXPECT_TRUE(Quality.ReservedName);
  EXPECT_EQ(Quality.References, SymbolQualitySignals().References);
  EXPECT_EQ(Quality.Category, SymbolQualitySignals::Variable);

  Symbol F = findSymbol(Symbols, "_f");
  F.References = 24; // TestTU doesn't count references, so fake it.
  Quality = {};
  Quality.merge(F);
  EXPECT_FALSE(Quality.Deprecated); // FIXME: Include deprecated bit in index.
  EXPECT_FALSE(Quality.ReservedName);
  EXPECT_EQ(Quality.References, 24u);
  EXPECT_EQ(Quality.Category, SymbolQualitySignals::Function);

  Quality = {};
  Quality.merge(CodeCompletionResult(&findDecl(AST, "_f"), /*Priority=*/42));
  EXPECT_TRUE(Quality.Deprecated);
  EXPECT_FALSE(Quality.ReservedName);
  EXPECT_EQ(Quality.References, SymbolQualitySignals().References);
  EXPECT_EQ(Quality.Category, SymbolQualitySignals::Function);

  Quality = {};
  Quality.merge(CodeCompletionResult("if"));
  EXPECT_EQ(Quality.Category, SymbolQualitySignals::Keyword);
}

TEST(QualityTests, SymbolRelevanceSignalExtraction) {
  TestTU Test;
  Test.HeaderCode = R"cpp(
  int header();
  int header_main();

  namespace hdr { class Bar {}; } // namespace hdr

  #define DEFINE_FLAG(X) \
  namespace flags { \
  int FLAGS_##X; \
  } \

  DEFINE_FLAG(FOO)
  )cpp";
  Test.Code = R"cpp(
  using hdr::Bar;

  using flags::FLAGS_FOO;

  int ::header_main() {}
  int main();

  [[deprecated]]
  int deprecated() { return 0; }

  namespace { struct X { void y() { int z; } }; }
  struct S{}
  )cpp";
  auto AST = Test.build();

  SymbolRelevanceSignals Relevance;
  Relevance.merge(CodeCompletionResult(&findDecl(AST, "deprecated"),
                                       /*Priority=*/42, nullptr, false,
                                       /*Accessible=*/false));
  EXPECT_EQ(Relevance.NameMatch, SymbolRelevanceSignals().NameMatch);
  EXPECT_TRUE(Relevance.Forbidden);
  EXPECT_EQ(Relevance.Scope, SymbolRelevanceSignals::GlobalScope);

  Relevance = {};
  Relevance.merge(CodeCompletionResult(&findDecl(AST, "main"), 42));
  EXPECT_FLOAT_EQ(Relevance.SemaProximityScore, 1.0f) << "Decl in current file";
  Relevance = {};
  Relevance.merge(CodeCompletionResult(&findDecl(AST, "header"), 42));
  EXPECT_FLOAT_EQ(Relevance.SemaProximityScore, 0.6f) << "Decl from header";
  Relevance = {};
  Relevance.merge(CodeCompletionResult(&findDecl(AST, "header_main"), 42));
  EXPECT_FLOAT_EQ(Relevance.SemaProximityScore, 1.0f)
      << "Current file and header";

  auto constructShadowDeclCompletionResult = [&](const std::string DeclName) {
    auto *Shadow =
        *dyn_cast<UsingDecl>(
             &findAnyDecl(AST,
                          [&](const NamedDecl &ND) {
                            if (const UsingDecl *Using =
                                    dyn_cast<UsingDecl>(&ND))
                              if (Using->shadow_size() &&
                                  Using->getQualifiedNameAsString() == DeclName)
                                return true;
                            return false;
                          }))
             ->shadow_begin();
    CodeCompletionResult Result(Shadow->getTargetDecl(), 42);
    Result.ShadowDecl = Shadow;
    return Result;
  };

  Relevance = {};
  Relevance.merge(constructShadowDeclCompletionResult("Bar"));
  EXPECT_FLOAT_EQ(Relevance.SemaProximityScore, 1.0f)
      << "Using declaration in main file";
  Relevance.merge(constructShadowDeclCompletionResult("FLAGS_FOO"));
  EXPECT_FLOAT_EQ(Relevance.SemaProximityScore, 1.0f)
      << "Using declaration in main file";

  Relevance = {};
  Relevance.merge(CodeCompletionResult(&findAnyDecl(AST, "X"), 42));
  EXPECT_EQ(Relevance.Scope, SymbolRelevanceSignals::FileScope);
  Relevance = {};
  Relevance.merge(CodeCompletionResult(&findAnyDecl(AST, "y"), 42));
  EXPECT_EQ(Relevance.Scope, SymbolRelevanceSignals::ClassScope);
  Relevance = {};
  Relevance.merge(CodeCompletionResult(&findAnyDecl(AST, "z"), 42));
  EXPECT_EQ(Relevance.Scope, SymbolRelevanceSignals::FunctionScope);
  // The injected class name is treated as the outer class name.
  Relevance = {};
  Relevance.merge(CodeCompletionResult(&findDecl(AST, "S::S"), 42));
  EXPECT_EQ(Relevance.Scope, SymbolRelevanceSignals::GlobalScope);
}

// Do the signals move the scores in the direction we expect?
TEST(QualityTests, SymbolQualitySignalsSanity) {
  SymbolQualitySignals Default;
  EXPECT_EQ(Default.evaluate(), 1);

  SymbolQualitySignals Deprecated;
  Deprecated.Deprecated = true;
  EXPECT_LT(Deprecated.evaluate(), Default.evaluate());

  SymbolQualitySignals ReservedName;
  ReservedName.ReservedName = true;
  EXPECT_LT(ReservedName.evaluate(), Default.evaluate());

  SymbolQualitySignals WithReferences, ManyReferences;
  WithReferences.References = 20;
  ManyReferences.References = 1000;
  EXPECT_GT(WithReferences.evaluate(), Default.evaluate());
  EXPECT_GT(ManyReferences.evaluate(), WithReferences.evaluate());

  SymbolQualitySignals Keyword, Variable, Macro, Constructor, Function;
  Keyword.Category = SymbolQualitySignals::Keyword;
  Variable.Category = SymbolQualitySignals::Variable;
  Macro.Category = SymbolQualitySignals::Macro;
  Constructor.Category = SymbolQualitySignals::Constructor;
  Function.Category = SymbolQualitySignals::Function;
  EXPECT_GT(Variable.evaluate(), Default.evaluate());
  EXPECT_GT(Keyword.evaluate(), Variable.evaluate());
  EXPECT_LT(Macro.evaluate(), Default.evaluate());
  EXPECT_LT(Constructor.evaluate(), Function.evaluate());
}

TEST(QualityTests, SymbolRelevanceSignalsSanity) {
  SymbolRelevanceSignals Default;
  EXPECT_EQ(Default.evaluate(), 1);

  SymbolRelevanceSignals Forbidden;
  Forbidden.Forbidden = true;
  EXPECT_LT(Forbidden.evaluate(), Default.evaluate());

  SymbolRelevanceSignals PoorNameMatch;
  PoorNameMatch.NameMatch = 0.2f;
  EXPECT_LT(PoorNameMatch.evaluate(), Default.evaluate());

  SymbolRelevanceSignals WithSemaProximity;
  WithSemaProximity.SemaProximityScore = 0.2f;
  EXPECT_GT(WithSemaProximity.evaluate(), Default.evaluate());

  SymbolRelevanceSignals IndexProximate;
  IndexProximate.SymbolURI = "unittest:/foo/bar.h";
  llvm::StringMap<SourceParams> ProxSources;
  ProxSources.try_emplace(testPath("foo/baz.h"));
  URIDistance Distance(ProxSources);
  IndexProximate.FileProximityMatch = &Distance;
  EXPECT_GT(IndexProximate.evaluate(), Default.evaluate());
  SymbolRelevanceSignals IndexDistant = IndexProximate;
  IndexDistant.SymbolURI = "unittest:/elsewhere/path.h";
  EXPECT_GT(IndexProximate.evaluate(), IndexDistant.evaluate())
      << IndexProximate << IndexDistant;
  EXPECT_GT(IndexDistant.evaluate(), Default.evaluate());

  SymbolRelevanceSignals Scoped;
  Scoped.Scope = SymbolRelevanceSignals::FileScope;
  EXPECT_EQ(Scoped.evaluate(), Default.evaluate());
  Scoped.Query = SymbolRelevanceSignals::CodeComplete;
  EXPECT_GT(Scoped.evaluate(), Default.evaluate());

  SymbolRelevanceSignals Instance;
  Instance.IsInstanceMember = false;
  EXPECT_EQ(Instance.evaluate(), Default.evaluate());
  Instance.Context = CodeCompletionContext::CCC_DotMemberAccess;
  EXPECT_LT(Instance.evaluate(), Default.evaluate());
  Instance.IsInstanceMember = true;
  EXPECT_EQ(Instance.evaluate(), Default.evaluate());
}

TEST(QualityTests, SortText) {
  EXPECT_LT(sortText(std::numeric_limits<float>::infinity()),
            sortText(1000.2f));
  EXPECT_LT(sortText(1000.2f), sortText(1));
  EXPECT_LT(sortText(1), sortText(0.3f));
  EXPECT_LT(sortText(0.3f), sortText(0));
  EXPECT_LT(sortText(0), sortText(-10));
  EXPECT_LT(sortText(-10), sortText(-std::numeric_limits<float>::infinity()));

  EXPECT_LT(sortText(1, "z"), sortText(0, "a"));
  EXPECT_LT(sortText(0, "a"), sortText(0, "z"));
}

TEST(QualityTests, NoBoostForClassConstructor) {
  auto Header = TestTU::withHeaderCode(R"cpp(
    class Foo {
    public:
      Foo(int);
    };
  )cpp");
  auto Symbols = Header.headerSymbols();
  auto AST = Header.build();

  const NamedDecl *Foo = &findDecl(AST, "Foo");
  SymbolRelevanceSignals Cls;
  Cls.merge(CodeCompletionResult(Foo, /*Priority=*/0));

  const NamedDecl *CtorDecl = &findAnyDecl(AST, [](const NamedDecl &ND) {
    return (ND.getQualifiedNameAsString() == "Foo::Foo") &&
           llvm::isa<CXXConstructorDecl>(&ND);
  });
  SymbolRelevanceSignals Ctor;
  Ctor.merge(CodeCompletionResult(CtorDecl, /*Priority=*/0));

  EXPECT_EQ(Cls.Scope, SymbolRelevanceSignals::GlobalScope);
  EXPECT_EQ(Ctor.Scope, SymbolRelevanceSignals::GlobalScope);
}

TEST(QualityTests, IsInstanceMember) {
  auto Header = TestTU::withHeaderCode(R"cpp(
    class Foo {
    public:
      static void foo() {}

      template <typename T> void tpl(T *t) {}

      void bar() {}
    };
  )cpp");
  auto Symbols = Header.headerSymbols();

  SymbolRelevanceSignals Rel;
  const Symbol &FooSym = findSymbol(Symbols, "Foo::foo");
  Rel.merge(FooSym);
  EXPECT_FALSE(Rel.IsInstanceMember);
  const Symbol &BarSym = findSymbol(Symbols, "Foo::bar");
  Rel.merge(BarSym);
  EXPECT_TRUE(Rel.IsInstanceMember);

  Rel.IsInstanceMember =false;
  const Symbol &TplSym = findSymbol(Symbols, "Foo::tpl");
  Rel.merge(TplSym);
  EXPECT_TRUE(Rel.IsInstanceMember);

  auto AST = Header.build();
  const NamedDecl *Foo = &findDecl(AST, "Foo::foo");
  const NamedDecl *Bar = &findDecl(AST, "Foo::bar");
  const NamedDecl *Tpl = &findDecl(AST, "Foo::tpl");

  Rel.IsInstanceMember = false;
  Rel.merge(CodeCompletionResult(Foo, /*Priority=*/0));
  EXPECT_FALSE(Rel.IsInstanceMember);
  Rel.merge(CodeCompletionResult(Bar, /*Priority=*/0));
  EXPECT_TRUE(Rel.IsInstanceMember);
  Rel.IsInstanceMember = false;
  Rel.merge(CodeCompletionResult(Tpl, /*Priority=*/0));
  EXPECT_TRUE(Rel.IsInstanceMember);
}

TEST(QualityTests, ConstructorQuality) {
  auto Header = TestTU::withHeaderCode(R"cpp(
    class Foo {
    public:
      Foo(int);
    };
  )cpp");
  auto Symbols = Header.headerSymbols();
  auto AST = Header.build();

  const NamedDecl *CtorDecl = &findAnyDecl(AST, [](const NamedDecl &ND) {
    return (ND.getQualifiedNameAsString() == "Foo::Foo") &&
           llvm::isa<CXXConstructorDecl>(&ND);
  });

  SymbolQualitySignals Q;
  Q.merge(CodeCompletionResult(CtorDecl, /*Priority=*/0));
  EXPECT_EQ(Q.Category, SymbolQualitySignals::Constructor);

  Q.Category = SymbolQualitySignals::Unknown;
  const Symbol &CtorSym = findSymbol(Symbols, "Foo::Foo");
  Q.merge(CtorSym);
  EXPECT_EQ(Q.Category, SymbolQualitySignals::Constructor);
}

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