//===----------------------------------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//

#include "NullEditorConsumer.h"
#include "SourceKit/Core/Context.h"
#include "SourceKit/Core/LangSupport.h"
#include "SourceKit/Core/NotificationCenter.h"
#include "SourceKit/Support/Concurrency.h"
#include "SourceKit/SwiftLang/Factory.h"
#include "swift/Basic/LLVMInitialize.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/TargetSelect.h"
#include "gtest/gtest.h"

using namespace SourceKit;
using namespace llvm;

static StringRef getRuntimeLibPath() {
  return sys::path::parent_path(SWIFTLIB_DIR);
}

static SmallString<128> getSwiftExecutablePath() {
  SmallString<128> path = sys::path::parent_path(getRuntimeLibPath());
  sys::path::append(path, "bin", "swift-frontend");
  return path;
}

static void *createCancellationToken() {
  static std::atomic<size_t> handle(1000);
  return reinterpret_cast<void *>(
      handle.fetch_add(1, std::memory_order_relaxed));
}

namespace {

struct TestCursorInfo {
  // Empty if no error.
  std::string Error;
  std::string InternalDiagnostic;
  std::string Name;
  std::string Typename;
  std::string Filename;
  unsigned Offset;
  unsigned Length;
};

class CursorInfoTest : public ::testing::Test {
  SourceKit::Context &Ctx;
  std::atomic<int> NumTasks;
  NullEditorConsumer Consumer;

public:
  SourceKit::Context &getContext() { return Ctx; }
  LangSupport &getLang() { return getContext().getSwiftLangSupport(); }

  void SetUp() override {
    NumTasks = 0;
  }

  CursorInfoTest()
      : Ctx(*new SourceKit::Context(getSwiftExecutablePath(),
                                    getRuntimeLibPath(),
                                    /*diagnosticDocumentationPath*/ "",
                                    SourceKit::createSwiftLangSupport,
                                    /*dispatchOnMain=*/false)) {
    INITIALIZE_LLVM();
    // This is avoiding destroying \p SourceKit::Context because another
    // thread may be active trying to use it to post notifications.
    // FIXME: Use shared_ptr ownership to avoid such issues.
  }

  void addNotificationReceiver(DocumentUpdateNotificationReceiver Receiver) {
    Ctx.getNotificationCenter()->addDocumentUpdateNotificationReceiver(Receiver);
  }

  void open(const char *DocName, StringRef Text,
            std::optional<ArrayRef<const char *>> CArgs = std::nullopt) {
    auto Args = CArgs.has_value() ? makeArgs(DocName, *CArgs)
                                  : std::vector<const char *>{};
    auto Buf = MemoryBuffer::getMemBufferCopy(Text, DocName);
    getLang().editorOpen(DocName, Buf.get(), Consumer, Args, std::nullopt);
  }

  void replaceText(StringRef DocName, unsigned Offset, unsigned Length,
                   StringRef Text) {
    auto Buf = MemoryBuffer::getMemBufferCopy(Text, DocName);
    getLang().editorReplaceText(DocName, Buf.get(), Offset, Length, Consumer);
  }

  TestCursorInfo
  getCursor(const char *DocName, unsigned Offset, ArrayRef<const char *> CArgs,
            SourceKitCancellationToken CancellationToken = nullptr,
            bool CancelOnSubsequentRequest = false) {
    auto Args = makeArgs(DocName, CArgs);
    Semaphore sema(0);

    TestCursorInfo TestInfo;
    getLang().getCursorInfo(
        DocName, DocName, Offset, /*Length=*/0, /*Actionables=*/false,
        /*SymbolGraph=*/false, CancelOnSubsequentRequest, Args,
        /*vfsOptions=*/std::nullopt, CancellationToken,
        [&](const RequestResult<CursorInfoData> &Result) {
          assert(!Result.isCancelled());
          if (Result.isError()) {
            TestInfo.Error = Result.getError().str();
            sema.signal();
            return;
          }
          const CursorInfoData &Info = Result.value();
          TestInfo.InternalDiagnostic = Info.InternalDiagnostic.str();
          if (!Info.Symbols.empty()) {
            const CursorSymbolInfo &MainSymbol = Info.Symbols[0];
            TestInfo.Name = std::string(MainSymbol.Name.str());
            TestInfo.Typename = MainSymbol.TypeName.str();
            TestInfo.Filename = MainSymbol.Location.Filename.str();
            TestInfo.Offset = MainSymbol.Location.Offset;
            TestInfo.Length = MainSymbol.Location.Length;
          }
          sema.signal();
        });

    bool expired = sema.wait(60 * 1000);
    if (expired)
      llvm::report_fatal_error("check took too long");
    return TestInfo;
  }

  unsigned findOffset(StringRef Val, StringRef Text) {
    auto pos = Text.find(Val);
    assert(pos != StringRef::npos);
    return pos;
  }

  void setNeedsSema(bool needsSema) { Consumer.needsSema = needsSema; }

private:
  std::vector<const char *> makeArgs(const char *DocName,
                                     ArrayRef<const char *> CArgs) {
    std::vector<const char *> Args = CArgs;
    Args.push_back(DocName);
    return Args;
  }
};

} // anonymous namespace

TEST_F(CursorInfoTest, FileNotExist) {
  const char *DocName = "test.swift";
  const char *Contents =
    "let foo = 0\n";
  const char *Args[] = { "<not-existent-file>" };

  open(DocName, Contents);
  auto FooOffs = findOffset("foo =", Contents);
  auto Info = getCursor(DocName, FooOffs, Args);
  EXPECT_STREQ("foo", Info.Name.c_str());
  EXPECT_STREQ("Int", Info.Typename.c_str());
}

static const char *ExpensiveInit =
    "[0:0,0:0,0:0,0:0,0:0,0:0,0:0]";

TEST_F(CursorInfoTest, EditAfter) {
  const char *DocName = "test.swift";
  const char *Contents =
    "let value = foo\n"
    "let foo = 0\n";
  const char *Args[] = { "-parse-as-library" };

  open(DocName, Contents);
  auto FooRefOffs = findOffset("foo", Contents);
  auto FooOffs = findOffset("foo =", Contents);
  auto Info = getCursor(DocName, FooRefOffs, Args);
  EXPECT_STREQ("foo", Info.Name.c_str());
  EXPECT_STREQ("Int", Info.Typename.c_str());
  EXPECT_STREQ(DocName, Info.Filename.c_str());
  EXPECT_EQ(FooOffs, Info.Offset);
  EXPECT_EQ(strlen("foo"), Info.Length);

  StringRef TextToReplace = "0";
  replaceText(DocName, findOffset(TextToReplace, Contents), TextToReplace.size(),
              ExpensiveInit);
  // Insert a space in front of 'foo' decl.
  replaceText(DocName, FooOffs, 0, " ");
  ++FooOffs;

  // Should not wait for the new AST, it should give the previous answer.
  Info = getCursor(DocName, FooRefOffs, Args);
  EXPECT_STREQ("foo", Info.Name.c_str());
  EXPECT_STREQ("Int", Info.Typename.c_str());
  EXPECT_STREQ(DocName, Info.Filename.c_str());
  EXPECT_EQ(FooOffs, Info.Offset);
  EXPECT_EQ(strlen("foo"), Info.Length);
}

TEST_F(CursorInfoTest, EditBefore) {
  const char *DocName = "test.swift";
  const char *Contents =
    "let foo = 0\n"
    "let value = foo;\n";
  const char *Args[] = { "-parse-as-library" };

  open(DocName, Contents);
  auto FooRefOffs = findOffset("foo;", Contents);
  auto FooOffs = findOffset("foo =", Contents);
  auto Info = getCursor(DocName, FooRefOffs, Args);
  EXPECT_STREQ("", Info.Error.c_str());
  EXPECT_STREQ("", Info.InternalDiagnostic.c_str());
  EXPECT_STREQ("foo", Info.Name.c_str());
  EXPECT_STREQ("Int", Info.Typename.c_str());
  EXPECT_STREQ(DocName, Info.Filename.c_str());
  EXPECT_EQ(FooOffs, Info.Offset);
  EXPECT_EQ(strlen("foo"), Info.Length);

  StringRef TextToReplace = "0";
  replaceText(DocName, findOffset(TextToReplace, Contents), TextToReplace.size(),
              ExpensiveInit);
  FooRefOffs += StringRef(ExpensiveInit).size() - TextToReplace.size();
  // Insert a space in front of 'foo' decl.
  replaceText(DocName, FooOffs, 0, " ");
  ++FooOffs;
  ++FooRefOffs;

  // Should not wait for the new AST, it should give the previous answer.
  Info = getCursor(DocName, FooRefOffs, Args);
  EXPECT_STREQ("", Info.Error.c_str());
  EXPECT_STREQ("", Info.InternalDiagnostic.c_str());
  EXPECT_STREQ("foo", Info.Name.c_str());
  EXPECT_STREQ("Int", Info.Typename.c_str());
  EXPECT_STREQ(DocName, Info.Filename.c_str());
  EXPECT_EQ(FooOffs, Info.Offset);
  EXPECT_EQ(strlen("foo"), Info.Length);
}

TEST_F(CursorInfoTest, CursorInfoMustWaitDueDeclLoc) {
  const char *DocName = "test.swift";
  const char *Contents =
    "let value = foo\n"
    "let foo = 0\n";
  const char *Args[] = { "-parse-as-library" };

  open(DocName, Contents);
  auto FooRefOffs = findOffset("foo", Contents);
  auto FooOffs = findOffset("foo =", Contents);
  auto Info = getCursor(DocName, FooRefOffs, Args);
  EXPECT_STREQ("", Info.Error.c_str());
  EXPECT_STREQ("", Info.InternalDiagnostic.c_str());
  EXPECT_STREQ("foo", Info.Name.c_str());
  EXPECT_STREQ("Int", Info.Typename.c_str());

  StringRef TextToReplace = "0";
  replaceText(DocName, findOffset(TextToReplace, Contents), TextToReplace.size(),
              ExpensiveInit);
  // Edit over the 'foo' decl.
  replaceText(DocName, FooOffs, strlen("foo"), "foo");

  // Should wait for the new AST, because the declaration location for the 'foo'
  // reference has been edited out.
  Info = getCursor(DocName, FooRefOffs, Args);
  EXPECT_STREQ("", Info.Error.c_str());
  EXPECT_STREQ("", Info.InternalDiagnostic.c_str());
  EXPECT_STREQ("foo", Info.Name.c_str());
  EXPECT_STREQ("[Int : Int]", Info.Typename.c_str());
  EXPECT_EQ(FooOffs, Info.Offset);
  EXPECT_EQ(strlen("foo"), Info.Length);
}

TEST_F(CursorInfoTest, CursorInfoMustWaitDueOffset) {
  const char *DocName = "test.swift";
  const char *Contents =
    "let value = foo\n"
    "let foo = 0\n";
  const char *Args[] = { "-parse-as-library" };

  open(DocName, Contents);
  auto FooRefOffs = findOffset("foo", Contents);
  auto FooOffs = findOffset("foo =", Contents);
  auto Info = getCursor(DocName, FooRefOffs, Args);
  EXPECT_STREQ("foo", Info.Name.c_str());
  EXPECT_STREQ("Int", Info.Typename.c_str());

  StringRef TextToReplace = "0";
  replaceText(DocName, findOffset(TextToReplace, Contents), TextToReplace.size(),
              ExpensiveInit);
  // Edit over the 'foo' reference.
  replaceText(DocName, FooRefOffs, strlen("foo"), "foo");

  // Should wait for the new AST, because the cursor location has been edited
  // out.
  Info = getCursor(DocName, FooRefOffs, Args);
  EXPECT_STREQ("foo", Info.Name.c_str());
  EXPECT_STREQ("[Int : Int]", Info.Typename.c_str());
  EXPECT_EQ(FooOffs, Info.Offset);
  EXPECT_EQ(strlen("foo"), Info.Length);
}

TEST_F(CursorInfoTest, CursorInfoMustWaitDueToken) {
  const char *DocName = "test.swift";
  const char *Contents =
    "let value = foo\n"
    "let foo = 0\n";
  const char *Args[] = { "-parse-as-library" };

  open(DocName, Contents);
  auto FooRefOffs = findOffset("foo", Contents);
  auto FooOffs = findOffset("foo =", Contents);
  auto Info = getCursor(DocName, FooRefOffs, Args);
  EXPECT_STREQ("foo", Info.Name.c_str());
  EXPECT_STREQ("Int", Info.Typename.c_str());

  StringRef TextToReplace = "0";
  replaceText(DocName, findOffset(TextToReplace, Contents), TextToReplace.size(),
              ExpensiveInit);
  // Change 'foo' to 'fog' by replacing the last character.
  replaceText(DocName, FooOffs+2, 1, "g");
  replaceText(DocName, FooRefOffs+2, 1, "g");

  // Should wait for the new AST, because the cursor location points to a
  // different token.
  Info = getCursor(DocName, FooRefOffs, Args);
  EXPECT_STREQ("fog", Info.Name.c_str());
  EXPECT_STREQ("[Int : Int]", Info.Typename.c_str());
  EXPECT_EQ(FooOffs, Info.Offset);
  EXPECT_EQ(strlen("fog"), Info.Length);
}

TEST_F(CursorInfoTest, CursorInfoMustWaitDueTokenRace) {
  const char *DocName = "test.swift";
  const char *Contents = "let value = foo\n"
                         "let foo = 0\n";
  const char *Args[] = {"-parse-as-library"};

  auto FooRefOffs = findOffset("foo", Contents);
  auto FooOffs = findOffset("foo =", Contents);

  // Open with args, kicking off an ast build. The hope of this tests is for
  // this AST to still be in the process of building when we start the cursor
  // info, to ensure the ASTManager doesn't try to handle this cursor info with
  // the wrong AST.
  setNeedsSema(true);
  open(DocName, Contents, llvm::ArrayRef(Args));
  // Change 'foo' to 'fog' by replacing the last character.
  replaceText(DocName, FooOffs + 2, 1, "g");
  replaceText(DocName, FooRefOffs + 2, 1, "g");

  // Should wait for the new AST, because the cursor location points to a
  // different token.
  auto Info = getCursor(DocName, FooRefOffs, Args);
  EXPECT_STREQ("fog", Info.Name.c_str());
  EXPECT_STREQ("Int", Info.Typename.c_str());
  EXPECT_EQ(FooOffs, Info.Offset);
  EXPECT_EQ(strlen("fog"), Info.Length);
}

TEST_F(CursorInfoTest, CursorInfoCancelsPreviousRequest) {
  // TODO: This test case relies on the following snippet being slow to type 
  // check so that the first cursor info request takes longer to execute than it 
  // takes time to schedule the second request. If that is fixed, we need to 
  // find a new way to cause slow type checking. rdar://80582770
  const char *SlowDocName = "slow.swift";
  const char *SlowContents = "func foo(x: Invalid1, y: Invalid2) {\n"
                             "    x / y / x / y / x / y / x / y\n"
                             "}\n";
  auto SlowOffset = findOffset("x", SlowContents);
  const char *Args[] = {"-parse-as-library"};
  std::vector<const char *> ArgsForSlow = llvm::ArrayRef(Args).vec();
  ArgsForSlow.push_back(SlowDocName);

  const char *FastDocName = "fast.swift";
  const char *FastContents = "func bar() {\n"
                             "    let foo = 123\n"
                             "}\n";
  auto FastOffset = findOffset("foo", FastContents);
  std::vector<const char *> ArgsForFast = llvm::ArrayRef(Args).vec();
  ArgsForFast.push_back(FastDocName);

  open(SlowDocName, SlowContents, llvm::ArrayRef(Args));
  open(FastDocName, FastContents, llvm::ArrayRef(Args));

  // Schedule a cursor info request that takes long to execute. This should be
  // cancelled as the next cursor info (which is faster) gets requested.
  Semaphore FirstCursorInfoSema(0);
  getLang().getCursorInfo(
      SlowDocName, SlowDocName, SlowOffset, /*Length=*/0, /*Actionables=*/false,
      /*SymbolGraph=*/false, /*CancelOnSubsequentRequest=*/true, ArgsForSlow,
      /*vfsOptions=*/std::nullopt, /*CancellationToken=*/nullptr,
      [&](const RequestResult<CursorInfoData> &Result) {
        EXPECT_TRUE(Result.isCancelled());
        FirstCursorInfoSema.signal();
      });

  auto Info = getCursor(FastDocName, FastOffset, Args,
                        /*CancellationToken=*/nullptr,
                        /*CancelOnSubsequentRequest=*/true);
  EXPECT_STREQ("foo", Info.Name.c_str());
  EXPECT_STREQ("Int", Info.Typename.c_str());
  EXPECT_EQ(FastOffset, Info.Offset);
  EXPECT_EQ(strlen("foo"), Info.Length);

  bool expired = FirstCursorInfoSema.wait(30 * 1000);
  if (expired)
    llvm::report_fatal_error("Did not receive a response for the first request");
}

TEST_F(CursorInfoTest, CursorInfoCancellation) {
  // TODO: This test case relies on the following snippet being slow to type
  // check so that the first cursor info request takes longer to execute than it
  // takes time to schedule the second request. If that is fixed, we need to
  // find a new way to cause slow type checking. rdar://80582770
  const char *SlowDocName = "slow.swift";
  const char *SlowContents = "func foo(x: Invalid1, y: Invalid2) {\n"
                             "    x / y / x / y / x / y / x / y\n"
                             "}\n";
  auto SlowOffset = findOffset("x", SlowContents);
  const char *Args[] = {"-parse-as-library"};
  std::vector<const char *> ArgsForSlow = llvm::ArrayRef(Args).vec();
  ArgsForSlow.push_back(SlowDocName);

  open(SlowDocName, SlowContents, llvm::ArrayRef(Args));

  SourceKitCancellationToken CancellationToken = createCancellationToken();

  // Schedule a cursor info request that takes long to execute. This should be
  // cancelled as the next cursor info (which is faster) gets requested.
  Semaphore CursorInfoSema(0);
  getLang().getCursorInfo(
      SlowDocName, SlowDocName, SlowOffset, /*Length=*/0, /*Actionables=*/false,
      /*SymbolGraph=*/false, /*CancelOnSubsequentRequest=*/false, ArgsForSlow,
      /*vfsOptions=*/std::nullopt, /*CancellationToken=*/CancellationToken,
      [&](const RequestResult<CursorInfoData> &Result) {
        EXPECT_TRUE(Result.isCancelled());
        CursorInfoSema.signal();
      });

  getContext().getRequestTracker()->cancel(CancellationToken);

  bool expired = CursorInfoSema.wait(30 * 1000);
  if (expired)
    llvm::report_fatal_error("Did not receive a response for the first request");
}