//===-- ClangdLSPServerTests.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 "Annotations.h"
#include "ClangdLSPServer.h"
#include "LSPClient.h"
#include "Protocol.h"
#include "TestFS.h"
#include "support/Logger.h"
#include "support/TestTracer.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/JSON.h"
#include "llvm/Testing/Support/SupportHelpers.h"
#include "gmock/gmock.h"
#include "gtest/gtest.h"

namespace clang {
namespace clangd {
namespace {

MATCHER_P(DiagMessage, M, "") {
  if (const auto *O = arg.getAsObject()) {
    if (const auto Msg = O->getString("message"))
      return *Msg == M;
  }
  return false;
}

class LSPTest : public ::testing::Test, private clangd::Logger {
protected:
  LSPTest() : LogSession(*this) {
    ClangdServer::Options &Base = Opts;
    Base = ClangdServer::optsForTest();
  }

  LSPClient &start() {
    EXPECT_FALSE(Server.hasValue()) << "Already initialized";
    Server.emplace(Client.transport(), FS, Opts);
    ServerThread.emplace([&] { EXPECT_TRUE(Server->run()); });
    Client.call("initialize", llvm::json::Object{});
    return Client;
  }

  void stop() {
    assert(Server);
    Client.call("shutdown", nullptr);
    Client.notify("exit", nullptr);
    Client.stop();
    ServerThread->join();
    Server.reset();
    ServerThread.reset();
  }

  ~LSPTest() {
    if (Server)
      stop();
  }

  MockFS FS;
  ClangdLSPServer::Options Opts;

private:
  // Color logs so we can distinguish them from test output.
  void log(Level L, const llvm::formatv_object_base &Message) override {
    raw_ostream::Colors Color;
    switch (L) {
    case Level::Verbose:
      Color = raw_ostream::BLUE;
      break;
    case Level::Error:
      Color = raw_ostream::RED;
      break;
    default:
      Color = raw_ostream::YELLOW;
      break;
    }
    std::lock_guard<std::mutex> Lock(LogMu);
    (llvm::outs().changeColor(Color) << Message << "\n").resetColor();
  }
  std::mutex LogMu;

  LoggingSession LogSession;
  llvm::Optional<ClangdLSPServer> Server;
  llvm::Optional<std::thread> ServerThread;
  LSPClient Client;
};

TEST_F(LSPTest, GoToDefinition) {
  Annotations Code(R"cpp(
    int [[fib]](int n) {
      return n >= 2 ? ^fib(n - 1) + fib(n - 2) : 1;
    }
  )cpp");
  auto &Client = start();
  Client.didOpen("foo.cpp", Code.code());
  auto &Def = Client.call("textDocument/definition",
                          llvm::json::Object{
                              {"textDocument", Client.documentID("foo.cpp")},
                              {"position", Code.point()},
                          });
  llvm::json::Value Want = llvm::json::Array{llvm::json::Object{
      {"uri", Client.uri("foo.cpp")}, {"range", Code.range()}}};
  EXPECT_EQ(Def.takeValue(), Want);
}

TEST_F(LSPTest, Diagnostics) {
  auto &Client = start();
  Client.didOpen("foo.cpp", "void main(int, char**);");
  EXPECT_THAT(Client.diagnostics("foo.cpp"),
              llvm::ValueIs(testing::ElementsAre(
                  DiagMessage("'main' must return 'int' (fix available)"))));

  Client.didChange("foo.cpp", "int x = \"42\";");
  EXPECT_THAT(Client.diagnostics("foo.cpp"),
              llvm::ValueIs(testing::ElementsAre(
                  DiagMessage("Cannot initialize a variable of type 'int' with "
                              "an lvalue of type 'const char [3]'"))));

  Client.didClose("foo.cpp");
  EXPECT_THAT(Client.diagnostics("foo.cpp"), llvm::ValueIs(testing::IsEmpty()));
}

TEST_F(LSPTest, DiagnosticsHeaderSaved) {
  auto &Client = start();
  Client.didOpen("foo.cpp", R"cpp(
    #include "foo.h"
    int x = VAR;
  )cpp");
  EXPECT_THAT(Client.diagnostics("foo.cpp"),
              llvm::ValueIs(testing::ElementsAre(
                  DiagMessage("'foo.h' file not found"),
                  DiagMessage("Use of undeclared identifier 'VAR'"))));
  // Now create the header.
  FS.Files["foo.h"] = "#define VAR original";
  Client.notify(
      "textDocument/didSave",
      llvm::json::Object{{"textDocument", Client.documentID("foo.h")}});
  EXPECT_THAT(Client.diagnostics("foo.cpp"),
              llvm::ValueIs(testing::ElementsAre(
                  DiagMessage("Use of undeclared identifier 'original'"))));
  // Now modify the header from within the "editor".
  FS.Files["foo.h"] = "#define VAR changed";
  Client.notify(
      "textDocument/didSave",
      llvm::json::Object{{"textDocument", Client.documentID("foo.h")}});
  // Foo.cpp should be rebuilt with new diagnostics.
  EXPECT_THAT(Client.diagnostics("foo.cpp"),
              llvm::ValueIs(testing::ElementsAre(
                  DiagMessage("Use of undeclared identifier 'changed'"))));
}

TEST_F(LSPTest, RecordsLatencies) {
  trace::TestTracer Tracer;
  auto &Client = start();
  llvm::StringLiteral MethodName = "method_name";
  EXPECT_THAT(Tracer.takeMetric("lsp_latency", MethodName), testing::SizeIs(0));
  llvm::consumeError(Client.call(MethodName, {}).take().takeError());
  stop();
  EXPECT_THAT(Tracer.takeMetric("lsp_latency", MethodName), testing::SizeIs(1));
}
} // namespace
} // namespace clangd
} // namespace clang