/*
 * Copyright (C) 2017 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <fstream>
#include <sstream>

#include "ftrace_procfs.h"
#include "gmock/gmock.h"
#include "gtest/gtest.h"

using testing::HasSubstr;
using testing::Not;

namespace perfetto {
namespace {

const char kTracingPath[] = "/sys/kernel/debug/tracing/";
const char kTracePath[] = "/sys/kernel/debug/tracing/trace";

void ResetFtrace(FtraceProcfs* ftrace) {
  ftrace->DisableAllEvents();
  ftrace->ClearTrace();
  ftrace->EnableTracing();
}

std::string GetTraceOutput() {
  std::ifstream fin(kTracePath, std::ios::in);
  if (!fin) {
    ADD_FAILURE() << "Could not read trace output";
    return "";
  }
  std::ostringstream stream;
  stream << fin.rdbuf();
  fin.close();
  return stream.str();
}

}  // namespace

TEST(FtraceProcfsIntegrationTest, ClearTrace) {
  FtraceProcfs ftrace(kTracingPath);
  ResetFtrace(&ftrace);
  ftrace.WriteTraceMarker("Hello, World!");
  ftrace.ClearTrace();
  EXPECT_THAT(GetTraceOutput(), Not(HasSubstr("Hello, World!")));
}

TEST(FtraceProcfsIntegrationTest, TraceMarker) {
  FtraceProcfs ftrace(kTracingPath);
  ResetFtrace(&ftrace);
  ftrace.WriteTraceMarker("Hello, World!");
  EXPECT_THAT(GetTraceOutput(), HasSubstr("Hello, World!"));
}

TEST(FtraceProcfsIntegrationTest, EnableDisableEvent) {
  FtraceProcfs ftrace(kTracingPath);
  ResetFtrace(&ftrace);
  ftrace.EnableEvent("sched", "sched_switch");
  sleep(1);
  EXPECT_THAT(GetTraceOutput(), HasSubstr("sched_switch"));

  ftrace.DisableEvent("sched", "sched_switch");
  ftrace.ClearTrace();
  sleep(1);
  EXPECT_THAT(GetTraceOutput(), Not(HasSubstr("sched_switch")));
}

TEST(FtraceProcfsIntegrationTest, EnableDisableTracing) {
  FtraceProcfs ftrace(kTracingPath);
  ResetFtrace(&ftrace);
  EXPECT_TRUE(ftrace.IsTracingEnabled());
  ftrace.WriteTraceMarker("Before");
  ftrace.DisableTracing();
  EXPECT_FALSE(ftrace.IsTracingEnabled());
  ftrace.WriteTraceMarker("During");
  ftrace.EnableTracing();
  EXPECT_TRUE(ftrace.IsTracingEnabled());
  ftrace.WriteTraceMarker("After");
  EXPECT_THAT(GetTraceOutput(), HasSubstr("Before"));
  EXPECT_THAT(GetTraceOutput(), Not(HasSubstr("During")));
  EXPECT_THAT(GetTraceOutput(), HasSubstr("After"));
}

TEST(FtraceProcfsIntegrationTest, ReadFormatFile) {
  FtraceProcfs ftrace(kTracingPath);
  std::string format = ftrace.ReadEventFormat("ftrace", "print");
  EXPECT_THAT(format, HasSubstr("name: print"));
  EXPECT_THAT(format, HasSubstr("field:char buf"));
}

TEST(FtraceProcfsIntegrationTest, ReadAvailableEvents) {
  FtraceProcfs ftrace(kTracingPath);
  std::string format = ftrace.ReadAvailableEvents();
  EXPECT_THAT(format, HasSubstr("sched:sched_switch"));
}

TEST(FtraceProcfsIntegrationTest, CanOpenTracePipeRaw) {
  FtraceProcfs ftrace(kTracingPath);
  EXPECT_TRUE(ftrace.OpenPipeForCpu(0));
}

}  // namespace perfetto