/*
 * Copyright 2017-present Facebook, Inc.
 *
 * 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 <folly/logging/xlog.h>

#include <folly/logging/LogConfigParser.h>
#include <folly/logging/LogHandler.h>
#include <folly/logging/LogMessage.h>
#include <folly/logging/LoggerDB.h>
#include <folly/logging/test/TestLogHandler.h>
#include <folly/logging/test/XlogHeader1.h>
#include <folly/logging/test/XlogHeader2.h>
#include <folly/portability/Constexpr.h>
#include <folly/portability/GMock.h>
#include <folly/portability/GTest.h>
#include <folly/test/TestUtils.h>
#include <chrono>
#include <thread>

using namespace folly;
using std::make_shared;
using testing::ElementsAre;
using testing::ElementsAreArray;
using namespace std::chrono_literals;

XLOG_SET_CATEGORY_NAME("xlog_test.main_file")

namespace {
class XlogTest : public testing::Test {
 public:
  XlogTest() {
    // Note that the XLOG* macros always use the main LoggerDB singleton.
    // There is no way to get them to use a test LoggerDB during unit tests.
    //
    // In order to ensure that changes to the LoggerDB singleton do not persist
    // across test functions we reset the configuration to a fixed state before
    // each test starts.
    auto config =
        parseLogConfig(".=WARN:default; default=stream:stream=stderr");
    LoggerDB::get().resetConfig(config);
  }
};
} // namespace

TEST_F(XlogTest, xlogName) {
  EXPECT_EQ("xlog_test.main_file", XLOG_GET_CATEGORY_NAME());
  EXPECT_EQ("xlog_test.main_file", XLOG_GET_CATEGORY()->getName());
}

TEST_F(XlogTest, xlogIf) {
  auto handler = make_shared<TestLogHandler>();
  LoggerDB::get().getCategory("xlog_test")->addHandler(handler);
  auto& messages = handler->getMessages();

  // info messages are not enabled initially.
  EXPECT_FALSE(XLOG_IS_ON(INFO));
  EXPECT_TRUE(XLOG_IS_ON(ERR));
  XLOG_IF(INFO, false, "testing 1");
  EXPECT_EQ(0, messages.size());
  messages.clear();

  XLOG_IF(INFO, true, "testing 1");
  EXPECT_EQ(0, messages.size());
  messages.clear();

  // Increase the log level, then log a message.
  LoggerDB::get().setLevel("xlog_test.main_file", LogLevel::DBG1);
  XLOG_IF(DBG1, false, "testing: ", 1, 2, 3);
  ASSERT_EQ(0, messages.size());
  messages.clear();

  XLOG_IF(DBG1, true, "testing: ", 1, 2, 3);
  ASSERT_EQ(1, messages.size());
  messages.clear();

  // more complex conditional expressions
  std::array<bool, 2> conds = {{false, true}};
  for (unsigned i = 0; i < conds.size(); i++) {
    for (unsigned j = 0; j < conds.size(); j++) {
      XLOG_IF(DBG1, conds[i] && conds[j], "testing conditional");
      EXPECT_EQ((conds[i] && conds[j]) ? 1 : 0, messages.size());
      messages.clear();

      XLOG_IF(DBG1, conds[i] || conds[j], "testing conditional");
      EXPECT_EQ((conds[i] || conds[j]) ? 1 : 0, messages.size());
      messages.clear();
    }
  }

  XLOG_IF(DBG1, 0x6 & 0x2, "More conditional 1");
  EXPECT_EQ(1, messages.size());
  messages.clear();

  XLOG_IF(DBG1, 0x6 | 0x2, "More conditional 2");
  EXPECT_EQ(1, messages.size());
  messages.clear();

  XLOG_IF(DBG1, 0x6 | 0x2 ? true : false, "More conditional 3");
  EXPECT_EQ(1, messages.size());
  messages.clear();

  XLOG_IF(DBG1, 0x6 | 0x2 ? true : false, "More conditional 3");
  EXPECT_EQ(1, messages.size());
  messages.clear();

  XLOG_IF(DBG1, 0x3 & 0x4 ? true : false, "More conditional 4");
  EXPECT_EQ(0, messages.size());
  messages.clear();

  XLOG_IF(DBG1, false ? true : false, "More conditional 5");
  EXPECT_EQ(0, messages.size());
  messages.clear();

  XLOGF_IF(DBG1, false, "number: {:>3d}; string: {}", 12, "foo");
  ASSERT_EQ(0, messages.size());
  messages.clear();
  XLOGF_IF(DBG1, true, "number: {:>3d}; string: {}", 12, "foo");
  ASSERT_EQ(1, messages.size());
  messages.clear();
}

TEST_F(XlogTest, xlog) {
  auto handler = make_shared<TestLogHandler>();
  LoggerDB::get().getCategory("xlog_test")->addHandler(handler);
  auto& messages = handler->getMessages();

  // info messages are not enabled initially.
  EXPECT_FALSE(XLOG_IS_ON(INFO));
  EXPECT_TRUE(XLOG_IS_ON(ERR));
  XLOG(INFO, "testing 1");
  EXPECT_EQ(0, messages.size());
  messages.clear();

  // Increase the log level, then log a message.
  LoggerDB::get().setLevel("xlog_test.main_file", LogLevel::DBG1);

  XLOG(DBG1, "testing: ", 1, 2, 3);
  ASSERT_EQ(1, messages.size());
  EXPECT_EQ("testing: 123", messages[0].first.getMessage());
  EXPECT_TRUE(messages[0].first.getFileName().endsWith("XlogTest.cpp"))
      << "unexpected file name: " << messages[0].first.getFileName();
  EXPECT_EQ(LogLevel::DBG1, messages[0].first.getLevel());
  EXPECT_EQ("xlog_test.main_file", messages[0].first.getCategory()->getName());
  EXPECT_EQ("xlog_test", messages[0].second->getName());
  messages.clear();

  XLOGF(WARN, "number: {:>3d}; string: {}", 12, "foo");
  ASSERT_EQ(1, messages.size());
  EXPECT_EQ("number:  12; string: foo", messages[0].first.getMessage());
  EXPECT_TRUE(messages[0].first.getFileName().endsWith("XlogTest.cpp"))
      << "unexpected file name: " << messages[0].first.getFileName();
  EXPECT_EQ(LogLevel::WARN, messages[0].first.getLevel());
  EXPECT_EQ("xlog_test.main_file", messages[0].first.getCategory()->getName());
  EXPECT_EQ("xlog_test", messages[0].second->getName());
  messages.clear();

  XLOG(DBG2, "this log check should not pass");
  EXPECT_EQ(0, messages.size());
  messages.clear();

  // Test stream arguments to XLOG()
  XLOG(INFO) << "stream test: " << 1 << ", two, " << 3;
  ASSERT_EQ(1, messages.size());
  EXPECT_EQ("stream test: 1, two, 3", messages[0].first.getMessage());
  EXPECT_TRUE(messages[0].first.getFileName().endsWith("XlogTest.cpp"))
      << "unexpected file name: " << messages[0].first.getFileName();
  EXPECT_EQ(LogLevel::INFO, messages[0].first.getLevel());
  EXPECT_EQ("xlog_test.main_file", messages[0].first.getCategory()->getName());
  EXPECT_EQ("xlog_test", messages[0].second->getName());
  messages.clear();
}

TEST_F(XlogTest, perFileCategoryHandling) {
  using namespace logging_test;

  auto handler = make_shared<TestLogHandler>();
  LoggerDB::get().getCategory("folly.logging.test")->addHandler(handler);
  LoggerDB::get().setLevel("folly.logging.test", LogLevel::DBG9);
  auto& messages = handler->getMessages();

  // Use the simple helper function in XlogHeader2
  testXlogHdrFunction("factor", 99);
  ASSERT_EQ(1, messages.size());
  EXPECT_EQ("test: factor=99", messages[0].first.getMessage());
  EXPECT_TRUE(messages[0].first.getFileName().endsWith("XlogHeader2.h"))
      << "unexpected file name: " << messages[0].first.getFileName();
  EXPECT_EQ(LogLevel::DBG3, messages[0].first.getLevel());
  EXPECT_EQ(
      "folly.logging.test.XlogHeader2.h",
      messages[0].first.getCategory()->getName());
  EXPECT_EQ("folly.logging.test", messages[0].second->getName());
  messages.clear();

  // Test the loop function from XlogHeader1
  testXlogHdrLoop(3, "hello world");
  ASSERT_EQ(5, messages.size());
  EXPECT_EQ("starting: hello world", messages[0].first.getMessage());
  EXPECT_TRUE(messages[0].first.getFileName().endsWith("XlogHeader1.h"))
      << "unexpected file name: " << messages[0].first.getFileName();
  EXPECT_EQ(LogLevel::DBG1, messages[0].first.getLevel());
  EXPECT_EQ(
      "folly.logging.test.XlogHeader1.h",
      messages[0].first.getCategory()->getName());
  EXPECT_EQ("folly.logging.test", messages[0].second->getName());

  EXPECT_EQ("test: hello world", messages[1].first.getMessage());
  EXPECT_EQ("test: hello world", messages[2].first.getMessage());
  EXPECT_EQ("test: hello world", messages[3].first.getMessage());
  EXPECT_EQ("finished: hello world", messages[4].first.getMessage());
  EXPECT_EQ(LogLevel::DBG5, messages[1].first.getLevel());
  EXPECT_EQ(LogLevel::DBG5, messages[2].first.getLevel());
  EXPECT_EQ(LogLevel::DBG5, messages[3].first.getLevel());
  EXPECT_EQ(LogLevel::DBG1, messages[4].first.getLevel());
  messages.clear();

  // Reduce the log level so that the messages inside the loop
  // should not be logged.
  LoggerDB::get().setLevel("folly.logging.test", LogLevel::DBG2);
  testXlogHdrLoop(300, "hello world");
  ASSERT_EQ(2, messages.size());
  EXPECT_EQ("starting: hello world", messages[0].first.getMessage());
  EXPECT_EQ("finished: hello world", messages[1].first.getMessage());
  messages.clear();

  // Call the helpers function in XlogFile1.cpp and XlogFile2.cpp and makes
  // sure their categories are reported correctly.
  testXlogFile1Dbg1("foobar 1234");
  ASSERT_EQ(1, messages.size());
  EXPECT_EQ("file1: foobar 1234", messages[0].first.getMessage());
  EXPECT_EQ(
      "folly.logging.test.XlogFile1.cpp",
      messages[0].first.getCategory()->getName());
  messages.clear();

  testXlogFile2Dbg1("hello world");
  ASSERT_EQ(1, messages.size());
  EXPECT_EQ("file2: hello world", messages[0].first.getMessage());
  EXPECT_EQ(
      "folly.logging.test.XlogFile2.cpp",
      messages[0].first.getCategory()->getName());
  messages.clear();

  // Adjust the log level and make sure the changes take effect for the .cpp
  // file categories
  LoggerDB::get().setLevel("folly.logging.test", LogLevel::INFO);
  testXlogFile1Dbg1("log check should fail now");
  testXlogFile2Dbg1("this should fail too");
  EXPECT_EQ(0, messages.size());
  messages.clear();

  LoggerDB::get().setLevel("folly.logging.test.XlogFile1", LogLevel::DBG1);
  testXlogFile1Dbg1("this log check should pass now");
  testXlogFile2Dbg1("but this one should still fail");
  ASSERT_EQ(1, messages.size());
  EXPECT_EQ(
      "file1: this log check should pass now", messages[0].first.getMessage());
  EXPECT_EQ(
      "folly.logging.test.XlogFile1.cpp",
      messages[0].first.getCategory()->getName());
  messages.clear();
}

TEST_F(XlogTest, rateLimiting) {
  auto handler = make_shared<TestLogHandler>();
  LoggerDB::get().getCategory("xlog_test")->addHandler(handler);
  LoggerDB::get().setLevel("xlog_test", LogLevel::DBG1);

  // Test XLOG_EVERY_N
  for (size_t n = 0; n < 50; ++n) {
    XLOG_EVERY_N(DBG1, 7, "msg ", n);
  }
  EXPECT_THAT(
      handler->getMessageValues(),
      ElementsAre(
          "msg 0",
          "msg 7",
          "msg 14",
          "msg 21",
          "msg 28",
          "msg 35",
          "msg 42",
          "msg 49"));
  handler->clearMessages();

  // Test XLOG_EVERY_MS and XLOG_N_PER_MS
  // We test these together to minimize the number of sleep operations.
  for (size_t n = 0; n < 10; ++n) {
    // Integer arguments are treated as millisecond
    XLOG_EVERY_MS(DBG1, 100, "int arg ", n);
    // Other duration arguments also work, as long as they are
    // coarser than milliseconds
    XLOG_EVERY_MS(DBG1, 100ms, "ms arg ", n);
    XLOG_EVERY_MS(DBG1, 1s, "s arg ", n);

    // Use XLOG_N_PER_MS() too
    XLOG_N_PER_MS(DBG1, 2, 100, "2x int arg ", n);
    XLOG_N_PER_MS(DBG1, 1, 100ms, "1x ms arg ", n);
    XLOG_N_PER_MS(DBG1, 3, 1s, "3x s arg ", n);

    // Sleep for 100ms between iterations 5 and 6
    if (n == 5) {
      /* sleep override */ std::this_thread::sleep_for(110ms);
    }
  }
  EXPECT_THAT(
      handler->getMessageValues(),
      ElementsAreArray({
          "int arg 0",
          "ms arg 0",
          "s arg 0",
          "2x int arg 0",
          "1x ms arg 0",
          "3x s arg 0",
          "2x int arg 1",
          "3x s arg 1",
          "3x s arg 2",
          "int arg 6",
          "ms arg 6",
          "2x int arg 6",
          "1x ms arg 6",
          "2x int arg 7",
      }));
  handler->clearMessages();
}

TEST_F(XlogTest, getXlogCategoryName) {
  EXPECT_EQ("foo.cpp", getXlogCategoryNameForFile("foo.cpp"));
  EXPECT_EQ("foo.h", getXlogCategoryNameForFile("foo.h"));

  // Directory separators should be translated to "." during LogName
  // canonicalization
  EXPECT_EQ("src/test/foo.cpp", getXlogCategoryNameForFile("src/test/foo.cpp"));
  EXPECT_EQ(
      "src.test.foo.cpp",
      LogName::canonicalize(getXlogCategoryNameForFile("src/test/foo.cpp")));
  EXPECT_EQ("src/test/foo.h", getXlogCategoryNameForFile("src/test/foo.h"));
  EXPECT_EQ(
      "src.test.foo.h",
      LogName::canonicalize(getXlogCategoryNameForFile("src/test/foo.h")));

  // Buck's directory prefixes for generated source files
  // should be stripped out
  EXPECT_EQ(
      "myproject.generated_header.h",
      LogName::canonicalize(getXlogCategoryNameForFile(
          "buck-out/gen/myproject#headers/myproject/generated_header.h")));
  EXPECT_EQ(
      "foo.bar.test.h",
      LogName::canonicalize(getXlogCategoryNameForFile(
          "buck-out/gen/foo/bar#header-map,headers/foo/bar/test.h")));
}

TEST(Xlog, xlogStripFilename) {
  EXPECT_STREQ("c/d.txt", xlogStripFilename("/a/b/c/d.txt", "/a/b"));
  EXPECT_STREQ("c/d.txt", xlogStripFilename("/a/b/c/d.txt", "/a/b/"));
  EXPECT_STREQ(
      "ships/cruiser.cpp",
      xlogStripFilename(
          "/home/johndoe/src/spacesim/ships/cruiser.cpp",
          "/home/johndoe/src/spacesim"));
  EXPECT_STREQ(
      "ships/cruiser.cpp",
      xlogStripFilename("src/spacesim/ships/cruiser.cpp", "src/spacesim"));

  // Test with multiple prefixes
  EXPECT_STREQ("c/d.txt", xlogStripFilename("/a/b/c/d.txt", "/x/y:1/2:/a/b"));
  EXPECT_STREQ("c/d.txt", xlogStripFilename("/a/b/c/d.txt", "/x/y:/a/b:/1/2"));

  EXPECT_STREQ(
      "/foobar/src/test.cpp", xlogStripFilename("/foobar/src/test.cpp", "/foo"))
      << "should only strip full directory name matches";
  EXPECT_STREQ(
      "src/test.cpp",
      xlogStripFilename("/foobar/src/test.cpp", "/foo:/foobar"));

  EXPECT_STREQ(
      "/a/b/c/d.txt", xlogStripFilename("/a/b/c/d.txt", "/a/b/c/d.txt"))
      << "should not strip if the result will be empty";
  EXPECT_STREQ("c/d.txt", xlogStripFilename("/a/b/c/d.txt", ":/x/y::/a/b:"))
      << "empty prefixes in the prefix list should be ignored";

  EXPECT_STREQ("d.txt", xlogStripFilename("/a/b/c/d.txt", "/a/b/c:/a"))
      << "only the first prefix match should be honored";
  EXPECT_STREQ("b/c/d.txt", xlogStripFilename("/a/b/c/d.txt", "/a:/a/b/c"))
      << "only the first prefix match should be honored";

  // xlogStripFilename() should ideally be a purely compile-time evaluation.
  // Use a static_assert() to ensure that it can be evaluated at compile time.
  // We use EXPECT_STREQ() checks above for most of the testing since it
  // produces nicer messages on failure.
  static_assert(
      constexpr_strcmp(
          xlogStripFilename("/my/project/src/test.cpp", "/my/project"),
          "src/test.cpp") == 0,
      "incorrect xlogStripFilename() behavior");
}