// Copyright The OpenTelemetry Authors
// SPDX-License-Identifier: Apache-2.0

#include <gtest/gtest.h>
#include <stdint.h>
#include <array>
#include <chrono>
#include <initializer_list>
#include <iostream>
#include <sstream>
#include <string>
#include <utility>

#include "opentelemetry/common/attribute_value.h"
#include "opentelemetry/common/key_value_iterable_view.h"
#include "opentelemetry/common/timestamp.h"
#include "opentelemetry/exporters/ostream/span_exporter.h"
#include "opentelemetry/nostd/shared_ptr.h"
#include "opentelemetry/nostd/span.h"
#include "opentelemetry/nostd/string_view.h"
#include "opentelemetry/sdk/resource/resource.h"
#include "opentelemetry/sdk/trace/exporter.h"
#include "opentelemetry/sdk/trace/processor.h"
#include "opentelemetry/sdk/trace/recordable.h"
#include "opentelemetry/sdk/trace/simple_processor.h"
#include "opentelemetry/trace/span_context.h"
#include "opentelemetry/trace/span_id.h"
#include "opentelemetry/trace/span_metadata.h"
#include "opentelemetry/trace/trace_flags.h"
#include "opentelemetry/trace/trace_id.h"
#include "opentelemetry/trace/trace_state.h"
#include "ostream_capture.h"

using namespace opentelemetry::exporter::ostream::test;

namespace trace         = opentelemetry::trace;
namespace common        = opentelemetry::common;
namespace nostd         = opentelemetry::nostd;
namespace trace_sdk     = opentelemetry::sdk::trace;
namespace resource      = opentelemetry::sdk::resource;
namespace exportertrace = opentelemetry::exporter::trace;

using Attributes = std::initializer_list<std::pair<nostd::string_view, common::AttributeValue>>;

class TestResource : public resource::Resource
{
public:
  TestResource(const resource::ResourceAttributes &attributes = resource::ResourceAttributes())
      : resource::Resource(attributes)
  {}
};

// Testing Shutdown functionality of OStreamSpanExporter, should expect no data to be sent to Stream
TEST(OStreamSpanExporter, Shutdown)
{
  auto exporter  = std::unique_ptr<trace_sdk::SpanExporter>(new exportertrace::OStreamSpanExporter);
  auto processor = std::shared_ptr<trace_sdk::SpanProcessor>(
      new trace_sdk::SimpleSpanProcessor(std::move(exporter)));

  auto recordable = processor->MakeRecordable();
  recordable->SetName("Test Span");

  // Capture the output of cerr
  const auto captured = WithOStreamCapture(std::cerr, [&]() {
    EXPECT_TRUE(processor->Shutdown());
    processor->OnEnd(std::move(recordable));
  });
  std::string err_message =
      "[Ostream Trace Exporter] Exporting 1 span(s) failed, exporter is shutdown";
  EXPECT_TRUE(captured.find(err_message) != std::string::npos);
}

constexpr const char *kDefaultSpanPrinted =
    "{\n"
    "  name          : \n"
    "  trace_id      : 00000000000000000000000000000000\n"
    "  span_id       : 0000000000000000\n"
    "  tracestate    : \n"
    "  parent_span_id: 0000000000000000\n"
    "  start         : 0\n"
    "  duration      : 0\n"
    "  description   : \n"
    "  span kind     : Internal\n"
    "  status        : Unset\n"
    "  attributes    : \n"
    "  events        : \n"
    "  links         : \n"
    "  resources     : \n"
    "  instr-lib     : unknown_service\n"
    "}\n";

// Testing what a default span that is not changed will print out, either all 0's or empty values
TEST(OStreamSpanExporter, PrintDefaultSpan)
{
  std::stringstream output;
  auto exporter =
      std::unique_ptr<trace_sdk::SpanExporter>(new exportertrace::OStreamSpanExporter(output));
  auto processor = std::shared_ptr<trace_sdk::SpanProcessor>(
      new trace_sdk::SimpleSpanProcessor(std::move(exporter)));

  auto recordable = processor->MakeRecordable();

  processor->OnEnd(std::move(recordable));

  EXPECT_EQ(output.str(), kDefaultSpanPrinted);
}

TEST(OStreamSpanExporter, PrintSpanWithBasicFields)
{
  std::stringstream output;
  auto exporter =
      std::unique_ptr<trace_sdk::SpanExporter>(new exportertrace::OStreamSpanExporter(output));
  auto processor = std::shared_ptr<trace_sdk::SpanProcessor>(
      new trace_sdk::SimpleSpanProcessor(std::move(exporter)));

  auto recordable = processor->MakeRecordable();

  constexpr uint8_t trace_id_buf[]       = {1, 2, 3, 4, 5, 6, 7, 8, 1, 2, 3, 4, 5, 6, 7, 8};
  constexpr uint8_t span_id_buf[]        = {1, 2, 3, 4, 5, 6, 7, 8};
  constexpr uint8_t parent_span_id_buf[] = {8, 7, 6, 5, 4, 3, 2, 1};
  trace::TraceId trace_id{trace_id_buf};
  trace::SpanId span_id{span_id_buf};
  trace::SpanId parent_span_id{parent_span_id_buf};
  const auto trace_state = trace::TraceState::GetDefault()->Set("state1", "value");
  const trace::SpanContext span_context{
      trace_id, span_id, trace::TraceFlags{trace::TraceFlags::kIsSampled}, true, trace_state};

  recordable->SetIdentity(span_context, parent_span_id);
  recordable->SetName("Test Span");
  common::SystemTimestamp now(std::chrono::system_clock::now());
  recordable->SetStartTime(now);
  recordable->SetDuration(std::chrono::nanoseconds(100));
  recordable->SetStatus(trace::StatusCode::kOk, "Test Description");
  recordable->SetSpanKind(trace::SpanKind::kClient);

  TestResource resource1(resource::ResourceAttributes({{"key1", "val1"}}));
  recordable->SetResource(resource1);

  processor->OnEnd(std::move(recordable));

  std::string start = std::to_string(now.time_since_epoch().count());

  std::string expectedOutput =
      "{\n"
      "  name          : Test Span\n"
      "  trace_id      : 01020304050607080102030405060708\n"
      "  span_id       : 0102030405060708\n"
      "  tracestate    : state1=value\n"
      "  parent_span_id: 0807060504030201\n"
      "  start         : " +
      start +
      "\n"
      "  duration      : 100\n"
      "  description   : Test Description\n"
      "  span kind     : Client\n"
      "  status        : Ok\n"
      "  attributes    : \n"
      "  events        : \n"
      "  links         : \n"
      "  resources     : \n"
      "\tkey1: val1\n"
      "  instr-lib     : unknown_service\n"
      "}\n";
  EXPECT_EQ(output.str(), expectedOutput);
}

TEST(OStreamSpanExporter, PrintSpanWithAttribute)
{
  std::stringstream output;
  auto exporter =
      std::unique_ptr<trace_sdk::SpanExporter>(new exportertrace::OStreamSpanExporter(output));
  auto processor = std::shared_ptr<trace_sdk::SpanProcessor>(
      new trace_sdk::SimpleSpanProcessor(std::move(exporter)));

  auto recordable = processor->MakeRecordable();

  recordable->SetAttribute("attr1", "string");

  processor->OnEnd(std::move(recordable));

  std::string expectedOutput =
      "{\n"
      "  name          : \n"
      "  trace_id      : 00000000000000000000000000000000\n"
      "  span_id       : 0000000000000000\n"
      "  tracestate    : \n"
      "  parent_span_id: 0000000000000000\n"
      "  start         : 0\n"
      "  duration      : 0\n"
      "  description   : \n"
      "  span kind     : Internal\n"
      "  status        : Unset\n"
      "  attributes    : \n"
      "\tattr1: string\n"
      "  events        : \n"
      "  links         : \n"
      "  resources     : \n"
      "  instr-lib     : unknown_service\n"
      "}\n";
  EXPECT_EQ(output.str(), expectedOutput);
}

TEST(OStreamSpanExporter, PrintSpanWithArrayAttribute)
{
  std::stringstream output;
  auto exporter =
      std::unique_ptr<trace_sdk::SpanExporter>(new exportertrace::OStreamSpanExporter(output));
  auto processor = std::shared_ptr<trace_sdk::SpanProcessor>(
      new trace_sdk::SimpleSpanProcessor(std::move(exporter)));

  auto recordable = processor->MakeRecordable();

  std::array<int, 3> array1 = {1, 2, 3};
  nostd::span<int> span1{array1.data(), array1.size()};
  recordable->SetAttribute("array1", span1);

  processor->OnEnd(std::move(recordable));

  std::string expectedOutput =
      "{\n"
      "  name          : \n"
      "  trace_id      : 00000000000000000000000000000000\n"
      "  span_id       : 0000000000000000\n"
      "  tracestate    : \n"
      "  parent_span_id: 0000000000000000\n"
      "  start         : 0\n"
      "  duration      : 0\n"
      "  description   : \n"
      "  span kind     : Internal\n"
      "  status        : Unset\n"
      "  attributes    : \n"
      "\tarray1: [1,2,3]\n"
      "  events        : \n"
      "  links         : \n"
      "  resources     : \n"
      "  instr-lib     : unknown_service\n"
      "}\n";
  EXPECT_EQ(output.str(), expectedOutput);
}

TEST(OStreamSpanExporter, PrintSpanWithEvents)
{
  std::stringstream output;
  auto exporter =
      std::unique_ptr<trace_sdk::SpanExporter>(new exportertrace::OStreamSpanExporter(output));
  auto processor = std::shared_ptr<trace_sdk::SpanProcessor>(
      new trace_sdk::SimpleSpanProcessor(std::move(exporter)));

  auto recordable = processor->MakeRecordable();
  common::SystemTimestamp now(std::chrono::system_clock::now());
  common::SystemTimestamp next(std::chrono::system_clock::now() + std::chrono::seconds(1));

  std::string now_str  = std::to_string(now.time_since_epoch().count());
  std::string next_str = std::to_string(next.time_since_epoch().count());

  recordable->AddEvent("hello", now);
  recordable->AddEvent("world", next,
                       common::KeyValueIterableView<Attributes>({{"attr1", "string"}}));

  processor->OnEnd(std::move(recordable));

  std::string expectedOutput =
      "{\n"
      "  name          : \n"
      "  trace_id      : 00000000000000000000000000000000\n"
      "  span_id       : 0000000000000000\n"
      "  tracestate    : \n"
      "  parent_span_id: 0000000000000000\n"
      "  start         : 0\n"
      "  duration      : 0\n"
      "  description   : \n"
      "  span kind     : Internal\n"
      "  status        : Unset\n"
      "  attributes    : \n"
      "  events        : \n"
      "\t{\n"
      "\t  name          : hello\n"
      "\t  timestamp     : " +
      now_str +
      "\n"
      "\t  attributes    : \n"
      "\t}\n"
      "\t{\n"
      "\t  name          : world\n"
      "\t  timestamp     : " +
      next_str +
      "\n"
      "\t  attributes    : \n"
      "\t\tattr1: string\n"
      "\t}\n"
      "  links         : \n"
      "  resources     : \n"
      "  instr-lib     : unknown_service\n"
      "}\n";
  EXPECT_EQ(output.str(), expectedOutput);
}

TEST(OStreamSpanExporter, PrintSpanWithLinks)
{
  std::stringstream output;
  auto exporter =
      std::unique_ptr<trace_sdk::SpanExporter>(new exportertrace::OStreamSpanExporter(output));
  auto processor = std::shared_ptr<trace_sdk::SpanProcessor>(
      new trace_sdk::SimpleSpanProcessor(std::move(exporter)));

  auto recordable = processor->MakeRecordable();

  // produce valid SpanContext with pseudo span and trace Id.
  uint8_t span_id_buf[trace::SpanId::kSize] = {
      1,
  };
  trace::SpanId span_id{span_id_buf};
  uint8_t trace_id_buf[trace::TraceId::kSize] = {
      2,
  };
  trace::TraceId trace_id{trace_id_buf};
  const auto span_context =
      trace::SpanContext(trace_id, span_id, trace::TraceFlags{trace::TraceFlags::kIsSampled}, true);

  // and another to check preserving order.
  uint8_t span_id_buf2[trace::SpanId::kSize] = {
      3,
  };
  trace::SpanId span_id2{span_id_buf2};
  const auto span_context2 =
      trace::SpanContext(trace_id, span_id2, trace::TraceFlags{trace::TraceFlags::kIsSampled}, true,
                         trace::TraceState::FromHeader("state1=value"));

  recordable->AddLink(span_context);
  recordable->AddLink(span_context2,
                      common::KeyValueIterableView<Attributes>({{"attr1", "string"}}));

  processor->OnEnd(std::move(recordable));

  std::string expectedOutput =
      "{\n"
      "  name          : \n"
      "  trace_id      : 00000000000000000000000000000000\n"
      "  span_id       : 0000000000000000\n"
      "  tracestate    : \n"
      "  parent_span_id: 0000000000000000\n"
      "  start         : 0\n"
      "  duration      : 0\n"
      "  description   : \n"
      "  span kind     : Internal\n"
      "  status        : Unset\n"
      "  attributes    : \n"
      "  events        : \n"
      "  links         : \n"
      "\t{\n"
      "\t  trace_id      : 02000000000000000000000000000000\n"
      "\t  span_id       : 0100000000000000\n"
      "\t  tracestate    : \n"
      "\t  attributes    : \n"
      "\t}\n"
      "\t{\n"
      "\t  trace_id      : 02000000000000000000000000000000\n"
      "\t  span_id       : 0300000000000000\n"
      "\t  tracestate    : state1=value\n"
      "\t  attributes    : \n"
      "\t\tattr1: string\n"
      "\t}\n"
      "  resources     : \n"
      "  instr-lib     : unknown_service\n"
      "}\n";
  EXPECT_EQ(output.str(), expectedOutput);
}

// Test with the three common ostreams, tests are more of a sanity check and usage examples.
TEST(OStreamSpanExporter, PrintSpanToCout)
{
  auto exporter  = std::unique_ptr<trace_sdk::SpanExporter>(new exportertrace::OStreamSpanExporter);
  auto processor = std::shared_ptr<trace_sdk::SpanProcessor>(
      new trace_sdk::SimpleSpanProcessor(std::move(exporter)));

  auto recordable = processor->MakeRecordable();

  const auto captured =
      WithOStreamCapture(std::cout, [&]() { processor->OnEnd(std::move(recordable)); });

  EXPECT_EQ(captured, kDefaultSpanPrinted);
}

TEST(OStreamSpanExporter, PrintSpanToCerr)
{
  auto exporter =
      std::unique_ptr<trace_sdk::SpanExporter>(new exportertrace::OStreamSpanExporter(std::cerr));
  auto processor = std::shared_ptr<trace_sdk::SpanProcessor>(
      new trace_sdk::SimpleSpanProcessor(std::move(exporter)));

  auto recordable = processor->MakeRecordable();

  const auto captured =
      WithOStreamCapture(std::cerr, [&]() { processor->OnEnd(std::move(recordable)); });

  EXPECT_EQ(captured, kDefaultSpanPrinted);
}

TEST(OStreamSpanExporter, PrintSpanToClog)
{
  auto exporter =
      std::unique_ptr<trace_sdk::SpanExporter>(new exportertrace::OStreamSpanExporter(std::clog));
  auto processor = std::shared_ptr<trace_sdk::SpanProcessor>(
      new trace_sdk::SimpleSpanProcessor(std::move(exporter)));

  auto recordable = processor->MakeRecordable();

  const auto captured =
      WithOStreamCapture(std::clog, [&]() { processor->OnEnd(std::move(recordable)); });

  EXPECT_EQ(captured, kDefaultSpanPrinted);
}