// Copyright 2020 Google LLC
//
// 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
//
//     https://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 <unistd.h>

#include <fstream>
#include <iostream>
#include <memory>
#include <streambuf>
#include <string>

#include "gtest/gtest.h"
#include "contrib/jsonnet/jsonnet_base_sandbox.h"
#include "sandboxed_api/util/path.h"
#include "sandboxed_api/util/status_matchers.h"

namespace {

class JsonnetTest : public ::testing::Test {
 protected:
  enum Evaluation { kBase, kMultipleFiles, kYamlStream };

  void SetUp() override {
    // Get paths to where input and output is stored.
    char buffer[256];
    int error = readlink("/proc/self/exe", buffer, 256);
    ASSERT_GE(error, 0);

    std::pair<absl::string_view, absl::string_view> parts_of_path =
        sapi::file::SplitPath(buffer);
    absl::string_view binary_path = parts_of_path.first;

    std::string input_path =
        sapi::file::JoinPath(binary_path, "tests_input", "dummy_input");
    std::string output_path =
        sapi::file::JoinPath(binary_path, "tests_output", "dummy_input");

    // Set up sandbox and api.
    sandbox_ = std::make_unique<JsonnetBaseSandbox>(input_path, output_path);
    ASSERT_THAT(sandbox_->Init(), sapi::IsOk());
    api_ = std::make_unique<JsonnetApi>(sandbox_.get());

    // Initialize library's main structure.
    SAPI_ASSERT_OK_AND_ASSIGN(JsonnetVm * vm_ptr, api_->c_jsonnet_make());
    vm_ = std::make_unique<sapi::v::RemotePtr>(vm_ptr);
  }

  void TearDown() override {
    if (jsonnet_vm_was_used_) {
      SAPI_ASSERT_OK_AND_ASSIGN(
          char* result, api_->c_jsonnet_realloc(vm_.get(), output_.get(), 0));
    }
    ASSERT_THAT(api_->c_jsonnet_destroy(vm_.get()), sapi::IsOk());
    if (input_was_read_) {
      ASSERT_THAT(api_->c_free_input(input_.get()), sapi::IsOk());
    }
  }

  // Reads input from file.
  void ReadInput(const char* filename);

  // Evaluates jsonnet code.
  void EvaluateJsonnetCode(Evaluation type, bool expected_correct);

  // Writes output to file.
  void WriteOutput(const char* filename_or_directory, Evaluation type);

  // Reads the output written to a file by library function / expected output.
  std::string ReadOutput(const char* filename);

  std::unique_ptr<JsonnetBaseSandbox> sandbox_;
  std::unique_ptr<JsonnetApi> api_;
  std::unique_ptr<sapi::v::RemotePtr> input_;
  std::unique_ptr<sapi::v::RemotePtr> output_;
  std::unique_ptr<sapi::v::RemotePtr> vm_;

  std::string input_filename_in_sandboxee_;
  bool jsonnet_vm_was_used_ = false;
  bool input_was_read_ = false;
};

void JsonnetTest::ReadInput(const char* filename) {
  std::string in_file_in_sandboxee(std::string("/input/") +
                                   basename(const_cast<char*>(&filename[0])));
  input_filename_in_sandboxee_ = std::move(in_file_in_sandboxee);
  sapi::v::ConstCStr in_file_var(input_filename_in_sandboxee_.c_str());

  SAPI_ASSERT_OK_AND_ASSIGN(char* input_ptr,
                            api_->c_read_input(0, in_file_var.PtrBefore()));
  input_ = std::make_unique<sapi::v::RemotePtr>(input_ptr);

  input_was_read_ = true;
}

void JsonnetTest::EvaluateJsonnetCode(Evaluation type, bool expected_correct) {
  sapi::v::ConstCStr in_file_var(input_filename_in_sandboxee_.c_str());
  sapi::v::Int error;
  char* output_ptr;

  switch (type) {
    case kBase: {
      SAPI_ASSERT_OK_AND_ASSIGN(
          output_ptr,
          api_->c_jsonnet_evaluate_snippet(vm_.get(), in_file_var.PtrBefore(),
                                           input_.get(), error.PtrAfter()));
      break;
    }

    case kMultipleFiles: {
      SAPI_ASSERT_OK_AND_ASSIGN(
          output_ptr, api_->c_jsonnet_evaluate_snippet_multi(
                          vm_.get(), in_file_var.PtrBefore(), input_.get(),
                          error.PtrAfter()));
      break;
    }

    case kYamlStream: {
      SAPI_ASSERT_OK_AND_ASSIGN(
          output_ptr, api_->c_jsonnet_evaluate_snippet_stream(
                          vm_.get(), in_file_var.PtrBefore(), input_.get(),
                          error.PtrAfter()));
      break;
    }
  }

  if (expected_correct) {
    ASSERT_THAT(error.GetValue(), testing::Eq(0));
  } else {
    ASSERT_THAT(error.GetValue(), testing::Eq(1));
  }

  output_ = std::make_unique<sapi::v::RemotePtr>(output_ptr);

  jsonnet_vm_was_used_ = true;
}

void JsonnetTest::WriteOutput(const char* filename_or_directory,
                              Evaluation type) {
  bool success;

  switch (type) {
    case kBase: {
      std::string out_file_in_sandboxee(
          std::string("/output/") +
          basename(const_cast<char*>(&filename_or_directory[0])));
      sapi::v::ConstCStr out_file_var(out_file_in_sandboxee.c_str());

      SAPI_ASSERT_OK_AND_ASSIGN(
          success,
          api_->c_write_output_file(output_.get(), out_file_var.PtrBefore()));
      break;
    }
    case kMultipleFiles: {
      std::string out_file_in_sandboxee(std::string("/output/"));
      sapi::v::ConstCStr out_file_var(out_file_in_sandboxee.c_str());
      SAPI_ASSERT_OK_AND_ASSIGN(
          success, api_->c_write_multi_output_files(
                       output_.get(), out_file_var.PtrBefore(), false));
      break;
    }

    case kYamlStream: {
      std::string out_file_in_sandboxee(
          std::string("/output/") +
          basename(const_cast<char*>(&filename_or_directory[0])));
      sapi::v::ConstCStr out_file_var(out_file_in_sandboxee.c_str());
      SAPI_ASSERT_OK_AND_ASSIGN(
          success,
          api_->c_write_output_stream(output_.get(), out_file_var.PtrBefore()));
      break;
    }
  }

  ASSERT_THAT(success, testing::Eq(true));
}

std::string JsonnetTest::ReadOutput(const char* filename) {
  std::ifstream input_stream(filename);
  std::string contents((std::istreambuf_iterator<char>(input_stream)),
                       std::istreambuf_iterator<char>());
  return contents;
}

// One file evaluation to one file
TEST_F(JsonnetTest, OneFileNoDependencies) {
  constexpr char kInputFile[] = "arith.jsonnet";
  constexpr char kOutputFile[] = "arith_output";
  constexpr char kOutputToRead[] = "tests_output/arith_output";
  constexpr char kOutputToExpect[] = "tests_expected_output/arith.golden";

  ReadInput(kInputFile);
  EvaluateJsonnetCode(kBase, true);
  WriteOutput(kOutputFile, kBase);

  std::string produced_output = ReadOutput(kOutputToRead);
  std::string expected_output = ReadOutput(kOutputToExpect);

  ASSERT_STREQ(produced_output.c_str(), expected_output.c_str());
}

// One file evaluating to one file, dependent on some other files
TEST_F(JsonnetTest, OneFileSomeDependencies) {
  constexpr char kInputFile[] = "negroni.jsonnet";
  constexpr char kOutputFile[] = "negroni_output";
  constexpr char kOutputToRead[] = "tests_output/negroni_output";
  constexpr char kOutputToExpect[] = "tests_expected_output/negroni.golden";

  ReadInput(kInputFile);
  EvaluateJsonnetCode(kBase, true);
  WriteOutput(kOutputFile, kBase);

  const std::string produced_output = ReadOutput(kOutputToRead);
  const std::string expected_output = ReadOutput(kOutputToExpect);

  ASSERT_STREQ(produced_output.c_str(), expected_output.c_str());
}

// One file evaluating to two files
TEST_F(JsonnetTest, MultipleFiles) {
  constexpr char kInputFile[] = "multiple_files_example.jsonnet";
  constexpr char kOutputFile[] = "";
  constexpr char kOutputToRead1[] = "tests_output/first_file.json";
  constexpr char kOutputToRead2[] = "tests_output/second_file.json";
  constexpr char kOutputToExpect1[] = "tests_expected_output/first_file.json";
  constexpr char kOutputToExpect2[] = "tests_expected_output/second_file.json";

  ReadInput(kInputFile);
  EvaluateJsonnetCode(kMultipleFiles, true);
  WriteOutput(kOutputFile, kMultipleFiles);

  const std::string produced_output_1 = ReadOutput(kOutputToRead1);
  const std::string produced_output_2 = ReadOutput(kOutputToRead2);
  const std::string expected_output_1 = ReadOutput(kOutputToExpect1);
  const std::string expected_output_2 = ReadOutput(kOutputToExpect2);

  ASSERT_STREQ(produced_output_1.c_str(), expected_output_1.c_str());
  ASSERT_STREQ(produced_output_2.c_str(), expected_output_2.c_str());
}

// One file evaluating to yaml stream format
TEST_F(JsonnetTest, YamlStream) {
  constexpr char kInputFile[] = "yaml_stream_example.jsonnet";
  constexpr char kOutputFile[] = "yaml_stream_example.yaml";
  constexpr char kOutputToRead[] = "tests_output/yaml_stream_example.yaml";
  constexpr char kOutputToExpect[] =
      "tests_expected_output/yaml_stream_example.yaml";

  ReadInput(kInputFile);
  EvaluateJsonnetCode(kYamlStream, true);
  WriteOutput(kOutputFile, kYamlStream);

  const std::string produced_output = ReadOutput(kOutputToRead);
  const std::string expected_output = ReadOutput(kOutputToExpect);

  ASSERT_STREQ(produced_output.c_str(), expected_output.c_str());
}

// One file depended on some other files not accessible by the sandbox
TEST_F(JsonnetTest, BadEvaluation) {
  constexpr char kInputFile[] = "imports.jsonnet";

  ReadInput(kInputFile);
  EvaluateJsonnetCode(kBase, false);
}

}  // namespace