#include <etl/crc32.h>

#include <catch2/catch_test_macros.hpp>
#include <filesystem>
#include <fstream>
#include <random>

#include "fsfw/serialize/SerializeIF.h"
#include "fsfw_hal/host/HostFilesystem.h"

using namespace std;

TEST_CASE("Host Filesystem", "[hal][host]") {
  namespace fs = filesystem;
  auto hostFs = HostFilesystem();
  auto tmpDir = fs::temp_directory_path();
  fs::path file0 = tmpDir / "hello.txt";
  fs::path file1 = tmpDir / "hello2.txt";
  fs::path dir0 = tmpDir / "test_dir";
  fs::path fileInDir0 = dir0 / "hello.txt";
  fs::path dirWithParent = dir0 / "test_dir";

  REQUIRE_NOTHROW(fs::remove(file0));
  REQUIRE_NOTHROW(fs::remove(file1));
  REQUIRE_NOTHROW(fs::remove_all(dir0));

  SECTION("Create file") {
    REQUIRE(hostFs.createFile(file0.c_str()) == returnvalue::OK);
    CHECK(fs::is_regular_file(file0));
    REQUIRE(fs::exists(file0));
  }

  SECTION("Remove File") {
    REQUIRE(hostFs.createFile(file0.c_str()) == returnvalue::OK);
    CHECK(fs::is_regular_file(file0));
    REQUIRE(fs::exists(file0));
    REQUIRE(hostFs.removeFile(file0.c_str()) == returnvalue::OK);
    REQUIRE(not fs::exists(file0));
  }

  SECTION("Create Directory") {
    REQUIRE(hostFs.createDirectory(dir0.c_str()) == returnvalue::OK);
    CHECK(fs::is_directory(dir0));
    REQUIRE(fs::exists(dir0));
  }

  SECTION("Remove Directory") {
    REQUIRE(hostFs.createDirectory(dir0.c_str()) == returnvalue::OK);
    REQUIRE(fs::exists(dir0));
    REQUIRE(hostFs.removeDirectory(dir0.c_str(), false, nullptr) == returnvalue::OK);
    REQUIRE(not fs::exists(dir0));
  }

  SECTION("Rename File") {
    REQUIRE(hostFs.createFile(file0.c_str()) == returnvalue::OK);
    CHECK(fs::is_regular_file(file0));
    REQUIRE(fs::exists(file0));
    REQUIRE(hostFs.rename(file0.c_str(), file1.c_str()) == returnvalue::OK);
  }

  SECTION("Write To File") {
    std::string data = "hello world!";
    REQUIRE(hostFs.createFile(file0.c_str()) == returnvalue::OK);
    CHECK(fs::is_regular_file(file0));
    REQUIRE(fs::exists(file0));
    CHECK(hostFs.writeToFile(file0.c_str(), 0, reinterpret_cast<const uint8_t*>(data.c_str()),
                             data.size()) == returnvalue::OK);
    CHECK(fs::file_size(file0) == data.size());
    ifstream ifile(file0);
    std::array<char, 524> readBuf{};
    ifile.read(readBuf.data(), sizeof(readBuf));
    std::string readBackString(readBuf.data());
    CHECK(data == readBackString);
  }

  SECTION("Write To File, Check Not Truncated") {
    std::random_device dev;
    std::mt19937 rng(dev());
    std::uniform_int_distribution<std::mt19937::result_type> distU8(1, 255);
    std::array<uint8_t, 512> randData{};
    for (uint8_t& byte : randData) {
      byte = distU8(rng);
    }
    REQUIRE(hostFs.createFile(file0.c_str()) == returnvalue::OK);
    CHECK(fs::is_regular_file(file0));
    REQUIRE(fs::exists(file0));
    // Write first file chunk
    CHECK(hostFs.writeToFile(file0.c_str(), 0, randData.cbegin(), randData.size() - 256) ==
          returnvalue::OK);
    CHECK(hostFs.writeToFile(file0.c_str(), 256, randData.cbegin() + 256, 256) == returnvalue::OK);
    std::ifstream rf(file0, ios::binary);
    std::array<uint8_t, 512> readBack{};
    REQUIRE(std::filesystem::file_size(file0) == 512);
    rf.read(reinterpret_cast<char*>(readBack.data()), readBack.size());
    for (size_t i = 0; i < 512; i++) {
      CHECK(randData[i] == readBack[i]);
    }
  }

  SECTION("Read From File") {
    std::string data = "hello world!";
    REQUIRE(hostFs.createFile(file0.c_str()) == returnvalue::OK);
    CHECK(fs::is_regular_file(file0));
    ofstream of(file0);
    of.write(data.c_str(), static_cast<unsigned int>(data.size()));
    of.close();
    CHECK(fs::file_size(file0) == data.size());
    REQUIRE(fs::exists(file0));
    std::array<uint8_t, 256> readBuf{};
    uint8_t* readPtr = readBuf.data();
    size_t readSize = data.size();
    size_t actuallyRead = 0;
    CHECK(hostFs.readFromFile(file0.c_str(), 0, readSize, readPtr, actuallyRead, readBuf.size()) ==
          returnvalue::OK);
    std::string readBackString(reinterpret_cast<const char*>(readBuf.data()));
    CHECK(readSize == data.size());
    CHECK(data == readBackString);
  }

  SECTION("Invalid Input does not crash") {
    FileOpParams params(nullptr, 10);
    REQUIRE(hostFs.createFile(nullptr) != returnvalue::OK);
    REQUIRE(hostFs.createDirectory(nullptr) != returnvalue::OK);
    REQUIRE(hostFs.createFile(nullptr) != returnvalue::OK);
    REQUIRE(hostFs.removeDirectory(nullptr, false, nullptr) != returnvalue::OK);
    REQUIRE(hostFs.removeFile(nullptr) != returnvalue::OK);
    REQUIRE(hostFs.rename(nullptr, nullptr) != returnvalue::OK);
    REQUIRE(hostFs.writeToFile(nullptr, 0, nullptr, 0) != returnvalue::OK);
    size_t readLen = 0;
    REQUIRE(hostFs.readFromFile(nullptr, 0, 0, nullptr, readLen, 20) != returnvalue::OK);
  }

  SECTION("Create File but already exists") {
    FilesystemParams params(file0.c_str());
    REQUIRE(hostFs.createFile(file0.c_str()) == returnvalue::OK);
    REQUIRE(hostFs.createFile(file0.c_str()) == HasFileSystemIF::FILE_ALREADY_EXISTS);
  }

  SECTION("Remove File but does not exist") {
    REQUIRE(hostFs.removeFile(file0.c_str()) == HasFileSystemIF::FILE_DOES_NOT_EXIST);
  }

  SECTION("Create Directory but already exists") {
    FileOpParams params(file0.c_str(), 12);
    REQUIRE(hostFs.createDirectory(file0.c_str()) == returnvalue::OK);
    REQUIRE(hostFs.createDirectory(file0.c_str()) == HasFileSystemIF::DIRECTORY_ALREADY_EXISTS);
  }

  SECTION("Remove Directory but does not exist") {
    FilesystemParams params(dir0.c_str());
    REQUIRE(hostFs.removeDirectory(dir0.c_str(), false, nullptr) ==
            HasFileSystemIF::DIRECTORY_DOES_NOT_EXIST);
  }

  SECTION("Remove Directory but is file") {
    ofstream of(file0);
    REQUIRE(hostFs.removeDirectory(file0.c_str(), false, nullptr) ==
            HasFileSystemIF::NOT_A_DIRECTORY);
  }

  SECTION("Read from file but does not exist") {
    std::string data = "hello world!";
    std::array<uint8_t, 16> readBuf{};
    uint8_t* readPtr = readBuf.data();
    size_t readSize = 0;
    CHECK(hostFs.readFromFile(file0.c_str(), 0, data.size(), readPtr, readSize, readBuf.size()) ==
          HasFileSystemIF::FILE_DOES_NOT_EXIST);
  }

  SECTION("Write to file but does not exist") {
    std::string data = "hello world!";
    CHECK(hostFs.writeToFile(file0.c_str(), 0, reinterpret_cast<const uint8_t*>(data.c_str()),
                             data.size()) == HasFileSystemIF::FILE_DOES_NOT_EXIST);
  }

  SECTION("Remove recursively") {
    fs::create_directory(dir0.c_str());
    ofstream of(fileInDir0);
    CHECK(fs::is_directory(dir0));
    CHECK(fs::is_regular_file(fileInDir0));
    REQUIRE(hostFs.removeDirectory(dir0.c_str(), true, nullptr) == returnvalue::OK);
    CHECK(not fs::is_directory(dir0));
    CHECK(not fs::is_regular_file(fileInDir0));
  }

  SECTION("Non-Recursive Removal Fails") {
    fs::create_directory(dir0.c_str());
    ofstream of(fileInDir0);
    CHECK(fs::is_directory(dir0));
    CHECK(fs::is_regular_file(fileInDir0));
    REQUIRE(hostFs.removeDirectory(dir0.c_str(), false, nullptr) ==
            HasFileSystemIF::DIRECTORY_NOT_EMPTY);
  }

  SECTION("Create directory with parent directory") {
    CHECK(hostFs.createDirectory(dirWithParent.c_str(), true, nullptr) == returnvalue::OK);
    CHECK(fs::is_directory(dir0));
    CHECK(fs::is_directory(dirWithParent));
  }

  SECTION("Read but provided buffer too small") {
    std::string data = "hello world!";
    FileOpParams params(file0.c_str(), data.size());
    ofstream of(file0);
    of.write(data.c_str(), static_cast<unsigned int>(data.size()));
    of.close();
    CHECK(fs::file_size(file0) == data.size());
    REQUIRE(fs::exists(file0));
    std::array<uint8_t, 15> readBuf{};
    uint8_t* readPtr = readBuf.data();
    size_t readSize = 0;
    CHECK(hostFs.readFromFile(file0.c_str(), 0, data.size(), readPtr, readSize, 5) ==
          SerializeIF::BUFFER_TOO_SHORT);
    ;
  }

  REQUIRE_NOTHROW(fs::remove(file0));
  REQUIRE_NOTHROW(fs::remove(file1));
  REQUIRE_NOTHROW(fs::remove_all(dir0));
}