test_that("read_dot_env reads variables from .env file", {
  # Create a temporary .env file
  temp_env_file <- tempfile("test", fileext = ".env")
  writeLines(c("DB_HOST=localhost", "DB_USER=root", 'DB_PASS="secret"'), temp_env_file)

  # Read the .env file
  env_vars <- read_dot_env(temp_env_file)

  # Check if the variables are read correctly
  expect_equal(env_vars$DB_HOST, "localhost")
  expect_equal(env_vars$DB_USER, "root")
  expect_equal(env_vars$DB_PASS, "secret")
  expect_equal(env_vars$DB_PORT, NULL)

  # Clean up temporary file
  unlink(temp_env_file)
})

test_that("read_dot_env skips comments, empty lines, and other special casees", {
  # Create a temporary .env file with comments and empty lines
  temp_env_file <- tempfile("test", fileext = ".env")
  writeLines(
    c(
      "# This is a comment",
      "",
      "DB_HOST=localhost",
      "# Another comment",
      "DB_USER=root",
      " ",
      "DB_PW='sdf=dfdfa=xcd'",
      "DB_PW_2=sdf=dfdfa=xcd",
      'DB_PW_3="sdf=dfdfa=xcd"',
      "DB_NAME='db' # Test DB"
    ),
    temp_env_file
  )

  # Read the .env file
  env_vars <- read_dot_env(temp_env_file)

  # Check if the comments and empty lines are ignored
  expect_equal(env_vars$DB_HOST, "localhost")
  expect_equal(env_vars$DB_USER, "root")
  expect_equal(env_vars$DB_PW, "sdf=dfdfa=xcd")
  expect_equal(env_vars$DB_PW_2, "sdf=dfdfa=xcd")
  expect_equal(env_vars$DB_PW_3, "sdf=dfdfa=xcd")
  expect_equal(env_vars$DB_NAME, "'db' # Test DB")

  # Clean up temporary file
  unlink(temp_env_file)
})

test_that("read_dot_env returns NULL if no variables are found", {
  # Create a temporary empty .env file
  temp_env_file <- tempfile("test", fileext = ".env")
  writeLines(c("# This is a comment", ""), temp_env_file)

  # Read the .env file
  env_vars <- read_dot_env(temp_env_file)

  # Check if it returns NULL
  expect_null(env_vars)

  # Clean up temporary file
  unlink(temp_env_file)
})

test_that("read_dot_env defaults to .env in current directory if no path is provided", {
  # Create a temporary .env file in the current working directory
  dir_temp <- tempdir()
  temp_env_file <- file.path(dir_temp, '.env')
  writeLines(c("DB_HOST=localhost", "DB_USER=root"), temp_env_file)

  # Check that read_dot_env can read the file without specifying path
  setwd(dir_temp)
  env_vars <- read_dot_env()

  # Check if the variables are read correctly
  expect_equal(env_vars$DB_HOST, "localhost")
  expect_equal(env_vars$DB_USER, "root")

  # Clean up temporary file
  unlink(temp_env_file)
})

test_that("read_dot_env throws an error when the file doesn't exist", {
  # A path that doesn't exist
  non_existent_file <- tempfile("nonexistent_file", fileext = ".env")

  # Expect error due to missing file
  expect_error(read_dot_env(non_existent_file), "dot-env file does not exist")
})