class Cppcheck < Formula
  desc "Static analysis of C and C++ code"
  homepage "https://sourceforge.net/projects/cppcheck/"
  url "https://github.com/danmar/cppcheck/archive/2.4.1.tar.gz"
  sha256 "11a9d9fe5305a105561655c45d2cd83cb30fbc87b41d0569de1b00a1a314867f"
  license "GPL-3.0-or-later"
  head "https://github.com/danmar/cppcheck.git"

  bottle do
    sha256 arm64_big_sur: "48768ad6f9d3eea1736bf2c91071d2c85883bf5485e0ceaf1cdf2d6f80c85743"
    sha256 big_sur:       "4aa26128b5b22730d005a2c1faed82d2e5ff5072331765915f812bd6279e7077"
    sha256 catalina:      "7522e2ef04467bbd45f23d50242b35bdac552c6f5bcdef795ae52f1122d83fad"
    sha256 mojave:        "8bc9e90fb422973484d1df7338b0b4ecd3d4a4839d57c688079d597620dd8332"
    sha256 x86_64_linux:  "8707840f5a8fd2ed1b13acaa3398a56695d55b3ea5e7f44df65e87945d07ae1f"
  end

  depends_on "cmake" => :build
  depends_on "python@3.9" => [:build, :test]
  depends_on "pcre"

  uses_from_macos "libxml2"

  def install
    args = std_cmake_args + %W[
      -DHAVE_RULES=ON
      -DUSE_MATCHCOMPILER=ON
      -DPYTHON_EXECUTABLE=#{Formula["python@3.9"].opt_bin}/python3
    ]
    system "cmake", "-S", ".", "-B", "build", *args
    system "cmake", "--build", "build"
    system "cmake", "--install", "build"

    # Move the python addons to the cppcheck pkgshare folder
    (pkgshare/"addons").install Dir.glob("addons/*.py")
  end

  test do
    # Execution test with an input .cpp file
    test_cpp_file = testpath/"test.cpp"
    test_cpp_file.write <<~EOS
      #include <iostream>
      using namespace std;

      int main()
      {
        cout << "Hello World!" << endl;
        return 0;
      }

      class Example
      {
        public:
          int GetNumber() const;
          explicit Example(int initialNumber);
        private:
          int number;
      };

      Example::Example(int initialNumber)
      {
        number = initialNumber;
      }
    EOS
    system "#{bin}/cppcheck", test_cpp_file

    # Test the "out of bounds" check
    test_cpp_file_check = testpath/"testcheck.cpp"
    test_cpp_file_check.write <<~EOS
      int main()
      {
      char a[10];
      a[10] = 0;
      return 0;
      }
    EOS
    output = shell_output("#{bin}/cppcheck #{test_cpp_file_check} 2>&1")
    assert_match "out of bounds", output

    # Test the addon functionality: sampleaddon.py imports the cppcheckdata python
    # module and uses it to parse a cppcheck dump into an OOP structure. We then
    # check the correct number of detected tokens and function names.
    addons_dir = pkgshare/"addons"
    cppcheck_module = "#{name}data"
    expect_token_count = 55
    expect_function_names = "main,GetNumber,Example"
    assert_parse_message = "Error: sampleaddon.py: failed: can't parse the #{name} dump."

    sample_addon_file = testpath/"sampleaddon.py"
    sample_addon_file.write <<~EOS
      #!/usr/bin/env #{Formula["python@3.9"].opt_bin}/python3
      """A simple test addon for #{name}, prints function names and token count"""
      import sys
      from importlib import machinery, util
      # Manually import the '#{cppcheck_module}' module
      spec = machinery.PathFinder().find_spec("#{cppcheck_module}", ["#{addons_dir}"])
      cpp_check_data = util.module_from_spec(spec)
      spec.loader.exec_module(cpp_check_data)

      for arg in sys.argv[1:]:
          # Parse the dump file generated by #{name}
          configKlass = cpp_check_data.parsedump(arg)
          if len(configKlass.configurations) == 0:
              sys.exit("#{assert_parse_message}") # Parse failure
          fConfig = configKlass.configurations[0]
          # Pick and join the function names in a string, separated by ','
          detected_functions = ','.join(fn.name for fn in fConfig.functions)
          detected_token_count = len(fConfig.tokenlist)
          # Print the function names on the first line and the token count on the second
          print("%s\\n%s" %(detected_functions, detected_token_count))
    EOS

    system "#{bin}/cppcheck", "--dump", test_cpp_file
    test_cpp_file_dump = "#{test_cpp_file}.dump"
    assert_predicate testpath/test_cpp_file_dump, :exist?
    output = shell_output(Formula["python@3.9"].opt_bin/"python3 #{sample_addon_file} #{test_cpp_file_dump}")
    assert_match "#{expect_function_names}\n#{expect_token_count}", output
  end
end
