#include <iostream>
#include <fstream>
#include <vector>

enum file_extension
{
    C,
    PY,
    JS,
    UNDEFINED
};

bool string_ends_with(const std::string& str, const std::string& ending)
{
    return !str.compare(str.size() - ending.size(), str.size(), ending) && str.length() >= ending.length();
}

file_extension get_file_extension(const std::string& filename)
{
    if (string_ends_with(filename, ".py"))
        return PY;
    if (string_ends_with(filename, ".js"))
        return JS;
    if (string_ends_with(filename, ".c"))
        return C;
    return UNDEFINED;
}

void search_comments(const std::string& filename)
{
    std::vector<std::string> comment_tokens;
    switch (get_file_extension(filename))
    {
    case PY:
        comment_tokens = {"#", "\"\"\""};
        break;

    case C:
    case JS:
        comment_tokens = {"//", "/*"};
        break;

    default:
        std::cout << "Incorrect file extension. Allowed file extensions are: .c, .js, .py" << std::endl;
        return;
    }
    std::ifstream fin(filename);
    if (!fin.is_open())
    {
        std::cout << "Unable to open file, check if it exists" << std::endl;
        return;
    }
    fin.close();

    std::string line;
    while (std::getline(fin, line))
    {
        for (const auto& token: comment_tokens)
        {
            if (line.find(token) != std::string::npos)
            {
                std::cout << "File contains comments" << std::endl;
                return;
            }
        }
    }
    std::cout << "File does not contain comments" << std::endl;
}

int main(int argc, const char* argv[])
{
    if (argc < 1)
    {
        std::cout << "Specify the file to check comments" << std::endl;
        return 0;
    }
    std::cout << argv[0] << std::endl;
    search_comments(argv[0]);
    return 0;
}