version_check.hpp

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// -----------------------------------------------------------------------------------------------------
// Copyright (c) 2006-2020, Knut Reinert & Freie Universität Berlin
// Copyright (c) 2016-2020, Knut Reinert & MPI für molekulare Genetik
// This file may be used, modified and/or redistributed under the terms of the 3-clause BSD-License
// shipped with this file and also available at: https://github.com/seqan/seqan3/blob/master/LICENSE
// -----------------------------------------------------------------------------------------------------
 
#pragma once
 
#include <sys/stat.h>
 
#include <chrono>
#include <fstream>
#include <future>
#include <iostream>
#include <regex>
 
#include <seqan3/version.hpp>
#include <seqan3/core/detail/terminal.hpp>
#include <seqan3/io/detail/misc.hpp>
#include <seqan3/io/detail/safe_filesystem_entry.hpp>
#include <seqan3/std/charconv>
 
namespace seqan3::detail
{
 
// ---------------------------------------------------------------------------------------------------------------------
// function call_server()
// ---------------------------------------------------------------------------------------------------------------------
 
inline void call_server(std::string const & command, std::promise<bool> prom)
{
    // system call - http response is stored in a file '.config/seqan/{appname}_version'
    if (system(command.c_str()))
        prom.set_value(false);
    else
        prom.set_value(true);
}
 
// ---------------------------------------------------------------------------------------------------------------------
// version_checker
// ---------------------------------------------------------------------------------------------------------------------
 
class version_checker
{
public:
    version_checker() = delete;
    version_checker(version_checker const &) = default;             
    version_checker & operator=(version_checker const &) = default; 
    version_checker(version_checker &&) = default;                  
    version_checker & operator=(version_checker &&) = default;      
    ~version_checker() = default;                                   
 
    version_checker(std::string name_, std::string const & version_, std::string const & app_url = std::string{}) :
        name{std::move(name_)}
    {
        assert(std::regex_match(name, std::regex{"^[a-zA-Z0-9_-]+$"})); // check on construction of the argument parser
 
        if (!app_url.empty())
        {
            message_app_update.pop_back(); // remove second newline
            message_app_update.append("[APP INFO] :: Visit " + app_url + " for updates.\n\n");
        }
 
#if defined(NDEBUG)
        timestamp_filename = cookie_path / (name + "_usr.timestamp");
#else
        timestamp_filename = cookie_path / (name + "_dev.timestamp");
#endif
        std::smatch versionMatch;
 
        // Ensure version string is not corrupt
        if (!version_.empty() && /*regex allows version prefix instead of exact match */
            std::regex_search(version_, versionMatch, std::regex("^([[:digit:]]+\\.[[:digit:]]+\\.[[:digit:]]+).*")))
        {
            version = versionMatch.str(1); // in case the git revision number is given take only version number
        }
    }
 
    void operator()(std::promise<bool> prom)
    {
        std::array<int, 3> empty_version{0, 0, 0};
        std::array<int, 3> srv_app_version{};
        std::array<int, 3> srv_seqan_version{};
 
        std::ifstream version_file{cookie_path / (name + ".version")};
 
        if (version_file.is_open())
        {
            std::string line{};
            std::getline(version_file, line); // get first line which should only contain the version number of the app
 
        if (line != unregistered_app)
            srv_app_version = get_numbers_from_version_string(line);
#if !defined(NDEBUG)
        else
            std::cerr << message_unregistered_app;
#endif // !defined(NDEBUG)
 
            std::getline(version_file, line); // get second line which should only contain the version number of seqan
            srv_seqan_version = get_numbers_from_version_string(line);
 
            version_file.close();
        }
 
#if !defined(NDEBUG) // only check seqan version in debug
        if (srv_seqan_version != empty_version)
        {
            std::array<int, 3> seqan_version = {SEQAN3_VERSION_MAJOR, SEQAN3_VERSION_MINOR, SEQAN3_VERSION_PATCH};
 
            if (seqan_version < srv_seqan_version)
                std::cerr << message_seqan3_update;
        }
#endif
 
        if (srv_app_version != empty_version) // app version
        {
#if defined(NDEBUG) // only check app version in release
            if (get_numbers_from_version_string(version) < srv_app_version)
                std::cerr << message_app_update;
#endif // defined(NDEBUG)
 
#if !defined(NDEBUG) // only notify developer that app version should be updated on server
            if (get_numbers_from_version_string(version) > srv_app_version)
                std::cerr << message_registered_app_update;
#endif // !defined(NDEBUG)
        }
 
        std::cerr << std::flush;
 
        std::string program = get_program();
 
        if (program.empty())
        {
            prom.set_value(false);
            return;
        }
 
        // 'cookie_path' is no user input and `name` is escaped on construction of the argument parser.
        std::filesystem::path out_file = cookie_path / (name + ".version");
 
        // build up command for server call
        std::string command = program +              // no user defined input
                              " " +
                              out_file.string() +
                              " " +
                              std::string{"http://seqan-update.informatik.uni-tuebingen.de/check/SeqAn3_"} +
#ifdef __linux
                              "Linux" +
#elif __APPLE__
                              "MacOS" +
#elif defined(_WIN32)
                              "Windows" +
#elif __FreeBSD__
                              "FreeBSD" +
#elif __OpenBSD__
                              "OpenBSD" +
#else
                              "unknown" +
#endif
#if __x86_64__ || __ppc64__
                              "_64_" +
#else
                              "_32_" +
#endif
                              name +                 // !user input! escaped on construction of the argument parser
                              "_" +
                              version +              // !user input! escaped on construction of the version_checker
#if defined(_WIN32)
                              "; exit  [int] -not $?}\" > nul 2>&1";
#else
                              " > /dev/null 2>&1";
#endif
 
        // launch a separate thread to not defer runtime.
        std::thread(call_server, command, std::move(prom)).detach();
    }
 
    static std::filesystem::path get_path()
    {
        using namespace std::filesystem;
 
        path tmp_path;
 
        tmp_path = std::string{getenv(home_env_name)};
        tmp_path /= ".config";
 
        // First, create .config if it does not already exist.
        std::error_code err;
        create_directory(tmp_path, err);
 
        // If this did not fail we, create the seqan subdirectory.
        if (!err)
        {
            tmp_path /= "seqan";
            create_directory(tmp_path, err);
        }
 
        // .config/seqan cannot be created, try tmp directory.
        if (err)
            tmp_path = temp_directory_path(); // choose temp dir instead
 
        // check if files can be written inside dir
        path dummy = tmp_path / "dummy.txt";
        std::ofstream file{dummy};
        detail::safe_filesystem_entry file_guard{dummy};
 
        bool is_open = file.is_open();
        bool is_good = file.good();
        file.close();
        file_guard.remove_no_throw();
 
        if (!is_good || !is_open) // no write permissions
        {
            tmp_path.clear(); // empty path signals no available directory to write to, version check will not be done
        }
 
        return tmp_path;
    }
 
    bool decide_if_check_is_performed(bool developer_approval, std::optional<bool> user_approval)
    {
        if (!developer_approval)
            return false;
 
        if (std::getenv("SEQAN3_NO_VERSION_CHECK") != nullptr) // environment variable was set
            return false;
 
        if (user_approval.has_value())
            return user_approval.value();
 
        // version check was not explicitly handled so let's check the cookie
        if (std::filesystem::exists(cookie_path))
        {
            std::ifstream timestamp_file{timestamp_filename};
            std::string cookie_line{};
 
            if (timestamp_file.is_open())
            {
                std::getline(timestamp_file, cookie_line); // first line contains the timestamp
 
                if (get_time_diff_to_current(cookie_line) < 86400/*one day in seconds*/)
                {
                    return false;
                }
 
                std::getline(timestamp_file, cookie_line); // second line contains the last user decision
 
                if (cookie_line == "NEVER")
                {
                    return false;
                }
                else if (cookie_line == "ALWAYS")
                {
                    return true;
                }
                // else we do not return but continue to ask the user
 
                timestamp_file.close();
            }
        }
 
        // Up until now, the user did not specify the --version-check option, the environment variable was not set,
        // nor did the the cookie tell us what to do. We will now ask the user if possible or do the check by default.
        write_cookie("ASK"); // Ask again next time when we read the cookie, if this is not overwritten.
 
        if (detail::is_terminal()) // LCOV_EXCL_START
        {
            std::cerr << R"(
#######################################################################
   Automatic Update Notifications
#######################################################################
 
 This app can look for updates automatically in the background,
 do you want to do that?
 
    [a] Always perform version checks for this app (the default).
    [n] Never perform version checks for this app.
    [y] Yes, perform a version check now, and ask again tomorrow.
    [s] Skip the version check now, but ask again tomorrow.
 
 Please enter one of [a, n, y, s] and press [RETURN].
 
 For more information, see:
 https://github.com/seqan/seqan3/wiki/Update-Notifications
 
#######################################################################
 
)";
            std::string line{};
            std::getline(std::cin, line);
            line.resize(1); // ignore everything but the first char or resizes the empty string to the default
 
            switch (line[0])
            {
                case 'y':
                {
                    return true;
                }
                case 's':
                {
                    return false;
                }
                case 'n':
                {
                    write_cookie(std::string{"NEVER"}); // overwrite cookie
                    return false;
                }
                default:
                {
                    write_cookie(std::string{"ALWAYS"}); // overwrite cookie
                    return true;
                }
            }
        }
        else // if !detail::is_terminal()
        {
            std::cerr << R"(
#######################################################################
   Automatic Update Notifications
#######################################################################
 This app performs automatic checks for updates. For more information
 see: https://github.com/seqan/seqan3/wiki/Update-Notifications
#######################################################################
 
)";
            return true; // default: check version if you cannot ask the user
        }
    } // LCOV_EXCL_STOP
 
    static constexpr std::string_view unregistered_app = "UNREGISTERED_APP";
    static constexpr std::string_view message_seqan3_update =
        "[SEQAN3 INFO] :: A new SeqAn version is available online.\n"
        "[SEQAN3 INFO] :: Please visit www.github.com/seqan/seqan3.git for an update\n"
        "[SEQAN3 INFO] :: or inform the developer of this app.\n"
        "[SEQAN3 INFO] :: If you don't wish to receive further notifications, set --version-check OFF.\n\n";
    static constexpr std::string_view message_unregistered_app =
        "[SEQAN3 INFO] :: Thank you for using SeqAn!\n"
        "[SEQAN3 INFO] :: Do you wish to register your app for update notifications?\n"
        "[SEQAN3 INFO] :: Just send an email to support@seqan.de with your app name and version number.\n"
        "[SEQAN3 INFO] :: If you don't wish to receive further notifications, set --version-check OFF.\n\n";
    static constexpr std::string_view message_registered_app_update =
        "[APP INFO] :: We noticed the app version you use is newer than the one registered with us.\n"
        "[APP INFO] :: Please send us an email with the new version so we can correct it (support@seqan.de)\n\n";
    std::string message_app_update =
        "[APP INFO] :: A new version of this application is now available.\n"
        "[APP INFO] :: If you don't wish to receive further notifications, set --version-check OFF.\n\n";
        /*Might be extended if a url is given on construction.*/
 
    static constexpr char const * home_env_name
    {
#if defined(_WIN32)
        "UserProfile"
#else
        "HOME"
#endif
    };
 
    std::string name;
    std::string version{"0.0.0"};
    std::regex version_regex{"^[[:digit:]]+\\.[[:digit:]]+\\.[[:digit:]]+$"};
    std::filesystem::path cookie_path = get_path();
    std::filesystem::path timestamp_filename;
 
private:
    static std::string get_program()
    {
#if defined(_WIN32)
        return "powershell.exe -NoLogo -NonInteractive -Command \"& {Invoke-WebRequest -erroraction 'silentlycontinue' -OutFile";
#else  // Unix based platforms.
        if (!system("/usr/bin/env -i wget --version > /dev/null 2>&1"))
            return "/usr/bin/env -i wget --timeout=10 --tries=1 -q -O";
        else if (!system("/usr/bin/env -i curl --version > /dev/null 2>&1"))
            return "/usr/bin/env -i curl --connect-timeout 10 -o";
    // In case neither wget nor curl is available try ftp/fetch if system is OpenBSD/FreeBSD.
    // Note, both systems have ftp/fetch command installed by default so we do not guard against it.
    #if defined(__OpenBSD__)
        return "/usr/bin/env -i ftp -w10 -Vo";
    #elif defined(__FreeBSD__)
        return "/usr/bin/env -i fetch --timeout=10 -o";
    #else
        return "";
    #endif // __OpenBSD__
#endif  // defined(_WIN32)
    }
 
    double get_time_diff_to_current(std::string const & str_time) const
    {
        namespace co = std::chrono;
        double curr = co::duration_cast<co::seconds>(co::system_clock::now().time_since_epoch()).count();
 
        double d_time{};
        std::from_chars(str_time.data(), str_time.data() + str_time.size(), d_time);
 
        return curr - d_time;
    }
 
    std::array<int, 3> get_numbers_from_version_string(std::string const & str) const
    {
        std::array<int, 3> result{};
 
        if (!std::regex_match(str, version_regex))
            return result;
 
        auto res = std::from_chars(str.data(), str.data() + str.size(), result[0]); // stops and sets res.ptr at '.'
        res = std::from_chars(res.ptr + 1, str.data() + str.size(), result[1]);
        res = std::from_chars(res.ptr + 1, str.data() + str.size(), result[2]);
 
        return result;
    }
 
    template <typename msg_type>
    void write_cookie(msg_type && msg)
    {
        // The current time
        namespace co = std::chrono;
        auto curr = co::duration_cast<co::seconds>(co::system_clock::now().time_since_epoch()).count();
 
        std::ofstream timestamp_file{timestamp_filename};
 
        if (timestamp_file.is_open())
        {
            timestamp_file << curr << '\n' << msg;
            timestamp_file.close();
        }
    }
};
 
} // namespace seqan3