help.hpp

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/*
    SPDX-FileCopyrightText: 2026 Igor Mironchik <igor.mironchik@gmail.com>
    SPDX-License-Identifier: MIT
*/
 
#ifndef ARGS__HELP_HPP__INCLUDED
#define ARGS__HELP_HPP__INCLUDED
 
// Args include.
#include "arg.hpp"
#include "command.hpp"
#include "context.hpp"
#include "exceptions.hpp"
#include "help_printer_iface.hpp"
#include "types.hpp"
#include "utils.hpp"
 
// C++ include.
#include <memory>
 
#ifdef ARGS_TESTING
#ifndef ARGS_QSTRING_BUILD
// C++ include.
#include <sstream>
#endif
#endif
 
namespace Args
{
 
#ifdef ARGS_TESTING
#ifdef ARGS_WSTRING_BUILD
extern std::wstringstream g_argsOutStream;
#elif defined(ARGS_QSTRING_BUILD)
extern OutStreamType g_argsOutStream;
#else
extern std::stringstream g_argsOutStream;
#endif
#else
static OutStreamType &g_argsOutStream = outStream();
#endif // ARGS_TESTING
 
//
// Help
//

class Help : public Arg
{
public:
    explicit Help(bool throwExceptionOnPrint = true);

    Help &setExecutable(const String &exe);

    Help &setAppDescription(const String &desc);

    Help &setLineLength(String::size_type length);

    Help &setPrinter(std::unique_ptr<HelpPrinterIface> p);
 
protected:
    void process(
        Context &context) override;

    void setCmdLine(CmdLine *cmdLine) override
    {
        Arg::setCmdLine(cmdLine);
 
        m_printer->setCmdLine(cmdLine);
    }
 
private:
    std::unique_ptr<HelpPrinterIface> m_printer;
    bool m_throwExceptionOnPrint;
}; // class Help
 
//
// Help
//
 
inline Help &Help::setExecutable(const String &exe)
{
    m_printer->setExecutable(exe);
    return *this;
}
 
inline Help &Help::setAppDescription(const String &desc)
{
    m_printer->setAppDescription(desc);
    return *this;
}
 
inline Help &Help::setLineLength(String::size_type length)
{
    m_printer->setLineLength(length);
    return *this;
}
 
inline Help &Help::setPrinter(std::unique_ptr<HelpPrinterIface> p)
{
    m_printer.reset(p.release());
    return *this;
}
 
inline void Help::process(Context &context)
{
    if (!context.atEnd()) {
        String arg = *context.next();
 
        // Argument or flag.
        if (details::isArgument(arg) || details::isFlag(arg)) {
            m_printer->print(arg, g_argsOutStream);
            // Command?
        } else {
            auto *tmp = m_printer->findArgument(arg);
 
            // Command.
            if (tmp && tmp->type() == ArgType::Command) {
                bool printed = false;
 
                auto *cmd = static_cast<Command *>(tmp);
 
                while (!context.atEnd()) {
                    arg = *context.next();
 
                    if (tmp && tmp->type() == ArgType::Command) {
                        cmd = static_cast<Command *>(tmp);
 
                        // Argument or flag.
                        if (details::isArgument(arg) || details::isFlag(arg)) {
                            m_printer->print(arg, g_argsOutStream, cmd);
 
                            printed = true;
 
                            break;
                        }
                        // Command?
                        else {
                            tmp = cmd->findChild(arg);
                        }
                    } else {
                        break;
                    }
                }
 
                if (!printed) {
                    if (tmp) {
                        m_printer->print(tmp->name(), g_argsOutStream, (cmd != tmp ? cmd : nullptr));
                    } else {
                        m_printer->print(g_argsOutStream);
                    }
                }
            } else {
                m_printer->print(g_argsOutStream);
            }
        }
    } else {
        m_printer->print(g_argsOutStream);
    }
 
    setDefined(true);
 
    if (m_throwExceptionOnPrint) {
        throw HelpHasBeenPrintedException();
    }
}
 
} /* namespace Args */
 
#endif // ARGS__HELP_HPP__INCLUDED