#include "parameters_parser.hh"

namespace Kakoune
{

String generate_switches_doc(const SwitchMap& switches)
{
    String res;
    for (auto& sw : switches)
        res += format(" -{} {}: {}\n", sw.key,
                      sw.value.takes_arg ? "<arg>" : "",
                      sw.value.description);
    return res;
}

ParametersParser::ParametersParser(ParameterList params,
                                   const ParameterDesc& desc)
    : m_params(params),
      m_desc(desc)
{
    bool only_pos = desc.flags & ParameterDesc::Flags::SwitchesAsPositional;
    for (size_t i = 0; i < params.size(); ++i)
    {
        if (not only_pos and params[i] == "--")
            only_pos = true;
        else if (not only_pos and params[i].length() > 0 and params[i][0_byte] == '-')
        {
            auto it = m_desc.switches.find(params[i].substr(1_byte));
            if (it == m_desc.switches.end())
                throw unknown_option(params[i]);

            if (it->value.takes_arg)
            {
                ++i;
                if (i == params.size() or params[i][0_byte] == '-')
                   throw missing_option_value(it->key);
            }
        }
        else // positional
        {
            if (desc.flags & ParameterDesc::Flags::SwitchesOnlyAtStart)
                only_pos = true;
            m_positional_indices.push_back(i);
        }
    }
    size_t count = m_positional_indices.size();
    if (count > desc.max_positionals or count < desc.min_positionals)
        throw wrong_argument_count();
}

Optional<StringView> ParametersParser::get_switch(StringView name) const
{
    auto it = m_desc.switches.find(name);
    kak_assert(it != m_desc.switches.end());
    for (size_t i = 0; i < m_params.size(); ++i)
    {
        const auto& param = m_params[i];
        if (param[0_byte] == '-' and param.substr(1_byte) == name)
            return it->value.takes_arg ? m_params[i+1] : StringView{};

        if (param == "--")
            break;
    }
    return {};
}

}