#include <format>
#include <larra/jid.hpp>

namespace larra::xmpp {

auto ParseBareJid(std::string_view jid, std::size_t at) -> BareJid {
  return {.username = static_cast<std::string>(jid.substr(0, at)), .server = static_cast<std::string>(jid.substr(at + 1))};
}

auto ParseBareResourceJid(std::string_view jid, std::size_t slash) -> BareResourceJid {
  return {.server = static_cast<std::string>(jid.substr(0, slash)), .resource = static_cast<std::string>(jid.substr(slash + 1))};
}

auto ParseFullJid(std::string_view jid, std::size_t at, std::size_t slash) -> FullJid {
  return {.username = static_cast<std::string>(jid.substr(0, at)),
          .server = static_cast<std::string>(jid.substr(at + 1, slash - at - 1)),
          .resource = static_cast<std::string>(jid.substr(slash + 1))};
}

auto BareJid::Parse(std::string_view jid) -> BareJid {
  const auto at = jid.find('@');
  if(at == std::string_view::npos) {
    throw std::invalid_argument("Invalid string for jid");
  }

  return ParseBareJid(jid, at);
}

auto BareResourceJid::Parse(std::string_view jid) -> BareResourceJid {
  const auto slash = jid.find('/');
  if(slash == std::string_view::npos) {
    throw std::invalid_argument("Invalid string for jid");
  }

  return ParseBareResourceJid(jid, slash);
}

auto FullJid::Parse(std::string_view jid) -> FullJid {
  const auto at = jid.find('@');
  const auto slash = jid.find('/', at);
  if(at == std::string_view::npos || slash == std::string_view::npos) {
    throw std::invalid_argument("Invalid string for jid");
  }

  return ParseFullJid(jid, at, slash);
}

auto Jid::Parse(std::string_view jid) -> Jid {
  const auto at = jid.find('@');
  const auto slash = jid.find('/', at == std::string_view::npos ? 0 : at);
  if(at == std::string_view::npos) {
    return ParseBareResourceJid(jid, slash);
  }
  if(slash == std::string_view::npos) {
    return ParseBareJid(jid, at);
  }
  return ParseFullJid(jid, at, slash);
}

auto ToString(const BareJid& jid) -> std::string {
  return std::format("{}@{}", jid.username, jid.server);
}

auto ToString(const BareResourceJid& jid) -> std::string {
  return std::format("{}/{}", jid.server, jid.resource);
}

auto ToString(const FullJid& jid) -> std::string {
  return std::format("{}@{}/{}", jid.username, jid.server, jid.resource);
}

auto ToString(const Jid& jid) -> std::string {
  return std::visit<std::string>(
      [](const auto& jid) -> std::string {
        return ToString(jid);
      },
      jid);
}

}  // namespace larra::xmpp