#include "ReplServer.h"

#include "common/cross_sockets/XSocket.h"

#include "third-party/fmt/core.h"
#include <common/versions.h>

// TODO - basically REPL to listen and inject commands into a running REPL
// - we will need a C++ side client as well which will let us communicate with the repl via for
// example, ImgUI
//
// TODO - The server also needs to eventually return the result of the evaluation

// Known Issues:
// - doesn't handle disconnects/reconnects

void ReplServer::write_on_accept() {
  ping_response();
}

void ReplServer::read_data() {
  int desired_size = (int)sizeof(ReplServerHeader);
  int got = 0;

  while (got < desired_size) {
    ASSERT(got + desired_size < buffer_size);
    int sock = accepted_socket;
    auto x = read_from_socket(sock, header_buffer + got, desired_size - got);
    if (want_exit_callback()) {
      return;
    }
    got += x > 0 ? x : 0;
  }

  auto* header = (ReplServerHeader*)(header_buffer);

  lock();

  // get the body of the message
  desired_size = header->length;
  got = 0;
  while (got < desired_size) {
    ASSERT(got + desired_size < buffer_size);
    auto x = read_from_socket(accepted_socket, buffer + got, desired_size - got);
    if (want_exit_callback()) {
      return;
    }
    got += x > 0 ? x : 0;
  }

  switch (header->type) {
    case ReplServerMessageType::PING:
      ping_response();
      break;
    case ReplServerMessageType::EVAL:
      std::string msg;
      msg.assign(buffer, got);
      compile_msg(msg);
      break;
  }

  unlock();
}

void ReplServer::send_data(void* buf, u16 len) {
  lock();
  if (client_connected) {
    int bytes_sent = 0;
    while (bytes_sent < len) {
      int wrote = write_to_socket(accepted_socket, (char*)(buf) + bytes_sent, len - bytes_sent);
      bytes_sent += wrote;
      if (!client_connected || want_exit_callback()) {
        unlock();
        return;
      }
    }
  }
  unlock();
}

void ReplServer::set_compiler(std::shared_ptr<Compiler> _compiler) {
  compiler = std::move(_compiler);
}

void ReplServer::ping_response() {
  std::string ping = fmt::format("Connected to OpenGOAL v{}.{} nREPL!",
                                 versions::GOAL_VERSION_MAJOR, versions::GOAL_VERSION_MINOR);
  lock();
  write_to_socket(accepted_socket, ping.c_str(), ping.size());
  unlock();
}

void ReplServer::compile_msg(const std::string_view& msg) {
  if (compiler == nullptr) {
    return;
  }
  compiler->lock();
  compiler->eval_and_print(compiler->read_from_string(msg.data()));
  compiler->unlock();
}