#include <cstdio>
#include <SDL3/SDL.h>
#include <GL/glew.h>
#include <SDL3/SDL_events.h>

#include "terminal.h"
#include "client_network.h"
#include "gfx/txt_renderer.h"
#include "gfx/types.h"

Terminal::Terminal(ClientNetwork* network) : _network(network) {
  /* Placeholder welcome message to history. */
  _should_close   = false;
  _scroll_offset  = 0;
  _prompt         = "";
}

Terminal::~Terminal(void) {}

void Terminal::update(void) {

}

void Terminal::add_history(const std::string& line) {
  std::string line_with_spaces;
  for(char ch : line) {
    if(ch == '\t') {
      line_with_spaces += "   ";
    } else {
      line_with_spaces += ch;
    }
  }
  _history.push_back(line_with_spaces);

  if(line == "__CLOSE_CONNECTION__") {
    _history.back() = "Connection closed by server.";
    _should_close = true;
  }
}

void Terminal::set_prompt(const std::string& prompt) {
  _prompt = prompt;
}

bool Terminal::close(void) { return _should_close; }

void Terminal::_on_ret_press(void) {
  std::string command = _input_buffer;
  _input_buffer.clear(); /* Clear the input buffer immediately. */

  /* Add the command to history. */
  _history.push_back(_prompt + "> " + command);

  if(command == "clear") {
    _history.clear();
    return;
  }

  _network->send(command);

  /* TODO: Ugly hack. Refactor to pass window height
   * We need the window height to know if we should
   * auto-scroll, but we don't have it here.
   * Assume the height of 500 for now.
   */
  int visible_lines = (500-5.0f)/20.0f; /* Subtract padding. */
  if((int)_history.size()+1 > visible_lines) {
    _scroll_offset = (_history.size()+1) - visible_lines+1;
  }
}

void Terminal::handle_input(SDL_Event* event) {
  if(event->type == SDL_EVENT_TEXT_INPUT) {
    /* Append chars to the input buffer. */
    _input_buffer += event->text.text;
  } else if(event->type == SDL_EVENT_KEY_DOWN) {
    /* Handle special keys. */
    if(event->key.key == SDLK_BACKSPACE && _input_buffer.length() > 0) {
      _input_buffer.pop_back();
    } else if(event->key.key == SDLK_RETURN) {
      _on_ret_press();
    }
  }
}

void Terminal::scroll(int amount, int win_content_height) {
  /* amount > 0 = scroll up. amount < 0 = scroll down. */
  _scroll_offset += amount;

  /* Lower bound: Don't scroll below the top of the history. */
  if(_scroll_offset < 0) {
    _scroll_offset = 0;
  }
  /* Upper bound: Don't scroll past the last command. */
  float line_height = 20.0f;
  int visible_lines = win_content_height / line_height;
  int max_scroll = (_history.size()+1) - visible_lines;
  if(max_scroll < 0) max_scroll = 0;
  if(_scroll_offset > max_scroll) {
    _scroll_offset = max_scroll;
  }
}

void Terminal::render(TextRenderer* renderer, int x, int y, int width, int height,
                      bool show_cursor) {

  const Color white = { 1.0f, 1.0f, 1.0f };
  const Color green = { 0.2f, 1.0f, 0.2f };
  float line_height = 20.0f;
  float padding     = 5.0f;

  /* Enable scissor test to clip rendering to the window content area. */
  glEnable(GL_SCISSOR_TEST);
  glScissor(x, y, width, height);

  /* Draw History. */
  for(size_t i = _scroll_offset; i < _history.size(); ++i) {
    float y_pos = (y+height) - padding - line_height - ((i - _scroll_offset) * line_height);
    renderer->render_text(_history[i].c_str(), x+padding, y_pos, 1.0f, white);
  }

  /* Draw current input line. */
  std::string line_to_render = _prompt + "> " + _input_buffer;
  if(show_cursor) {
    line_to_render += "_";
  }
  float prompt_y_pos = (y+height) - padding - line_height
    - ((_history.size()-_scroll_offset)*line_height);
  renderer->render_text(line_to_render.c_str(), x+padding, prompt_y_pos, 1.0f, green);

  /* Disable scissor test. */
  glDisable(GL_SCISSOR_TEST);
}