#include "ui/root_layout.h"
#include "ui/ui_handler.h"
#include "ui/app_registry.h"
#include "esp_log.h"

#define TAG "RootLayout"

// Display dimensions
#define DISPLAY_WIDTH 800
#define DISPLAY_HEIGHT 480

// Layout dimensions
#define HEADER_HEIGHT 40
#define NAV_BAR_HEIGHT 50
#define APP_CONTAINER_HEIGHT (DISPLAY_HEIGHT - HEADER_HEIGHT - NAV_BAR_HEIGHT)

// forward-declare local event callback
static void on_home_button_clicked(lv_event_t* event);

RootLayout::RootLayout(UIHandler* ui_handler)
  : _ui_handler(ui_handler) { }

esp_err_t RootLayout::init(lv_obj_t* parent) {
  if (!parent) {
    ESP_LOGE(TAG, "Parent object is null");
    return ESP_ERR_INVALID_ARG;
  }

  ESP_LOGI(TAG, "Initializing RootLayout");

  if (create_layout(parent) != ESP_OK) {
    ESP_LOGE(TAG, "Failed to create layout");
    return ESP_FAIL;
  }

  ESP_LOGI(TAG, "RootLayout initialized successfully");
  return ESP_OK;
}

esp_err_t RootLayout::deinit(void) {
  ESP_LOGI(TAG, "Deinitializing RootLayout");

  // LVGL will handle cleanup when parent is destroyed
  _header = nullptr;
  _header_label = nullptr;
  _app_container = nullptr;
  _nav_bar = nullptr;
  _back_button = nullptr;

  return ESP_OK;
}

esp_err_t RootLayout::create_layout(lv_obj_t* parent) {
  // Configure parent as flexbox column layout
  lv_obj_set_flex_flow(parent, LV_FLEX_FLOW_COLUMN);
  lv_obj_set_flex_align(parent, LV_FLEX_ALIGN_START, LV_FLEX_ALIGN_START, LV_FLEX_ALIGN_START);
  lv_obj_set_style_pad_all(parent, 0, 0);
  lv_obj_set_style_pad_gap(parent, 0, 0);

  // Create header (top, fixed height)
  _header = lv_obj_create(parent);
  lv_obj_set_width(_header, lv_pct(100));
  lv_obj_set_height(_header, HEADER_HEIGHT);
  lv_obj_set_style_bg_color(_header, lv_color_hex(0xFFFFFF), 0);
  lv_obj_set_style_border_width(_header, 0, 0);
  lv_obj_set_style_border_color(_header, lv_color_hex(0x000000), 0);
  lv_obj_set_style_border_width(_header, 1, LV_BORDER_SIDE_BOTTOM);
  lv_obj_set_style_pad_all(_header, 0, 0);
  lv_obj_set_style_radius(_header, 0, 0);

  _header_label = lv_label_create(_header);
  lv_label_set_text(_header_label, "App");
  lv_obj_set_style_text_color(_header_label, lv_color_black(), 0);
  lv_obj_align(_header_label, LV_ALIGN_LEFT_MID, 10, 0);

  // Create app container (middle, flexible - grows to fill available space)
  _app_container = lv_obj_create(parent);
  lv_obj_set_width(_app_container, lv_pct(100));
  lv_obj_set_flex_grow(_app_container, 1);
  lv_obj_set_style_bg_color(_app_container, lv_color_white(), 0);
  lv_obj_set_style_border_width(_app_container, 0, 0);
  lv_obj_set_style_pad_all(_app_container, 0, 0);
  lv_obj_set_style_radius(_app_container, 0, 0);

  // Create navigation bar (bottom, fixed height)
  _nav_bar = lv_obj_create(parent);
  lv_obj_set_width(_nav_bar, lv_pct(100));
  lv_obj_set_height(_nav_bar, NAV_BAR_HEIGHT);
  lv_obj_set_style_bg_color(_nav_bar, lv_color_hex(0xFFFFFF), 0);
  lv_obj_set_style_border_color(_nav_bar, lv_color_hex(0x000000), 0);
  lv_obj_set_style_border_width(_nav_bar, 1, LV_BORDER_SIDE_TOP);
  lv_obj_set_style_pad_all(_nav_bar, 5, 0);
  lv_obj_set_style_radius(_nav_bar, 0, 0);

  // Configure nav bar as flexbox row layout with space-between
  lv_obj_set_flex_flow(_nav_bar, LV_FLEX_FLOW_ROW);
  lv_obj_set_flex_align(_nav_bar, LV_FLEX_ALIGN_SPACE_BETWEEN, LV_FLEX_ALIGN_CENTER, LV_FLEX_ALIGN_CENTER);

  // Create back button (aligned to start by flex layout)
  _back_button = lv_btn_create(_nav_bar);
  lv_obj_set_size(_back_button, 60, NAV_BAR_HEIGHT - 10);
  lv_obj_set_style_bg_color(_back_button, lv_color_hex(0x555555), 0);
  lv_obj_add_event_cb(_back_button, on_back_button_clicked, LV_EVENT_CLICKED, _ui_handler);
  lv_obj_add_flag(_back_button, LV_OBJ_FLAG_HIDDEN);

  // Add back arrow label
  lv_obj_t* back_label = lv_label_create(_back_button);
  lv_label_set_text(back_label, LV_SYMBOL_LEFT);
  lv_obj_set_style_text_color(back_label, lv_color_black(), 0);
  lv_obj_align(back_label, LV_ALIGN_CENTER, 0, 0);

  // Create home button (aligned to end by flex layout)
  lv_obj_t* home_button = lv_btn_create(_nav_bar);
  lv_obj_set_size(home_button, 60, NAV_BAR_HEIGHT - 10);
  lv_obj_set_style_bg_color(home_button, lv_color_hex(0x555555), 0);
  lv_obj_t* home_label = lv_label_create(home_button);
  lv_label_set_text(home_label, LV_SYMBOL_HOME);
  lv_obj_set_style_text_color(home_label, lv_color_white(), 0);
  lv_obj_align(home_label, LV_ALIGN_CENTER, 0, 0);
  lv_obj_add_event_cb(home_button, on_home_button_clicked, LV_EVENT_CLICKED, _ui_handler);

  ESP_LOGI(TAG, "Layout created with flexible design: Header=%d, NavBar=%d",
    HEADER_HEIGHT, NAV_BAR_HEIGHT);

  return ESP_OK;
}

void RootLayout::update_header(std::string app_name) {
  if (!_header_label) {
    return;
  }

  if (app_name.empty() == false) {
    lv_label_set_text(_header_label, app_name.c_str());
  } else {
    lv_label_set_text(_header_label, "App");
  }
}

esp_err_t RootLayout::render_app_icons(void) {
  if (!_nav_bar) {
    ESP_LOGE(TAG, "Navigation bar not initialized");
    return ESP_FAIL;
  }

  // Clear existing app container content (icons are rendered in the app area)
  if (!_app_container) {
    ESP_LOGE(TAG, "App container not initialized");
    return ESP_FAIL;
  }
  lv_obj_clean(_app_container);

  // Get all registered apps from registry
  const auto& app_descriptors = AppRegistry::instance().get_app_descriptors();

  if (app_descriptors.empty()) {
    ESP_LOGW(TAG, "No apps registered in AppRegistry");
    lv_obj_t* nav_label = lv_label_create(_nav_bar);
    lv_label_set_text(nav_label, "No apps available");
    lv_obj_set_style_text_color(nav_label, lv_color_white(), 0);
    lv_obj_align(nav_label, LV_ALIGN_CENTER, 0, 0);
    return ESP_OK;
  }

  ESP_LOGI(TAG, "Rendering %d app icons", (int)app_descriptors.size());

  // Calculate icon spacing inside the app container
  int icon_count = app_descriptors.size();
  int icon_width = 96;
  int icon_height = 96;
  int icon_spacing = DISPLAY_WIDTH / (icon_count + 1);
  int x_offset = icon_spacing;
  int y_offset = (APP_CONTAINER_HEIGHT - icon_height) / 2;

  // Render each app icon into the app container
  for (size_t i = 0; i < app_descriptors.size(); i++) {
    AppDescriptor* descriptor = app_descriptors[i];

    lv_obj_t* icon_container = lv_obj_create(_app_container);
    lv_obj_set_size(icon_container, icon_width, icon_height);
    lv_obj_set_pos(icon_container, x_offset - icon_width / 2, y_offset);
    lv_obj_set_style_bg_opa(icon_container, LV_OPA_TRANSP, 0);
    lv_obj_set_style_pad_all(icon_container, 0, 0);
    // add a border for debugging
    lv_obj_set_style_border_color(icon_container, lv_color_hex(0x000000), 0);
    lv_obj_set_style_border_width(icon_container, 1, 0);

    lv_obj_set_user_data(icon_container, descriptor);

    descriptor->draw_icon(icon_container);

    lv_obj_add_flag(icon_container, LV_OBJ_FLAG_CLICKABLE);
    lv_obj_add_event_cb(icon_container, on_app_icon_clicked, LV_EVENT_CLICKED, _ui_handler);

    x_offset += icon_spacing;
  }

  return ESP_OK;
}

void RootLayout::show_back_button(void) {
  if (_back_button) {
    lv_obj_clear_flag(_back_button, LV_OBJ_FLAG_HIDDEN);
  }
}

void RootLayout::hide_back_button(void) {
  if (_back_button) {
    lv_obj_add_flag(_back_button, LV_OBJ_FLAG_HIDDEN);
  }
}

void RootLayout::on_app_icon_clicked(lv_event_t* event) {
  // Use the current target (the object the callback was attached to)
  // instead of the event target, which may be a child (like a label).
  lv_obj_t* icon_container = static_cast<lv_obj_t*>(lv_event_get_current_target(event));
  UIHandler* handler = static_cast<UIHandler*>(lv_event_get_user_data(event));
  AppDescriptor* descriptor = static_cast<AppDescriptor*>(lv_obj_get_user_data(icon_container));

  if (!handler || !descriptor) {
    ESP_LOGE(TAG, "Invalid event data in app icon click");
    return;
  }

  ESP_LOGI(TAG, "App icon clicked: %s", descriptor->get_name().c_str());
  handler->switch_app(descriptor);
}

void RootLayout::on_back_button_clicked(lv_event_t* event) {
  UIHandler* handler = static_cast<UIHandler*>(lv_event_get_user_data(event));

  if (!handler) {
    ESP_LOGE(TAG, "Invalid handler in back button click");
    return;
  }

  // Get the active app
  UIApp* active_app = handler->get_active_app();
  if (!active_app) {
    ESP_LOGW(TAG, "Back button pressed but no active app");
    return;
  }

  // Let the app handle the back button press
  bool handled = active_app->on_back_button_pressed();

  if (handled) {
    ESP_LOGI(TAG, "Back button handled by app: %s", active_app->get_name());
  } else {
    ESP_LOGI(TAG, "Back button not handled by app, returning to main screen");
    handler->return_to_main_screen();
  }
}

static void on_home_button_clicked(lv_event_t* event) {
  UIHandler* handler = static_cast<UIHandler*>(lv_event_get_user_data(event));

  if (!handler) {
    ESP_LOGE(TAG, "Invalid handler in home button click");
    return;
  }

  handler->return_to_main_screen();
}