#include "apps/mtr_app.h"
#include "external/mtr/arrival.h"
#include "esp_log.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"

#define TAG "MtrApp"

// Event type for network ready
#define EVENT_NETWORK_READY 1

MtrApp::MtrApp() {
  _mtr_handler = std::make_unique<MTRNextTrainHandler>();
}

esp_err_t MtrApp::init(lv_obj_t* container) {
  if (!container) {
    ESP_LOGE(TAG, "Container is null");
    return ESP_ERR_INVALID_ARG;
  }

  _container = container;
  ESP_LOGI(TAG, "Initializing MTR app...");

  // Create page stack
  _page_stack = std::make_unique<PageStack>(container);

  // Load all lines
  _all_lines = _mtr_handler->get_lines();
  ESP_LOGI(TAG, "Loaded %zu MTR lines", _all_lines.size());

  // Build initial line selection page
  _page_stack->push([this](lv_obj_t* page) {
    this->build_line_selection_page(page);
    });

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

esp_err_t MtrApp::deinit(void) {
  ESP_LOGI(TAG, "Deinitializing MTR app");

  // Clear page stack
  if (_page_stack) {
    _page_stack->clear();
    _page_stack.reset();
  }

  // Clear state
  _selected_line_code.clear();
  _selected_station_code.clear();
  _selected_line_info = nullptr;
  _all_lines.clear();

  return ESP_OK;
}

std::string MtrApp::get_name(void) const {
  return "MTR";
}

bool MtrApp::on_back_button_pressed(void) {
  if (_page_stack && _page_stack->depth() > 1) {
    _page_stack->pop();
    return true;  // Handled
  }
  return false;  // Not handled, go back to main menu
}

void MtrApp::handle_event(uint32_t event_type, void* event_data) {
  if (event_type == EVENT_NETWORK_READY) {
    ESP_LOGI(TAG, "Network ready event received");
  }
}

void MtrApp::build_line_selection_page(lv_obj_t* page_container) {
  ESP_LOGI(TAG, "Building line selection page");

  // Title
  lv_obj_t* title = lv_label_create(page_container);
  lv_label_set_text(title, "選擇路綫 Select Line");
  lv_obj_set_style_text_color(title, lv_color_black(), 0);
  lv_obj_align(title, LV_ALIGN_TOP_MID, 0, 10);

  // Scrollable container for line buttons
  lv_obj_t* scroll_container = lv_obj_create(page_container);
  lv_obj_set_size(scroll_container, lv_pct(95), lv_pct(85));
  lv_obj_align(scroll_container, LV_ALIGN_TOP_MID, 0, 40);
  lv_obj_set_flex_flow(scroll_container, LV_FLEX_FLOW_COLUMN);
  lv_obj_set_flex_align(scroll_container, LV_FLEX_ALIGN_START, LV_FLEX_ALIGN_CENTER, LV_FLEX_ALIGN_CENTER);
  lv_obj_set_style_pad_all(scroll_container, 5, 0);
  lv_obj_set_style_pad_row(scroll_container, 8, 0);

  // Create button for each line
  for (size_t i = 0; i < _all_lines.size(); i++) {
    LineInfo* line = &_all_lines[i];

    lv_obj_t* btn = lv_btn_create(scroll_container);
    lv_obj_set_size(btn, lv_pct(95), 60);

    // Set button color based on line color
    uint32_t color = parse_color_hex(line->color());
    lv_obj_set_style_bg_color(btn, lv_color_hex(color), 0);

    // Button label
    lv_obj_t* label = lv_label_create(btn);
    lv_label_set_text_fmt(label, "%s", line->code());
    lv_obj_set_style_text_color(label, lv_color_white(), 0);
    lv_obj_center(label);

    // Store line pointer in user data
    lv_obj_add_event_cb(btn, line_button_event_cb, LV_EVENT_CLICKED, this);
    lv_obj_set_user_data(btn, (void*)line);
  }

  ESP_LOGI(TAG, "Created %zu line buttons", _all_lines.size());
}

void MtrApp::build_station_selection_page(lv_obj_t* page_container) {
  ESP_LOGI(TAG, "Building station selection page for line: %s", _selected_line_code.c_str());

  if (!_selected_line_info) {
    ESP_LOGE(TAG, "No line info selected");
    return;
  }

  // Title with line code
  lv_obj_t* title = lv_label_create(page_container);
  lv_label_set_text_fmt(title, "%s 路綫車站", _selected_line_code.c_str());
  lv_obj_set_style_text_color(title, lv_color_black(), 0);
  lv_obj_align(title, LV_ALIGN_TOP_MID, 0, 10);

  // Scrollable container for station buttons
  lv_obj_t* scroll_container = lv_obj_create(page_container);
  lv_obj_set_size(scroll_container, lv_pct(95), lv_pct(85));
  lv_obj_align(scroll_container, LV_ALIGN_TOP_MID, 0, 40);
  lv_obj_set_flex_flow(scroll_container, LV_FLEX_FLOW_COLUMN);
  lv_obj_set_flex_align(scroll_container, LV_FLEX_ALIGN_START, LV_FLEX_ALIGN_CENTER, LV_FLEX_ALIGN_CENTER);
  lv_obj_set_style_pad_all(scroll_container, 5, 0);
  lv_obj_set_style_pad_row(scroll_container, 6, 0);

  // Create button for each station
  const std::vector<StationInfo>* stations = _selected_line_info->stations();
  for (size_t i = 0; i < stations->size(); i++) {
    const StationInfo* station = &(*stations)[i];

    lv_obj_t* btn = lv_btn_create(scroll_container);
    lv_obj_set_size(btn, lv_pct(95), 50);
    lv_obj_set_style_bg_color(btn, lv_color_hex(0x4CAF50), 0);

    // Button label with station name and code
    lv_obj_t* label = lv_label_create(btn);
    lv_label_set_text_fmt(label, "%s (%s)", station->name(), station->code());
    lv_obj_set_style_text_color(label, lv_color_white(), 0);
    lv_obj_center(label);

    // Store station pointer in user data
    lv_obj_add_event_cb(btn, station_button_event_cb, LV_EVENT_CLICKED, this);
    lv_obj_set_user_data(btn, (void*)station);
  }

  ESP_LOGI(TAG, "Created %zu station buttons", stations->size());
}

void MtrApp::build_arrival_page(lv_obj_t* page_container) {
  ESP_LOGI(TAG, "Building arrival page");

  // Title
  lv_obj_t* title = lv_label_create(page_container);
  lv_label_set_text_fmt(title, "%s - %s", _selected_line_code.c_str(), _selected_station_code.c_str());
  lv_obj_set_style_text_color(title, lv_color_black(), 0);
  lv_obj_align(title, LV_ALIGN_TOP_MID, 0, 10);

  // Loading message
  lv_obj_t* loading_label = lv_label_create(page_container);
  lv_label_set_text(loading_label, "載入中... Loading...");
  lv_obj_set_style_text_color(loading_label, lv_color_black(), 0);
  lv_obj_center(loading_label);

  // Refresh button
  lv_obj_t* refresh_btn = lv_btn_create(page_container);
  lv_obj_set_size(refresh_btn, 120, 50);
  lv_obj_align(refresh_btn, LV_ALIGN_BOTTOM_MID, 0, -10);
  lv_obj_add_event_cb(refresh_btn, refresh_button_event_cb, LV_EVENT_CLICKED, this);

  lv_obj_t* refresh_label = lv_label_create(refresh_btn);
  lv_label_set_text(refresh_label, LV_SYMBOL_REFRESH " 重新整理");
  lv_obj_set_style_text_color(refresh_label, lv_color_white(), 0);
  lv_obj_center(refresh_label);

  // Load arrival data asynchronously
  load_arrival_data(page_container);
}

void MtrApp::load_arrival_data(lv_obj_t* page_container) {
  if (!_network_handler) {
    ESP_LOGW(TAG, "Network handler not set, cannot fetch arrival data");
    // Update UI to show error
    lv_obj_t* error_label = lv_label_create(page_container);
    lv_label_set_text(error_label, "網絡未就緒\nNetwork not ready");
    lv_obj_set_style_text_color(error_label, lv_color_black(), 0);
    lv_obj_align(error_label, LV_ALIGN_CENTER, 0, -30);
    return;
  }

  ESP_LOGI(TAG, "Fetching arrival data for %s/%s", _selected_line_code.c_str(), _selected_station_code.c_str());

  StationArrivalInfo* arrival_info = nullptr;
  MtrArrivalErrorCode error_code = _mtr_handler->get_next_arrival_info(
    _network_handler,
    _selected_line_code,
    _selected_station_code,
    arrival_info,
    Language::TC
  );

  // Clear loading message
  lv_obj_clean(page_container);

  // Recreate title
  lv_obj_t* title = lv_label_create(page_container);
  lv_label_set_text_fmt(title, "%s - %s", _selected_line_code.c_str(), _selected_station_code.c_str());
  lv_obj_set_style_text_color(title, lv_color_black(), 0);
  lv_obj_align(title, LV_ALIGN_TOP_MID, 0, 10);

  if (error_code != MtrArrivalErrorCode::NONE || !arrival_info) {
    ESP_LOGE(TAG, "Failed to fetch arrival info, error code: %d", (int)error_code);

    lv_obj_t* error_label = lv_label_create(page_container);
    lv_label_set_text(error_label, "無法取得班次資料\nFailed to fetch arrival data");
    lv_obj_set_style_text_color(error_label, lv_color_black(), 0);
    lv_obj_center(error_label);
    return;
  }

  // Create scrollable container for arrivals
  lv_obj_t* scroll_container = lv_obj_create(page_container);
  lv_obj_set_size(scroll_container, lv_pct(95), lv_pct(75));
  lv_obj_align(scroll_container, LV_ALIGN_TOP_MID, 0, 45);
  lv_obj_set_style_pad_all(scroll_container, 10, 0);

  int y_offset = 0;

  // Display UP direction trains
  lv_obj_t* up_header = lv_label_create(scroll_container);
  lv_label_set_text(up_header, "上行 UP:");
  lv_obj_set_style_text_color(up_header, lv_color_black(), 0);
  lv_obj_set_pos(up_header, 0, y_offset);
  y_offset += 30;

  const std::vector<ArrivalInfo>* up_arrivals = arrival_info->up_arrivals();
  if (up_arrivals->empty()) {
    lv_obj_t* no_train = lv_label_create(scroll_container);
    lv_label_set_text(no_train, "  暫無班次 No trains");
    lv_obj_set_style_text_color(no_train, lv_color_hex(0x666666), 0);
    lv_obj_set_pos(no_train, 10, y_offset);
    y_offset += 25;
  } else {
    for (const auto& arrival : *up_arrivals) {
      lv_obj_t* arrival_label = lv_label_create(scroll_container);
      lv_label_set_text_fmt(arrival_label, "  %s → %s", arrival.arrival_time(), arrival.destination());
      lv_obj_set_style_text_color(arrival_label, lv_color_black(), 0);
      lv_obj_set_pos(arrival_label, 10, y_offset);
      y_offset += 25;
    }
  }

  y_offset += 10;

  // Display DOWN direction trains
  lv_obj_t* down_header = lv_label_create(scroll_container);
  lv_label_set_text(down_header, "下行 DOWN:");
  lv_obj_set_style_text_color(down_header, lv_color_black(), 0);
  lv_obj_set_pos(down_header, 0, y_offset);
  y_offset += 30;

  const std::vector<ArrivalInfo>* down_arrivals = arrival_info->down_arrivals();
  if (down_arrivals->empty()) {
    lv_obj_t* no_train = lv_label_create(scroll_container);
    lv_label_set_text(no_train, "  暫無班次 No trains");
    lv_obj_set_style_text_color(no_train, lv_color_hex(0x666666), 0);
    lv_obj_set_pos(no_train, 10, y_offset);
    y_offset += 25;
  } else {
    for (const auto& arrival : *down_arrivals) {
      lv_obj_t* arrival_label = lv_label_create(scroll_container);
      lv_label_set_text_fmt(arrival_label, "  %s → %s", arrival.arrival_time(), arrival.destination());
      lv_obj_set_style_text_color(arrival_label, lv_color_black(), 0);
      lv_obj_set_pos(arrival_label, 10, y_offset);
      y_offset += 25;
    }
  }

  // Clean up
  if (arrival_info != nullptr) {
    delete arrival_info;
  }

  // Refresh button
  lv_obj_t* refresh_btn = lv_btn_create(page_container);
  lv_obj_set_size(refresh_btn, 120, 50);
  lv_obj_align(refresh_btn, LV_ALIGN_BOTTOM_MID, 0, -10);
  lv_obj_add_event_cb(refresh_btn, refresh_button_event_cb, LV_EVENT_CLICKED, this);

  lv_obj_t* refresh_label = lv_label_create(refresh_btn);
  lv_label_set_text(refresh_label, LV_SYMBOL_REFRESH " 重新整理");
  lv_obj_set_style_text_color(refresh_label, lv_color_white(), 0);
  lv_obj_center(refresh_label);

  ESP_LOGI(TAG, "Arrival data displayed successfully");
}

uint32_t MtrApp::parse_color_hex(const char* hex_str) {
  if (!hex_str || hex_str[0] != '#') {
    return 0x808080;  // Default gray
  }

  // Skip the '#' character
  hex_str++;

  uint32_t color = 0;
  sscanf(hex_str, "%" SCNx32, &color);
  return color;
}

void MtrApp::line_button_event_cb(lv_event_t* e) {
  lv_event_code_t code = lv_event_get_code(e);
  if (code == LV_EVENT_CLICKED) {
    MtrApp* app = (MtrApp*)lv_event_get_user_data(e);
    lv_obj_t* btn = (lv_obj_t*)lv_event_get_target(e);
    LineInfo* line = (LineInfo*)lv_obj_get_user_data(btn);

    if (app && line) {
      ESP_LOGI(TAG, "Line selected: %s", line->code());
      app->_selected_line_code = line->code();
      app->_selected_line_info = line;

      // Push station selection page
      app->_page_stack->push([app](lv_obj_t* page) {
        app->build_station_selection_page(page);
        });
    }
  }
}

void MtrApp::station_button_event_cb(lv_event_t* e) {
  lv_event_code_t code = lv_event_get_code(e);
  if (code == LV_EVENT_CLICKED) {
    MtrApp* app = (MtrApp*)lv_event_get_user_data(e);
    lv_obj_t* btn = (lv_obj_t*)lv_event_get_target(e);
    const StationInfo* station = (const StationInfo*)lv_obj_get_user_data(btn);

    if (app && station) {
      ESP_LOGI(TAG, "Station selected: %s (%s)", station->name(), station->code());
      app->_selected_station_code = station->code();

      // Push arrival page
      app->_page_stack->push([app](lv_obj_t* page) {
        app->build_arrival_page(page);
        });
    }
  }
}

void MtrApp::refresh_button_event_cb(lv_event_t* e) {
  lv_event_code_t code = lv_event_get_code(e);
  if (code == LV_EVENT_CLICKED) {
    MtrApp* app = (MtrApp*)lv_event_get_user_data(e);
    if (app && app->_page_stack && app->_page_stack->current_page()) {
      ESP_LOGI(TAG, "Refresh button clicked");
      app->load_arrival_data(app->_page_stack->current_page());
    }
  }
}

// MtrAppDescriptor implementation
MtrApp* MtrAppDescriptor::_app_instance = nullptr;

MtrAppDescriptor::MtrAppDescriptor()
  : AppDescriptor("MTR", []() -> UIApp* {
  if (!MtrAppDescriptor::_app_instance) {
    MtrAppDescriptor::_app_instance = new MtrApp();
  }
  return MtrAppDescriptor::_app_instance;
    }()) {
  // Register with AppRegistry
  AppRegistry::instance().register_app(this);
  ESP_LOGI(TAG, "MtrApp registered with AppRegistry");
}

void MtrAppDescriptor::draw_icon(lv_obj_t* parent) {
  // Create MTR icon with train symbol
  lv_obj_t* icon_label = lv_label_create(parent);
  lv_label_set_text(icon_label, LV_SYMBOL_GPS "\nMTR");
  lv_obj_set_style_text_color(icon_label, lv_color_white(), 0);
  lv_obj_set_style_text_align(icon_label, LV_TEXT_ALIGN_CENTER, 0);
  lv_obj_center(icon_label);
}