/**
 * Trading Notifications Store
 *
 * Zustand store for managing in-app trading notifications.
 * Handles toasts, notification history, and settings.
 */

import { create } from "zustand";
import { persist } from "zustand/middleware";
import type {
  TradingNotification,
  NotificationSettings,
  CreateNotificationOptions,
  NotificationType,
  SoundType,
} from "../types";
import {
  DEFAULT_NOTIFICATION_SETTINGS,
  MAX_STORED_NOTIFICATIONS,
  NOTIFICATION_SETTINGS_KEY,
} from "../types";

// ============================================================================
// TOAST TIMEOUT TRACKING
// Prevents memory leaks by tracking setTimeout IDs for auto-dismiss
// ============================================================================
const toastTimeouts = new Map<string, NodeJS.Timeout>();

/**
 * Clear a specific toast timeout
 */
function clearToastTimeout(id: string): void {
  const timeoutId = toastTimeouts.get(id);
  if (timeoutId) {
    clearTimeout(timeoutId);
    toastTimeouts.delete(id);
  }
}

/**
 * Clear all toast timeouts (for cleanup)
 */
function clearAllToastTimeouts(): void {
  for (const [id, timeoutId] of toastTimeouts) {
    clearTimeout(timeoutId);
  }
  toastTimeouts.clear();
}

// ============================================================================
// STORE STATE INTERFACE
// ============================================================================

interface TradingNotificationsState {
  // Notification list
  notifications: TradingNotification[];
  // Active toasts (currently showing)
  activeToasts: TradingNotification[];
  // Unread count
  unreadCount: number;
  // Settings
  settings: NotificationSettings;

  // Actions
  addNotification: (options: CreateNotificationOptions) => string;
  removeNotification: (id: string) => void;
  markAsRead: (id: string) => void;
  markAllAsRead: () => void;
  clearNotifications: () => void;
  clearOldNotifications: (maxAge: number) => void;

  // Toast management
  dismissToast: (id: string) => void;
  dismissAllToasts: () => void;

  // Settings
  updateSettings: (settings: Partial<NotificationSettings>) => void;
  resetSettings: () => void;

  // Helpers
  isInQuietHours: () => boolean;
  shouldShowNotification: (type: NotificationType) => boolean;
  shouldPlaySound: (type: NotificationType) => boolean;
  shouldShowPush: (type: NotificationType) => boolean;
}

// ============================================================================
// HELPER FUNCTIONS
// ============================================================================

function generateId(): string {
  return `notif-${Date.now()}-${Math.random().toString(36).substr(2, 9)}`;
}

function isInQuietHours(settings: NotificationSettings): boolean {
  if (!settings.quietHoursEnabled) return false;

  const now = new Date();
  const currentHours = now.getHours();
  const currentMinutes = now.getMinutes();
  const currentTime = currentHours * 60 + currentMinutes;

  const [startH, startM] = settings.quietHoursStart.split(":").map(Number);
  const [endH, endM] = settings.quietHoursEnd.split(":").map(Number);
  const startTime = startH * 60 + startM;
  const endTime = endH * 60 + endM;

  // Handle overnight quiet hours (e.g., 22:00 - 08:00)
  if (startTime > endTime) {
    return currentTime >= startTime || currentTime < endTime;
  }

  return currentTime >= startTime && currentTime < endTime;
}

// ============================================================================
// STORE
// ============================================================================

export const useTradingNotificationsStore = create<TradingNotificationsState>()(
  persist(
    (set, get) => ({
      notifications: [],
      activeToasts: [],
      unreadCount: 0,
      settings: DEFAULT_NOTIFICATION_SETTINGS,

      // Add a new notification
      addNotification: (options: CreateNotificationOptions): string => {
        const { settings, notifications, activeToasts } = get();

        // Check if notifications are enabled
        if (!settings.enabled) return "";

        // Check quiet hours
        if (isInQuietHours(settings)) return "";

        // Check type preferences
        const typePrefs = settings.typePreferences[options.type];
        if (!typePrefs?.enabled) return "";

        const id = generateId();
        const notification: TradingNotification = {
          ...options,
          id,
          timestamp: Date.now(),
          read: false,
          showToast: options.showToast ?? typePrefs.showToast,
          playSound: options.playSound ?? typePrefs.playSound,
          duration: options.duration ?? settings.toastDuration,
        };

        // Add to notifications list
        const updatedNotifications = [notification, ...notifications].slice(
          0,
          MAX_STORED_NOTIFICATIONS
        );

        // Add to active toasts if needed
        let updatedToasts = activeToasts;
        if (notification.showToast && settings.toastEnabled) {
          // Limit active toasts
          updatedToasts = [notification, ...activeToasts].slice(
            0,
            settings.maxToasts
          );
        }

        set({
          notifications: updatedNotifications,
          activeToasts: updatedToasts,
          unreadCount: get().unreadCount + 1,
        });

        // Auto-dismiss toast after duration (if not persistent)
        if (notification.showToast && notification.duration && notification.duration > 0) {
          // Track the timeout ID to prevent memory leaks
          const timeoutId = setTimeout(() => {
            // Clean up timeout tracking
            toastTimeouts.delete(id);
            get().dismissToast(id);
          }, notification.duration);
          toastTimeouts.set(id, timeoutId);
        }

        return id;
      },

      // Remove a notification
      removeNotification: (id: string) => {
        const { notifications, activeToasts } = get();
        const notification = notifications.find((n) => n.id === id);
        const wasUnread = notification && !notification.read;

        // Clear any pending timeout for this notification
        clearToastTimeout(id);

        set({
          notifications: notifications.filter((n) => n.id !== id),
          activeToasts: activeToasts.filter((n) => n.id !== id),
          unreadCount: wasUnread
            ? Math.max(0, get().unreadCount - 1)
            : get().unreadCount,
        });
      },

      // Mark notification as read
      markAsRead: (id: string) => {
        const { notifications } = get();
        const notification = notifications.find((n) => n.id === id);

        if (notification && !notification.read) {
          set({
            notifications: notifications.map((n) =>
              n.id === id ? { ...n, read: true } : n
            ),
            unreadCount: Math.max(0, get().unreadCount - 1),
          });
        }
      },

      // Mark all as read
      markAllAsRead: () => {
        const { notifications } = get();
        set({
          notifications: notifications.map((n) => ({ ...n, read: true })),
          unreadCount: 0,
        });
      },

      // Clear all notifications
      clearNotifications: () => {
        // Clear all pending toast timeouts
        clearAllToastTimeouts();

        set({
          notifications: [],
          activeToasts: [],
          unreadCount: 0,
        });
      },

      // Clear old notifications
      clearOldNotifications: (maxAge: number) => {
        const { notifications } = get();
        const cutoff = Date.now() - maxAge;
        const filtered = notifications.filter((n) => n.timestamp > cutoff);
        const unreadFiltered = filtered.filter((n) => !n.read).length;

        set({
          notifications: filtered,
          unreadCount: unreadFiltered,
        });
      },

      // Dismiss a toast
      dismissToast: (id: string) => {
        const { activeToasts } = get();

        // Clear any pending timeout for this toast
        clearToastTimeout(id);

        set({
          activeToasts: activeToasts.filter((n) => n.id !== id),
        });
      },

      // Dismiss all toasts
      dismissAllToasts: () => {
        // Clear all pending toast timeouts
        clearAllToastTimeouts();

        set({ activeToasts: [] });
      },

      // Update settings
      updateSettings: (newSettings: Partial<NotificationSettings>) => {
        const { settings } = get();
        set({
          settings: { ...settings, ...newSettings },
        });
      },

      // Reset settings to defaults
      resetSettings: () => {
        set({ settings: DEFAULT_NOTIFICATION_SETTINGS });
      },

      // Check if in quiet hours
      isInQuietHours: () => {
        return isInQuietHours(get().settings);
      },

      // Check if should show notification
      shouldShowNotification: (type: NotificationType) => {
        const { settings } = get();
        if (!settings.enabled) return false;
        if (isInQuietHours(settings)) return false;
        const typePrefs = settings.typePreferences[type];
        return typePrefs?.enabled ?? true;
      },

      // Check if should play sound
      shouldPlaySound: (type: NotificationType) => {
        const { settings } = get();
        if (!settings.enabled || !settings.sound.enabled) return false;
        if (isInQuietHours(settings)) return false;
        const typePrefs = settings.typePreferences[type];
        return typePrefs?.playSound ?? false;
      },

      // Check if should show push notification
      shouldShowPush: (type: NotificationType) => {
        const { settings } = get();
        if (!settings.enabled || !settings.pushEnabled) return false;
        if (settings.pushPermission !== "granted") return false;
        if (isInQuietHours(settings)) return false;
        const typePrefs = settings.typePreferences[type];
        return typePrefs?.pushNotification ?? false;
      },
    }),
    {
      name: NOTIFICATION_SETTINGS_KEY,
      partialize: (state) => ({
        settings: state.settings,
        // Don't persist active toasts, they should be cleared on reload
      }),
    }
  )
);

// ============================================================================
// SELECTORS
// ============================================================================

export const selectUnreadNotifications = (
  state: TradingNotificationsState
): TradingNotification[] => state.notifications.filter((n) => !n.read);

export const selectNotificationsByType = (
  state: TradingNotificationsState,
  type: NotificationType
): TradingNotification[] => state.notifications.filter((n) => n.type === type);

export const selectRecentNotifications = (
  state: TradingNotificationsState,
  limit: number = 10
): TradingNotification[] => state.notifications.slice(0, limit);