/**
 * NavigationController - Centralized navigation logic for WellNuo app
 *
 * This service provides all routing decisions based on user state,
 * beneficiary data, and equipment status.
 *
 * USAGE:
 * import { NavigationController } from '@/services/NavigationController';
 * const { path, params } = NavigationController.getRouteAfterLogin(profile, beneficiaries);
 * router.replace(path);
 */

import type { Beneficiary, EquipmentStatus } from '@/types';

// ==================== ROUTE CONSTANTS ====================

export const ROUTES = {
  // Auth Flow
  AUTH: {
    LOGIN: '/(auth)/login',
    VERIFY_OTP: '/(auth)/verify-otp',
    ENTER_NAME: '/(auth)/enter-name',
    ADD_LOVED_ONE: '/(auth)/add-loved-one',
    PURCHASE: '/(auth)/purchase',
    ACTIVATE: '/(auth)/activate',
    WELCOME_BACK: '/(auth)/welcome-back',
    COMPLETE_PROFILE: '/(auth)/complete-profile',
  },
  // Main Tabs
  TABS: {
    DASHBOARD: '/(tabs)/dashboard',
    BENEFICIARIES: '/(tabs)',  // index.tsx shows beneficiary list
    CHAT: '/(tabs)/chat',
    VOICE: '/(tabs)/voice',
    PROFILE: '/(tabs)/profile',
  },
  // Beneficiary Management
  BENEFICIARY: {
    ADD: '/(tabs)/beneficiaries/add',
    DETAIL: (id: number) => `/(tabs)/beneficiaries/${id}` as const,
    SUBSCRIPTION: (id: number) => `/(tabs)/beneficiaries/${id}/subscription` as const,
    EQUIPMENT: (id: number) => `/(tabs)/beneficiaries/${id}/equipment` as const,
    SHARE: (id: number) => `/(tabs)/beneficiaries/${id}/share` as const,
  },
  // Profile
  PROFILE: {
    INDEX: '/(tabs)/profile',
    EDIT: '/(tabs)/profile/edit',
    NOTIFICATIONS: '/(tabs)/profile/notifications',
    LANGUAGE: '/(tabs)/profile/language',
    PRIVACY: '/(tabs)/profile/privacy',
    TERMS: '/(tabs)/profile/terms',
    SUPPORT: '/(tabs)/profile/support',
    ABOUT: '/(tabs)/profile/about',
    HELP: '/(tabs)/profile/help',
  },
} as const;

// ==================== TYPE DEFINITIONS ====================

export interface NavigationResult {
  path: string;
  params?: Record<string, string | number | boolean>;
}

export interface UserProfile {
  id: number;
  email: string;
  firstName: string | null;
  lastName: string | null;
  phone: string | null;
}

// ==================== NAVIGATION CONTROLLER ====================

export const NavigationController = {
  /**
   * Determine where to navigate after successful OTP verification
   *
   * Flow:
   * 1. New user without name → enter-name
   * 2. User without beneficiaries → add-loved-one
   * 3. User has beneficiary without devices → check hasDevices
   *    - hasDevices=false → purchase (need to buy equipment)
   *    - hasDevices=true but equipment not activated → activate
   * 4. User has active beneficiary → dashboard
   */
  getRouteAfterLogin(
    profile: UserProfile | null,
    beneficiaries: Beneficiary[]
  ): NavigationResult {
    // Step 1: Check if user has name
    if (!profile?.firstName) {
      return {
        path: ROUTES.AUTH.ENTER_NAME,
      };
    }

    // Step 2: Check if user has any beneficiaries
    if (!beneficiaries || beneficiaries.length === 0) {
      return {
        path: ROUTES.AUTH.ADD_LOVED_ONE,
      };
    }

    // Step 3: Multiple beneficiaries - go to list, let user choose
    if (beneficiaries.length > 1) {
      return {
        path: ROUTES.TABS.BENEFICIARIES,
      };
    }

    // Step 4: Single beneficiary - check if needs setup
    const singleBeneficiary = beneficiaries[0];
    const isActive = singleBeneficiary.hasDevices ||
                     singleBeneficiary.equipmentStatus === 'active' ||
                     singleBeneficiary.equipmentStatus === 'demo';

    if (isActive) {
      // Single active beneficiary - go to dashboard
      return {
        path: ROUTES.TABS.DASHBOARD,
      };
    }

    // Single beneficiary needs setup
    return this.getRouteForBeneficiarySetup(singleBeneficiary);
  },

  /**
   * Determine where to navigate for beneficiary equipment setup
   */
  getRouteForBeneficiarySetup(beneficiary: Beneficiary): NavigationResult {
    const status = beneficiary.equipmentStatus || 'none';

    switch (status) {
      case 'none':
        // No equipment ordered - go to purchase
        return {
          path: ROUTES.AUTH.PURCHASE,
          params: { beneficiaryId: beneficiary.id },
        };

      case 'ordered':
      case 'shipped':
        // Equipment is on the way - can show tracking or wait screen
        // For now, go to equipment status page
        return {
          path: ROUTES.BENEFICIARY.EQUIPMENT(beneficiary.id),
          params: { beneficiaryId: beneficiary.id },
        };

      case 'delivered':
        // Equipment delivered, needs activation
        return {
          path: ROUTES.AUTH.ACTIVATE,
          params: { beneficiaryId: beneficiary.id },
        };

      case 'active':
      case 'demo':
        // Already active, go to dashboard
        return {
          path: ROUTES.TABS.DASHBOARD,
        };

      default:
        // Unknown status - go to dashboard
        return {
          path: ROUTES.TABS.DASHBOARD,
        };
    }
  },

  /**
   * After creating a new beneficiary, determine next step
   *
   * @param beneficiaryId - ID of newly created beneficiary
   * @param hasExistingDevices - User indicated they already have WellNuo devices
   */
  getRouteAfterAddBeneficiary(
    beneficiaryId: number,
    hasExistingDevices: boolean
  ): NavigationResult {
    if (hasExistingDevices) {
      // User has existing devices - go directly to activation
      return {
        path: ROUTES.AUTH.ACTIVATE,
        params: { beneficiaryId },
      };
    }

    // User needs to purchase equipment
    return {
      path: ROUTES.AUTH.PURCHASE,
      params: { beneficiaryId },
    };
  },

  /**
   * After successful purchase, navigate to next step
   */
  getRouteAfterPurchase(
    beneficiaryId: number,
    purchaseResult: { skipToActivate?: boolean; demo?: boolean }
  ): NavigationResult {
    if (purchaseResult.demo || purchaseResult.skipToActivate) {
      // Demo mode or skip - go to activate
      return {
        path: ROUTES.AUTH.ACTIVATE,
        params: { beneficiaryId, demo: purchaseResult.demo },
      };
    }

    // Normal purchase - wait for equipment delivery
    // Go to equipment tracking page
    return {
      path: ROUTES.BENEFICIARY.EQUIPMENT(beneficiaryId),
      params: { beneficiaryId },
    };
  },

  /**
   * After successful activation, navigate to beneficiary detail page
   */
  getRouteAfterActivation(beneficiaryId: number): NavigationResult {
    return {
      path: ROUTES.BENEFICIARY.DETAIL(beneficiaryId),
      params: { justActivated: true },
    };
  },

  /**
   * Get route for returning user (already has account)
   *
   * Used when user logs in with existing account
   */
  getRouteForReturningUser(
    profile: UserProfile,
    beneficiaries: Beneficiary[]
  ): NavigationResult {
    // Same logic as after login, but could add welcome-back screen
    return this.getRouteAfterLogin(profile, beneficiaries);
  },

  /**
   * Check if user should see onboarding
   */
  shouldShowOnboarding(
    isNewUser: boolean,
    profile: UserProfile | null
  ): boolean {
    return isNewUser || !profile?.firstName;
  },

  /**
   * Get route for a specific beneficiary action
   */
  getBeneficiaryRoute(
    beneficiary: Beneficiary,
    action: 'view' | 'subscription' | 'equipment' | 'share'
  ): NavigationResult {
    switch (action) {
      case 'view':
        return { path: ROUTES.BENEFICIARY.DETAIL(beneficiary.id) };
      case 'subscription':
        return { path: ROUTES.BENEFICIARY.SUBSCRIPTION(beneficiary.id) };
      case 'equipment':
        return { path: ROUTES.BENEFICIARY.EQUIPMENT(beneficiary.id) };
      case 'share':
        return { path: ROUTES.BENEFICIARY.SHARE(beneficiary.id) };
      default:
        return { path: ROUTES.BENEFICIARY.DETAIL(beneficiary.id) };
    }
  },

  /**
   * Determine if beneficiary card should show "Setup Equipment" button
   */
  shouldShowEquipmentSetup(beneficiary: Beneficiary): boolean {
    return !beneficiary.hasDevices &&
           beneficiary.equipmentStatus !== 'active' &&
           beneficiary.equipmentStatus !== 'demo';
  },

  /**
   * Get call-to-action for beneficiary based on status
   */
  getBeneficiaryCallToAction(
    beneficiary: Beneficiary
  ): { label: string; action: () => NavigationResult } | null {
    const status = beneficiary.equipmentStatus || 'none';

    if (beneficiary.hasDevices || status === 'active' || status === 'demo') {
      // No CTA needed - beneficiary is active
      return null;
    }

    switch (status) {
      case 'none':
        return {
          label: 'Setup Equipment',
          action: () => ({
            path: ROUTES.AUTH.PURCHASE,
            params: { beneficiaryId: beneficiary.id },
          }),
        };

      case 'ordered':
        return {
          label: 'Track Delivery',
          action: () => ({
            path: ROUTES.BENEFICIARY.EQUIPMENT(beneficiary.id),
          }),
        };

      case 'shipped':
        return {
          label: 'Track Package',
          action: () => ({
            path: ROUTES.BENEFICIARY.EQUIPMENT(beneficiary.id),
          }),
        };

      case 'delivered':
        return {
          label: 'Activate Equipment',
          action: () => ({
            path: ROUTES.AUTH.ACTIVATE,
            params: { beneficiaryId: beneficiary.id },
          }),
        };

      default:
        return null;
    }
  },

  /**
   * Get status text for equipment
   */
  getEquipmentStatusText(status: EquipmentStatus | undefined): string {
    switch (status) {
      case 'none':
        return 'No equipment';
      case 'ordered':
        return 'Equipment ordered';
      case 'shipped':
        return 'In transit';
      case 'delivered':
        return 'Ready to activate';
      case 'active':
        return 'Active';
      case 'demo':
        return 'Demo mode';
      default:
        return 'Unknown';
    }
  },

  /**
   * Get status color for equipment
   */
  getEquipmentStatusColor(status: EquipmentStatus | undefined): string {
    switch (status) {
      case 'none':
        return '#888888'; // gray
      case 'ordered':
        return '#FFA500'; // orange
      case 'shipped':
        return '#007AFF'; // blue
      case 'delivered':
        return '#34C759'; // green
      case 'active':
        return '#34C759'; // green
      case 'demo':
        return '#9C27B0'; // purple
      default:
        return '#888888'; // gray
    }
  },
};

export default NavigationController;