import { NextRequest, NextResponse } from 'next/server';
import { verifyToken } from './jwt';
import { Role } from '@/types';
import { hasPermission, hasAnyPermission, Permission, isAdmin, isSuperAdmin } from './roles';

export interface AuthenticatedUser {
  userId: string;
  email: string;
  role: Role;
}

export interface AuthenticatedRequest extends NextRequest {
  user: AuthenticatedUser;
}

export type AuthMiddlewareOptions = {
  requiredPermissions?: Permission[];
  anyPermission?: Permission[];
  requireAdmin?: boolean;
  requireSuperAdmin?: boolean;
  roles?: Role[];
};

export function withAuth(
  handler: (req: AuthenticatedRequest) => Promise<NextResponse>,
  options?: AuthMiddlewareOptions
) {
  return async (req: NextRequest): Promise<NextResponse> => {
    const authHeader = req.headers.get('authorization');
    const token = authHeader?.replace('Bearer ', '');

    if (!token) {
      return NextResponse.json(
        { error: 'Unauthorized', message: 'Authentication required' },
        { status: 401 }
      );
    }

    try {
      const payload = verifyToken(token);
      const userRole = payload.role as Role;

      // Check super admin requirement
      if (options?.requireSuperAdmin && !isSuperAdmin(userRole)) {
        return NextResponse.json(
          { error: 'Forbidden', message: 'Super admin access required' },
          { status: 403 }
        );
      }

      // Check admin requirement
      if (options?.requireAdmin && !isAdmin(userRole)) {
        return NextResponse.json(
          { error: 'Forbidden', message: 'Admin access required' },
          { status: 403 }
        );
      }

      // Check role if required (legacy support)
      if (options?.roles && !options.roles.includes(userRole)) {
        return NextResponse.json(
          { error: 'Forbidden', message: 'Insufficient permissions' },
          { status: 403 }
        );
      }

      // Check required permissions (all must match)
      if (options?.requiredPermissions?.length) {
        const hasAll = options.requiredPermissions.every(p =>
          hasPermission(userRole, p)
        );
        if (!hasAll) {
          return NextResponse.json(
            { error: 'Forbidden', message: 'Insufficient permissions' },
            { status: 403 }
          );
        }
      }

      // Check any permission (at least one must match)
      if (options?.anyPermission?.length) {
        if (!hasAnyPermission(userRole, options.anyPermission)) {
          return NextResponse.json(
            { error: 'Forbidden', message: 'Insufficient permissions' },
            { status: 403 }
          );
        }
      }

      // Add user to request
      (req as AuthenticatedRequest).user = {
        userId: payload.userId,
        email: payload.email,
        role: userRole,
      };

      return handler(req as AuthenticatedRequest);
    } catch (error) {
      return NextResponse.json(
        { error: 'Unauthorized', message: 'Invalid token' },
        { status: 401 }
      );
    }
  };
}

// Helper to create protected API routes
export function createProtectedRoute(
  options: AuthMiddlewareOptions,
  handler: (req: AuthenticatedRequest) => Promise<NextResponse>
) {
  return withAuth(handler, options);
}

// Helper for checking specific roles
export function requireRole(...roles: Role[]) {
  return { roles };
}

// Convenience wrappers
export function withAdminAuth(handler: (req: AuthenticatedRequest) => Promise<NextResponse>) {
  return withAuth(handler, { requireAdmin: true });
}

export function withSuperAdminAuth(handler: (req: AuthenticatedRequest) => Promise<NextResponse>) {
  return withAuth(handler, { requireSuperAdmin: true });
}

// Permission-based wrappers
export function withPermissions(
  permissions: Permission[],
  handler: (req: AuthenticatedRequest) => Promise<NextResponse>
) {
  return withAuth(handler, { requiredPermissions: permissions });
}

export function withAnyPermission(
  permissions: Permission[],
  handler: (req: AuthenticatedRequest) => Promise<NextResponse>
) {
  return withAuth(handler, { anyPermission: permissions });
}