import { headers } from "next/headers";
import { NextResponse } from "next/server";
import { auth } from "./auth";
import { hasPermission, type Permission } from "./permissions";

// Extended user type with custom fields
type UserWithRole = {
  id: string;
  email: string;
  name: string;
  role?: string;
  requires_setup?: boolean;
  [key: string]: unknown;
};

/**
 * Get the current session from the request headers
 * Use this in API routes and server components
 */
export async function getSession() {
  const session = await auth.api.getSession({
    headers: await headers(),
  });
  return session;
}

/**
 * Require authentication for an API route
 * Returns the session if authenticated, or a 401 response if not
 */
export async function requireAuth() {
  const session = await getSession();
  
  if (!session) {
    return {
      session: null,
      error: NextResponse.json(
        { error: "Unauthorized" },
        { status: 401 }
      ),
    };
  }
  
  return { session, error: null };
}

/**
 * Require specific permissions for an API route
 * Returns the session if authorized, or a 403 response if not
 */
export async function requirePermission(
  resource: Permission["resource"],
  action: string
) {
  const { session, error } = await requireAuth();
  
  if (error) {
    return { session: null, error };
  }
  
  const userRole = (session!.user as UserWithRole).role || "user";
  
  if (!hasPermission(userRole, resource, action)) {
    return {
      session: null,
      error: NextResponse.json(
        { error: "Forbidden" },
        { status: 403 }
      ),
    };
  }
  
  return { session, error: null };
}

/**
 * Require admin or super-admin role
 */
export async function requireAdmin() {
  const { session, error } = await requireAuth();
  
  if (error) {
    return { session: null, error };
  }
  
  const userRole = (session!.user as UserWithRole).role || "user";
  
  if (userRole !== "admin" && userRole !== "super-admin") {
    return {
      session: null,
      error: NextResponse.json(
        { error: "Forbidden - Admin access required" },
        { status: 403 }
      ),
    };
  }
  
  return { session, error: null };
}

/**
 * Require super-admin role
 */
export async function requireSuperAdmin() {
  const { session, error } = await requireAuth();
  
  if (error) {
    return { session: null, error };
  }
  
  const userRole = (session!.user as UserWithRole).role || "user";
  
  if (userRole !== "super-admin") {
    return {
      session: null,
      error: NextResponse.json(
        { error: "Forbidden - Super admin access required" },
        { status: 403 }
      ),
    };
  }
  
  return { session, error: null };
}

/**
 * Check if the current user has a specific permission
 * Use this in server components for conditional rendering
 */
export async function checkPermission(
  resource: Permission["resource"],
  action: string
): Promise<boolean> {
  const session = await getSession();
  
  if (!session) {
    return false;
  }
  
  const userRole = (session.user as UserWithRole).role || "user";
  return hasPermission(userRole, resource, action);
}

/**
 * Check if the current user is an admin or super-admin
 */
export async function isAdmin(): Promise<boolean> {
  const session = await getSession();
  
  if (!session) {
    return false;
  }
  
  const userRole = (session.user as UserWithRole).role || "user";
  return userRole === "admin" || userRole === "super-admin";
}

/**
 * Check if the current user is a super-admin
 */
export async function isSuperAdmin(): Promise<boolean> {
  const session = await getSession();
  
  if (!session) {
    return false;
  }
  
  return (session.user as UserWithRole).role === "super-admin";
}