import { router } from '../../appRouter';

/**
 * Resolves the active frontend route (path + search query).
 * Falls back to window.location if router is not directly accessible.
 * @returns {string} e.g. "/artikel" or "/artikel/ART-10042" or "/artikel?target=kabel"
 */
export function getCurrentRoute() {
  if (typeof window !== 'undefined' && window.location) {
    const { pathname = '/', search = '' } = window.location;
    return `${pathname}${search}`;
  }
  return '/artikel';
}

/**
 * Builds the <USERENV><ROUTE>...</ROUTE></USERENV> XML prefix for LLM agent prompts.
 * @param {string} [route]
 * @returns {string}
 */
export function buildUserEnvPrefix(route) {
  const resolvedRoute = route || getCurrentRoute();
  return `<USERENV><ROUTE>${resolvedRoute}</ROUTE></USERENV>`;
}

export const USER_ENV_REGEX = /<USERENV>[\s\S]*?(?:<\/USERENV>|$)\s*/gi;

/**
 * Strips <USERENV>...</USERENV> tags from a message so it is not rendered in the chat view.
 * @param {string} text
 * @returns {string}
 */
export function stripUserEnv(text) {
  if (typeof text !== 'string' || !text.includes('<USERENV')) {
    return text || '';
  }
  return text.replace(USER_ENV_REGEX, '').trim();
}

/**
 * Prepends the <USERENV><ROUTE>...</ROUTE></USERENV> block to the user prompt if not already present.
 * @param {string} text
 * @param {string} [route]
 * @returns {string}
 */
export function attachUserEnv(text = '', route) {
  const trimmed = typeof text === 'string' ? text.trim() : '';
  if (trimmed.includes('<USERENV')) {
    return trimmed;
  }
  const prefix = buildUserEnvPrefix(route);
  return trimmed ? `${prefix}\n\n${trimmed}` : prefix;
}

/**
 * Checks if a tool name is the set-user-route tool.
 * @param {string} name
 * @returns {boolean}
 */
export function isSetUserRouteTool(name) {
  if (!name || typeof name !== 'string') return false;
  const n = name.trim().toLowerCase();
  return n === 'set-user-route' || n === 'set_user_route';
}

/**
 * Extracts the target route string from tool data arguments/parameters/result/content.
 * @param {object} data
 * @returns {string|null}
 */
export function extractRouteFromToolData(data) {
  if (!data) return null;
  // 1. From result
  if (data.result) {
    if (typeof data.result === 'object' && data.result.route) {
      return String(data.result.route);
    }
    if (typeof data.result === 'string') {
      try {
        const parsed = JSON.parse(data.result);
        if (parsed?.route) return String(parsed.route);
      } catch {}
    }
  }
  // 2. From arguments or parameters
  const args = data.arguments || data.parameters;
  if (args) {
    if (typeof args === 'object' && args.route) {
      return String(args.route);
    }
    if (typeof args === 'string') {
      try {
        const parsed = JSON.parse(args);
        if (parsed?.route) return String(parsed.route);
      } catch {}
    }
  }
  // 3. From content
  if (data.content) {
    if (typeof data.content === 'object' && data.content.route) {
      return String(data.content.route);
    }
    if (typeof data.content === 'string') {
      try {
        const parsed = JSON.parse(data.content);
        if (parsed?.route) return String(parsed.route);
      } catch {}
    }
  }
  return null;
}

const navigatedToolCallIds = new Set();

/**
 * Navigates the application to the given client route.
 * @param {string} route
 * @param {string} [toolCallId]
 */
export async function navigateToClientRoute(route, toolCallId) {
  if (!route || typeof route !== 'string') return;
  const target = route.trim();
  if (!target) return;

  if (toolCallId) {
    if (navigatedToolCallIds.has(toolCallId)) return;
    navigatedToolCallIds.add(toolCallId);
  }

  try {
    if (router?.navigate) {
      const current = router.state?.location
        ? `${router.state.location.pathname}${router.state.location.search || ''}`
        : (typeof window !== 'undefined' ? `${window.location.pathname}${window.location.search || ''}` : '');
      if (current !== target) {
        void router.navigate(target);
      }
      return;
    }
  } catch (err) {
    console.warn('[userEnv] Router navigation failed:', err);
  }

  if (typeof window !== 'undefined' && window.location) {
    window.location.href = target;
  }
}