import { IUpdateSessionRequest } from "@/entities/session/types";
import { useCallback, useMemo, useState, useEffect } from "react";
import { setSessionIdToCookie } from "@/entities/session/serverActions";
import { metricService } from "@/services/analytics/metricService";
import {
  SessionCollector,
  FingerprintCollector,
  FacebookCollector,
  parseUtmParams,
  getOrCreateAnonymousId,
  type CreateSessionResponse,
  type UpdateSessionData,
  type SessionFingerprintData,
  type SessionFacebookData,
} from "@wit-lab-llc/frontend-shared";
import { parseQueryParams } from "@/shared/utils/url";

// TODO: Get locale from context or i18n
const locale = "en";

// Debug logging helper - only logs in development
const isDev = process.env.NODE_ENV === "development";
const debugLog = (message: string, ...args: unknown[]) => {
  if (isDev) {
    console.log(`🔍 [useSession] ${message}`, ...args);
  }
};

// Singleton instances
let sessionCollectorInstance: SessionCollector | null = null;
let fingerprintCollectorInstance: FingerprintCollector | null = null;
let facebookCollectorInstance: FacebookCollector | null = null;

// Module-level flag to track if data collection has been done (persists across remounts)
let dataCollectionDone = false;

function getSessionCollector(): SessionCollector {
  if (!sessionCollectorInstance) {
    sessionCollectorInstance = new SessionCollector();
  }
  return sessionCollectorInstance;
}

function getFingerprintCollector(): FingerprintCollector {
  if (!fingerprintCollectorInstance) {
    fingerprintCollectorInstance = new FingerprintCollector();
  }
  return fingerprintCollectorInstance;
}

function getFacebookCollector(): FacebookCollector {
  if (!facebookCollectorInstance) {
    facebookCollectorInstance = new FacebookCollector();
  }
  return facebookCollectorInstance;
}

interface IUseSessionProps {
  funnelId: string;
  googleAnalyticsId?: string;
}

export const useSession = ({ funnelId, googleAnalyticsId }: IUseSessionProps) => {
  const [collector] = useState(() => getSessionCollector());
  const [fingerprintCollector] = useState(() => getFingerprintCollector());
  const [facebookCollector] = useState(() => getFacebookCollector());
  const [isError, setIsError] = useState(false);

  // Get current session ID from collector
  const sessionId = collector.getSessionId();

  // Collect fingerprint and facebook data on mount (only once per app lifecycle)
  useEffect(() => {
    if (typeof window === "undefined" || dataCollectionDone) return;
    dataCollectionDone = true;

    // Collect data in background
    debugLog("Starting fingerprint and Facebook data collection...");
    Promise.all([
      fingerprintCollector.collect().catch((e) => {
        debugLog("Fingerprint collection failed:", e);
        return null;
      }),
      Promise.resolve(facebookCollector.collect()),
    ]).then(([fpResult, fbResult]) => {
      debugLog("✅ Data collection completed", {
        fingerprint: fpResult ? { visitorId: fpResult.visitorId, confidence: fpResult.confidence } : null,
        facebook: fbResult ? { fbp: fbResult.fbp, fbc: fbResult.fbc, fbclid: fbResult.fbclid } : null,
      });
    });
  }, [fingerprintCollector, facebookCollector]);

  const createSession = useCallback(async (): Promise<CreateSessionResponse> => {
    if (typeof window === "undefined") {
      return { sessionId: "", status: "error" };
    }

    try {
      const query = parseQueryParams();
      const utm = parseUtmParams();
      const anonymousId = getOrCreateAnonymousId();
      const lastActivityAt = new Date().toISOString();

      // Get fingerprint data for session
      let fingerprint: SessionFingerprintData | undefined;
      try {
        debugLog("Getting fingerprint data for session...");
        const fpData = await fingerprintCollector.getOrCollect();
        if (fpData) {
          const payload = fingerprintCollector.toServerPayload();
          fingerprint = {
            visitorId: fpData.visitorId,
            confidence: fpData.confidence,
            collectedAt: fpData.collectedAt,
            ...payload,
          } as SessionFingerprintData;
          debugLog("✅ Fingerprint data ready", {
            visitorId: fingerprint.visitorId,
            confidence: fingerprint.confidence,
          });
        }
      } catch (e) {
        console.warn("[useSession] Failed to collect fingerprint:", e);
      }

      // Get facebook data for session
      let facebookData: SessionFacebookData | undefined;
      try {
        debugLog("Getting Facebook data for session...");
        const fbData = facebookCollector.getData() || facebookCollector.collect();
        if (fbData) {
          facebookData = {
            fbp: fbData.fbp ?? undefined,
            fbc: fbData.fbc ?? undefined,
            fbclid: fbData.fbclid ?? undefined,
            externalId: fingerprint?.visitorId, // Use visitorId as external_id
            landingPage: fbData.landingPage ?? undefined,
            referrer: fbData.referrer,
            clientUserAgent: fbData.userAgent,
            eventSourceUrl: fbData.currentUrl,
            browserLanguage: fbData.browserLanguage,
            screenResolution: fbData.screenResolution,
            viewportSize: fbData.viewportSize,
            colorDepth: fbData.colorDepth,
            devicePixelRatio: fbData.devicePixelRatio,
            touchSupport: fbData.touchSupport,
            cookiesEnabled: fbData.cookiesEnabled,
            doNotTrack: fbData.doNotTrack,
            collectedAt: fbData.collectedAt,
          };
          debugLog("✅ Facebook data ready", {
            fbp: facebookData.fbp,
            fbc: facebookData.fbc,
            fbclid: facebookData.fbclid,
            externalId: facebookData.externalId,
            landingPage: facebookData.landingPage,
          });
        }
      } catch (e) {
        console.warn("[useSession] Failed to collect Facebook data:", e);
      }

      debugLog("Creating session with data:", {
        source: funnelId,
        hasFingerprint: !!fingerprint,
        hasFacebookData: !!facebookData,
        utm,
      });

      const response = await collector.create({
        source: funnelId,
        feature: "stripe",
        locale,
        sign: false,
        utm,
        anonymousId,
        query,
        landingQuery: query,
        lastActivityAt,
        fingerprint,
        facebookData,
      });

      debugLog("Session creation response:", response);

      if (response.sessionId && response.status !== "error") {
        // Set cookie for server-side access
        await setSessionIdToCookie("activeSessionId", response.sessionId);

        // For old sessions, update with current feature and data
        if (response.status === "old") {
          debugLog("Updating old session with current feature and data...");
          await collector.update({
            feature: "stripe",
            anonymousId,
            query,
            lastActivityAt: new Date().toISOString(),
          });
        }

        // Send analytics only for new sessions
        if (response.status === "success") {
          metricService.userParams({
            sessionId: response.sessionId,
          });

          metricService.sendVisitContext({
            sessionId: response.sessionId,
            funnelId,
            gaId: googleAnalyticsId,
          });
        }

        return response;
      }

      setIsError(true);
      return { status: "error", sessionId: "" };
    } catch (error) {
      debugLog("❌ Session creation failed:", error);
      console.error("Session creation failed:", error);
      setIsError(true);
      return { status: "error", sessionId: "" };
    }
  }, [collector, funnelId, googleAnalyticsId, fingerprintCollector, facebookCollector]);

  const updateSession = useCallback(
    async (data: IUpdateSessionRequest["data"]) => {
      try {
        const query = parseQueryParams();
        const anonymousId = getOrCreateAnonymousId();

        // Convert to library's UpdateSessionData format
        const updateData: UpdateSessionData = {
          feature: "stripe",
          anonymousId,
          query,
          lastActivityAt: new Date().toISOString(),
          ...data,
        };

        const result = await collector.update(updateData, {
          source: funnelId,
          feature: "stripe",
          locale,
          sign: false,
          utm: parseUtmParams(),
          anonymousId,
          query,
          landingQuery: query,
          lastActivityAt: new Date().toISOString(),
        });

        return result;
      } catch (error) {
        debugLog("❌ Session update failed:", error);
        console.error("Session update failed:", error);
        return null;
      }
    },
    [collector, funnelId]
  );

  const deleteSession = useCallback(() => {
    collector.delete(funnelId);
  }, [collector, funnelId]);

  return useMemo(
    () => ({
      session: sessionId,
      isError,
      createSession,
      updateSession,
      deleteSession,
    }),
    [sessionId, isError, createSession, deleteSession, updateSession]
  );
};