import { useApi } from "@/api";
import { PayloadUpdate, ResponseCreate } from "@/api/resources/Session";
import { ESourceAuthorization } from "@/api/resources/User";
import { getClientTimezone, language } from "@/locales";
import { actions, selectors } from "@/store";
import { useCallback, useEffect, useMemo, useRef, useState } from "react"
import { useDispatch, useSelector } from "react-redux";
import {
    FingerprintCollector,
    FacebookCollector,
    type SessionFingerprintData,
    type SessionFacebookData,
    getOrCreateAnonymousId,
} from "@wit-lab-llc/frontend-shared";
import { parseQueryParams } from "@/services/url";

let fingerprintCollectorInstance: FingerprintCollector | null = null;
let facebookCollectorInstance: FacebookCollector | null = null;

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

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

export const useSession = () => {
    const dispatch = useDispatch();
    const api = useApi();
    const session = useSelector(selectors.selectSession);

    const feature = useSelector(selectors.selectFeature)
    const { checked, dateOfCheck } = useSelector(selectors.selectPrivacyPolicy);
    const utm = useSelector(selectors.selectUTM);

    const timezone = getClientTimezone();

    const [isError, setIsError] = useState(false);
    const [fingerprintCollector] = useState(() => getFingerprintCollector());
    const [facebookCollector] = useState(() => getFacebookCollector());
    const dataCollectedRef = useRef(false);

    const visitTtlMs = 30 * 60 * 1000;

    const getVisitStorageKey = useCallback((source: ESourceAuthorization) => {
        return `${source}_visit`;
    }, []);

    const readVisit = useCallback((source: ESourceAuthorization) => {
        try {
            const raw = localStorage.getItem(getVisitStorageKey(source));
            if (!raw) return null;
            return JSON.parse(raw) as {
                sessionId: string;
                startedAt: number;
                lastActivityAt: number;
                anonymousId?: string;
                landingQuery?: Record<string, string>;
                lastQuery?: Record<string, string>;
            };
        } catch {
            return null;
        }
    }, [getVisitStorageKey]);

    const writeVisit = useCallback((source: ESourceAuthorization, visit: {
        sessionId: string;
        startedAt: number;
        lastActivityAt: number;
        anonymousId?: string;
        landingQuery?: Record<string, string>;
        lastQuery?: Record<string, string>;
    }) => {
        localStorage.setItem(getVisitStorageKey(source), JSON.stringify(visit));
        localStorage.setItem(`${source}_sessionId`, visit.sessionId);
    }, [getVisitStorageKey]);

    useEffect(() => {
        if (typeof window === "undefined" || dataCollectedRef.current) return;
        dataCollectedRef.current = true;

        Promise.all([
            fingerprintCollector.collect().catch(() => null),
            Promise.resolve(facebookCollector.collect()),
        ]).then(() => {
            console.log("[useSession] Fingerprint and Facebook data collected");
        });
    }, [fingerprintCollector, facebookCollector]);

    const createSession = useCallback(async (source: ESourceAuthorization): Promise<ResponseCreate> => {
        const nowMs = Date.now();
        const existingVisit = readVisit(source);
        if (existingVisit && nowMs - existingVisit.lastActivityAt <= visitTtlMs) {
            const nextQuery = parseQueryParams();
            const nextAnonymousId = existingVisit.anonymousId ?? getOrCreateAnonymousId();
            writeVisit(source, {
                ...existingVisit,
                lastActivityAt: nowMs,
                lastQuery: nextQuery,
                anonymousId: nextAnonymousId,
            });
            dispatch(actions.session.update({ session: existingVisit.sessionId, source }));
            localStorage.setItem(`${source}_sessionId`, existingVisit.sessionId);
            return { sessionId: existingVisit.sessionId, status: "old" };
        }

        try {
            let fingerprint: SessionFingerprintData | undefined;
            try {
                const fpData = await fingerprintCollector.getOrCollect();
                if (fpData) {
                    const payload = fingerprintCollector.toServerPayload();
                    fingerprint = {
                        visitorId: fpData.visitorId,
                        confidence: fpData.confidence,
                        collectedAt: fpData.collectedAt,
                        ...payload,
                    } as SessionFingerprintData;
                }
            } catch (e) {
                console.warn("[useSession] Failed to collect fingerprint:", e);
            }

            let facebookData: SessionFacebookData | undefined;
            try {
                const fbData = facebookCollector.getData() || facebookCollector.collect();
                if (fbData) {
                    facebookData = {
                        fbp: fbData.fbp ?? undefined,
                        fbc: fbData.fbc ?? undefined,
                        fbclid: fbData.fbclid ?? undefined,
                        externalId: fingerprint?.visitorId,
                        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,
                    };
                }
            } catch (e) {
                console.warn("[useSession] Failed to collect Facebook data:", e);
            }

            const sessionParams = {
                feature,
                locale: language,
                timezone,
                source,
                sign: checked,
                signDate: dateOfCheck.length ? dateOfCheck : undefined,
                utm,
                anonymousId: getOrCreateAnonymousId(),
                query: parseQueryParams(),
                landingQuery: parseQueryParams(),
                lastActivityAt: new Date().toISOString(),
                domain: window.location.hostname,
                fingerprint,
                facebookData,
            };
            console.log('Creating session with parameters:', sessionParams);
            const sessionFromServer = await api.createSession(sessionParams);
            console.log('Session creation response:', sessionFromServer);
            if (sessionFromServer?.sessionId?.length && sessionFromServer?.status === "success") {
                dispatch(actions.session.update({
                    session: sessionFromServer.sessionId,
                    source
                }));
                localStorage.setItem(`${source}_sessionId`, sessionFromServer.sessionId);
                const q = parseQueryParams();
                writeVisit(source, {
                    sessionId: sessionFromServer.sessionId,
                    startedAt: Date.now(),
                    lastActivityAt: Date.now(),
                    anonymousId: sessionParams.anonymousId,
                    landingQuery: q,
                    lastQuery: q,
                });
                return sessionFromServer
            }
            console.error('Session creation failed - invalid response:', sessionFromServer);
            setIsError(true);
            return {
                status: "error",
                sessionId: ""
            }
        } catch (error) {
            console.error('Session creation failed with error:', error);
            setIsError(true);
            return {
                status: "error",
                sessionId: ""
            }
        }
    }, [api, checked, dateOfCheck, dispatch, feature, session, timezone, utm, fingerprintCollector, facebookCollector, readVisit, visitTtlMs, writeVisit])

    const updateSession = useCallback(async (data: Omit<PayloadUpdate["data"], "feature">, source: ESourceAuthorization, sessionId?: string) => {
        try {
            const _sessionId = sessionId || session[source];
            const result = await api.updateSession({
                sessionId: _sessionId,
                data: {
                    feature,
                    anonymousId: getOrCreateAnonymousId(),
                    query: parseQueryParams(),
                    lastActivityAt: new Date().toISOString(),
                    ...data
                }
            });

            if (_sessionId) {
                const nowMs = Date.now();
                const existingVisit = readVisit(source);
                if (existingVisit && existingVisit.sessionId === _sessionId) {
                    writeVisit(source, {
                        ...existingVisit,
                        lastActivityAt: nowMs,
                        lastQuery: parseQueryParams(),
                        anonymousId: getOrCreateAnonymousId(),
                    });
                }
            }
            return result;
        } catch (error) {
            console.log(error)
        }
    }, [api, feature, session, readVisit, writeVisit])

    const deleteSession = useCallback(async (source: ESourceAuthorization) => {
        localStorage.removeItem(`${source}_sessionId`);
        localStorage.removeItem(getVisitStorageKey(source));
        dispatch(actions.session.update({
            session: "",
            source
        }))
    }, [dispatch, getVisitStorageKey])

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