import { useCallback, useEffect, useRef, useState } from "react";
import { fetchPosts } from "../../api/client";
import { categoryCode, matchesSubFilter, matchesTimeFilter } from "./mapFilter";
import { haversineKm } from "./mapGeo";
import { createMarkerForPost, clearAllMarkers } from "./markerManager";

export function usePostsEngine({
  mapRef,
  viewParams,
  mainFilter,
  subFilter,
  timeFilter,
  markersRef,
  expandedElRef,
}) {
  const allPostsRef = useRef([]);
  const lastFetchRef = useRef({ center: null, radiusKm: null, filterKey: "" });
  const delayedFetchRef = useRef(null);

  const [status, setStatus] = useState("Loading posts...");
  const [visiblePosts, setVisiblePosts] = useState([]);
  const [loadingPosts, setLoadingPosts] = useState(false);
  const [loadError, setLoadError] = useState("");

  const rebuildMarkersForFilters = useCallback(
    (tf) => {
      const map = mapRef.current;
      if (!map) return;

      // If expanded is open and we are inside ignore window, do not rebuild (it closes the popup)
      try {
        const until = map.__swIgnoreRebuildUntil || 0;
        if (expandedElRef?.current && until && Date.now() < until) return;
      } catch {}

      clearAllMarkers(markersRef, expandedElRef);

      const posts = allPostsRef.current || [];
      const catCode = categoryCode(mainFilter);

      const visible = posts.filter((p) => {
        if (catCode) {
          const pc = (p.category || p.Category || "").toString().toUpperCase();
          if (pc !== catCode) return false;
        }
        if (!matchesSubFilter(p, subFilter)) return false;
        if (!matchesTimeFilter(p.created_at || p.CreatedAt, tf)) return false;
        return true;
      });

      visible.forEach((post) => createMarkerForPost(post, mapRef, markersRef, expandedElRef));

      setVisiblePosts(visible);
      setStatus(visible.length ? "" : "No posts found.");
    },
    [mapRef, markersRef, expandedElRef, mainFilter, subFilter]
  );

  useEffect(() => {
    rebuildMarkersForFilters(timeFilter);
  }, [timeFilter, mainFilter, subFilter, rebuildMarkersForFilters]);

  useEffect(() => {
    const map = mapRef.current;
    if (!map) return;
    if (!viewParams.center) return;

    let cancelled = false;

    async function load() {
      const mapObj = mapRef.current;

      // Delay fetch while popup is open (prevents marker clear/rebuild)
      try {
        const until = mapObj?.__swIgnoreFetchUntil || 0;
        if (until && Date.now() < until) {
          const wait = Math.min(4000, until - Date.now());
          if (delayedFetchRef.current) clearTimeout(delayedFetchRef.current);
          delayedFetchRef.current = setTimeout(load, wait + 25);
          return;
        }
      } catch {}

      const [lng, lat] = viewParams.center;
      const radiusKm = viewParams.radiusKm || 750;
      const filterKey = `${mainFilter}|${subFilter}`;

      const last = lastFetchRef.current;

      if (last.center && last.filterKey === filterKey) {
        const [lastLng, lastLat] = last.center;
        const distKm = haversineKm(lastLat, lastLng, viewParams.center[1], lng);

        const lastR = last.radiusKm || 0;
        const radiusChanged = !lastR || Math.abs(radiusKm - lastR) / Math.max(lastR, 1) >= 0.25;

        const minMoveKm = Math.max(50, radiusKm * 0.25);

        if (!radiusChanged && distKm < minMoveKm) return;
      }

      try {
        setStatus("Loading posts...");
        setLoadingPosts(true);
        setLoadError("");

        const catCode = categoryCode(mainFilter);
        const subCatParam =
          subFilter && subFilter.toUpperCase() !== "ALL" && subFilter !== "All" ? subFilter : "";

        const newPosts = await fetchPosts({
          category: catCode,
          subCategory: subCatParam,
          time: "",
          lat,
          lon: lng,
          radiusKm,
        });

        if (cancelled) return;

        const existing = allPostsRef.current || [];
        const byId = new Map();
        for (const p of existing) {
          if (p && typeof p.id !== "undefined") byId.set(p.id, p);
        }
        if (Array.isArray(newPosts)) {
          for (const p of newPosts) {
            if (p && typeof p.id !== "undefined" && !byId.has(p.id)) byId.set(p.id, p);
          }
        }

        allPostsRef.current = Array.from(byId.values());
        lastFetchRef.current = { center: [...viewParams.center], radiusKm, filterKey };

        rebuildMarkersForFilters(timeFilter);
        setLoadingPosts(false);
      } catch (err) {
        console.error("Erreur chargement posts:", err);
        if (!cancelled) {
          setStatus("Error loading posts.");
          setLoadError("Error loading posts.");
          setLoadingPosts(false);
        }
      }
    }

    load();
    return () => {
      cancelled = true;
      if (delayedFetchRef.current) {
        try { clearTimeout(delayedFetchRef.current); } catch {}
        delayedFetchRef.current = null;
      }
    };
  }, [viewParams, mainFilter, subFilter, mapRef, rebuildMarkersForFilters, timeFilter]);

  const handleIncomingPost = useCallback(
    (p) => {
      allPostsRef.current = [...allPostsRef.current, p];

      const catCode = categoryCode(mainFilter);
      if (catCode) {
        const pc = (p.category || p.Category || "").toString().toUpperCase();
        if (pc !== catCode) return;
      }
      if (!matchesSubFilter(p, subFilter)) return;
      if (!matchesTimeFilter(p.created_at || p.CreatedAt, timeFilter)) return;

      createMarkerForPost(p, mapRef, markersRef, expandedElRef);
      setVisiblePosts((current) => [...current, p]);
    },
    [mainFilter, subFilter, timeFilter, mapRef, markersRef, expandedElRef]
  );

  return { status, visiblePosts, loadingPosts, loadError, handleIncomingPost };
}