import { useEffect, useState, useRef, useCallback, useMemo } from 'react';
import './App.css';
import { getUser } from './auth/authService';
import { getStoredPasskeyUser } from './auth/passkeyService';
import { fromOidcUser, type AuthUser } from './auth/types';
import AlertError from './components/AlertError';
import LoginModal from './components/LoginModal';
import AuthCallback from './components/AuthCallback';
import { Map } from './components/Map';
import { FilterPanel, type ParameterValues, DEFAULT_FILTER_VALUES, Metric } from './components/FilterPanel';
import { VisualizationCard } from './components/VisualizationCard';
import { Header } from './components/Header';
import { StatsBar, type ViewMode } from './components/StatsBar';
import { ListView } from './components/ListView';
import { StreamingProgressBar } from './components/StreamingProgressBar';
import { Sheet, SheetContent, SheetTrigger } from './components/ui/sheet';
import { Button } from './components/ui/button';
import { Filter } from 'lucide-react';
import type { GeoJSONFeatureCollection, PropertyProperties, PropertyFeature, POI, POITravelFilter } from '@/types';
import { refreshListings, fetchTasksForUser, streamListingGeoJSON, fetchUserPOIs, type StreamingProgress } from '@/services';
import { poiMetricPropertyName, injectPoiMetricProperty } from '@/utils/poiUtils';
import { useTaskWebSocket } from '@/hooks/useTaskWebSocket';

function App() {
  const [listingData, setListingData] = useState<GeoJSONFeatureCollection | null>(null);
  const [taskID, setTaskID] = useState<string | null>(null);
  const [user, setUser] = useState<AuthUser | null>(null);
  const [queryParameters, setQueryParameters] = useState<ParameterValues | null>(null);
  const [submitError, setSubmitError] = useState<string | null>(null);
  const [alertDialogIsOpen, setAlertDialogIsOpen] = useState(false);
  const [isLoading, setIsLoading] = useState(false);
  const [viewMode, setViewMode] = useState<ViewMode>('map');
  const [mobileFilterOpen, setMobileFilterOpen] = useState(false);
  const [highlightedProperty, setHighlightedProperty] = useState<string | null>(null);
  const [streamingProgress, setStreamingProgress] = useState<StreamingProgress | null>(null);
  const [userPOIs, setUserPOIs] = useState<POI[]>([]);
  const [poiPickerActive, setPoiPickerActive] = useState(false);
  const [pickedPoiLocation, setPickedPoiLocation] = useState<{ lat: number; lng: number } | null>(null);
  const [poiMetricSelection, setPoiMetricSelection] = useState<{
    poiId: number;
    poiName: string;
    travelMode: 'WALK' | 'BICYCLE' | 'TRANSIT';
  } | null>(null);
  const [poiTravelFilters, setPoiTravelFilters] = useState<Record<number, POITravelFilter>>({});
  const [currentMetric, setCurrentMetric] = useState<Metric>(DEFAULT_FILTER_VALUES.metric);

  // WebSocket-based real-time task progress
  const { tasks: wsTasks, isConnected: wsConnected, subscribe: wsSubscribe } = useTaskWebSocket(user);

  // Ref to track accumulated features during streaming
  const accumulatedFeaturesRef = useRef<PropertyFeature[]>([]);
  // Ref to track if initial load has been triggered
  const initialLoadTriggeredRef = useRef(false);
  // Ref to abort in-flight streaming requests
  const abortControllerRef = useRef<AbortController | null>(null);

  // Check if this is the callback route - render dedicated component
  if (window.location.pathname === '/callback') {
    return <AuthCallback />;
  }

  useEffect(() => {
    // Check passkey user first, then fall back to OIDC
    const passkeyUser = getStoredPasskeyUser();
    if (passkeyUser) {
      setUser(passkeyUser);
    } else {
      getUser().then((oidcUser) => {
        if (oidcUser) {
          setUser(fromOidcUser(oidcUser));
        }
      });
    }
  }, []);

  const handlePasskeyLogin = (passkeyUser: AuthUser) => {
    setUser(passkeyUser);
  };

  useEffect(() => {
    if (!user) {
      return;
    }
    fetchTasksForUser(user).then((tasks) => {
      if (tasks && tasks.length > 0) {
        setTaskID(tasks[0]);
      }
    });
  }, [user, taskID]);

  // Load user's POIs
  useEffect(() => {
    if (!user) return;
    fetchUserPOIs(user).then(setUserPOIs).catch(() => {});
  }, [user]);

  // Load listings function - used by both auto-load and manual submit
  const loadListings = useCallback(async (parameters: ParameterValues) => {
    if (!user) return;

    // Abort any in-flight streaming request
    if (abortControllerRef.current) {
      abortControllerRef.current.abort();
    }
    const controller = new AbortController();
    abortControllerRef.current = controller;

    setQueryParameters(parameters);
    setMobileFilterOpen(false);
    setIsLoading(true);
    accumulatedFeaturesRef.current = [];
    setStreamingProgress({ count: 0 });
    setListingData(null);

    // Dedup safety net: track seen URLs to prevent duplicate features
    const seenUrls = new Set<string>();

    let updateScheduled = false;

    const flushUpdate = () => {
      updateScheduled = false;
      setListingData({
        type: 'FeatureCollection',
        features: [...accumulatedFeaturesRef.current]
      });
    };

    const scheduleUpdate = () => {
      if (!updateScheduled) {
        updateScheduled = true;
        requestAnimationFrame(flushUpdate);
      }
    };

    try {
      for await (const batch of streamListingGeoJSON(user, parameters, (progress) => {
        setStreamingProgress(progress);
      }, { includePoiDistances: userPOIs.length > 0, signal: controller.signal })) {
        // Deduplicate features by URL
        const uniqueBatch = batch.filter((feature) => {
          const url = feature.properties?.url;
          if (!url || seenUrls.has(url)) return false;
          seenUrls.add(url);
          return true;
        });
        if (uniqueBatch.length > 0) {
          accumulatedFeaturesRef.current.push(...uniqueBatch);
          scheduleUpdate();
        }
      }
      // Final flush to ensure all data is rendered
      flushUpdate();
    } catch (error) {
      // Silently ignore AbortError — it means we intentionally cancelled
      if (error instanceof DOMException && error.name === 'AbortError') {
        return;
      }
      if (error instanceof Error) {
        setSubmitError(error.message);
      } else {
        setSubmitError(String(error));
      }
      setAlertDialogIsOpen(true);
    } finally {
      // Only clear loading state if this controller is still the current one
      if (abortControllerRef.current === controller) {
        setIsLoading(false);
        setStreamingProgress(null);
      }
    }
  }, [user, userPOIs]);

  // Compute processed listing data: inject synthetic POI metric property & apply max travel filter
  const processedListingData = useMemo(() => {
    if (!listingData) return null;

    let features = listingData.features;

    // Inject synthetic flat property for the selected POI metric
    if (poiMetricSelection) {
      features = injectPoiMetricProperty(
        features,
        poiMetricSelection.poiId,
        poiMetricSelection.travelMode,
      );
    }

    // Filter by per-POI max travel time (AND logic: listing must satisfy all active filters)
    const activeFilters = Object.entries(poiTravelFilters)
      .filter(([, f]) => f.maxMinutes !== undefined)
      .map(([id, f]) => ({ poiId: Number(id), travelMode: f.travelMode, maxMinutes: f.maxMinutes! }));

    if (activeFilters.length > 0) {
      features = features.filter((f) => {
        const distances = f.properties.poi_distances;
        if (!distances) return false;
        return activeFilters.every((filter) => {
          const dist = distances.find(
            (d) => d.poi_id === filter.poiId && d.travel_mode === filter.travelMode,
          );
          return dist !== undefined && dist.duration_seconds <= filter.maxMinutes * 60;
        });
      });
    }

    return { ...listingData, features };
  }, [listingData, poiMetricSelection, poiTravelFilters]);

  // Compute the effective metric string for the heatmap
  const effectiveMetric = useMemo(() => {
    if (queryParameters?.metric === Metric.poi_travel && poiMetricSelection) {
      return poiMetricPropertyName(poiMetricSelection.poiId, poiMetricSelection.travelMode);
    }
    return queryParameters?.metric;
  }, [queryParameters?.metric, poiMetricSelection]);

  // Auto-load data with default filters when user is authenticated
  useEffect(() => {
    if (!user || initialLoadTriggeredRef.current) {
      return;
    }
    initialLoadTriggeredRef.current = true;

    const defaultParams: ParameterValues = {
      ...DEFAULT_FILTER_VALUES,
      available_from: new Date(),
    };

    loadListings(defaultParams);
  }, [user, loadListings]);

  const handleTaskCompleted = useCallback(() => {
    if (queryParameters) {
      loadListings(queryParameters);
    }
  }, [queryParameters, loadListings]);

  if (!user) {
    return <LoginModal isOpen={user === null} onPasskeyLogin={handlePasskeyLogin} />;
  }

  const onSubmit = async (action: 'fetch-data' | 'visualize', parameters: ParameterValues) => {
    if (action === 'visualize') {
      loadListings(parameters);
    } else if (action === 'fetch-data') {
      setQueryParameters(parameters);
      setMobileFilterOpen(false);
      setIsLoading(true);
      try {
        const data = await refreshListings(user!, parameters);
        setTaskID(data.task_id);
        if (data.task_id) wsSubscribe(data.task_id);
      } catch (error) {
        if (error instanceof Error) {
          setSubmitError(error.message);
        } else {
          setSubmitError(String(error));
        }
        setAlertDialogIsOpen(true);
      } finally {
        setIsLoading(false);
      }
    }
  };

  const handleMetricChange = (metric: Metric) => {
    setCurrentMetric(metric);
    setQueryParameters(prev => prev ? { ...prev, metric } : null);
  };

  const handlePropertyClick = (property: PropertyProperties, _coordinates: [number, number]) => {
    setHighlightedProperty(property.url);
    // Optionally: pan map to coordinates
  };

  const renderMainContent = () => {
    if (!processedListingData) {
      return (
        <div className="flex-1 flex items-center justify-center bg-muted/20">
          <div className="text-center p-8 max-w-md">
            {isLoading ? (
              <>
                <div className="text-6xl mb-4 animate-pulse">🏠</div>
                <h2 className="text-xl font-semibold mb-2">Loading Properties...</h2>
                <p className="text-muted-foreground mb-4">
                  Fetching listings with default filters. You can adjust filters on the left.
                </p>
              </>
            ) : (
              <>
                <div className="text-6xl mb-4">🏠</div>
                <h2 className="text-xl font-semibold mb-2">Welcome to Property Explorer</h2>
                <p className="text-muted-foreground mb-4">
                  Use the filters on the left to find properties. Apply filters to visualize existing data or refresh to fetch new listings.
                </p>
              </>
            )}
          </div>
        </div>
      );
    }

    if (processedListingData.features.length === 0) {
      return (
        <div className="flex-1 flex items-center justify-center">
          <div className="text-center p-8">
            <div className="text-6xl mb-4">🔍</div>
            <h2 className="text-xl font-semibold mb-2">No listings found</h2>
            <p className="text-muted-foreground">
              Try adjusting the filters or run a data refresh to fetch new listings.
            </p>
          </div>
        </div>
      );
    }

    return (
      <>
        {/* Map View */}
        {(viewMode === 'map' || viewMode === 'split') && (
          <div className={`relative ${viewMode === 'split' ? 'w-1/2' : 'flex-1'}`} style={{ minHeight: 0 }}>
            <Map
              listingData={processedListingData}
              queryParameters={queryParameters}
              effectiveMetric={effectiveMetric}
              onPropertyClick={handlePropertyClick}
              pois={userPOIs}
              isPickingPOI={poiPickerActive}
              onPoiLocationPick={handlePoiLocationPick}
              onCancelPoiPicking={handleCancelPoiPicking}
            />
          </div>
        )}

        {/* List View */}
        {(viewMode === 'list' || viewMode === 'split') && (
          <div className={`${viewMode === 'split' ? 'w-1/2 border-l' : 'flex-1'}`}>
            <ListView
              listingData={processedListingData}
              onPropertyClick={handlePropertyClick}
              highlightedPropertyUrl={highlightedProperty}
              poiMetricSelection={poiMetricSelection}
            />
          </div>
        )}
      </>
    );
  };

  const handleTaskCancelled = () => {
    setTaskID(null);
  };

  const handlePOITaskCreated = (taskId: string) => {
    setTaskID(taskId);
    if (taskId) wsSubscribe(taskId);
    // Refresh POI list in case new ones were created
    if (user) {
      fetchUserPOIs(user).then(setUserPOIs).catch(() => {});
    }
  };

  const handleStartPoiPicking = () => {
    setPoiPickerActive(true);
    setPickedPoiLocation(null);
  };

  const handlePoiLocationPick = (lat: number, lng: number) => {
    setPickedPoiLocation({ lat, lng });
    setPoiPickerActive(false);
  };

  const handleCancelPoiPicking = () => {
    setPoiPickerActive(false);
  };

  return (
    <div className="h-screen flex flex-col overflow-hidden">
      {/* Header */}
      <Header
        user={user}
        taskID={taskID}
        onTaskCancelled={handleTaskCancelled}
        onTaskCompleted={handleTaskCompleted}
        wsTasks={wsTasks}
        wsConnected={wsConnected}
        wsSubscribe={wsSubscribe}
      />

      {/* Main content area */}
      <div className="flex-1 flex overflow-hidden min-h-0">
        {/* Filter Panel - Desktop (fixed sidebar) */}
        <div className="hidden md:block w-80 shrink-0 h-full overflow-hidden">
          <div className="h-full flex flex-col">
            <div className="flex-1 min-h-0">
              <FilterPanel
                onSubmit={onSubmit}
                currentMetric={currentMetric}
                isLoading={isLoading}
                listingCount={processedListingData?.features.length}
                user={user}
                onTaskCreated={handlePOITaskCreated}
                onStartPoiPicking={handleStartPoiPicking}
                pickedPoiLocation={pickedPoiLocation}
                userPOIs={userPOIs}
                poiTravelFilters={poiTravelFilters}
                onPoiTravelFiltersChange={setPoiTravelFilters}
              />
            </div>
            <div className="shrink-0 p-4 border-r">
              <VisualizationCard
                metric={currentMetric}
                onMetricChange={handleMetricChange}
                userPOIs={userPOIs}
                onPoiMetricChange={setPoiMetricSelection}
              />
            </div>
          </div>
        </div>

        {/* Filter Panel - Mobile (sheet) */}
        <div className="md:hidden fixed bottom-4 right-4 z-50">
          <Sheet open={mobileFilterOpen} onOpenChange={setMobileFilterOpen}>
            <SheetTrigger asChild>
              <Button size="lg" className="rounded-full shadow-lg h-14 w-14">
                <Filter className="h-6 w-6" />
              </Button>
            </SheetTrigger>
            <SheetContent side="left" className="w-80 p-0">
              <div className="h-full flex flex-col">
                <div className="flex-1 min-h-0">
                  <FilterPanel
                    onSubmit={onSubmit}
                    currentMetric={currentMetric}
                    isLoading={isLoading}
                    listingCount={processedListingData?.features.length}
                    user={user}
                    onTaskCreated={handlePOITaskCreated}
                    onStartPoiPicking={handleStartPoiPicking}
                    pickedPoiLocation={pickedPoiLocation}
                    userPOIs={userPOIs}
                    poiTravelFilters={poiTravelFilters}
                    onPoiTravelFiltersChange={setPoiTravelFilters}
                  />
                </div>
                <div className="shrink-0 p-4">
                  <VisualizationCard
                    metric={currentMetric}
                    onMetricChange={handleMetricChange}
                    userPOIs={userPOIs}
                    onPoiMetricChange={setPoiMetricSelection}
                  />
                </div>
              </div>
            </SheetContent>
          </Sheet>
        </div>

        {/* Main View Area */}
        <div className="flex-1 flex flex-col overflow-hidden min-h-0">
          {/* Streaming Progress Bar */}
          <div className="relative shrink-0">
            <StreamingProgressBar progress={streamingProgress} isLoading={isLoading} />
          </div>

          {/* Map/List Container */}
          <div className="flex-1 flex overflow-hidden min-h-0">
            {renderMainContent()}
          </div>

          {/* Stats Bar */}
          {processedListingData && processedListingData.features.length > 0 && (
            <div className="shrink-0">
              <StatsBar
                listingData={processedListingData}
                viewMode={viewMode}
                onViewModeChange={setViewMode}
              />
            </div>
          )}
        </div>
      </div>

      {/* Error Dialog */}
      <AlertError message={submitError} open={alertDialogIsOpen} setIsOpen={setAlertDialogIsOpen} />
    </div>
  );
}

export default App;