'use client';

import { useState, useEffect, useCallback } from 'react';
import { Box, Typography, Button, Paper, CircularProgress, Grid } from '@mui/material';
import { AppShell } from '@/components/layouts/AppShell/AppShell';
import { ProtectedRoute } from '@/components/common/ProtectedRoute';
import { EmailVerificationBanner } from '@/components/common/EmailVerificationBanner';
import { ErrorBoundary } from '@/components/common/ErrorBoundary';
import { DataErrorFallback } from '@/components/common/ErrorFallbacks';
import { NetworkStatusIndicator } from '@/components/common/NetworkStatusIndicator';
import { StatGridSkeleton } from '@/components/common/LoadingSkeletons';
import DynamicChildDashboard from '@/components/dashboard/DynamicChildDashboard';
import {
  Restaurant,
  Hotel,
  BabyChangingStation,
  Insights,
  SmartToy,
  Analytics,
  MedicalServices,
} from '@mui/icons-material';
import { motion } from 'framer-motion';
import { useAuth } from '@/lib/auth/AuthContext';
import { useRouter } from 'next/navigation';
import { childrenApi, Child } from '@/lib/api/children';
import { trackingApi } from '@/lib/api/tracking';
import { format, formatDistanceToNow } from 'date-fns';
import { useRealTimeActivities } from '@/hooks/useWebSocket';
import { useTranslation } from '@/hooks/useTranslation';
import { analyticsApi } from '@/lib/api/analytics';
import { useTheme } from '@mui/material/styles';
import { useDispatch, useSelector } from 'react-redux';
import { fetchChildren, selectSelectedChild } from '@/store/slices/childrenSlice';
import { AppDispatch, RootState } from '@/store/store';

export default function HomePage() {
  const { t } = useTranslation('dashboard');
  const theme = useTheme();
  const { user, isLoading: authLoading } = useAuth();
  const router = useRouter();
  const dispatch = useDispatch<AppDispatch>();
  const selectedChild = useSelector(selectSelectedChild);
  const familyId = user?.families?.[0]?.familyId;
  const [selectedChildId, setSelectedChildId] = useState<string | null>(null);
  const [predictions, setPredictions] = useState<any>(null);
  const [predictionsLoading, setPredictionsLoading] = useState(false);
  const [children, setChildren] = useState<Child[]>([]);
  const [recentActivities, setRecentActivities] = useState<any[]>([]);
  const [todaySummary, setTodaySummary] = useState<any>(null);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState<any>(null);

  // Load children
  useEffect(() => {
    if (familyId && !authLoading) {
      loadChildren();
    }
  }, [familyId, authLoading]);

  const loadChildren = async () => {
    if (!familyId) return;

    try {
      const data = await childrenApi.getChildren(familyId);
      setChildren(data);
      if (data.length > 0 && !selectedChildId) {
        setSelectedChildId(data[0].id);
      }
    } catch (err) {
      console.error('Failed to load children:', err);
      setError(err);
    }
  };

  // Load dashboard data when child selected
  useEffect(() => {
    if (selectedChildId) {
      loadDashboardData();
    }
  }, [selectedChildId]);

  const loadDashboardData = async () => {
    if (!selectedChildId) return;

    setLoading(true);
    try {
      // Load recent activities
      const activities = await trackingApi.getActivities(selectedChildId);
      setRecentActivities(activities.slice(0, 10));

      // Calculate today's summary from activities
      const today = new Date();
      today.setHours(0, 0, 0, 0);
      const todayActivities = activities.filter((a: any) => {
        const activityDate = new Date(a.timestamp || a.startedAt);
        return activityDate >= today;
      });

      const summary = {
        feedingCount: todayActivities.filter((a: any) => a.type === 'feeding').length,
        sleepCount: todayActivities.filter((a: any) => a.type === 'sleep').length,
        diaperCount: todayActivities.filter((a: any) => a.type === 'diaper').length,
        medicationCount: todayActivities.filter((a: any) => ['medication', 'medicine'].includes(a.type)).length,
        totalFeedingAmount: todayActivities
          .filter((a: any) => a.type === 'feeding')
          .reduce((sum: number, a: any) => sum + (a.data?.amount || 0), 0),
        totalSleepDuration: todayActivities
          .filter((a: any) => a.type === 'sleep')
          .reduce((sum: number, a: any) => {
            const start = new Date(a.startedAt);
            const end = a.endedAt ? new Date(a.endedAt) : new Date();
            return sum + (end.getTime() - start.getTime()) / (1000 * 60);
          }, 0),
      };

      setTodaySummary(summary);
      setError(null);
    } catch (err) {
      console.error('Failed to load dashboard data:', err);
      setError(err);
    } finally {
      setLoading(false);
    }
  };

  const refetch = loadDashboardData;

  // Real-time activity handler
  const refreshDashboard = useCallback(async () => {
    console.log('[HomePage] Refreshing dashboard data...');
    await refetch();
  }, [refetch]);

  // Subscribe to real-time activity updates
  useRealTimeActivities(
    refreshDashboard, // On activity created
    refreshDashboard, // On activity updated
    refreshDashboard  // On activity deleted
  );

  // Sync selectedChildId with Redux selectedChild
  useEffect(() => {
    if (selectedChild?.id && selectedChild.id !== selectedChildId) {
      setSelectedChildId(selectedChild.id);
    }
  }, [selectedChild, selectedChildId]);

  // Fetch predictions when selectedChildId changes
  useEffect(() => {
    const fetchPredictions = async () => {
      if (!selectedChildId) return;

      setPredictionsLoading(true);
      try {
        const predictionData = await analyticsApi.getPredictions(selectedChildId);
        setPredictions(predictionData);
      } catch (err) {
        console.error('Failed to fetch predictions:', err);
        setPredictions(null);
      } finally {
        setPredictionsLoading(false);
      }
    };

    fetchPredictions();
  }, [selectedChildId]);

  const quickActions = [
    { icon: <Restaurant />, label: t('quickActions.feeding'), color: theme.palette.primary.main, path: '/track/feeding' },
    { icon: <Hotel />, label: t('quickActions.sleep'), color: theme.palette.secondary.main, path: '/track/sleep' },
    { icon: <BabyChangingStation />, label: t('quickActions.diaper'), color: theme.palette.warning.main, path: '/track/diaper' },
    { icon: <MedicalServices />, label: t('quickActions.medical'), color: theme.palette.error.main, path: '/track/medicine' },
    { icon: <Insights />, label: t('quickActions.activities'), color: theme.palette.success.main, path: '/track/activity' },
    { icon: <SmartToy />, label: t('quickActions.aiAssistant'), color: theme.palette.info.main, path: '/ai-assistant' },
  ];

  const formatSleepHours = (minutes: number) => {
    const hours = Math.floor(minutes / 60);
    const mins = minutes % 60;
    if (hours > 0 && mins > 0) {
      return `${hours}h ${mins}m`;
    } else if (hours > 0) {
      return `${hours}h`;
    } else {
      return `${mins}m`;
    }
  };

  const isLoading = authLoading || loading;

  // Build child metrics object for DynamicChildDashboard
  const childMetrics = children.reduce((acc: any, child: any) => {
    // Use todaySummary for selected child, or zero for others
    if (child.id === selectedChildId && todaySummary) {
      acc[child.id] = {
        feedingCount: todaySummary.feedingCount || 0,
        sleepDuration: todaySummary.totalSleepDuration || 0,
        diaperCount: todaySummary.diaperCount || 0,
        medicationCount: todaySummary.medicationCount || 0,
      };
    } else {
      acc[child.id] = {
        feedingCount: 0,
        sleepDuration: 0,
        diaperCount: 0,
        medicationCount: 0,
      };
    }
    return acc;
  }, {});

  const handleChildSelect = (childId: string) => {
    setSelectedChildId(childId);
  };

  return (
    <ProtectedRoute>
      <AppShell>
        <NetworkStatusIndicator />
        <Box>
          <EmailVerificationBanner />

          <motion.div
            initial={{ opacity: 0, y: 20 }}
            animate={{ opacity: 1, y: 0 }}
            transition={{ duration: 0.5 }}
          >
            <Typography variant="h4" component="h1" gutterBottom fontWeight="600" sx={{ mb: 1 }}>
              {user?.name ? t('welcomeBackWithName', { name: user.name }) : t('welcomeBack')} 👋
            </Typography>
          <Typography variant="body1" sx={{ mb: 4, color: 'text.primary' }}>
            {t('subtitle')}
          </Typography>

          {/* Quick Actions */}
          <Typography variant="h6" component="h2" gutterBottom fontWeight="600" sx={{ mb: 2 }}>
            {t('quickActions.title')}
          </Typography>
          <Grid container spacing={2} sx={{ mb: 4 }}>
            {quickActions.map((action, index) => (
              <Grid size={{ xs: 6, sm: 4, md: 2 }} key={action.label}>
                <motion.div
                  initial={{ opacity: 0, scale: 0.9 }}
                  animate={{ opacity: 1, scale: 1 }}
                  transition={{ duration: 0.3, delay: index * 0.1 }}
                  style={{ height: '100%' }}
                >
                  <Paper
                    component="button"
                    onClick={() => router.push(action.path)}
                    onKeyDown={(e) => {
                      if (e.key === 'Enter' || e.key === ' ') {
                        e.preventDefault();
                        router.push(action.path);
                      }
                    }}
                    aria-label={t('quickActions.navigateTo', { action: action.label })}
                    sx={{
                      p: 3,
                      height: '140px', // Fixed height for consistency
                      minHeight: '140px', // Ensure minimum height
                      width: '100%', // Full width of grid container
                      display: 'flex',
                      flexDirection: 'column',
                      alignItems: 'center',
                      justifyContent: 'center',
                      textAlign: 'center',
                      cursor: 'pointer',
                      bgcolor: action.color,
                      color: 'white',
                      border: 'none',
                      transition: 'transform 0.2s',
                      '&:hover': {
                        transform: 'scale(1.05)',
                      },
                      '&:focus-visible': {
                        outline: '3px solid white',
                        outlineOffset: '-3px',
                        transform: 'scale(1.05)',
                      },
                    }}
                  >
                    <Box sx={{ fontSize: 48, mb: 1 }} aria-hidden="true">{action.icon}</Box>
                    <Typography variant="body1" fontWeight="600">
                      {action.label}
                    </Typography>
                  </Paper>
                </motion.div>
              </Grid>
            ))}
          </Grid>

          {/* Today's Summary - Dynamic Multi-Child Dashboard */}
          <Typography variant="h6" component="h2" gutterBottom fontWeight="600" sx={{ mb: 2 }}>
            {t('summary.title')}
          </Typography>
          <ErrorBoundary
            isolate
            fallback={<DataErrorFallback error={new Error('Failed to load summary')} />}
          >
            {isLoading ? (
              <StatGridSkeleton count={3} />
            ) : children.length === 0 ? (
              <Paper sx={{ p: 3 }}>
                <Box sx={{ textAlign: 'center', py: 4 }}>
                  <Typography variant="body2" sx={{ color: 'rgba(0, 0, 0, 0.7)' }}>
                    {t('summary.noChild')}
                  </Typography>
                </Box>
              </Paper>
            ) : (
              <DynamicChildDashboard
                childMetrics={childMetrics}
                onChildSelect={handleChildSelect}
              />
            )}
          </ErrorBoundary>

          {/* Next Predicted Activity */}
          <Box sx={{ mt: 4 }}>
            <Paper sx={{ p: 3, bgcolor: 'primary.light' }}>
              <Typography variant="body2" sx={{ color: 'rgba(0, 0, 0, 0.7)' }} gutterBottom>
                {t('predictions.title')}
              </Typography>
              {predictionsLoading ? (
                <Box sx={{ display: 'flex', alignItems: 'center', gap: 2 }}>
                  <CircularProgress size={20} />
                  <Typography variant="body2">Loading predictions...</Typography>
                </Box>
              ) : predictions?.sleep?.nextNapTime || predictions?.feeding?.nextFeedingTime ? (
                <>
                  {predictions.sleep?.nextNapTime && (
                    <>
                      <Typography variant="h6" fontWeight="600" gutterBottom>
                        Nap time {formatDistanceToNow(new Date(predictions.sleep.nextNapTime), { addSuffix: true })}
                      </Typography>
                      <Typography variant="body2" sx={{ color: 'rgba(0, 0, 0, 0.7)' }}>
                        {predictions.sleep.reasoning || t('predictions.basedOnPatterns')}
                      </Typography>
                    </>
                  )}
                  {!predictions.sleep?.nextNapTime && predictions.feeding?.nextFeedingTime && (
                    <>
                      <Typography variant="h6" fontWeight="600" gutterBottom>
                        Feeding time {formatDistanceToNow(new Date(predictions.feeding.nextFeedingTime), { addSuffix: true })}
                      </Typography>
                      <Typography variant="body2" sx={{ color: 'rgba(0, 0, 0, 0.7)' }}>
                        {predictions.feeding.reasoning || t('predictions.basedOnPatterns')}
                      </Typography>
                    </>
                  )}
                </>
              ) : (
                <Typography variant="body1" sx={{ color: 'rgba(0, 0, 0, 0.7)' }}>
                  {t('predictions.notEnoughData')}
                </Typography>
              )}
            </Paper>
          </Box>
          </motion.div>
        </Box>
      </AppShell>
    </ProtectedRoute>
  );
}