'use client';

import { useState, useEffect } from 'react';
import {
  Box,
  Typography,
  Grid,
  Card,
  CardContent,
  Select,
  MenuItem,
  FormControl,
  InputLabel,
  CircularProgress,
  Alert,
  Tab,
  Tabs,
  Chip,
  List,
  ListItem,
  ListItemIcon,
  ListItemText,
  useTheme,
} from '@mui/material';
import {
  TrendingUp,
  Restaurant,
  Hotel,
  BabyChangingStation,
  Warning,
  CheckCircle,
  Timeline,
  Assessment,
} from '@mui/icons-material';
import { AppShell } from '@/components/layouts/AppShell/AppShell';
import { ProtectedRoute } from '@/components/common/ProtectedRoute';
import { childrenApi, Child } from '@/lib/api/children';
import { analyticsApi, PatternInsights, PredictionInsights } from '@/lib/api/analytics';
import PredictionsCard from '@/components/features/analytics/PredictionsCard';
import { extractError } from '@/lib/utils/errorHandler';
import GrowthSpurtAlert from '@/components/features/analytics/GrowthSpurtAlert';
import WeeklyReportCard from '@/components/features/analytics/WeeklyReportCard';
import MonthlyReportCard from '@/components/features/analytics/MonthlyReportCard';
import { useAuth } from '@/lib/auth/AuthContext';

interface TabPanelProps {
  children?: React.ReactNode;
  index: number;
  value: number;
}

function TabPanel(props: TabPanelProps) {
  const { children, value, index, ...other } = props;

  return (
    <div
      role="tabpanel"
      hidden={value !== index}
      id={`analytics-tabpanel-${index}`}
      aria-labelledby={`analytics-tab-${index}`}
      {...other}
    >
      {value === index && <Box sx={{ py: 3 }}>{children}</Box>}
    </div>
  );
}

export default function AnalyticsPage() {
  const theme = useTheme();
  const { user } = useAuth();
  const [children, setChildren] = useState<Child[]>([]);
  const [selectedChildId, setSelectedChildId] = useState<string>('');
  const [tabValue, setTabValue] = useState(0);
  const [loading, setLoading] = useState(true);
  const [insights, setInsights] = useState<PatternInsights | null>(null);
  const [predictions, setPredictions] = useState<PredictionInsights | null>(null);
  const [insightsLoading, setInsightsLoading] = useState(false);
  const [predictionsLoading, setPredictionsLoading] = useState(false);
  const [days, setDays] = useState<number>(7);
  const [error, setError] = useState<string>('');

  const familyId = user?.families?.[0]?.familyId;

  useEffect(() => {
    if (familyId) {
      loadChildren();
    }
  }, [familyId]);

  useEffect(() => {
    if (selectedChildId && children.length > 0) {
      // Validate that selectedChildId belongs to current user's children
      const childExists = children.some(child => child.id === selectedChildId);
      if (childExists) {
        loadInsights();
        loadPredictions();
      } else {
        console.warn('[AnalyticsPage] Selected child not found in user\'s children, resetting');
        setSelectedChildId(children[0].id);
        setError('Selected child not found. Showing data for your first child.');
      }
    }
  }, [selectedChildId, days, children]);

  const loadChildren = async () => {
    if (!familyId) {
      setLoading(false);
      setError('No family found');
      return;
    }

    try {
      console.log('[AnalyticsPage] Loading children for familyId:', familyId);
      const data = await childrenApi.getChildren(familyId);
      console.log('[AnalyticsPage] Loaded children:', data);
      setChildren(data);

      if (data.length > 0) {
        const existingChildStillValid = data.some(child => child.id === selectedChildId);
        if (!selectedChildId || !existingChildStillValid) {
          setSelectedChildId(data[0].id);
        }
      }
      setError('');
    } catch (error: any) {
      console.error('[AnalyticsPage] Failed to load children:', error);
      const errorData = extractError(error);
      setError(errorData.userMessage || errorData.message);
    } finally {
      setLoading(false);
    }
  };

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

    setInsightsLoading(true);
    try {
      const data = await analyticsApi.getInsights(selectedChildId, days);
      setInsights(data);
    } catch (error: any) {
      console.error('Failed to load insights:', error);
      const errorData = extractError(error);
      console.error('Insights error:', errorData.message);
    } finally {
      setInsightsLoading(false);
    }
  };

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

    setPredictionsLoading(true);
    try {
      const data = await analyticsApi.getPredictions(selectedChildId);
      setPredictions(data);
    } catch (error: any) {
      console.error('Failed to load predictions:', error);
      const errorData = extractError(error);
      console.error('Predictions error:', errorData.message);
    } finally {
      setPredictionsLoading(false);
    }
  };

  if (loading) {
    return (
      <ProtectedRoute>
        <AppShell>
          <Box sx={{ display: 'flex', justifyContent: 'center', alignItems: 'center', minHeight: '60vh' }}>
            <CircularProgress />
          </Box>
        </AppShell>
      </ProtectedRoute>
    );
  }

  if (children.length === 0) {
    return (
      <ProtectedRoute>
        <AppShell>
          <Box sx={{ p: 3 }}>
            <Alert severity="info">Add a child to your family to view analytics and predictions.</Alert>
          </Box>
        </AppShell>
      </ProtectedRoute>
    );
  }

  return (
    <ProtectedRoute>
      <AppShell>
        <Box sx={{ p: 3 }}>
          {/* Header */}
          <Box sx={{ mb: 3 }}>
            <Typography variant="h4" gutterBottom>
              Analytics & Predictions
            </Typography>
            <Typography variant="body2" color="text.secondary">
              AI-powered insights and predictions for your child's patterns
            </Typography>
          </Box>

          {/* Child Selector and Date Range */}
          <Grid container spacing={2} sx={{ mb: 3 }}>
            <Grid item xs={12} md={6}>
              <FormControl fullWidth>
                <InputLabel>Child</InputLabel>
                <Select
                  value={selectedChildId}
                  label="Child"
                  onChange={(e) => setSelectedChildId(e.target.value)}
                >
                  {children.map((child) => (
                    <MenuItem key={child.id} value={child.id}>
                      {child.name}
                    </MenuItem>
                  ))}
                </Select>
              </FormControl>
            </Grid>
            <Grid item xs={12} md={6}>
              <FormControl fullWidth>
                <InputLabel>Date Range</InputLabel>
                <Select value={days} label="Date Range" onChange={(e) => setDays(Number(e.target.value))}>
                  <MenuItem value={7}>Last 7 days</MenuItem>
                  <MenuItem value={14}>Last 14 days</MenuItem>
                  <MenuItem value={30}>Last 30 days</MenuItem>
                </Select>
              </FormControl>
            </Grid>
          </Grid>

          {/* Growth Spurt Alert */}
          {insights?.growthSpurt && <GrowthSpurtAlert growthSpurt={insights.growthSpurt} />}

          {/* Tabs */}
          <Box sx={{ borderBottom: 1, borderColor: 'divider', mb: 2 }}>
            <Tabs value={tabValue} onChange={(e, newValue) => setTabValue(newValue)}>
              <Tab label="Predictions" icon={<TrendingUp />} iconPosition="start" />
              <Tab label="Patterns" icon={<Timeline />} iconPosition="start" />
              <Tab label="Reports" icon={<Assessment />} iconPosition="start" />
              <Tab label="Recommendations" icon={<CheckCircle />} iconPosition="start" />
            </Tabs>
          </Box>

          {/* Tab Panels */}
          <TabPanel value={tabValue} index={0}>
            <Grid container spacing={3}>
              <Grid item xs={12}>
                <PredictionsCard predictions={predictions} loading={predictionsLoading} />
              </Grid>
            </Grid>
          </TabPanel>

          <TabPanel value={tabValue} index={1}>
            <Grid container spacing={3}>
              {/* Sleep Patterns */}
              {insights?.sleep && (
                <Grid item xs={12} md={6}>
                  <Card>
                    <CardContent>
                      <Box sx={{ display: 'flex', alignItems: 'center', mb: 2 }}>
                        <Hotel sx={{ mr: 1, color: theme.palette.secondary.main }} />
                        <Typography variant="h6">Sleep Patterns</Typography>
                        <Chip
                          size="small"
                          label={insights.sleep.trend}
                          color={
                            insights.sleep.trend === 'improving'
                              ? 'success'
                              : insights.sleep.trend === 'declining'
                                ? 'error'
                                : 'default'
                          }
                          sx={{ ml: 'auto' }}
                        />
                      </Box>

                      <Grid container spacing={2}>
                        <Grid item xs={6}>
                          <Typography variant="body2" color="text.secondary">
                            Avg Duration
                          </Typography>
                          <Typography variant="h6">{Math.round(insights.sleep.averageDuration)} min</Typography>
                        </Grid>
                        <Grid item xs={6}>
                          <Typography variant="body2" color="text.secondary">
                            Night Wakings
                          </Typography>
                          <Typography variant="h6">{insights.sleep.nightWakings}</Typography>
                        </Grid>
                        <Grid item xs={6}>
                          <Typography variant="body2" color="text.secondary">
                            Avg Bedtime
                          </Typography>
                          <Typography variant="h6">{insights.sleep.averageBedtime}</Typography>
                        </Grid>
                        <Grid item xs={6}>
                          <Typography variant="body2" color="text.secondary">
                            Avg Wake Time
                          </Typography>
                          <Typography variant="h6">{insights.sleep.averageWakeTime}</Typography>
                        </Grid>
                        <Grid item xs={6}>
                          <Typography variant="body2" color="text.secondary">
                            Nap Count
                          </Typography>
                          <Typography variant="h6">{insights.sleep.napCount}</Typography>
                        </Grid>
                        <Grid item xs={6}>
                          <Typography variant="body2" color="text.secondary">
                            Consistency
                          </Typography>
                          <Typography variant="h6">{Math.round(insights.sleep.consistency * 100)}%</Typography>
                        </Grid>
                      </Grid>
                    </CardContent>
                  </Card>
                </Grid>
              )}

              {/* Feeding Patterns */}
              {insights?.feeding && (
                <Grid item xs={12} md={6}>
                  <Card>
                    <CardContent>
                      <Box sx={{ display: 'flex', alignItems: 'center', mb: 2 }}>
                        <Restaurant sx={{ mr: 1, color: theme.palette.primary.main }} />
                        <Typography variant="h6">Feeding Patterns</Typography>
                        <Chip
                          size="small"
                          label={insights.feeding.trend}
                          color={
                            insights.feeding.trend === 'increasing'
                              ? 'success'
                              : insights.feeding.trend === 'decreasing'
                                ? 'error'
                                : 'default'
                          }
                          sx={{ ml: 'auto' }}
                        />
                      </Box>

                      <Grid container spacing={2}>
                        <Grid item xs={6}>
                          <Typography variant="body2" color="text.secondary">
                            Total Feedings
                          </Typography>
                          <Typography variant="h6">{insights.feeding.totalFeedings}</Typography>
                        </Grid>
                        <Grid item xs={6}>
                          <Typography variant="body2" color="text.secondary">
                            Avg Interval
                          </Typography>
                          <Typography variant="h6">{insights.feeding.averageInterval.toFixed(1)} hrs</Typography>
                        </Grid>
                        <Grid item xs={6}>
                          <Typography variant="body2" color="text.secondary">
                            Avg Duration
                          </Typography>
                          <Typography variant="h6">{Math.round(insights.feeding.averageDuration)} min</Typography>
                        </Grid>
                        <Grid item xs={6}>
                          <Typography variant="body2" color="text.secondary">
                            Consistency
                          </Typography>
                          <Typography variant="h6">{Math.round(insights.feeding.consistency * 100)}%</Typography>
                        </Grid>
                      </Grid>

                      {Object.keys(insights.feeding.feedingMethod).length > 0 && (
                        <Box sx={{ mt: 2 }}>
                          <Typography variant="body2" color="text.secondary" gutterBottom>
                            Feeding Methods
                          </Typography>
                          {Object.entries(insights.feeding.feedingMethod).map(([method, count]) => (
                            <Chip
                              key={method}
                              label={`${method}: ${count}`}
                              size="small"
                              sx={{ mr: 0.5, mb: 0.5 }}
                            />
                          ))}
                        </Box>
                      )}
                    </CardContent>
                  </Card>
                </Grid>
              )}

              {/* Diaper Patterns */}
              {insights?.diaper && (
                <Grid item xs={12} md={6}>
                  <Card>
                    <CardContent>
                      <Box sx={{ display: 'flex', alignItems: 'center', mb: 2 }}>
                        <BabyChangingStation sx={{ mr: 1, color: theme.palette.warning.main }} />
                        <Typography variant="h6">Diaper Patterns</Typography>
                        <Chip
                          size="small"
                          label={insights.diaper.isHealthy ? 'Healthy' : 'Needs Attention'}
                          color={insights.diaper.isHealthy ? 'success' : 'warning'}
                          sx={{ ml: 'auto' }}
                        />
                      </Box>

                      <Grid container spacing={2}>
                        <Grid item xs={6}>
                          <Typography variant="body2" color="text.secondary">
                            Wet/Day
                          </Typography>
                          <Typography variant="h6">{insights.diaper.wetDiapersPerDay.toFixed(1)}</Typography>
                        </Grid>
                        <Grid item xs={6}>
                          <Typography variant="body2" color="text.secondary">
                            Dirty/Day
                          </Typography>
                          <Typography variant="h6">{insights.diaper.dirtyDiapersPerDay.toFixed(1)}</Typography>
                        </Grid>
                        <Grid item xs={12}>
                          <Typography variant="body2" color="text.secondary">
                            Avg Interval
                          </Typography>
                          <Typography variant="h6">{insights.diaper.averageInterval.toFixed(1)} hrs</Typography>
                        </Grid>
                      </Grid>

                      {insights.diaper.notes && (
                        <Alert severity="info" sx={{ mt: 2 }}>
                          {insights.diaper.notes}
                        </Alert>
                      )}
                    </CardContent>
                  </Card>
                </Grid>
              )}
            </Grid>

            {insightsLoading && (
              <Box sx={{ display: 'flex', justifyContent: 'center', py: 4 }}>
                <CircularProgress />
              </Box>
            )}

            {!insightsLoading && !insights && (
              <Alert severity="info">Not enough data to analyze patterns yet. Track more activities!</Alert>
            )}
          </TabPanel>

          <TabPanel value={tabValue} index={2}>
            <Grid container spacing={3}>
              <Grid item xs={12}>
                <WeeklyReportCard childId={selectedChildId} />
              </Grid>
              <Grid item xs={12}>
                <MonthlyReportCard childId={selectedChildId} />
              </Grid>
            </Grid>
          </TabPanel>

          <TabPanel value={tabValue} index={3}>
            <Grid container spacing={3}>
              {/* Recommendations */}
              {insights?.recommendations && insights.recommendations.length > 0 && (
                <Grid item xs={12} md={6}>
                  <Card>
                    <CardContent>
                      <Box sx={{ display: 'flex', alignItems: 'center', mb: 2 }}>
                        <CheckCircle sx={{ mr: 1, color: 'success.main' }} />
                        <Typography variant="h6">Recommendations</Typography>
                      </Box>
                      <List>
                        {insights.recommendations.map((rec, index) => (
                          <ListItem key={index}>
                            <ListItemIcon>
                              <CheckCircle color="success" />
                            </ListItemIcon>
                            <ListItemText primary={rec} />
                          </ListItem>
                        ))}
                      </List>
                    </CardContent>
                  </Card>
                </Grid>
              )}

              {/* Concerns */}
              {insights?.concernsDetected && insights.concernsDetected.length > 0 && (
                <Grid item xs={12} md={6}>
                  <Card>
                    <CardContent>
                      <Box sx={{ display: 'flex', alignItems: 'center', mb: 2 }}>
                        <Warning sx={{ mr: 1, color: 'warning.main' }} />
                        <Typography variant="h6">Concerns Detected</Typography>
                      </Box>
                      <List>
                        {insights.concernsDetected.map((concern, index) => (
                          <ListItem key={index}>
                            <ListItemIcon>
                              <Warning color="warning" />
                            </ListItemIcon>
                            <ListItemText primary={concern} />
                          </ListItem>
                        ))}
                      </List>
                      <Alert severity="warning" sx={{ mt: 2 }}>
                        If you have concerns about your child's health, please consult with your pediatrician.
                      </Alert>
                    </CardContent>
                  </Card>
                </Grid>
              )}

              {(!insights?.recommendations || insights.recommendations.length === 0) &&
                (!insights?.concernsDetected || insights.concernsDetected.length === 0) && (
                  <Grid item xs={12}>
                    <Alert severity="info">No recommendations or concerns at this time. Keep tracking!</Alert>
                  </Grid>
                )}
            </Grid>
          </TabPanel>
        </Box>
      </AppShell>
    </ProtectedRoute>
  );
}