'use client';

import { useState, useEffect } from 'react';
import {
  Box,
  Typography,
  Button,
  Paper,
  TextField,
  FormControl,
  InputLabel,
  Select,
  MenuItem,
  IconButton,
  Alert,
  CircularProgress,
  Card,
  CardContent,
  Dialog,
  DialogTitle,
  DialogContent,
  DialogContentText,
  DialogActions,
  Chip,
  Snackbar,
} from '@mui/material';
import {
  ArrowBack,
  Save,
  ChildCare,
  Delete,
  Refresh,
  Add,
  DirectionsWalk,
  Toys,
  MusicNote,
} from '@mui/icons-material';
import { useRouter } from 'next/navigation';
import { AppShell } from '@/components/layouts/AppShell/AppShell';
import { ProtectedRoute } from '@/components/common/ProtectedRoute';
import { withErrorBoundary } from '@/components/common/ErrorFallbacks';
import { useAuth } from '@/lib/auth/AuthContext';
import { trackingApi, Activity } from '@/lib/api/tracking';
import { childrenApi, Child } from '@/lib/api/children';
import { VoiceInputButton } from '@/components/voice/VoiceInputButton';
import { FormSkeleton, ActivityListSkeleton } from '@/components/common/LoadingSkeletons';
import { motion } from 'framer-motion';
import { useLocalizedDate } from '@/hooks/useLocalizedDate';
import { useTranslation } from '@/hooks/useTranslation';
import { useDispatch, useSelector } from 'react-redux';
import { fetchChildren, selectChild, selectSelectedChild, childrenSelectors } from '@/store/slices/childrenSlice';
import { AppDispatch, RootState } from '@/store/store';
import ChildSelector from '@/components/common/ChildSelector';
import { useErrorMessage } from '@/components/common/ErrorMessage';
import { formatErrorMessage } from '@/lib/utils/errorHandler';

interface ActivityData {
  activityType: string;
  duration?: number;
  description?: string;
}

function ActivityTrackPage() {
  const router = useRouter();
  const { user } = useAuth();
  const { formatDistanceToNow } = useLocalizedDate();
  const { t } = useTranslation('tracking');
  const dispatch = useDispatch<AppDispatch>();

  // Redux state
  const children = useSelector((state: RootState) => childrenSelectors.selectAll(state));
  const selectedChild = useSelector(selectSelectedChild);
  const familyId = user?.families?.[0]?.familyId;

  // Local state
  const [selectedChildIds, setSelectedChildIds] = useState<string[]>([]);

  // Activity state
  const [activityType, setActivityType] = useState<string>('play');
  const [duration, setDuration] = useState<string>('');
  const [description, setDescription] = useState<string>('');

  // Common state
  const [notes, setNotes] = useState<string>('');
  const [recentActivities, setRecentActivities] = useState<Activity[]>([]);
  const [loading, setLoading] = useState(false);
  const [activitiesLoading, setActivitiesLoading] = useState(false);
  const { error, showError, clearError, hasError } = useErrorMessage();
  const [successMessage, setSuccessMessage] = useState<string | null>(null);

  // Delete confirmation dialog
  const [deleteDialogOpen, setDeleteDialogOpen] = useState(false);
  const [activityToDelete, setActivityToDelete] = useState<string | null>(null);

  // Load children from Redux
  useEffect(() => {
    if (familyId && children.length === 0) {
      dispatch(fetchChildren(familyId));
    }
  }, [familyId, dispatch, children.length]);

  // Sync selectedChildIds with Redux selectedChild
  useEffect(() => {
    if (selectedChild?.id) {
      setSelectedChildIds([selectedChild.id]);
    }
  }, [selectedChild]);

  // Load recent activities when child is selected
  useEffect(() => {
    if (selectedChild?.id) {
      loadRecentActivities();
    }
  }, [selectedChild?.id]);

  const loadRecentActivities = async () => {
    if (!selectedChild?.id) return;

    try {
      setActivitiesLoading(true);
      const activities = await trackingApi.getActivities(selectedChild.id, 'activity');
      // Sort by timestamp descending and take last 10
      const sorted = activities.sort((a, b) =>
        new Date(b.timestamp).getTime() - new Date(a.timestamp).getTime()
      ).slice(0, 10);
      setRecentActivities(sorted);
    } catch (err: any) {
      console.error('Failed to load recent activities:', err);
    } finally {
      setActivitiesLoading(false);
    }
  };

  const handleSubmit = async () => {
    if (!selectedChild?.id) {
      showError({ message: 'Please select a child', code: 'NO_CHILD_SELECTED' });
      return;
    }

    // Validation
    if (!activityType) {
      showError({ message: 'Please select activity type', code: 'VALIDATION_ERROR' });
      return;
    }

    try {
      setLoading(true);
      clearError();

      const data: ActivityData = {
        activityType,
        duration: duration ? parseInt(duration) : undefined,
        description: description || undefined,
      };

      await trackingApi.createActivity(selectedChild.id, {
        type: 'activity',
        timestamp: new Date().toISOString(),
        data,
        notes: notes || undefined,
      });

      setSuccessMessage(t('activity.success'));

      // Reset form
      resetForm();

      // Reload recent activities
      await loadRecentActivities();
    } catch (err: any) {
      console.error('Failed to save activity:', err);
      showError(err);
    } finally {
      setLoading(false);
    }
  };

  const resetForm = () => {
    setActivityType('play');
    setDuration('');
    setDescription('');
    setNotes('');
  };

  const handleDeleteClick = (activityId: string) => {
    setActivityToDelete(activityId);
    setDeleteDialogOpen(true);
  };

  const handleDeleteConfirm = async () => {
    if (!activityToDelete) return;

    try {
      setLoading(true);
      await trackingApi.deleteActivity(activityToDelete);
      setSuccessMessage(t('activity.deleted'));
      setDeleteDialogOpen(false);
      setActivityToDelete(null);
      await loadRecentActivities();
    } catch (err: any) {
      console.error('Failed to delete activity:', err);
      showError(err);
    } finally {
      setLoading(false);
    }
  };

  const getActivityTypeIcon = (type: string) => {
    switch (type) {
      case 'play':
        return <Toys />;
      case 'walk':
        return <DirectionsWalk />;
      case 'music':
        return <MusicNote />;
      default:
        return <ChildCare />;
    }
  };

  const getActivityDetails = (activity: Activity) => {
    const data = activity.data as ActivityData;
    let details = data.activityType.charAt(0).toUpperCase() + data.activityType.slice(1);
    if (data.duration) {
      details += ` - ${data.duration} min`;
    }
    if (data.description) {
      details += ` - ${data.description}`;
    }
    return details;
  };

  const childrenLoading = useSelector((state: RootState) => state.children.loading);

  if (childrenLoading && children.length === 0) {
    return (
      <ProtectedRoute>
        <AppShell>
          <Box>
            <Typography variant="h4" fontWeight="600" sx={{ mb: 3 }}>
              {t('trackActivity')}
            </Typography>
            <Paper sx={{ p: 3, mb: 3 }}>
              <FormSkeleton />
            </Paper>
            <Typography variant="h6" fontWeight="600" sx={{ mb: 2 }}>
              {t('activity.recentActivities')}
            </Typography>
            <ActivityListSkeleton count={3} />
          </Box>
        </AppShell>
      </ProtectedRoute>
    );
  }

  if (!familyId || children.length === 0) {
    return (
      <ProtectedRoute>
        <AppShell>
          <Card>
            <CardContent sx={{ textAlign: 'center', py: 8 }}>
              <ChildCare sx={{ fontSize: 64, color: 'text.secondary', mb: 2 }} />
              <Typography variant="h6" color="text.secondary" gutterBottom>
                {t('common.noChildrenAdded')}
              </Typography>
              <Typography variant="body2" color="text.secondary" sx={{ mb: 3 }}>
                {t('common.noChildrenMessage')}
              </Typography>
              <Button
                variant="contained"
                startIcon={<Add />}
                onClick={() => router.push('/children')}
              >
                {t('common.addChild')}
              </Button>
            </CardContent>
          </Card>
        </AppShell>
      </ProtectedRoute>
    );
  }

  return (
    <ProtectedRoute>
      <AppShell>
        <Box>
          <Box sx={{ display: 'flex', alignItems: 'center', mb: 3 }}>
            <IconButton onClick={() => router.back()} sx={{ mr: 2 }}>
              <ArrowBack />
            </IconButton>
            <Typography variant="h4" fontWeight="600" sx={{ flex: 1 }}>
              {t('trackActivity')}
            </Typography>
            <VoiceInputButton
              onTranscript={(transcript) => {
                console.log('[Activity] Voice transcript:', transcript);
              }}
              onClassifiedIntent={(result) => {
                if (result.intent === 'activity' && result.structuredData) {
                  const data = result.structuredData;
                  // Auto-fill form with voice data
                  if (data.activityType) setActivityType(data.activityType);
                  if (data.duration) setDuration(data.duration.toString());
                  if (data.description) setDescription(data.description);
                }
              }}
              size="medium"
            />
          </Box>

          {hasError && (
            <Alert severity="error" sx={{ mb: 3 }} onClose={clearError}>
              {formatErrorMessage(error)}
            </Alert>
          )}

          <motion.div
            initial={{ opacity: 0, y: 20 }}
            animate={{ opacity: 1, y: 0 }}
            transition={{ duration: 0.3 }}
          >
            {/* Child Selector */}
            {children.length > 0 && (
              <Paper sx={{ p: 2, mb: 3 }}>
                <ChildSelector
                  children={children}
                  selectedChildIds={selectedChildIds}
                  onChange={(childIds) => {
                    setSelectedChildIds(childIds);
                    if (childIds.length > 0) {
                      dispatch(selectChild(childIds[0]));
                    }
                  }}
                  mode="single"
                  label={t('common.selectChild')}
                  required
                />
              </Paper>
            )}

            {/* Main Form */}
            <Paper sx={{ p: 3, mb: 3 }}>
              <Box sx={{ display: 'flex', alignItems: 'center', mb: 3 }}>
                <ChildCare sx={{ fontSize: 36, color: 'success.main', mr: 2 }} />
                <Typography variant="h6" fontWeight="600">
                  {t('activity.title')}
                </Typography>
              </Box>

              <FormControl fullWidth sx={{ mb: 3 }}>
                <InputLabel>{t('activity.type')}</InputLabel>
                <Select
                  value={activityType}
                  onChange={(e) => setActivityType(e.target.value)}
                  label={t('activity.type')}
                >
                  <MenuItem value="play">{t('activity.types.play')}</MenuItem>
                  <MenuItem value="walk">{t('activity.types.walk')}</MenuItem>
                  <MenuItem value="music">{t('activity.types.music')}</MenuItem>
                  <MenuItem value="reading">{t('activity.types.reading')}</MenuItem>
                  <MenuItem value="tummy_time">{t('activity.types.tummyTime')}</MenuItem>
                  <MenuItem value="outdoor">{t('activity.types.outdoor')}</MenuItem>
                  <MenuItem value="other">{t('activity.types.other')}</MenuItem>
                </Select>
              </FormControl>

              <TextField
                fullWidth
                label={t('activity.duration')}
                type="number"
                value={duration}
                onChange={(e) => setDuration(e.target.value)}
                sx={{ mb: 3 }}
                placeholder={t('activity.placeholders.duration')}
              />

              <TextField
                fullWidth
                label={t('activity.description')}
                value={description}
                onChange={(e) => setDescription(e.target.value)}
                sx={{ mb: 3 }}
                placeholder={t('activity.placeholders.description')}
              />

              <TextField
                fullWidth
                label={t('activity.notes')}
                multiline
                rows={3}
                value={notes}
                onChange={(e) => setNotes(e.target.value)}
                sx={{ mb: 3 }}
                placeholder={t('activity.placeholders.notes')}
              />

              <Button
                fullWidth
                type="button"
                variant="contained"
                size="large"
                startIcon={<Save />}
                onClick={handleSubmit}
                disabled={loading}
              >
                {loading ? t('common.loading') : t('activity.logActivity')}
              </Button>
            </Paper>

            {/* Recent Activities */}
            <Paper sx={{ p: 3 }}>
              <Box sx={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center', mb: 2 }}>
                <Typography variant="h6" fontWeight="600">
                  {t('activity.recentActivities')}
                </Typography>
                <IconButton onClick={loadRecentActivities} disabled={activitiesLoading}>
                  <Refresh />
                </IconButton>
              </Box>

              {activitiesLoading ? (
                <Box sx={{ display: 'flex', justifyContent: 'center', py: 4 }}>
                  <CircularProgress size={30} />
                </Box>
              ) : recentActivities.length === 0 ? (
                <Box sx={{ textAlign: 'center', py: 4 }}>
                  <Typography variant="body2" color="text.secondary">
                    {t('noEntries')}
                  </Typography>
                </Box>
              ) : (
                <Box sx={{ display: 'flex', flexDirection: 'column', gap: 2 }}>
                  {recentActivities.map((activity, index) => {
                    const data = activity.data as ActivityData;
                    if (!data || !data.activityType) {
                      console.warn('[Activity] Activity missing activityType:', activity);
                      return null;
                    }
                    return (
                      <motion.div
                        key={activity.id}
                        initial={{ opacity: 0, y: 10 }}
                        animate={{ opacity: 1, y: 0 }}
                        transition={{ duration: 0.2, delay: index * 0.05 }}
                      >
                        <Card variant="outlined">
                          <CardContent>
                            <Box sx={{ display: 'flex', alignItems: 'flex-start', gap: 2 }}>
                              <Box sx={{ mt: 0.5 }}>
                                {getActivityTypeIcon(data.activityType)}
                              </Box>
                              <Box sx={{ flex: 1 }}>
                                <Box sx={{ display: 'flex', alignItems: 'center', gap: 1, mb: 0.5 }}>
                                  <Typography variant="body1" fontWeight="600">
                                    {data.activityType.charAt(0).toUpperCase() + data.activityType.slice(1).replace('_', ' ')}
                                  </Typography>
                                  <Chip
                                    label={formatDistanceToNow(new Date(activity.timestamp), { addSuffix: true })}
                                    size="small"
                                    variant="outlined"
                                  />
                                </Box>
                                <Typography variant="body2" color="text.secondary" sx={{ mb: 1 }}>
                                  {getActivityDetails(activity)}
                                </Typography>
                                {activity.notes && (
                                  <Typography variant="body2" color="text.secondary" sx={{ fontStyle: 'italic' }}>
                                    {activity.notes}
                                  </Typography>
                                )}
                              </Box>
                              <Box sx={{ display: 'flex', gap: 0.5 }}>
                                <IconButton
                                  size="small"
                                  color="error"
                                  onClick={() => handleDeleteClick(activity.id)}
                                  disabled={loading}
                                >
                                  <Delete />
                                </IconButton>
                              </Box>
                            </Box>
                          </CardContent>
                        </Card>
                      </motion.div>
                    );
                  })}
                </Box>
              )}
            </Paper>
          </motion.div>
        </Box>

        {/* Delete Confirmation Dialog */}
        <Dialog
          open={deleteDialogOpen}
          onClose={() => setDeleteDialogOpen(false)}
        >
          <DialogTitle>{t('common.delete')} {t('activity.title')}?</DialogTitle>
          <DialogContent>
            <DialogContentText>
              {t('confirmDelete')}
            </DialogContentText>
          </DialogContent>
          <DialogActions>
            <Button onClick={() => setDeleteDialogOpen(false)} disabled={loading}>
              {t('common.cancel')}
            </Button>
            <Button onClick={handleDeleteConfirm} color="error" disabled={loading}>
              {loading ? 'Deleting...' : t('common.delete')}
            </Button>
          </DialogActions>
        </Dialog>

        {/* Success Snackbar */}
        <Snackbar
          open={!!successMessage}
          autoHideDuration={3000}
          onClose={() => setSuccessMessage(null)}
          message={successMessage}
        />
      </AppShell>
    </ProtectedRoute>
  );
}

export default withErrorBoundary(ActivityTrackPage, 'form');
