'use client';

import { useState, useEffect } from 'react';
import { Box, Typography, CircularProgress, Alert, ToggleButtonGroup, ToggleButton } from '@mui/material';
import {
  BarChart,
  Bar,
  LineChart,
  Line,
  XAxis,
  YAxis,
  CartesianGrid,
  Tooltip,
  Legend,
  ResponsiveContainer,
  PieChart,
  Pie,
  Cell,
} from 'recharts';
import { format, subDays } from 'date-fns';
import apiClient from '@/lib/api/client';

interface FeedingData {
  date: string;
  breastfeeding: number;
  bottle: number;
  solids: number;
  total: number;
}

interface FeedingTypeData {
  name: string;
  value: number;
  color: string;
}

const COLORS = {
  breastfeeding: '#FFB6C1',
  bottle: '#FFA5B0',
  solids: '#FF94A5',
};

export default function FeedingFrequencyGraph() {
  const [data, setData] = useState<FeedingData[]>([]);
  const [typeData, setTypeData] = useState<FeedingTypeData[]>([]);
  const [isLoading, setIsLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);
  const [chartType, setChartType] = useState<'bar' | 'line'>('bar');

  useEffect(() => {
    fetchFeedingData();
  }, []);

  const fetchFeedingData = async () => {
    try {
      setIsLoading(true);
      const endDate = new Date();
      const startDate = subDays(endDate, 6);

      const response = await apiClient.get('/api/v1/activities/feeding', {
        params: {
          startDate: startDate.toISOString(),
          endDate: endDate.toISOString(),
        },
      });

      const feedingActivities = response.data.data;
      const dailyData: { [key: string]: FeedingData } = {};

      // Initialize 7 days of data
      for (let i = 0; i < 7; i++) {
        const date = subDays(endDate, 6 - i);
        const dateStr = format(date, 'MMM dd');
        dailyData[dateStr] = {
          date: dateStr,
          breastfeeding: 0,
          bottle: 0,
          solids: 0,
          total: 0,
        };
      }

      // Count feeding types by day
      const typeCounts = {
        breastfeeding: 0,
        bottle: 0,
        solids: 0,
      };

      feedingActivities.forEach((activity: any) => {
        const dateStr = format(new Date(activity.timestamp), 'MMM dd');
        if (dailyData[dateStr]) {
          const type = activity.type?.toLowerCase() || 'bottle';

          if (type === 'breastfeeding' || type === 'breast') {
            dailyData[dateStr].breastfeeding += 1;
            typeCounts.breastfeeding += 1;
          } else if (type === 'bottle' || type === 'formula') {
            dailyData[dateStr].bottle += 1;
            typeCounts.bottle += 1;
          } else if (type === 'solids' || type === 'solid') {
            dailyData[dateStr].solids += 1;
            typeCounts.solids += 1;
          }

          dailyData[dateStr].total += 1;
        }
      });

      setData(Object.values(dailyData));

      // Prepare pie chart data
      const pieData: FeedingTypeData[] = [
        {
          name: 'Breastfeeding',
          value: typeCounts.breastfeeding,
          color: COLORS.breastfeeding,
        },
        {
          name: 'Bottle',
          value: typeCounts.bottle,
          color: COLORS.bottle,
        },
        {
          name: 'Solids',
          value: typeCounts.solids,
          color: COLORS.solids,
        },
      ].filter((item) => item.value > 0);

      setTypeData(pieData);
    } catch (err: any) {
      console.error('Failed to fetch feeding data:', err);
      setError(err.response?.data?.message || 'Failed to load feeding data');
    } finally {
      setIsLoading(false);
    }
  };

  const handleChartTypeChange = (
    event: React.MouseEvent<HTMLElement>,
    newType: 'bar' | 'line' | null
  ) => {
    if (newType !== null) {
      setChartType(newType);
    }
  };

  if (isLoading) {
    return (
      <Box sx={{ display: 'flex', justifyContent: 'center', py: 4 }}>
        <CircularProgress />
      </Box>
    );
  }

  if (error) {
    return (
      <Alert severity="error" sx={{ borderRadius: 2 }}>
        {error}
      </Alert>
    );
  }

  return (
    <Box>
      <Box sx={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center', mb: 3 }}>
        <Box>
          <Typography variant="h6" gutterBottom fontWeight="600">
            Weekly Feeding Patterns
          </Typography>
          <Typography variant="body2" color="text.secondary">
            Track feeding frequency and types over the past 7 days
          </Typography>
        </Box>
        <ToggleButtonGroup
          value={chartType}
          exclusive
          onChange={handleChartTypeChange}
          size="small"
        >
          <ToggleButton value="bar">Bar</ToggleButton>
          <ToggleButton value="line">Line</ToggleButton>
        </ToggleButtonGroup>
      </Box>

      {/* Feeding Frequency Chart */}
      <Box sx={{ mb: 4 }}>
        <Typography variant="subtitle1" gutterBottom fontWeight="600">
          Daily Feeding Frequency by Type
        </Typography>
        <ResponsiveContainer width="100%" height={300}>
          {chartType === 'bar' ? (
            <BarChart data={data}>
              <CartesianGrid strokeDasharray="3 3" stroke="#f0f0f0" />
              <XAxis dataKey="date" stroke="#666" />
              <YAxis stroke="#666" label={{ value: 'Count', angle: -90, position: 'insideLeft' }} />
              <Tooltip
                contentStyle={{
                  backgroundColor: 'rgba(255, 255, 255, 0.95)',
                  border: 'none',
                  borderRadius: 8,
                  boxShadow: '0 4px 6px rgba(0, 0, 0, 0.1)',
                }}
              />
              <Legend />
              <Bar dataKey="breastfeeding" stackId="a" fill={COLORS.breastfeeding} name="Breastfeeding" />
              <Bar dataKey="bottle" stackId="a" fill={COLORS.bottle} name="Bottle" />
              <Bar dataKey="solids" stackId="a" fill={COLORS.solids} name="Solids" />
            </BarChart>
          ) : (
            <LineChart data={data}>
              <CartesianGrid strokeDasharray="3 3" stroke="#f0f0f0" />
              <XAxis dataKey="date" stroke="#666" />
              <YAxis stroke="#666" label={{ value: 'Count', angle: -90, position: 'insideLeft' }} />
              <Tooltip
                contentStyle={{
                  backgroundColor: 'rgba(255, 255, 255, 0.95)',
                  border: 'none',
                  borderRadius: 8,
                  boxShadow: '0 4px 6px rgba(0, 0, 0, 0.1)',
                }}
              />
              <Legend />
              <Line
                type="monotone"
                dataKey="total"
                stroke={COLORS.breastfeeding}
                strokeWidth={3}
                dot={{ fill: COLORS.breastfeeding, r: 5 }}
                name="Total Feedings"
              />
            </LineChart>
          )}
        </ResponsiveContainer>
      </Box>

      {/* Feeding Type Distribution */}
      {typeData.length > 0 && (
        <Box>
          <Typography variant="subtitle1" gutterBottom fontWeight="600">
            Feeding Type Distribution (7 days)
          </Typography>
          <ResponsiveContainer width="100%" height={300}>
            <PieChart>
              <Pie
                data={typeData}
                cx="50%"
                cy="50%"
                labelLine={false}
                label={({ name, percent }) => `${name}: ${(percent * 100).toFixed(0)}%`}
                outerRadius={100}
                fill="#8884d8"
                dataKey="value"
              >
                {typeData.map((entry, index) => (
                  <Cell key={`cell-${index}`} fill={entry.color} />
                ))}
              </Pie>
              <Tooltip
                contentStyle={{
                  backgroundColor: 'rgba(255, 255, 255, 0.95)',
                  border: 'none',
                  borderRadius: 8,
                  boxShadow: '0 4px 6px rgba(0, 0, 0, 0.1)',
                }}
              />
            </PieChart>
          </ResponsiveContainer>
        </Box>
      )}
    </Box>
  );
}
