import React, { useState, useEffect } from 'react';
import { View, StyleSheet, Dimensions, Text, FlatList } from 'react-native';
import * as SQLite from 'expo-sqlite';
import { LineChart } from 'react-native-chart-kit';
import { Modal, TouchableOpacity } from 'react-native';
import moment from 'moment';
import 'moment/locale/it'; // Import Italian locale for moment

const VisualizzaDati = () => {
  const [data, setData] = useState([]);
  const [selectedTransactions, setSelectedTransactions] = useState([]);
  const [modalVisible, setModalVisible] = useState(false);
  const [selectedDate, setSelectedDate] = useState('');
  const [currentWeek, setCurrentWeek] = useState(moment().startOf('week'));

  useEffect(() => {
    const interval = setInterval(() => {
      fetchData();
    }, 1000); // Aggiorna ogni 1 secondi

    return () => clearInterval(interval); // Pulisce l'intervallo quando il componente viene smontato
  }, []);

  async function fetchData() {
    try {
      const db = await SQLite.openDatabaseAsync('moneyAppDB');

      const result = await db.getAllAsync('SELECT * FROM transactions');
      const fetchedData = [];
      for (const row of result) {
        fetchedData.push(row);
      }

      // Raggruppa i dati per data e calcola la somma degli importi per il grafico
      const groupedData = fetchedData.reduce((acc, curr) => {
        const date = curr.date;
        if (!acc[date]) {
          acc[date] = 0;
        }
        acc[date] += curr.amount;
        return acc;
      }, {});

      // Trasforma l'oggetto raggruppato in un array di oggetti e ordina per data
      const chartDataArray = Object.keys(groupedData)
        .map(date => ({
          date,
          amount: groupedData[date],
        }))
        .sort((a, b) => new Date(a.date.split('-').reverse().join('-')) - new Date(b.date.split('-').reverse().join('-')));

      setData(chartDataArray);
    } catch (error) {
      console.error('Error fetching data:', error);
    }
  }

  const getWeekData = () => {
    const startOfWeek = currentWeek.clone().startOf('week');
    const endOfWeek = currentWeek.clone().endOf('week');
    const weekDates = [];
    for (let i = 0; i < 7; i++) {
      weekDates.push(startOfWeek.clone().add(i, 'days').format('DD-MM-YYYY'));
    }
    const weekData = weekDates.map(date => {
      const item = data.find(d => d.date === date);
      return {
        date,
        amount: item ? item.amount : 0,
      };
    });
    return weekData;
  };

  const getCurrentWeekText = () => {
    moment.locale('it'); // Set moment locale to Italian
    const startOfWeek = currentWeek.clone().startOf('week').format('DD MMMM');
    const endOfWeek = currentWeek.clone().endOf('week').format('DD MMMM');
    return `${startOfWeek} al ${endOfWeek}`;
  };

  const chartData = {
    labels: getWeekData().map(item => item.date),
    datasets: [
      {
        data: getWeekData().map(item => item.amount),
      },
    ],
  };

  const handleDataPointClick = async (dataPoint) => {
    const date = chartData.labels[dataPoint.index];
    setSelectedDate(date);
    try {
      const db = await SQLite.openDatabaseAsync('moneyAppDB');
      const result = await db.getAllAsync(`SELECT * FROM transactions WHERE date = ?`, [date]);
      setSelectedTransactions(result);
      setModalVisible(true);
    } catch (error) {
      console.error('Error fetching transactions for selected date:', error);
    }
  };

  const handlePrevWeek = () => {
    setCurrentWeek(currentWeek.clone().subtract(1, 'week'));
  };

  const handleNextWeek = () => {
    setCurrentWeek(currentWeek.clone().add(1, 'week'));
  };

  const getTotalForWeek = () => {
    const weekData = getWeekData();
    const total = weekData.reduce((acc, curr) => acc + curr.amount, 0);
    return total;
  };

  return (
    <FlatList
      data={[{ key: 'content' }]}
      renderItem={() => (
        <View style={styles.container}>
          {data.length === 0 ? (
            <Text style={styles.noDataText}>Nessun dato disponibile</Text>
          ) : (
            <>
              <Text style={styles.weekText}>{getCurrentWeekText()}</Text>
              <Text style={[styles.totalText, { color: getTotalForWeek() >= 0 ? 'green' : 'red' }]}>
                Totale: {getTotalForWeek().toFixed(2)} €
              </Text>
              <LineChart
                bezier
                data={chartData}
                width={Dimensions.get('window').width - 20} // from react-native
                height={300}
                verticalLabelRotation={30}
                yAxisLabel="€"
                chartConfig={{
                  backgroundColor: '#fff',
                  backgroundGradientFrom: '#000',
                  backgroundGradientTo: '#000',
                  decimalPlaces: 2, // optional, defaults to 2dp
                  color: (opacity = 1) => `#f57242`,
                  labelColor: (opacity = 1) => `rgba(255, 255, 255, ${opacity})`,
                  style: {
                    borderRadius: 10,
                  },
                  propsForDots: {
                    r: '6',
                    strokeWidth: '3',
                    stroke: '#3956e6',
                  },
                }}
                style={{
                  borderRadius: 15,
                }}
                onDataPointClick={handleDataPointClick}
              />
              
              <View style={styles.buttonContainer}>
                <TouchableOpacity
                  style={styles.navButton}
                  onPress={handlePrevWeek}
                >
                  <Text style={styles.navButtonText}>Settimana Precedente</Text>
                </TouchableOpacity>
                <TouchableOpacity
                  style={styles.navButton}
                  onPress={handleNextWeek}
                >
                  <Text style={styles.navButtonText}>Settimana Successiva</Text>
                </TouchableOpacity>
              </View>

              <Modal
                animationType="slide"
                transparent={true}
                visible={modalVisible}
                onRequestClose={() => setModalVisible(false)}
              >
                <View style={styles.centeredView}>
                  <View style={styles.modalView}>
                    <Text style={styles.modalTitle}>Transazioni del {selectedDate}</Text>
                    <FlatList
                      data={selectedTransactions}
                      keyExtractor={(item, index) => index.toString()}
                      renderItem={({ item }) => (
                        <View style={styles.transactionItem}>
                          <View><Text style={styles.transactionDescription}>{item.description}</Text></View>
                          <View>
                            <Text style={[styles.transactionAmount, { color: item.type === 'expense' ? 'red' : 'green' }]}>
                              {item.type === 'expense' ? '-' : '+'}{Math.abs(item.amount).toFixed(2)} €
                            </Text>
                          </View>
                        </View>
                      )}
                    />
                    <TouchableOpacity
                      style={styles.closeButton}
                      onPress={() => setModalVisible(false)}
                    >
                      <Text style={styles.closeButtonText}>Chiudi</Text>
                    </TouchableOpacity>
                  </View>
                </View>
              </Modal>
            </>
          )}
        </View>
      )}
      keyExtractor={item => item.key}
    />
  );
};


const styles = StyleSheet.create({
  container: {
    marginTop: 20,
    padding: 10,
  },
  buttonContainer: {
    justifyContent: 'space-between',
    flexDirection: 'row',
    marginVertical: 10,
  },
  noDataText: {
    color: '#000',
    fontSize: 16,
    textAlign: 'center',
    marginTop: 20,
  },
  transactionsContainer: {
  },
  transactionsTitle: {
    fontSize: 18,
    fontWeight: 'bold',
    color: '#fff',
    marginVertical: 15,
    textAlign: 'center',
  },
  transactionItem: {
    flexDirection: 'row',
    justifyContent: 'space-between',
    alignItems: 'center',
    padding: 15,
    marginVertical: 5,
    borderRadius: 10,
    width: '100%',
    backgroundColor: '#1a1a1a',
  },
  transactionDate: {
    color: '#fff',
    fontSize: 14,
  },
  transactionDescription: {
    color: '#fff',
    fontSize: 16,
  },
  transactionAmount: {
    color: 'red',
    fontSize: 16,
    fontWeight: 'bold',
  },
  centeredView: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center',
    marginTop: 22,
  },
  modalView: {
    margin: 20,
    height: 500,
    backgroundColor: '#000',
    borderRadius: 20,
    borderColor: '#3c3c3c',
    borderWidth: 2,
    padding: 20,
    alignItems: 'center',
  },
  modalTitle: {
    fontSize: 18,
    fontWeight: 'bold',
    marginBottom: 15,
    textAlign: 'center',
    color: '#fff'
  },
  navButton: {
    padding: 10,
    borderRadius: 5,
    margin: 2,
    backgroundColor: '#f57242',
  },
  navButtonText: {
    color: '#000',
    fontSize: 16,
  },
  closeButton: {
    marginTop: 20,
    padding: 10,
    borderRadius: 5,
    backgroundColor: '#fff',
  },
  closeButtonText: {
    color: '#000',
    fontSize: 16,
  },
  weekText: {
    color: '#fff',
    fontSize: 22,
    textAlign: 'center',
    paddingBottom: 20
  },
  totalText: {
    fontSize: 20,
    textAlign: 'center',
    marginBottom: 20,
  },
});

export default VisualizzaDati;