import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:flutter/material.dart';
import 'package:tugasakhir/models/history_model.dart';
import 'package:fl_chart/fl_chart.dart';

class HistoryScreen extends StatefulWidget {
  const HistoryScreen({Key? key}) : super(key: key);

  @override
  _HistoryScreenState createState() => _HistoryScreenState();
}

class _HistoryScreenState extends State<HistoryScreen> {
  List<History> historyList = [];
  String selectedUser = '';
  List<String> userNames = [];

  @override
  void initState() {
    super.initState();
    fetchHistoryData();
    fetchUserData();
  }

  void fetchHistoryData() async {
    try {
      FirebaseFirestore.instance
          .collection('history_timbangan')
          .orderBy('timestamp')
          .snapshots()
          .listen((event) {
        List<History> fetchedHistory = [];
        for (var doc in event.docs) {
          fetchedHistory.add(History(
            tanggal: (doc['timestamp'] as Timestamp).toDate(),
            berat: doc['berat'].toDouble(),
            tinggi: doc['tinggi'].toDouble(),
            bmi: doc['bmi'].toDouble(),
            user: doc['user'],
          ));
        }
        setState(() {
          historyList = fetchedHistory;
        });
      });
    } catch (e) {
      print("Error fetching data: $e");
    }
  }

  void fetchUserData() async {
    try {
      FirebaseFirestore.instance
          .collection('users')
          .get()
          .then((QuerySnapshot querySnapshot) {
        List<String> users = [];
        querySnapshot.docs.forEach((doc) {
          users.add(doc['nama']);
        });
        setState(() {
          userNames = users;
          if (userNames.isNotEmpty) {
            selectedUser = userNames[0];
          }
        });
      });
    } catch (e) {
      print("Error fetching user data: $e");
    }
  }

  Future<void> deleteUserData() async {
    try {
      var collection = FirebaseFirestore.instance.collection('history_timbangan');
      var snapshots = await collection
          .where('user', isEqualTo: selectedUser) // Filter by selected user
          .get();
      for (var doc in snapshots.docs) {
        await doc.reference.delete();
      }
      print('Data pengguna $selectedUser telah dihapus');
      setState(() {
        historyList.removeWhere((history) => history.user == selectedUser);
      });
    } catch (e) {
      print("Error deleting data: $e");
    }
  }

  Future<void> deleteUserAndHistoryData() async {
    try {
      var collection = FirebaseFirestore.instance.collection('history_timbangan');
      var snapshots = await collection
          .where('user', isEqualTo: selectedUser) // Filter by selected user
          .get();
      for (var doc in snapshots.docs) {
        await doc.reference.delete();
      }

      // Now delete the user from the 'users' collection
      var userDoc = await FirebaseFirestore.instance
          .collection('users')
          .where('nama', isEqualTo: selectedUser)
          .get();
      if (userDoc.docs.isNotEmpty) {
        await userDoc.docs.first.reference.delete(); // Delete the user's document from 'users' collection
      }

      print('Data pengguna $selectedUser dan data historinya telah dihapus');
      setState(() {
        historyList.removeWhere((history) => history.user == selectedUser);
        userNames.remove(selectedUser); // Remove the deleted user from the list
        if (userNames.isNotEmpty) {
          selectedUser = userNames[0]; // Set the first user as default
        }
      });
    } catch (e) {
      print("Error deleting user and history data: $e");
    }
  }

  @override
  Widget build(BuildContext context) {
    List<History> filteredHistoryList = historyList
        .where((history) => history.user == selectedUser)
        .toList()
        .take(8)
        .toList();

    return Scaffold(
      appBar: AppBar(
        backgroundColor: const Color(0xFF59A4EB),
        elevation: 0,
        title: Row(
          children: [
            const Icon(Icons.history, size: 36, color: Colors.white),
            const SizedBox(width: 10),
            Text(
              'History Pengukuran',
              style: const TextStyle(
                fontSize: 16,
                fontWeight: FontWeight.w600,
                color: Colors.white,
              ),
            ),
            const Spacer(),
          ],
        ),
      ),
      body: Padding(
        padding: const EdgeInsets.symmetric(horizontal: 16.0, vertical: 24.0),
        child: ListView(
          children: [
            const Text('Pilih User untuk Menampilkan Data Pengukuran',
                style: TextStyle(fontSize: 18, fontWeight: FontWeight.bold, color: Color(0xFF638BF7))),
            const SizedBox(height: 12),

            DropdownButton<String>(
              value: selectedUser.isEmpty ? null : selectedUser,
              onChanged: (String? newValue) {
                setState(() {
                  selectedUser = newValue!;
                });
              },
              items: userNames
                  .map<DropdownMenuItem<String>>((String value) {
                return DropdownMenuItem<String>(
                  value: value,
                  child: Text(value),
                );
              }).toList(),
            ),

            const SizedBox(height: 12),

            filteredHistoryList.isEmpty
                ? const Center(
                    child: Text(
                      'Tidak ada data',
                      style: TextStyle(fontSize: 18, fontWeight: FontWeight.bold, color: Colors.grey),
                    ),
                  )
                : Column(
                    children: [
                      SingleChildScrollView(
                        scrollDirection: Axis.horizontal,
                        child: DataTable(
                          columnSpacing: 16.0,
                          columns: const [
                            DataColumn(label: Text('Tanggal')),
                            DataColumn(label: Text('User')),
                            DataColumn(label: Text('Berat (kg)')),
                            DataColumn(label: Text('Tinggi (cm)')),
                            DataColumn(label: Text('BMI')),
                          ],
                          rows: filteredHistoryList
                              .map(
                                (history) => DataRow(cells: [
                                  DataCell(Text(
                                      "${history.tanggal.day}/${history.tanggal.month}/${history.tanggal.year}")),
                                  DataCell(Text(history.user)),
                                  DataCell(Text(history.berat.toStringAsFixed(1))),
                                  DataCell(Text(history.tinggi.toStringAsFixed(1))),
                                  DataCell(Text(history.bmi.toStringAsFixed(2))),
                                ]),
                              )
                              .toList(),
                        ),
                      ),
                      const SizedBox(height: 24),

                      const Text(
                        'Grafik Perubahan Pengukuran',
                        style: TextStyle(fontSize: 16, fontWeight: FontWeight.bold, color: Color(0xFF638BF7)),
                      ),
                      const SizedBox(height: 12),

                      _buildChart('Grafik Berat (kg)', Colors.blue, filteredHistoryList, (history) => history.berat),

                      const SizedBox(height: 24),

                      _buildChart('Grafik Tinggi (cm)', Colors.green, filteredHistoryList, (history) => history.tinggi),

                      const SizedBox(height: 12),
                    ],
                  ),

            const SizedBox(height: 24),
            ElevatedButton(
              onPressed: () {
                showDialog(
                  context: context,
                  builder: (BuildContext context) {
                    return AlertDialog(
                      title: const Text('Konfirmasi Penghapusan'),
                      content: const Text('Apakah Anda yakin ingin menghapus data pengguna ini?'),
                      actions: <Widget>[
                        TextButton(
                          onPressed: () {
                            Navigator.of(context).pop();
                          },
                          child: const Text('Batal'),
                        ),
                        TextButton(
                          onPressed: () {
                            deleteUserData();
                            Navigator.of(context).pop();
                          },
                          child: const Text('Hapus Data'),
                        ),
                      ],
                    );
                  },
                );
              },
              style: ElevatedButton.styleFrom(
                backgroundColor: Colors.red,
              ),
              child: const Text('Hapus Data Pengguna Ini'),
            ),
            const SizedBox(height: 24),
            ElevatedButton(
              onPressed: () {
                showDialog(
                  context: context,
                  builder: (BuildContext context) {
                    return AlertDialog(
                      title: const Text('Konfirmasi Penghapusan Semua Data'),
                      content: const Text('Apakah Anda yakin ingin menghapus semua data pengguna dan data historinya?'),
                      actions: <Widget>[
                        TextButton(
                          onPressed: () {
                            Navigator.of(context).pop();
                          },
                          child: const Text('Batal'),
                        ),
                        TextButton(
                          onPressed: () {
                            deleteUserAndHistoryData();
                            Navigator.of(context).pop();
                          },
                          child: const Text('Hapus Semua Data'),
                        ),
                      ],
                    );
                  },
                );
              },
              style: ElevatedButton.styleFrom(
                backgroundColor: Colors.red,
              ),
              child: const Text('Hapus Semua Data Pengguna dan Histori'),
            ),
          ],
        ),
      ),
    );
  }

  Widget _buildChart(String title, Color color, List<History> filteredHistoryList, double Function(History) dataExtractor) {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Text(
          title,
          style: const TextStyle(fontSize: 14, fontWeight: FontWeight.bold, color: Colors.black),
        ),
        const SizedBox(height: 12),
        SizedBox(
          height: 300,
          child: LineChart(
            LineChartData(
              gridData: FlGridData(show: true),
              titlesData: FlTitlesData(show: true),
              borderData: FlBorderData(show: true),
              minX: 0,
              maxX: filteredHistoryList.length.toDouble(),
              minY: 0,
              maxY: 100,
              lineBarsData: [
                LineChartBarData(
                  spots: filteredHistoryList
                      .asMap()
                      .map((index, history) => MapEntry(index, FlSpot(index.toDouble(), dataExtractor(history))))
                      .values
                      .toList(),
                  isCurved: true,
                  color: color,
                  barWidth: 4,
                  isStrokeCapRound: true,
                ),
              ],
            ),
          ),
        ),
      ],
    );
  }
}