import 'dart:math';
import 'package:flutter/material.dart';
import 'package:fl_chart/fl_chart.dart';
import 'package:firebase_database/firebase_database.dart';
import 'package:firebase_auth/firebase_auth.dart';

class DashboardPage extends StatefulWidget {
  const DashboardPage({super.key});

  @override
  State<DashboardPage> createState() => _DashboardPageState();
}

class _DashboardPageState extends State<DashboardPage> {
  final DatabaseReference dbRef =
      FirebaseDatabase.instance.ref("fermentasi");

  double s1 = 0;
  double s2 = 0;
  double s3 = 0;

  double suhuMin = 0;
  double suhuMax = 0;
  double suhuRata = 0;
  double prediksi = 0;

  String heater = "OFF";
  String fanHot = "OFF";
  String fanCold = "OFF";

  List<FlSpot> spots1 = [];
  List<FlSpot> spots2 = [];
  List<FlSpot> spots3 = [];

  int indexChart = 0;

  bool isRefreshing = false;

  @override
  void initState() {
    super.initState();
    listenFirebase();
  }

  // ================= FIREBASE LISTENER =================
  void listenFirebase() {
    dbRef.onValue.listen((event) {
      if (event.snapshot.value == null) return;

      final raw = event.snapshot.value as Map;
      final data = raw.map(
        (key, value) => MapEntry(key.toString(), value),
      );

      setState(() {
        // SENSOR
        s1 = double.tryParse(data["sensor1"].toString()) ?? 0;
        s2 = double.tryParse(data["sensor2"].toString()) ?? 0;
        s3 = double.tryParse(data["sensor3"].toString()) ?? 0;

        // STATISTIK
        suhuMin = double.tryParse(data["min"].toString()) ?? 0;
        suhuMax = double.tryParse(data["max"].toString()) ?? 0;
        suhuRata = double.tryParse(data["rata_rata"].toString()) ?? 0;
        prediksi = double.tryParse(data["prediksi"].toString()) ?? 0;

        // STATUS
        heater = data["status"]?["pemanas"]?.toString() ?? "OFF";
        fanHot = data["status"]?["kipas_panas"]?.toString() ?? "OFF";
        fanCold = data["status"]?["kipas_dingin"]?.toString() ?? "OFF";

        // ================= REALTIME GRAPH =================
        spots1.add(FlSpot(indexChart.toDouble(), s1));
        spots2.add(FlSpot(indexChart.toDouble(), s2));
        spots3.add(FlSpot(indexChart.toDouble(), s3));

        indexChart++;

        // limit data biar ringan
        if (spots1.length > 40) {
          spots1.removeAt(0);
          spots2.removeAt(0);
          spots3.removeAt(0);
        }
      });
    });
  }

  // ================= LOGOUT =================
  Future<void> logout() async {
    await FirebaseAuth.instance.signOut();
  }

  // ================= REFRESH BUTTON =================
  Future<void> refreshData() async {
    setState(() => isRefreshing = true);

    await Future.delayed(const Duration(milliseconds: 500));

    setState(() => isRefreshing = false);
  }

  // ================= GRAPH RANGE =================
  double getMinY() {
    List<double> all = [
      ...spots1.map((e) => e.y),
      ...spots2.map((e) => e.y),
      ...spots3.map((e) => e.y),
    ];

    if (all.isEmpty) return 29;
    return (all.reduce(min) - 1);
  }

  double getMaxY() {
    List<double> all = [
      ...spots1.map((e) => e.y),
      ...spots2.map((e) => e.y),
      ...spots3.map((e) => e.y),
    ];

    if (all.isEmpty) return 35;
    return (all.reduce(max) + 1);
  }

  // ================= UI =================
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text("Dashboard Fermentasi"),
        actions: [
          IconButton(
            icon: const Icon(Icons.logout),
            onPressed: logout,
          ),
        ],
      ),
      body: Container(
        decoration: const BoxDecoration(
          gradient: LinearGradient(
            colors: [Color(0xFF5F7F7A), Color(0xFFE6E9E8)],
            begin: Alignment.topCenter,
            end: Alignment.bottomCenter,
          ),
        ),
        child: SafeArea(
          child: SingleChildScrollView(
            padding: const EdgeInsets.all(16),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                const Text(
                  "MONITORING FERMENTASI TEMPE",
                  style: TextStyle(
                    color: Colors.white,
                    fontWeight: FontWeight.bold,
                  ),
                ),

                const SizedBox(height: 15),

                buildChart(),
                const SizedBox(height: 15),

                buildSensor(),
                const SizedBox(height: 15),

                buildStatistik(),
                const SizedBox(height: 15),

                buildStatus(),
                const SizedBox(height: 15),

                // ================= REFRESH BUTTON =================
                buildRefresh(),
              ],
            ),
          ),
        ),
      ),
    );
  }

  // ================= CHART =================
  Widget buildChart() {
    return Container(
      padding: const EdgeInsets.all(15),
      decoration: BoxDecoration(
        color: Colors.white,
        borderRadius: BorderRadius.circular(15),
      ),
      child: Column(
        children: [
          Row(
            mainAxisAlignment: MainAxisAlignment.spaceEvenly,
            children: const [
              Legend("Sensor 1", Colors.blue),
              Legend("Sensor 2", Colors.green),
              Legend("Sensor 3", Colors.orange),
            ],
          ),
          const SizedBox(height: 10),
          SizedBox(
            height: 230,
            child: LineChart(
              LineChartData(
                minY: getMinY(),
                maxY: getMaxY(),
                gridData: const FlGridData(show: true),
                lineBarsData: [
                  lineData(Colors.blue, spots1),
                  lineData(Colors.green, spots2),
                  lineData(Colors.orange, spots3),
                ],
              ),
            ),
          ),
        ],
      ),
    );
  }

  // ================= SENSOR =================
  Widget buildSensor() {
    return Container(
      padding: const EdgeInsets.all(15),
      decoration: BoxDecoration(
        color: Colors.white,
        borderRadius: BorderRadius.circular(15),
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          const Text("SENSOR",
              style: TextStyle(fontWeight: FontWeight.bold)),
          const SizedBox(height: 8),
          sensorRow("Sensor 1", s1, Colors.blue),
          sensorRow("Sensor 2", s2, Colors.green),
          sensorRow("Sensor 3", s3, Colors.orange),
        ],
      ),
    );
  }

  // ================= STATISTIK =================
  Widget buildStatistik() {
    return Row(
      children: [
        Expanded(
          child: Container(
            padding: const EdgeInsets.all(15),
            decoration: BoxDecoration(
              color: Colors.white,
              borderRadius: BorderRadius.circular(15),
            ),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                const Text("STATISTIK",
                    style: TextStyle(fontWeight: FontWeight.bold)),
                const SizedBox(height: 8),
                itemStat("Minimum", suhuMin),
                itemStat("Maksimum", suhuMax),
                itemStat("Rata-rata", suhuRata),
              ],
            ),
          ),
        ),
        const SizedBox(width: 10),
        Expanded(
          child: Container(
            padding: const EdgeInsets.all(15),
            decoration: BoxDecoration(
              color: Colors.white,
              borderRadius: BorderRadius.circular(15),
            ),
            child: Column(
              children: [
                const Text("PREDIKSI",
                    style: TextStyle(fontWeight: FontWeight.bold)),
                const SizedBox(height: 8),
                Text(
                  "${prediksi.toStringAsFixed(2)}°C",
                  style: const TextStyle(
                    fontSize: 26,
                    color: Colors.blue,
                    fontWeight: FontWeight.bold,
                  ),
                ),
                const Text("5 menit ke depan"),
              ],
            ),
          ),
        ),
      ],
    );
  }

  // ================= STATUS =================
  Widget buildStatus() {
    return Container(
      padding: const EdgeInsets.all(15),
      decoration: BoxDecoration(
        color: Colors.white,
        borderRadius: BorderRadius.circular(15),
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          const Text("STATUS SISTEM",
              style: TextStyle(fontWeight: FontWeight.bold)),
          const SizedBox(height: 8),
          statusRow("Pemanas", heater),
          statusRow("Kipas Pemanas", fanHot),
          statusRow("Kipas Pendingin", fanCold),
        ],
      ),
    );
  }

  // ================= REFRESH BUTTON =================
  Widget buildRefresh() {
    return SizedBox(
      width: double.infinity,
      child: ElevatedButton(
        onPressed: isRefreshing ? null : refreshData,
        child: isRefreshing
            ? const CircularProgressIndicator(color: Colors.white)
            : const Text("Refresh Data"),
      ),
    );
  }

  // ================= WIDGET =================
  Widget sensorRow(String label, double value, Color color) {
    return Row(
      mainAxisAlignment: MainAxisAlignment.spaceBetween,
      children: [
        Text(label),
        Text("${value.toStringAsFixed(2)}°C",
            style: TextStyle(color: color, fontWeight: FontWeight.bold)),
      ],
    );
  }

  Widget itemStat(String title, double val) {
    Color warna = (val < 30 || val > 40) ? Colors.red : Colors.black;

    return Row(
      mainAxisAlignment: MainAxisAlignment.spaceBetween,
      children: [
        Text(title, style: TextStyle(color: warna)),
        Text("${val.toStringAsFixed(2)}°C",
            style: TextStyle(color: warna, fontWeight: FontWeight.bold)),
      ],
    );
  }

  Widget statusRow(String label, String value) {
    Color warna = value == "ON" ? Colors.red : Colors.grey;

    return Row(
      mainAxisAlignment: MainAxisAlignment.spaceBetween,
      children: [
        Text(label),
        Text(value,
            style: TextStyle(color: warna, fontWeight: FontWeight.bold)),
      ],
    );
  }

  LineChartBarData lineData(Color color, List<FlSpot> spots) {
    return LineChartBarData(
      spots: spots,
      isCurved: true,
      color: color,
      dotData: const FlDotData(show: false),
    );
  }
}

class Legend extends StatelessWidget {
  final String text;
  final Color color;

  const Legend(this.text, this.color, {super.key});

  @override
  Widget build(BuildContext context) {
    return Row(
      children: [
        CircleAvatar(radius: 5, backgroundColor: color),
        const SizedBox(width: 5),
        Text(text),
      ],
    );
  }
}