import 'package:flutter/material.dart';
import 'package:firebase_database/firebase_database.dart';

class SendScreen extends StatefulWidget {
  final String myRfid;

  const SendScreen({super.key, required this.myRfid});

  @override
  State<SendScreen> createState() => _SendScreenState();
}

class _SendScreenState extends State<SendScreen> {
  final rfidController = TextEditingController();
  final nominalController = TextEditingController();

  bool loading = false;

  static const Color primaryColor = Color(0xFFA5CC36);

  // =========================
  // KEYBOARD CUSTOM
  // =========================
  void addNumber(String number) {
    setState(() {
      nominalController.text += number;
    });
  }

  void backspace() {
    setState(() {
      if (nominalController.text.isNotEmpty) {
        nominalController.text = nominalController.text.substring(
          0,
          nominalController.text.length - 1,
        );
      }
    });
  }

  void clearNominal() {
    setState(() {
      nominalController.clear();
    });
  }

  // =========================
  // ERROR DIALOG
  // =========================
  void _showErrorDialog(String pesan) {
    showDialog(
      context: context,
      builder: (_) => Dialog(
        shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(25)),
        child: Padding(
          padding: const EdgeInsets.all(25),
          child: Column(
            mainAxisSize: MainAxisSize.min,
            children: [
              Container(
                width: 90,
                height: 90,
                decoration: const BoxDecoration(
                  color: Colors.red,
                  shape: BoxShape.circle,
                ),
                child: const Icon(Icons.close, size: 60, color: Colors.white),
              ),
              const SizedBox(height: 20),
              const Text(
                "Transfer Gagal",
                style: TextStyle(fontSize: 22, fontWeight: FontWeight.bold),
              ),
              const SizedBox(height: 10),
              Text(pesan, textAlign: TextAlign.center),
              const SizedBox(height: 20),
              SizedBox(
                width: double.infinity,
                child: ElevatedButton(
                  onPressed: () => Navigator.pop(context),
                  child: const Text("OK"),
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }

  // =========================
  // SUCCESS DIALOG
  // =========================
  void _showSuccessDialog(int nominal, String tujuan) {
    showDialog(
      context: context,
      barrierDismissible: false,
      builder: (_) => Dialog(
        shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(30)),
        child: Padding(
          padding: const EdgeInsets.all(25),
          child: Column(
            mainAxisSize: MainAxisSize.min,
            children: [
              TweenAnimationBuilder(
                duration: const Duration(milliseconds: 700),
                tween: Tween(begin: 0.0, end: 1.0),
                builder: (context, value, child) {
                  return Transform.scale(
                    scale: value,
                    child: Container(
                      width: 100,
                      height: 100,
                      decoration: const BoxDecoration(
                        color: Color(0xFFA5CC36),
                        shape: BoxShape.circle,
                      ),
                      child: const Icon(
                        Icons.check,
                        size: 65,
                        color: Colors.black,
                      ),
                    ),
                  );
                },
              ),
              const SizedBox(height: 20),
              const Text(
                "Transfer Berhasil",
                style: TextStyle(fontSize: 24, fontWeight: FontWeight.bold),
              ),
              const SizedBox(height: 10),
              Text(
                "Rp $nominal berhasil dikirim ke",
                textAlign: TextAlign.center,
              ),
              const SizedBox(height: 5),
              Text(
                tujuan,
                style: const TextStyle(
                  fontWeight: FontWeight.bold,
                  fontSize: 18,
                ),
              ),
              const SizedBox(height: 25),
              SizedBox(
                width: double.infinity,
                child: ElevatedButton(
                  style: ElevatedButton.styleFrom(
                    backgroundColor: primaryColor,
                    foregroundColor: Colors.black,
                  ),
                  onPressed: () {
                    Navigator.pop(context);
                    Navigator.pop(context);
                  },
                  child: const Text("SELESAI"),
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }

  // =========================
  // TRANSFER LOGIC
  // =========================
  Future<void> kirimSaldo() async {
    final tujuan = rfidController.text.trim();
    final nominal = int.tryParse(nominalController.text) ?? 0;

    if (tujuan.isEmpty) {
      _showErrorDialog("RFID tujuan wajib diisi");
      return;
    }

    if (tujuan == widget.myRfid) {
      _showErrorDialog("Tidak dapat transfer ke akun sendiri");
      return;
    }

    if (nominal < 1000) {
      _showErrorDialog("Minimal transfer Rp1.000");
      return;
    }

    setState(() => loading = true);

    try {
      final db = FirebaseDatabase.instance.ref();

      final pengirimSnap = await db.child("users/${widget.myRfid}").get();

      final penerimaSnap = await db.child("users/$tujuan").get();

      if (!penerimaSnap.exists) {
        _showErrorDialog("RFID tujuan tidak ditemukan");
        return;
      }

      final saldoPengirim =
          (pengirimSnap.child("saldo").value as num?)?.toInt() ?? 0;

      final saldoPenerima =
          (penerimaSnap.child("saldo").value as num?)?.toInt() ?? 0;

      if (saldoPengirim < nominal) {
        _showErrorDialog("Saldo tidak mencukupi");
        return;
      }

      await db
          .child("users/${widget.myRfid}/saldo")
          .set(saldoPengirim - nominal);

      await db.child("users/$tujuan/saldo").set(saldoPenerima + nominal);

      final now = DateTime.now().toIso8601String();

      await db.child("users/${widget.myRfid}/history").push().set({
        "type": "transfer_keluar",
        "nilai": nominal,
        "tujuan": tujuan,
        "waktu": now,
      });

      await db.child("users/$tujuan/history").push().set({
        "type": "transfer_masuk",
        "nilai": nominal,
        "dari": widget.myRfid,
        "waktu": now,
      });

      if (!mounted) return;

      _showSuccessDialog(nominal, tujuan);
    } catch (e) {
      _showErrorDialog(e.toString());
    } finally {
      setState(() => loading = false);
    }
  }

  // =========================
  // KEYPAD UI
  // =========================
  Widget buildKeypad() {
    return Column(
      mainAxisAlignment: MainAxisAlignment.center,
      children: [
        for (var row in [
          ["1", "2", "3"],
          ["4", "5", "6"],
          ["7", "8", "9"],
          ["C", "0", "⌫"],
        ])
          Padding(
            padding: const EdgeInsets.symmetric(vertical: 4),
            child: Row(
              children: row.map((e) {
                final bool isAction = e == "C" || e == "⌫";

                return Expanded(
                  child: Padding(
                    padding: const EdgeInsets.symmetric(horizontal: 5),
                    child: SizedBox(
                      height: 60, // 🔥 penting: biar tidak terlalu tinggi
                      child: ElevatedButton(
                        style: ElevatedButton.styleFrom(
                          backgroundColor: isAction
                              ? (e == "C"
                                    ? Colors.redAccent
                                    : Colors.orangeAccent)
                              : const Color(0xFF2C2C2C),
                          foregroundColor: Colors.white,
                          elevation: 2,
                          shape: RoundedRectangleBorder(
                            borderRadius: BorderRadius.circular(14),
                            side: const BorderSide(color: Color(0xFF3A3A3A)),
                          ),
                        ),
                        onPressed: () {
                          if (e == "C") {
                            clearNominal();
                          } else if (e == "⌫") {
                            backspace();
                          } else {
                            addNumber(e);
                          }
                        },
                        child: Text(
                          e,
                          style: const TextStyle(
                            fontSize: 22,
                            fontWeight: FontWeight.bold,
                          ),
                        ),
                      ),
                    ),
                  ),
                );
              }).toList(),
            ),
          ),
      ],
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: const Color(0xFF0B1600),
      appBar: AppBar(
        backgroundColor: primaryColor,
        title: const Text("Kirim Saldo"),
      ),
      body: Padding(
        padding: const EdgeInsets.all(20),
        child: Column(
          children: [
            TextField(
              controller: rfidController,
              style: const TextStyle(color: Colors.white),
              decoration: const InputDecoration(
                labelText: "RFID UID Tujuan",
                labelStyle: TextStyle(color: Colors.white70),
              ),
            ),

            const SizedBox(height: 20),

            Container(
              width: double.infinity,
              padding: const EdgeInsets.all(15),
              decoration: BoxDecoration(
                color: const Color(0xFF1A1A1A),
                borderRadius: BorderRadius.circular(12),
              ),
              child: Text(
                nominalController.text.isEmpty
                    ? "Rp 0"
                    : "Rp ${nominalController.text}",
                style: const TextStyle(
                  color: Colors.white,
                  fontSize: 28,
                  fontWeight: FontWeight.bold,
                ),
              ),
            ),

            const SizedBox(height: 20),

            Expanded(child: buildKeypad()),

            SizedBox(
              width: double.infinity,
              height: 55,
              child: ElevatedButton(
                style: ElevatedButton.styleFrom(backgroundColor: primaryColor),
                onPressed: loading ? null : kirimSaldo,
                child: loading
                    ? const CircularProgressIndicator(color: Colors.black)
                    : const Text("Kirim"),
              ),
            ),
          ],
        ),
      ),
    );
  }
}