/// Admin-only dialog to create or edit a local test bank transaction.
library;

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:provider/provider.dart';

import '../models/bank.dart';
import '../models/transaction_meta.dart';
import '../providers/bank_provider.dart';
import '../utils/helpers.dart';

Future<BankTransaction?> showAdminCreateTransactionDialog(
  BuildContext context, {
  BankTransaction? existing,
}) {
  return showDialog<BankTransaction>(
    context: context,
    builder: (context) => _AdminCreateTransactionDialog(existing: existing),
  );
}

String _stripManualStamp(String description) =>
    description.replaceFirst(RegExp(r' ·#\d+$'), '');

class _AdminCreateTransactionDialog extends StatefulWidget {
  const _AdminCreateTransactionDialog({this.existing});

  final BankTransaction? existing;

  @override
  State<_AdminCreateTransactionDialog> createState() =>
      _AdminCreateTransactionDialogState();
}

class _AdminCreateTransactionDialogState
    extends State<_AdminCreateTransactionDialog> {
  late DateTime _date;
  late final TextEditingController _description;
  late final TextEditingController _amount;
  late final TextEditingController _currency;
  late TxFlowFilter _flow;
  late bool _pending;
  var _saving = false;
  String? _error;

  bool get _editing => widget.existing != null;

  @override
  void initState() {
    super.initState();
    final existing = widget.existing;
    if (existing != null) {
      final parsed = DateTime.tryParse(existing.date) ?? DateTime.now();
      _date = DateTime(parsed.year, parsed.month, parsed.day);
      _description = TextEditingController(
        text: _stripManualStamp(existing.description),
      );
      _amount = TextEditingController(
        text: existing.amount.abs().toStringAsFixed(2),
      );
      _currency = TextEditingController(text: existing.currency);
      _flow = existing.amount >= 0
          ? TxFlowFilter.income
          : TxFlowFilter.expense;
      _pending = existing.pending;
    } else {
      final now = DateTime.now();
      _date = DateTime(now.year, now.month, now.day);
      _description = TextEditingController(text: 'Test merchant');
      _amount = TextEditingController(text: '12.50');
      _currency = TextEditingController(text: 'EUR');
      _flow = TxFlowFilter.expense;
      _pending = false;
    }
  }

  @override
  void dispose() {
    _description.dispose();
    _amount.dispose();
    _currency.dispose();
    super.dispose();
  }

  Future<void> _pickDate() async {
    final picked = await showDatePicker(
      context: context,
      initialDate: _date,
      firstDate: DateTime(2015),
      lastDate: DateTime.now().add(const Duration(days: 365)),
    );
    if (picked == null || !mounted) return;
    setState(() => _date = DateTime(picked.year, picked.month, picked.day));
  }

  Future<void> _save() async {
    final raw = _amount.text.trim().replaceAll(',', '.');
    final parsed = double.tryParse(raw);
    if (parsed == null || parsed <= 0) {
      setState(() => _error = 'Enter a positive amount');
      return;
    }
    final signed = _flow == TxFlowFilter.income ? parsed : -parsed;
    setState(() {
      _saving = true;
      _error = null;
    });
    try {
      final bank = context.read<BankController>();
      final existing = widget.existing;
      final BankTransaction tx;
      if (existing != null) {
        tx = await bank.updateManualTransaction(
          previous: existing,
          date: _date,
          description: _description.text,
          amount: signed,
          currency: _currency.text,
          pending: _pending,
        );
      } else {
        tx = await bank.addManualTransaction(
          date: _date,
          description: _description.text,
          amount: signed,
          currency: _currency.text,
          pending: _pending,
        );
      }
      if (!mounted) return;
      Navigator.pop(context, tx);
    } catch (error) {
      if (!mounted) return;
      setState(() {
        _saving = false;
        _error = '$error';
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    return AlertDialog(
      title: Text(_editing ? 'Edit test transaction' : 'Create test transaction'),
      content: SingleChildScrollView(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            Text(
              _editing
                  ? 'Updates this device and removes the old row on the next PocketBase sync.'
                  : 'Saved on this device and included in the next PocketBase sync.',
              style: theme.textTheme.bodySmall?.copyWith(
                color: theme.colorScheme.onSurfaceVariant,
              ),
            ),
            const SizedBox(height: 16),
            ListTile(
              contentPadding: EdgeInsets.zero,
              title: const Text('Date'),
              subtitle: Text(formatDate(_date)),
              trailing: const Icon(Icons.calendar_today_outlined, size: 20),
              onTap: _saving ? null : _pickDate,
            ),
            TextField(
              controller: _description,
              enabled: !_saving,
              textCapitalization: TextCapitalization.sentences,
              decoration: const InputDecoration(
                labelText: 'Description',
              ),
            ),
            const SizedBox(height: 12),
            SegmentedButton<TxFlowFilter>(
              segments: const [
                ButtonSegment(
                  value: TxFlowFilter.expense,
                  label: Text('Expense'),
                  icon: Icon(Icons.north_east, size: 16),
                ),
                ButtonSegment(
                  value: TxFlowFilter.income,
                  label: Text('Income'),
                  icon: Icon(Icons.south_west, size: 16),
                ),
              ],
              selected: {_flow},
              onSelectionChanged: _saving
                  ? null
                  : (selection) {
                      setState(() => _flow = selection.first);
                    },
            ),
            const SizedBox(height: 12),
            Row(
              children: [
                Expanded(
                  flex: 2,
                  child: TextField(
                    controller: _amount,
                    enabled: !_saving,
                    keyboardType: const TextInputType.numberWithOptions(
                      decimal: true,
                    ),
                    inputFormatters: [
                      FilteringTextInputFormatter.allow(RegExp(r'[0-9.,]')),
                    ],
                    decoration: const InputDecoration(
                      labelText: 'Amount',
                    ),
                  ),
                ),
                const SizedBox(width: 12),
                Expanded(
                  child: TextField(
                    controller: _currency,
                    enabled: !_saving,
                    textCapitalization: TextCapitalization.characters,
                    decoration: const InputDecoration(
                      labelText: 'Currency',
                    ),
                  ),
                ),
              ],
            ),
            SwitchListTile(
              contentPadding: EdgeInsets.zero,
              title: const Text('Pending'),
              value: _pending,
              onChanged: _saving
                  ? null
                  : (value) => setState(() => _pending = value),
            ),
            if (_error != null)
              Padding(
                padding: const EdgeInsets.only(top: 4),
                child: Text(
                  _error!,
                  style: theme.textTheme.bodySmall?.copyWith(
                    color: theme.colorScheme.error,
                  ),
                ),
              ),
          ],
        ),
      ),
      actions: [
        TextButton(
          onPressed: _saving ? null : () => Navigator.pop(context),
          child: const Text('Cancel'),
        ),
        FilledButton(
          onPressed: _saving ? null : _save,
          child: _saving
              ? const SizedBox(
                  width: 18,
                  height: 18,
                  child: CircularProgressIndicator(strokeWidth: 2),
                )
              : Text(_editing ? 'Save' : 'Create'),
        ),
      ],
    );
  }
}