import 'package:flutter/material.dart';
import 'package:miaoji_zhang/shared/api/api_client.dart';
import 'package:miaoji_zhang/shared/api/business_api.dart';
import 'package:miaoji_zhang/shared/services/current_ledger_store.dart';
import 'package:miaoji_zhang/shared/theme/app_theme.dart';
import 'package:miaoji_zhang/shared/widgets/app_controls.dart';
import 'package:miaoji_zhang/shared/widgets/category_icon.dart';
import 'package:miaoji_zhang/shared/services/shanghai_time.dart';

class TransactionEditPage extends StatefulWidget {
  final TxItem transaction;

  const TransactionEditPage({super.key, required this.transaction});

  @override
  State<TransactionEditPage> createState() => _TransactionEditPageState();
}

class _TransactionEditPageState extends State<TransactionEditPage> {
  late final TextEditingController _amount;
  late final TextEditingController _note;
  late final TextEditingController _payment;
  late String _type;
  late int _ledgerId;
  late int _categoryId;
  late DateTime _occurredAt;
  List<CategoryItem> _categories = const [];
  bool _loading = true;
  bool _saving = false;

  @override
  void initState() {
    super.initState();
    final transaction = widget.transaction;
    _amount = TextEditingController(
      text: transaction.amount.toStringAsFixed(2),
    );
    _note = TextEditingController(text: transaction.note ?? '');
    _payment = TextEditingController(text: transaction.paymentMethod ?? '');
    _type = transaction.type;
    _ledgerId = transaction.ledgerId;
    _categoryId = transaction.categoryId;
    _occurredAt = transaction.occurredAt;
    _loadCategories();
  }

  @override
  void dispose() {
    _amount.dispose();
    _note.dispose();
    _payment.dispose();
    super.dispose();
  }

  Future<void> _loadCategories() async {
    setState(() => _loading = true);
    try {
      await CurrentLedgerStore.instance.ensureLoaded();
      final categories = await TxApi.categories(_type);
      if (!categories.any((category) => category.id == _categoryId) &&
          categories.isNotEmpty) {
        _categoryId = categories.first.id;
      }
      if (mounted) setState(() => _categories = categories);
    } catch (error) {
      if (mounted) _showError(error);
    } finally {
      if (mounted) setState(() => _loading = false);
    }
  }

  Future<void> _changeType(String type) async {
    if (type == _type) return;
    setState(() => _type = type);
    await _loadCategories();
  }

  Future<void> _pickDateTime() async {
    final value = await showJzDateTimeSheet(
      context,
      initial: _occurredAt,
      firstDate: DateTime(2000),
      lastDate: ShanghaiTime.now.add(const Duration(days: 1)),
      title: '选择发生时间',
    );
    if (value != null && mounted) setState(() => _occurredAt = value);
  }

  Future<void> _selectCategory() async {
    final value = await showJzOptionSheet<int>(
      context,
      title: '选择分类',
      options: _categories
          .map(
            (category) => JzOption(
              value: category.id,
              label: category.name,
              leading: CategoryIconBox(
                iconKey: category.iconKey,
                colorKey: category.colorKey,
                size: 32,
              ),
            ),
          )
          .toList(),
      selected: _categoryId,
    );
    if (value != null && mounted) setState(() => _categoryId = value);
  }

  Future<void> _selectLedger() async {
    final ledgers = CurrentLedgerStore.instance.ledgers;
    final value = await showJzOptionSheet<int>(
      context,
      title: '选择所属账本',
      options: ledgers
          .map(
            (ledger) => JzOption(
              value: ledger.id,
              label: ledger.name,
              subtitle: ledger.isDefault ? '当前默认账本' : null,
            ),
          )
          .toList(),
      selected: _ledgerId,
    );
    if (value != null && mounted) setState(() => _ledgerId = value);
  }

  Future<void> _save() async {
    final amount = double.tryParse(_amount.text.trim());
    if (amount == null || amount <= 0) {
      _showError(StateError('请输入正确金额'));
      return;
    }
    setState(() => _saving = true);
    try {
      final updated = await TxApi.update(
        widget.transaction.id,
        ledgerId: _ledgerId,
        categoryId: _categoryId,
        type: _type,
        amount: amount,
        note: _note.text.trim(),
        paymentMethod: _payment.text.trim(),
        occurredAt: _occurredAt,
      );
      if (mounted) Navigator.pop(context, updated);
    } catch (error) {
      if (mounted) _showError(error);
    } finally {
      if (mounted) setState(() => _saving = false);
    }
  }

  void _showError(Object error) {
    ScaffoldMessenger.of(
      context,
    ).showSnackBar(SnackBar(content: Text(apiErrorMessage(error))));
  }

  @override
  Widget build(BuildContext context) {
    final ledgers = CurrentLedgerStore.instance.ledgers;
    return Scaffold(
      appBar: AppBar(title: Text('编辑账单')),
      body: _loading
          ? Center(
              child: CircularProgressIndicator(
                color: AppTheme.primary,
                strokeWidth: 2,
              ),
            )
          : ListView(
              padding: const EdgeInsets.all(16),
              children: [
                JzSegmentedControl<String>(
                  value: _type,
                  options: const [
                    JzOption(value: 'expense', label: '支出'),
                    JzOption(value: 'income', label: '收入'),
                  ],
                  onChanged: _changeType,
                ),
                SizedBox(height: 14),
                TextField(
                  controller: _amount,
                  keyboardType: const TextInputType.numberWithOptions(
                    decimal: true,
                  ),
                  decoration: InputDecoration(
                    labelText: '金额',
                    prefixText: '¥ ',
                  ),
                ),
                SizedBox(height: 12),
                _SelectField(
                  label: '分类',
                  value:
                      _categories
                          .where((category) => category.id == _categoryId)
                          .map((category) => category.name)
                          .firstOrNull ??
                      '请选择',
                  onTap: _selectCategory,
                ),
                SizedBox(height: 12),
                _SelectField(
                  label: '所属账本',
                  value:
                      ledgers
                          .where((ledger) => ledger.id == _ledgerId)
                          .map((ledger) => ledger.name)
                          .firstOrNull ??
                      '请选择',
                  onTap: _selectLedger,
                ),
                SizedBox(height: 12),
                TextField(
                  controller: _note,
                  maxLength: 50,
                  decoration: InputDecoration(labelText: '备注'),
                ),
                SizedBox(height: 4),
                TextField(
                  controller: _payment,
                  maxLength: 20,
                  decoration: InputDecoration(labelText: '支付方式'),
                ),
                SizedBox(height: 4),
                ListTile(
                  contentPadding: EdgeInsets.zero,
                  title: Text('发生时间'),
                  subtitle: Text(_occurredAt.toString().substring(0, 16)),
                  trailing: Icon(Icons.chevron_right),
                  onTap: _pickDateTime,
                ),
                if (widget.transaction.sourceText?.isNotEmpty == true) ...[
                  SizedBox(height: 8),
                  InputDecorator(
                    decoration: InputDecoration(labelText: 'AI 原话（只读）'),
                    child: Text(widget.transaction.sourceText!),
                  ),
                ],
                SizedBox(height: 24),
                FilledButton(
                  onPressed: _saving ? null : _save,
                  child: Text(_saving ? '保存中...' : '保存修改'),
                ),
              ],
            ),
    );
  }
}

class _SelectField extends StatelessWidget {
  final String label;
  final String value;
  final VoidCallback onTap;

  const _SelectField({
    required this.label,
    required this.value,
    required this.onTap,
  });

  @override
  Widget build(BuildContext context) {
    return InkWell(
      onTap: onTap,
      borderRadius: BorderRadius.circular(14),
      child: InputDecorator(
        decoration: InputDecoration(labelText: label),
        child: Row(
          children: [
            Expanded(
              child: Text(
                value,
                style: TextStyle(fontSize: 13.5, fontWeight: FontWeight.w600),
              ),
            ),
            Icon(Icons.keyboard_arrow_down_rounded, color: context.jz.text3),
          ],
        ),
      ),
    );
  }
}