import 'package:dio/dio.dart';
import 'package:fintracker_api/fintracker_api.dart';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';

import '../../core/api/api_client.dart';
import '../../core/auth/auth_controller.dart';
import '../../core/widgets/async_value_view.dart';
import '../../core/widgets/empty_state.dart';
import '../../core/widgets/money_text.dart';
import 'providers.dart';

const _roleOrder = [AccountRole.liquid, AccountRole.savings, AccountRole.investment, AccountRole.debt];

String _roleLabel(AccountRole role) => switch (role) {
      AccountRole.liquid => 'Ликвидные',
      AccountRole.savings => 'Сбережения',
      AccountRole.investment => 'Инвестиции',
      AccountRole.debt => 'Долги',
      AccountRole.unknownDefaultOpenApi => 'Неизвестно',
    };

String _kindLabel(AccountKind kind) => switch (kind) {
      AccountKind.zmCash => 'Наличные',
      AccountKind.zmCard => 'Карта',
      AccountKind.zmChecking => 'Расчётный счёт',
      AccountKind.zmDeposit => 'Вклад',
      AccountKind.zmLoan => 'Кредит',
      AccountKind.zmEmoney => 'Электронные деньги',
      AccountKind.zmDebt => 'Долг',
      AccountKind.broker => 'Брокерский счёт',
      AccountKind.manualAsset => 'Актив вручную',
      AccountKind.unknownDefaultOpenApi => 'Неизвестно',
    };

/// Счета: every account grouped by role, with in-place role and
/// include-in-net-worth edits (`PATCH /accounts/{id}`). Archived accounts
/// collapse into their own section at the bottom regardless of role.
class AccountsPage extends ConsumerWidget {
  const AccountsPage({super.key});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final accounts = ref.watch(accountsProvider);

    return Scaffold(
      appBar: AppBar(title: const Text('Счета')),
      body: RefreshIndicator(
        onRefresh: () async => ref.invalidate(accountsProvider),
        child: AsyncValueView(
          value: accounts,
          onRetry: () => ref.invalidate(accountsProvider),
          data: (rows) {
            if (rows.isEmpty) {
              return ListView(
                children: const [
                  EmptyState(
                    icon: Icons.account_balance_outlined,
                    message: 'Счетов ещё нет — нужна синхронизация.',
                  ),
                ],
              );
            }
            final active = rows.where((a) => !a.archived).toList();
            final archived = rows.where((a) => a.archived).toList();
            return ListView(
              padding: const EdgeInsets.all(16),
              children: [
                for (final role in _roleOrder)
                  if (active.any((a) => a.role == role))
                    _RoleSection(
                      title: _roleLabel(role),
                      accounts: active.where((a) => a.role == role).toList(),
                    ),
                if (archived.isNotEmpty)
                  ExpansionTile(
                    title: Text('Архивные (${archived.length})'),
                    initiallyExpanded: false,
                    children: [for (final a in archived) _AccountTile(account: a)],
                  ),
              ],
            );
          },
        ),
      ),
    );
  }
}

class _RoleSection extends StatelessWidget {
  const _RoleSection({required this.title, required this.accounts});

  final String title;
  final List<AccountOut> accounts;

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.only(bottom: 16),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Padding(
            padding: const EdgeInsets.only(bottom: 4),
            child: Text(title, style: Theme.of(context).textTheme.titleMedium),
          ),
          for (final a in accounts) _AccountTile(account: a),
        ],
      ),
    );
  }
}

class _AccountTile extends ConsumerStatefulWidget {
  const _AccountTile({required this.account});

  final AccountOut account;

  @override
  ConsumerState<_AccountTile> createState() => _AccountTileState();
}

class _AccountTileState extends ConsumerState<_AccountTile> {
  bool _saving = false;

  Future<void> _patch(AccountPatch patch) async {
    setState(() => _saving = true);
    try {
      await ref.read(apiProvider).getAccountsApi().accountsPatch(
            accountId: widget.account.id,
            accountPatch: patch,
          );
      ref.invalidate(accountsProvider);
    } on DioException catch (e) {
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text(problemMessage(e))));
    } finally {
      if (mounted) setState(() => _saving = false);
    }
  }

  @override
  Widget build(BuildContext context) {
    final a = widget.account;
    return Card(
      child: Padding(
        padding: const EdgeInsets.fromLTRB(16, 8, 16, 8),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Row(
              children: [
                Expanded(
                  child: Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Text(a.name, style: Theme.of(context).textTheme.titleSmall),
                      Text(
                        '${_kindLabel(a.kind)} · ${a.currency}',
                        style: Theme.of(context).textTheme.bodySmall,
                      ),
                    ],
                  ),
                ),
                MoneyText(
                  a.balance ?? '0',
                  currency: a.currency,
                  style: Theme.of(context).textTheme.titleMedium,
                ),
              ],
            ),
            const SizedBox(height: 4),
            Row(
              children: [
                Expanded(
                  child: DropdownButtonFormField<AccountRole>(
                    initialValue: a.role,
                    isDense: true,
                    decoration: const InputDecoration(labelText: 'Роль', isDense: true),
                    items: [
                      for (final r in _roleOrder)
                        DropdownMenuItem(value: r, child: Text(_roleLabel(r))),
                    ],
                    onChanged: _saving ? null : (role) {
                      if (role != null) _patch(AccountPatch(role: role));
                    },
                  ),
                ),
                const SizedBox(width: 12),
                Column(
                  children: [
                    const Text('В капитал', style: TextStyle(fontSize: 11)),
                    Switch(
                      value: a.includeInNetWorth,
                      onChanged: _saving
                          ? null
                          : (v) => _patch(AccountPatch(includeInNetWorth: v)),
                    ),
                  ],
                ),
              ],
            ),
          ],
        ),
      ),
    );
  }
}