/// Balance tab: connect bank CTA, current balance, and refresh.
library;

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

import '../providers/bank_provider.dart';
import '../utils/connect_bank.dart';
import '../utils/helpers.dart';
import '../widgets/empty_state.dart';
import '../widgets/loading_view.dart';
import '../widgets/responsive_body.dart';

class BalanceScreen extends StatelessWidget {
  const BalanceScreen({super.key});

  @override
  Widget build(BuildContext context) {
    final bank = context.watch<BankController>();

    return Scaffold(
      appBar: AppBar(
        title: const Text('Balance'),
        actions: [
          IconButton(
            tooltip: 'Refresh',
            onPressed: bank.isLoading ? null : bank.refresh,
            icon: const Icon(Icons.refresh),
          ),
        ],
      ),
      body: RefreshIndicator(
        onRefresh: bank.refresh,
        child: ResponsiveBody(
          child: _BalanceBody(bank: bank),
        ),
      ),
    );
  }
}

class _BalanceBody extends StatelessWidget {
  const _BalanceBody({required this.bank});

  final BankController bank;

  @override
  Widget build(BuildContext context) {
    if (bank.isLoading && bank.balance == null && !bank.isLinked) {
      return const LoadingView(message: 'Checking bank link…');
    }

    if (!bank.isLinked) {
      return ListView(
        physics: const AlwaysScrollableScrollPhysics(),
        children: [
          EmptyState(
            icon: Icons.account_balance_outlined,
            title: 'Bank not linked',
            message: bank.error ??
                'Connect opens a sandbox bank login in-app. '
                'Stay in that WebView until it returns here. '
                'You should then see a balance and transactions.',
            actionLabel: bank.isConnecting ? 'Opening…' : 'Connect bank',
            onAction: () => runConnectBank(context, bank),
          ),
        ],
      );
    }

    if (bank.error != null && bank.balance == null) {
      return ListView(
        physics: const AlwaysScrollableScrollPhysics(),
        children: [
          EmptyState(
            icon: Icons.error_outline,
            title: 'Could not load balance',
            message: bank.error!,
            actionLabel: 'Retry',
            onAction: bank.refresh,
          ),
        ],
      );
    }

    final balance = bank.balance;
    final theme = Theme.of(context);
    final colors = theme.colorScheme;

    return ListView(
      physics: const AlwaysScrollableScrollPhysics(),
      padding: const EdgeInsets.only(top: 8, bottom: 32),
      children: [
        Container(
          width: double.infinity,
          padding: const EdgeInsets.all(24),
          decoration: BoxDecoration(
            borderRadius: BorderRadius.circular(20),
            gradient: LinearGradient(
              colors: [colors.primary, colors.tertiary],
            ),
            boxShadow: [
              BoxShadow(
                color: colors.primary.withValues(alpha: 0.28),
                blurRadius: 20,
                offset: const Offset(0, 10),
              ),
            ],
          ),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Text(
                'Current balance',
                style: theme.textTheme.labelMedium?.copyWith(
                  color: colors.onPrimary.withValues(alpha: 0.8),
                ),
              ),
              const SizedBox(height: 8),
              Text(
                balance == null
                    ? '—'
                    : formatMoney(balance.amount, balance.currency),
                style: theme.textTheme.headlineMedium?.copyWith(
                  color: colors.onPrimary,
                ),
              ),
              if (balance?.balanceType != null) ...[
                const SizedBox(height: 8),
                Text(
                  balance!.balanceType!,
                  style: theme.textTheme.labelMedium?.copyWith(
                    color: colors.onPrimary.withValues(alpha: 0.75),
                  ),
                ),
              ],
            ],
          ),
        ),
        const SizedBox(height: 20),
        ListTile(
          contentPadding: EdgeInsets.zero,
          leading: Icon(
            Icons.check_circle_outline,
            color: colors.primary,
          ),
          title: const Text('Linked'),
          subtitle: Text(
            bank.status.accountId == null
                ? bank.status.status
                : 'Account ${bank.status.accountId}',
          ),
        ),
        if (bank.error != null) ...[
          const SizedBox(height: 8),
          Text(
            bank.error!,
            style: theme.textTheme.bodyMedium?.copyWith(color: colors.error),
          ),
        ],
        const SizedBox(height: 12),
        OutlinedButton.icon(
          onPressed: bank.isConnecting
              ? null
              : () => runConnectBank(context, bank),
          icon: const Icon(Icons.link),
          label: Text(bank.isConnecting ? 'Opening…' : 'Reconnect bank'),
        ),
      ],
    );
  }
}