import 'package:flutter/cupertino.dart';
import 'package:please_pay_me/core/format/formatters.dart';
import 'package:please_pay_me/features/budgets/budgets_controller.dart';
import 'package:please_pay_me/features/expenses/expense_actions.dart';
import 'package:please_pay_me/features/journal/journal_controller.dart';
import 'package:please_pay_me/theme/theme.dart';
import 'package:please_pay_me/ui/ui.dart';
import 'package:provider/provider.dart';

/// Operations grouped by day, with current-budget / all-budgets scope.
class JournalScreen extends StatelessWidget {
  const JournalScreen({super.key});

  @override
  Widget build(BuildContext context) {
    final journal = context.watch<JournalController>();
    final budgets = context.watch<BudgetsController>();

    return CupertinoPageScaffold(
      backgroundColor: AppColors.of(context, AppColors.groupedBackground),
      child: CustomScrollView(
        physics: const BouncingScrollPhysics(parent: AlwaysScrollableScrollPhysics()),
        slivers: [
          AppLargeNavBar(
            title: 'Журнал',
            trailing: CupertinoButton(
              padding: EdgeInsets.zero,
              minimumSize: Size.zero,
              onPressed: budgets.hasBudgets
                  ? () => showExpenseFormSheet(context: context, controller: budgets)
                  : null,
              child: const AppIcon(CupertinoIcons.add_circled, color: AppColors.accent),
            ),
          ),
          CupertinoSliverRefreshControl(onRefresh: () => journal.load(silent: true)),
          SliverToBoxAdapter(
            child: Padding(
              padding: const EdgeInsets.only(top: AppSpacing.s2, bottom: AppSpacing.s4),
              child: AppSegmentedControl(
                labels: JournalScope.values.map((scope) => scope.label).toList(),
                index: JournalScope.values.indexOf(journal.scope),
                onChanged: (index) => journal.setScope(JournalScope.values[index]),
              ),
            ),
          ),
          SliverToBoxAdapter(
            child: journal.state.map(
              loading: () => AppListSection(
                children: List.generate(4, (_) => const AppSkeletonRow(hasLeading: false)),
              ),
              error: (message) => AppErrorView(message: message, onRetry: journal.load),
              data: (_) => _JournalBody(journal: journal),
            ),
          ),
          const SliverToBoxAdapter(child: SizedBox(height: AppSpacing.s7)),
        ],
      ),
    );
  }
}

class _JournalBody extends StatelessWidget {
  const _JournalBody({required this.journal});

  final JournalController journal;

  @override
  Widget build(BuildContext context) {
    final groups = journal.groups;

    if (groups.isEmpty) {
      final budgets = context.read<BudgetsController>();
      return AppEmptyState(
        icon: CupertinoIcons.doc_text,
        title: 'Операций пока нет',
        message: journal.scope == JournalScope.all
            ? 'Как только появится первая трата, она появится здесь.'
            : 'В текущем бюджете ещё ничего не потрачено.',
        actionLabel: budgets.hasBudgets ? 'Добавить трату' : null,
        onAction: budgets.hasBudgets
            ? () => showExpenseFormSheet(context: context, controller: budgets)
            : null,
      );
    }

    return Column(
      crossAxisAlignment: CrossAxisAlignment.stretch,
      children: [
        AppCard(
          child: Row(
            children: [
              Expanded(
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    const AppText.footnote('Всего операций'),
                    AppText.title('${journal.state.valueOrNull?.totalCount ?? 0}'),
                  ],
                ),
              ),
              Expanded(
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    const AppText.footnote('Сумма'),
                    AppText.title(formatMoney(journal.totalSum)),
                  ],
                ),
              ),
            ],
          ),
        ),
        const SizedBox(height: AppSpacing.s5),
        for (final group in groups) ...[
          AppListSection(
            header: formatRelativeDay(group.day),
            footer: 'Итого за день: ${formatMoney(group.total)}',
            children: [
              for (final expense in group.items)
                AppListTile(
                  title: expenseTitle(expense.note),
                  subtitle: formatWeekday(expense.spentAt),
                  value: expenseAmount(expense.amount),
                  showChevron: false,
                ),
            ],
          ),
          const SizedBox(height: AppSpacing.s5),
        ],
        if (journal.hasMore)
          Padding(
            padding: const EdgeInsets.symmetric(horizontal: AppSpacing.gutter),
            child: AppButton(
              label: 'Показать ещё',
              style: AppButtonStyle.gray,
              loading: journal.isLoadingMore,
              onPressed: journal.loadMore,
            ),
          ),
      ],
    );
  }
}