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

import '../core/api_service.dart';
import '../core/auth_service.dart';
import '../models/automation_rule.dart';
import 'automation_rule_form_screen.dart';

class AutomationRulesTab extends StatefulWidget {
  const AutomationRulesTab({super.key});

  @override
  State<AutomationRulesTab> createState() => _AutomationRulesTabState();
}

class _AutomationRulesTabState extends State<AutomationRulesTab> {
  late Future<List<AutomationRule>> _future;

  @override
  void initState() {
    super.initState();
    _future = _load();
  }

  Future<List<AutomationRule>> _load() => context.read<ApiService>().automationRules();

  Future<void> _refresh() async {
    final future = _load();
    setState(() => _future = future);
    await future;
  }

  Future<void> _openForm({AutomationRule? rule}) async {
    final saved = await Navigator.of(context).push<bool>(
      MaterialPageRoute(builder: (_) => AutomationRuleFormScreen(rule: rule)),
    );
    if (saved == true) _refresh();
  }

  Future<bool> _confirmDelete(AutomationRule rule) async {
    final confirmed = await showDialog<bool>(
      context: context,
      builder: (context) => AlertDialog(
        title: const Text('Удалить правило?'),
        content: const Text('Правило будет удалено без возможности восстановления.'),
        actions: [
          TextButton(onPressed: () => Navigator.pop(context, false), child: const Text('Отмена')),
          TextButton(onPressed: () => Navigator.pop(context, true), child: const Text('Удалить')),
        ],
      ),
    );
    if (confirmed != true || !mounted) return false;

    try {
      await context.read<ApiService>().deleteAutomationRule(rule.id);
      return true;
    } catch (e) {
      if (mounted) ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text('$e')));
      return false;
    }
  }

  @override
  Widget build(BuildContext context) {
    final isOwner = context.watch<AuthService>().user?.isOwner ?? false;

    return Scaffold(
      body: RefreshIndicator(
        onRefresh: _refresh,
        child: FutureBuilder<List<AutomationRule>>(
          future: _future,
          builder: (context, snapshot) {
            if (snapshot.connectionState != ConnectionState.done) {
              return const Center(child: CircularProgressIndicator());
            }
            if (snapshot.hasError) {
              return ListView(
                physics: const AlwaysScrollableScrollPhysics(),
                children: [
                  Padding(
                    padding: const EdgeInsets.all(24),
                    child: Text('${snapshot.error}', textAlign: TextAlign.center),
                  ),
                ],
              );
            }

            final rules = snapshot.data!;
            if (rules.isEmpty) {
              return ListView(
                physics: const AlwaysScrollableScrollPhysics(),
                children: const [
                  Padding(
                    padding: EdgeInsets.all(24),
                    child: Text('Правил пока нет.', textAlign: TextAlign.center),
                  ),
                ],
              );
            }

            return ListView.separated(
              physics: const AlwaysScrollableScrollPhysics(),
              itemCount: rules.length,
              separatorBuilder: (context, index) => const Divider(height: 1),
              itemBuilder: (context, index) {
                final rule = rules[index];
                final condition =
                    '${rule.conditionSourceDevice?.name ?? '?'}: ${rule.conditionSensorType} ${rule.conditionOperator} ${rule.conditionValue}';
                final action = rule.level != null
                    ? '${rule.actionType} (${rule.level}) → ${rule.targetDevice?.name ?? '?'}'
                    : '${rule.actionType} → ${rule.targetDevice?.name ?? '?'}';

                final tile = ListTile(
                  leading: Icon(rule.isActive ? Icons.bolt : Icons.bolt_outlined),
                  title: Text('ЕСЛИ $condition'),
                  subtitle: Text('ТО $action'),
                  isThreeLine: true,
                  onTap: isOwner ? () => _openForm(rule: rule) : null,
                );

                if (!isOwner) return tile;

                return Dismissible(
                  key: ValueKey(rule.id),
                  direction: DismissDirection.endToStart,
                  background: Container(
                    color: Theme.of(context).colorScheme.error,
                    alignment: Alignment.centerRight,
                    padding: const EdgeInsets.symmetric(horizontal: 20),
                    child: const Icon(Icons.delete, color: Colors.white),
                  ),
                  confirmDismiss: (_) => _confirmDelete(rule),
                  child: tile,
                );
              },
            );
          },
        ),
      ),
      floatingActionButton: isOwner
          ? FloatingActionButton(onPressed: () => _openForm(), child: const Icon(Icons.add))
          : null,
    );
  }
}