import 'dart:convert';

import 'package:flutter/material.dart';
import 'package:manager_app/l10n/app_localizations.dart';
import 'package:manager_app/Models/managerContext.dart';
import 'package:manager_app/app_context.dart';
import 'package:manager_app/Components/common_loader.dart';
import 'package:manager_app/constants.dart';
import 'package:manager_api_new/api.dart';
import 'package:provider/provider.dart';

class NotificationsScreen extends StatefulWidget {
  const NotificationsScreen({Key? key}) : super(key: key);

  @override
  _NotificationsScreenState createState() => _NotificationsScreenState();
}

class _NotificationsScreenState extends State<NotificationsScreen> {
  List<PushNotificationDTO> _notifications = [];
  bool _loading = true;
  String? _statusFilter;
  int _page = 0;
  static const _pageSize = 15;

  int get _totalCount => _notifications.length;
  int get _sentCount => _notifications.where((n) => n.status == 'Sent').length;
  int get _scheduledCount => _notifications.where((n) => n.status == 'Scheduled').length;
  int get _failedCount => _notifications.where((n) => n.status == 'Failed').length;

  List<PushNotificationDTO> get _filtered => _statusFilter == null
      ? _notifications
      : _notifications.where((n) => n.status == _statusFilter).toList();

  int get _pageCount => (_filtered.isEmpty ? 1 : (_filtered.length / _pageSize).ceil());
  List<PushNotificationDTO> get _paginated =>
      _filtered.skip(_page * _pageSize).take(_pageSize).toList();

  void _setFilter(String? status) {
    setState(() {
      _statusFilter = _statusFilter == status ? null : status;
      _page = 0;
    });
  }

  Future<void> _load(ManagerAppContext ctx) async {
    try {
      final response = await ctx.clientAPI!.notificationApi!.notificationGetWithHttpInfo();
      if (response.statusCode == 200) {
        final List<dynamic> json = jsonDecode(utf8.decode(response.bodyBytes));
        setState(() {
          _notifications = PushNotificationDTO.listFromJson(json);
          _loading = false;
        });
      }
    } catch (e) {
      setState(() => _loading = false);
    }
  }

  Future<bool> _send(ManagerAppContext ctx, String title, String body) async {
    final response = await ctx.clientAPI!.notificationApi!.notificationSendWithHttpInfo(
      SendNotificationRequest(title: title, body: body),
    );
    return response.statusCode == 200;
  }

  Future<bool> _schedule(ManagerAppContext ctx, String title, String body, DateTime scheduledAt) async {
    final response = await ctx.clientAPI!.notificationApi!.notificationScheduleWithHttpInfo(
      ScheduleNotificationRequest(title: title, body: body, scheduledAt: scheduledAt),
    );
    return response.statusCode == 200;
  }

  Future<bool> _cancel(ManagerAppContext ctx, String id) async {
    final response = await ctx.clientAPI!.notificationApi!.notificationCancelWithHttpInfo(id);
    return response.statusCode == 202;
  }

  void _showSendModal(BuildContext context, ManagerAppContext ctx) {
    final l = AppLocalizations.of(context)!;
    final titleCtrl = TextEditingController();
    final bodyCtrl = TextEditingController();
    bool isScheduled = false;
    DateTime? scheduledDate;
    TimeOfDay? scheduledTime;

    showDialog(
      context: context,
      builder: (_) => StatefulBuilder(builder: (ctx2, setLocal) {
        return AlertDialog(
          title: Text(l.newMessage),
          content: SizedBox(
            width: 480,
            child: Column(mainAxisSize: MainAxisSize.min, children: [
              TextField(
                controller: titleCtrl,
                decoration: InputDecoration(labelText: l.messageTitle),
              ),
              const SizedBox(height: 8),
              TextField(
                controller: bodyCtrl,
                decoration: InputDecoration(labelText: l.messageBody),
                maxLines: 3,
              ),
              const SizedBox(height: 16),
              Row(
                children: [
                  Checkbox(
                    value: isScheduled,
                    onChanged: (v) => setLocal(() => isScheduled = v ?? false),
                  ),
                  Text(l.schedule),
                ],
              ),
              if (isScheduled) ...[
                const SizedBox(height: 8),
                Row(children: [
                  Expanded(
                    child: OutlinedButton.icon(
                      icon: const Icon(Icons.calendar_today, size: 16),
                      label: Text(scheduledDate != null
                          ? '${scheduledDate!.day.toString().padLeft(2, '0')}/${scheduledDate!.month.toString().padLeft(2, '0')}/${scheduledDate!.year}'
                          : l.date),
                      onPressed: () async {
                        final d = await showDatePicker(
                          context: ctx2,
                          initialDate: DateTime.now().add(const Duration(hours: 1)),
                          firstDate: DateTime.now(),
                          lastDate: DateTime.now().add(const Duration(days: 365)),
                        );
                        if (d != null) setLocal(() => scheduledDate = d);
                      },
                    ),
                  ),
                  const SizedBox(width: 8),
                  Expanded(
                    child: OutlinedButton.icon(
                      icon: const Icon(Icons.access_time, size: 16),
                      label: Text(scheduledTime != null
                          ? scheduledTime!.format(ctx2)
                          : l.time),
                      onPressed: () async {
                        final t = await showTimePicker(
                          context: ctx2,
                          initialTime: TimeOfDay.now(),
                        );
                        if (t != null) setLocal(() => scheduledTime = t);
                      },
                    ),
                  ),
                ]),
              ],
            ]),
          ),
          actions: [
            TextButton(
              onPressed: () => Navigator.pop(ctx2),
              child: Text(l.cancel),
            ),
            ElevatedButton(
              onPressed: titleCtrl.text.isEmpty ? null : () async {
                Navigator.pop(ctx2);
                bool ok;
                if (isScheduled && scheduledDate != null && scheduledTime != null) {
                  final dt = DateTime(
                    scheduledDate!.year,
                    scheduledDate!.month,
                    scheduledDate!.day,
                    scheduledTime!.hour,
                    scheduledTime!.minute,
                  );
                  ok = await _schedule(ctx, titleCtrl.text, bodyCtrl.text, dt);
                } else {
                  ok = await _send(ctx, titleCtrl.text, bodyCtrl.text);
                }
                if (ok && context.mounted) {
                  await _load(ctx);
                }
              },
              child: Text(l.send),
            ),
          ],
        );
      }),
    );
  }

  void _confirmCancel(BuildContext context, ManagerAppContext ctx, PushNotificationDTO notif) {
    final l = AppLocalizations.of(context)!;
    showDialog(
      context: context,
      builder: (_) => AlertDialog(
        title: Text(l.cancelNotification),
        content: Text(l.cancelNotificationConfirm(notif.title ?? '')),
        actions: [
          TextButton(onPressed: () => Navigator.pop(context), child: Text(l.no)),
          ElevatedButton(
            style: ElevatedButton.styleFrom(backgroundColor: Colors.red),
            onPressed: () async {
              Navigator.pop(context);
              final ok = await _cancel(ctx, notif.id!);
              if (ok && context.mounted) await _load(ctx);
            },
            child: Text(l.cancel, style: const TextStyle(color: Colors.white)),
          ),
        ],
      ),
    );
  }

  static String _formatDate(DateTime? dt) {
    if (dt == null) return '—';
    final d = dt.toLocal();
    return '${d.day.toString().padLeft(2, '0')}/${d.month.toString().padLeft(2, '0')}/${d.year}  ${d.hour.toString().padLeft(2, '0')}:${d.minute.toString().padLeft(2, '0')}';
  }

  static Widget _statusChip(String status) {
    Color bg;
    Color fg;
    switch (status) {
      case 'Sent':
        bg = Colors.green.shade50;
        fg = Colors.green.shade700;
        break;
      case 'Scheduled':
        bg = Colors.blue.shade50;
        fg = Colors.blue.shade700;
        break;
      case 'Failed':
        bg = Colors.red.shade50;
        fg = Colors.red.shade700;
        break;
      default:
        bg = Colors.grey.shade100;
        fg = Colors.grey.shade700;
    }
    return Chip(
      label: Text(status, style: TextStyle(color: fg, fontSize: 12)),
      backgroundColor: bg,
      side: BorderSide(color: fg.withValues(alpha: 0.3)),
      padding: const EdgeInsets.symmetric(horizontal: 4),
      visualDensity: VisualDensity.compact,
    );
  }

  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addPostFrameCallback((_) {
      final ctx = Provider.of<AppContext>(context, listen: false).getContext() as ManagerAppContext;
      _load(ctx);
    });
  }

  @override
  Widget build(BuildContext context) {
    final l = AppLocalizations.of(context)!;
    final appContext = Provider.of<AppContext>(context);
    final ctx = appContext.getContext() as ManagerAppContext;

    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Row(
          mainAxisAlignment: MainAxisAlignment.spaceBetween,
          children: [
            Text(l.notificationsTitle,
                style: TextStyle(fontSize: 24, fontWeight: FontWeight.w600, color: kPrimaryColor)),
            ElevatedButton.icon(
              onPressed: () => _showSendModal(context, ctx),
              icon: const Icon(Icons.add),
              label: Text(l.newMessage),
            ),
          ],
        ),
        const SizedBox(height: 16),
        Row(
          children: [
            _KpiCard(
              label: l.allNotifications,
              count: _totalCount,
              color: Colors.blueGrey,
              selected: _statusFilter == null,
              onTap: () => _setFilter(null),
            ),
            const SizedBox(width: 12),
            _KpiCard(
              label: l.sentNotifications,
              count: _sentCount,
              color: Colors.green,
              selected: _statusFilter == 'Sent',
              onTap: () => _setFilter('Sent'),
            ),
            const SizedBox(width: 12),
            _KpiCard(
              label: l.scheduledNotifications,
              count: _scheduledCount,
              color: Colors.blue,
              selected: _statusFilter == 'Scheduled',
              onTap: () => _setFilter('Scheduled'),
            ),
            const SizedBox(width: 12),
            _KpiCard(
              label: l.failedNotifications,
              count: _failedCount,
              color: Colors.red,
              selected: _statusFilter == 'Failed',
              onTap: () => _setFilter('Failed'),
            ),
          ],
        ),
        const SizedBox(height: 16),
        if (_loading)
          const CommonLoader()
        else if (_notifications.isEmpty)
          Center(child: Text(l.noNotifications))
        else if (_filtered.isEmpty)
          Center(child: Text(l.noNotificationsForFilter))
        else
          Expanded(
            child: Card(
              elevation: 0,
              color: Colors.white,
              shape: RoundedRectangleBorder(
                borderRadius: BorderRadius.circular(8),
                side: BorderSide(color: Colors.grey.shade200),
              ),
              clipBehavior: Clip.antiAlias,
              child: Column(
                children: [
                  Expanded(
                    child: SingleChildScrollView(
                      child: SizedBox(
                        width: double.infinity,
                        child: DataTable(
                          horizontalMargin: 16,
                          columnSpacing: 24,
                          headingRowColor: WidgetStateProperty.all(Colors.grey.shade50),
                          dividerThickness: 1,
                          columns: [
                            DataColumn(label: Text(l.messageTitle, style: const TextStyle(fontWeight: FontWeight.w600))),
                            DataColumn(label: Text(l.topic, style: const TextStyle(fontWeight: FontWeight.w600))),
                            DataColumn(label: Text(l.date, style: const TextStyle(fontWeight: FontWeight.w600))),
                            DataColumn(label: Text(l.status, style: const TextStyle(fontWeight: FontWeight.w600))),
                            const DataColumn(label: Text('')),
                          ],
                          rows: _paginated.map((n) {
                            final isScheduled = n.status == 'Scheduled';
                            final date = isScheduled ? n.scheduledAt : n.sentAt;
                            return DataRow(cells: [
                              DataCell(Text(n.title ?? '')),
                              DataCell(Text(n.topic ?? '', style: const TextStyle(color: Colors.grey))),
                              DataCell(Text(_formatDate(date), style: const TextStyle(color: Colors.grey))),
                              DataCell(_statusChip(n.status ?? '')),
                              DataCell(isScheduled
                                  ? IconButton(
                                      icon: const Icon(Icons.delete_outline, color: Colors.red, size: 20),
                                      tooltip: l.tooltipCancelNotification,
                                      onPressed: () => _confirmCancel(context, ctx, n),
                                    )
                                  : const SizedBox()),
                            ]);
                          }).toList(),
                        ),
                      ),
                    ),
                  ),
                  Container(
                    decoration: BoxDecoration(
                      border: Border(top: BorderSide(color: Colors.grey.shade200)),
                    ),
                    padding: const EdgeInsets.symmetric(vertical: 8, horizontal: 16),
                    child: Row(
                      mainAxisAlignment: MainAxisAlignment.center,
                      children: [
                        IconButton(
                          icon: const Icon(Icons.chevron_left),
                          onPressed: _page > 0 ? () => setState(() => _page--) : null,
                        ),
                        Text('${_page + 1} / $_pageCount', style: const TextStyle(fontSize: 13)),
                        IconButton(
                          icon: const Icon(Icons.chevron_right),
                          onPressed: _page < _pageCount - 1 ? () => setState(() => _page++) : null,
                        ),
                        const SizedBox(width: 16),
                        Text(
                          l.resultsCount(_filtered.length),
                          style: const TextStyle(fontSize: 12, color: Colors.grey),
                        ),
                      ],
                    ),
                  ),
                ],
              ),
            ),
          ),
      ],
    );
  }
}

class _KpiCard extends StatelessWidget {
  final String label;
  final int count;
  final MaterialColor color;
  final bool selected;
  final VoidCallback onTap;

  const _KpiCard({
    required this.label,
    required this.count,
    required this.color,
    required this.selected,
    required this.onTap,
  });

  @override
  Widget build(BuildContext context) {
    return GestureDetector(
      onTap: onTap,
      child: AnimatedContainer(
        duration: const Duration(milliseconds: 150),
        width: 120,
        padding: const EdgeInsets.symmetric(vertical: 12, horizontal: 16),
        decoration: BoxDecoration(
          color: selected ? color.shade100 : color.shade50,
          borderRadius: BorderRadius.circular(8),
          border: Border.all(
            color: selected ? color.shade400 : color.shade200,
            width: selected ? 2 : 1,
          ),
        ),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Text('$count',
                style: TextStyle(fontSize: 28, fontWeight: FontWeight.bold, color: color.shade700)),
            const SizedBox(height: 2),
            Text(label,
                style: TextStyle(fontSize: 12, color: color.shade600)),
          ],
        ),
      ),
    );
  }
}