import 'dart:convert';

import 'package:flutter/material.dart';

import 'api.dart';

// ---------- общие ----------

typedef Json = Map<String, dynamic>;

class FutureBuilderJson extends StatelessWidget {
  const FutureBuilderJson(this.future, this.builder, {super.key});

  final Future<dynamic>? future;
  final Widget Function(dynamic data) builder;

  @override
  Widget build(BuildContext context) => FutureBuilder(
      future: future,
      builder: (context, snap) {
        if (snap.connectionState != ConnectionState.done) {
          return const Center(child: CircularProgressIndicator());
        }
        if (snap.hasError) {
          return Center(child: Text('Ошибка: ${snap.error}'));
        }
        return builder(snap.data);
      });
}

/// Выпадающий список атлетов (общий для 4 экранов).
class AthletePicker extends StatelessWidget {
  const AthletePicker({super.key, required this.selected, required this.onChanged});

  final int? selected;
  final void Function(int?) onChanged;

  @override
  Widget build(BuildContext context) =>
      FutureBuilderJson(Api.get('/api/admin/athletes'), (data) {
        final items = (data['items'] as List).cast<Json>();
        return DropdownButton<int>(
          hint: const Text('Атлет'),
          value: selected != null &&
                  items.any((a) => a['id'] == selected)
              ? selected
              : null,
          items: [
            for (final a in items)
              DropdownMenuItem(
                  value: a['id'] as int,
                  child: Text('${a['name']} (#${a['id']})'
                      '${a['isBlocked'] == true ? " [заблокирован]" : ""}')),
          ],
          onChanged: onChanged,
        );
      });
}

// ---------- 1. Атлеты ----------

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

  @override
  State<AthletesPage> createState() => _AthletesPageState();
}

class _AthletesPageState extends State<AthletesPage> {
  Future<dynamic>? _future;

  @override
  void initState() {
    super.initState();
    _reload();
  }

  void _reload() => setState(() => _future = Api.get('/api/admin/athletes'));

  @override
  Widget build(BuildContext context) =>
      Column(crossAxisAlignment: CrossAxisAlignment.stretch, children: [
        Padding(
          padding: const EdgeInsets.all(12),
          child: Align(
            alignment: Alignment.centerLeft,
            child: FilledButton.tonalIcon(
              onPressed: () => _createDialog(context),
              icon: const Icon(Icons.person_add),
              label: const Text('Добавить атлета'),
            ),
          ),
        ),
        Expanded(
          child: FutureBuilderJson(_future, (data) {
            final items = (data['items'] as List).cast<Json>();
            return SingleChildScrollView(
              scrollDirection: Axis.horizontal,
              child: DataTable(columns: const [
                DataColumn(label: Text('id')),
                DataColumn(label: Text('Имя')),
                DataColumn(label: Text('Заблокирован')),
                DataColumn(label: Text('Создан')),
                DataColumn(label: Text('Действия')),
              ], rows: [
                for (final a in items)
                  DataRow(cells: [
                    DataCell(Text('${a['id']}')),
                    DataCell(Text('${a['name']}')),
                    DataCell(Text(a['isBlocked'] == true ? 'да' : 'нет')),
                    DataCell(Text('${a['createdAt']}'.split('T').first)),
                    DataCell(Row(children: [
                      TextButton(
                          onPressed: () => _newKeyDialog(context, a),
                          child: const Text('Смена ключа')),
                      Switch(
                        value: a['isBlocked'] == true,
                        onChanged: (blocked) async {
                          await Api.post(
                              '/api/admin/athletes/${a['id']}/block',
                              {'isBlocked': blocked});
                          _reload();
                        },
                      ),
                    ])),
                  ]),
              ]),
            );
          }),
        ),
      ]);

  Future<void> _createDialog(BuildContext context) async {
    final nameController = TextEditingController();
    final key = await showDialog<String>(
      context: context,
      builder: (context) => AlertDialog(
        title: const Text('Новый атлет'),
        content: TextField(
            controller: nameController,
            decoration: const InputDecoration(labelText: 'Имя')),
        actions: [
          TextButton(
              onPressed: () => Navigator.pop(context), child: const Text('Отмена')),
          FilledButton(
              onPressed: () async {
                final created = await Api.post('/api/admin/athletes',
                    {'name': nameController.text});
                if (context.mounted) Navigator.pop(context, created['apiKey']);
              },
              child: const Text('Создать')),
        ],
      ),
    );
    _reload();
    if (key is String && mounted) {
      await showDialog(
        context: context,
        builder: (context) => AlertDialog(
          title: const Text('API-ключ создан'),
          content: Text('Ключ показывается ОДИН раз:\n\n$key\n\n'
              'Передайте его атлету для настройки телефона.'),
          actions: [
            FilledButton(
                onPressed: () => Navigator.pop(context),
                child: const Text('Понятно')),
          ],
        ),
      );
    }
  }

  Future<void> _newKeyDialog(BuildContext context, Json athlete) async {
    final reissued = await Api.post('/api/admin/athletes/${athlete['id']}/key');
    if (!mounted) return;
    await showDialog(
      context: context,
      builder: (context) => AlertDialog(
        title: const Text('Новый API-ключ'),
        content: Text('Старый ключ больше не работает.\n\n${reissued['apiKey']}'),
        actions: [
          FilledButton(
              onPressed: () => Navigator.pop(context), child: const Text('Ок')),
        ],
      ),
    );
    _reload();
  }
}

// ---------- 2. Тренировки ----------

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

  @override
  State<WorkoutsPage> createState() => _WorkoutsPageState();
}

class _WorkoutsPageState extends State<WorkoutsPage> {
  int? _athleteId;
  String? _from, _to;
  int _offset = 0;
  static const _limit = 50;

  String get _query {
    var query = 'athleteId=${_athleteId ?? ''}&limit=$_limit&offset=$_offset';
    if (_from != null && _from!.isNotEmpty) query += '&dateFrom=$_from';
    if (_to != null && _to!.isNotEmpty) query += '&dateTo=$_to';
    return query;
  }

  String get _csvQuery {
    var query = 'athleteId=${_athleteId ?? ''}';
    if (_from != null && _from!.isNotEmpty) query += '&dateFrom=$_from';
    if (_to != null && _to!.isNotEmpty) query += '&dateTo=$_to';
    return query;
  }

  @override
  Widget build(BuildContext context) => Column(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: [
          Padding(
            padding: const EdgeInsets.all(12),
            child: Wrap(spacing: 16, children: [
              AthletePicker(
                  selected: _athleteId,
                  onChanged: (id) => setState(() {
                    _athleteId = id;
                    _offset = 0;
                  })),
              SizedBox(
                  width: 130,
                  child: TextField(
                      onChanged: (v) => setState(() { _from = v; _offset = 0; }),
                      decoration: const InputDecoration(
                          hintText: 'с (ГГГГ-ММ-ДД)'))),
              SizedBox(
                  width: 130,
                  child: TextField(
                      onChanged: (v) => setState(() { _to = v; _offset = 0; }),
                      decoration: const InputDecoration(
                          hintText: 'по (ГГГГ-ММ-ДД)'))),
              OutlinedButton.icon(
                onPressed: () => Api.downloadCsv('/api/admin/workouts.csv?$_csvQuery'),
                icon: const Icon(Icons.download),
                label: const Text('CSV'),
              ),
            ]),
          ),
          Expanded(
            child: FutureBuilderJson(Api.get('/api/admin/workouts?$_query'),
                (data) {
              final items = (data['items'] as List).cast<Json>();
              final total = data['total'] as int;
              return Column(children: [
                Expanded(
                  child: SingleChildScrollView(
                    scrollDirection: Axis.horizontal,
                    child: DataTable(columns: const [
                      DataColumn(label: Text('Дата')),
                      DataColumn(label: Text('Атлет')),
                      DataColumn(label: Text('Мин')),
                      DataColumn(label: Text('Ср. пульс')),
                      DataColumn(label: Text('Подходы')),
                      DataColumn(label: Text('Adherence')),
                      DataColumn(label: Text('Вид')),
                    ], rows: [
                      for (final w in items)
                        DataRow(onSelectChanged: (_) => _openCard(w['workoutId']), cells: [
                          DataCell(Text('${w['startedAt']}'.split('T').first)),
                          DataCell(Text('${w['athleteName']}')),
                          DataCell(Text('${w['durationMin'] ?? '—'}')),
                          DataCell(Text('${w['avgHr'] ?? '—'}')),
                          DataCell(Text('${w['setsCount']}')),
                          DataCell(Text('${w['adherence'] ?? '—'}')),
                          DataCell(Text('${w['sessionKind']}')),
                        ]),
                    ]),
                  ),
                ),
                Row(mainAxisAlignment: MainAxisAlignment.center, children: [
                  TextButton(
                      onPressed: _offset >= _limit
                          ? () => setState(() => _offset -= _limit)
                          : null,
                      child: const Text('← Назад')),
                  Text(' ${_offset + 1}–${_offset + items.length} из $total '),
                  TextButton(
                      onPressed: _offset + _limit < total
                          ? () => setState(() => _offset += _limit)
                          : null,
                      child: const Text('Вперёд →')),
                ]),
              ]);
            }),
          ),
        ],
      );

  Future<void> _openCard(dynamic workoutId) async {
    final card = await Api.get('/api/admin/workouts/$workoutId');
    if (!mounted) return;
    await showDialog(
      context: context,
      builder: (context) => AlertDialog(
        title: Text('Тренировка ${card['startedAt']}'.split('T').first),
        content: SizedBox(
          width: 720,
          height: 480,
          child: DefaultTabController(
            length: 3,
            child: Column(children: [
              const TabBar(tabs: [
                Tab(text: 'План/факт'),
                Tab(text: 'Подходы (.fit)'),
                Tab(text: 'Пульсограмма'),
              ]),
              Expanded(
                child: TabBarView(children: [
                  _planFact(card),
                  _timeline(card),
                  _hrCurve(card),
                ]),
              ),
            ]),
          ),
        ),
        actions: [
          FilledButton(
              onPressed: () => Navigator.pop(context), child: const Text('Закрыть')),
        ],
      ),
    );
  }

  Widget _planFact(Json card) {
    final planFact = card['planFact'] as Json?;
    final plan = (planFact?['plan'] as List? ?? []).cast<Json>();
    if (plan.isEmpty) {
      return const Center(child: Text('План на этот день не найден'));
    }
    return DataTable(columns: const [
      DataColumn(label: Text('Упражнение')),
      DataColumn(label: Text('План')),
      DataColumn(label: Text('Факт')),
    ], rows: [
      for (final p in plan)
        DataRow(cells: [
          DataCell(Text('${p['exercise']}')),
          DataCell(Text(
              '${p['plannedSets']}×${p['plannedReps'] ?? '—'} @ ${p['plannedWeight'] ?? '—'} кг')),
          DataCell(Text(
              '${p['factSets']}×${p['factReps'] ?? '—'} @ ${p['factWeight'] ?? '—'} кг')),
        ]),
    ]);
  }

  Widget _timeline(Json card) {
    final timeline = (card['timeline'] as List? ?? []).cast<Json>();
    if (timeline.isEmpty) {
      return const Center(child: Text('Данных .fit нет'));
    }
    return ListView(children: [
      for (final t in timeline)
        ListTile(
          title: Text('Подход ${t['index']}: ${t['durationS']} c'),
          subtitle: Text('старт +${t['startOffsetS']} c · '
              'пульс ${t['avgHr'] ?? '—'}/${t['peakHr'] ?? '—'} · '
              'отдых ${t['restAfterS']} c'),
        ),
    ]);
  }

  Widget _hrCurve(Json card) {
    final curve = (card['hrCurve'] as List? ?? []).cast<Json>();
    if (curve.isEmpty) {
      return const Center(child: Text('Данных .fit нет'));
    }
    return CustomPaint(
      painter: _HrCurvePainter(curve),
      size: Size.infinite,
    );
  }
}

class _HrCurvePainter extends CustomPainter {
  _HrCurvePainter(this.points);

  final List<Json> points;

  @override
  void paint(Canvas canvas, Size size) {
    if (points.length < 2) return;
    final maxT = (points.last['t'] as num).toDouble();
    final minHr = points
        .map((p) => (p['hr'] as num).toDouble())
        .reduce((a, b) => a < b ? a : b);
    final maxHr = points
        .map((p) => (p['hr'] as num).toDouble())
        .reduce((a, b) => a > b ? a : b);
    final spanHr = (maxHr - minHr).clamp(1.0, double.infinity);
    Offset pointAt(Json p) => Offset(
          (p['t'] as num).toDouble() / maxT * size.width,
          size.height -
              ((p['hr'] as num).toDouble() - minHr) / spanHr * size.height,
        );
    final path = Path()..moveTo(0, pointAt(points.first).dy);
    for (final p in points) {
      final o = pointAt(p);
      path.lineTo(o.dx, o.dy);
    }
    final paintLine = Paint()
      ..color = const Color(0xFF4FC3F7)
      ..style = PaintingStyle.stroke
      ..strokeWidth = 2;
    canvas.drawPath(path, paintLine);
    final tp = TextPainter(textDirection: TextDirection.ltr);
    tp.text = const TextSpan(text: '');
    tp.layout();
    tp.paint(canvas, Offset.zero);
  }

  @override
  bool shouldRepaint(covariant CustomPainter oldDelegate) => true;
}

// ---------- 3. Программы ----------

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

  @override
  State<ProgramsPage> createState() => _ProgramsPageState();
}

class _ProgramsPageState extends State<ProgramsPage> {
  int? _athleteId;

  @override
  Widget build(BuildContext context) => Column(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: [
          Padding(
            padding: const EdgeInsets.all(12),
            child: AthletePicker(
                selected: _athleteId, onChanged: (id) => setState(() => _athleteId = id)),
          ),
          Expanded(
            child: _athleteId == null
                ? const Center(child: Text('Выберите атлета'))
                : FutureBuilderJson(
                    Api.get('/api/admin/programs?athleteId=$_athleteId'),
                    (data) {
                    final items = (data['items'] as List).cast<Json>();
                    if (items.isEmpty) {
                      return const Center(child: Text('Версий нет'));
                    }
                    return ListView(children: [
                      for (final v in items)
                        ListTile(
                          title: Text('v${v['version']} · ${v['status']} · '
                              '${v['author']}'),
                          subtitle: Text('${v['rationale']}'),
                          trailing: Wrap(children: [
                            if (v['author'] == 'rules' && v['status'] == 'draft')
                              TextButton(
                                onPressed: () => _confirm(
                                    'Применить предложение правил?',
                                    () => Api.post(
                                        '/api/admin/programs/${v['versionId']}/apply?athleteId=$_athleteId'),
                                    reload: true),
                                child: const Text('Применить'),
                              ),
                            if (v['status'] == 'draft')
                              TextButton(
                                onPressed: () => _confirm(
                                    'Активировать v${v['version']}?',
                                    () => Api.post(
                                        '/api/admin/programs/${v['versionId']}/activate?athleteId=$_athleteId'),
                                    reload: true),
                                child: const Text('Активировать'),
                              ),
                            TextButton(
                              onPressed: () => _showBody(
                                  v['versionId'], v['version']),
                              child: const Text('Body'),
                            ),
                          ]),
                        ),
                    ]);
                  }),
          ),
        ],
      );

  Future<void> _confirm(String title, Future<dynamic> Function() action,
      {bool reload = false}) async {
    final ok = await showDialog<bool>(
      context: context,
      builder: (context) => AlertDialog(
        title: Text(title),
        actions: [
          TextButton(
              onPressed: () => Navigator.pop(context, false),
              child: const Text('Отмена')),
          FilledButton(
              onPressed: () => Navigator.pop(context, true),
              child: const Text('Да')),
        ],
      ),
    );
    if (ok == true) {
      await action();
      if (reload && mounted) setState(() {});
    }
  }

  Future<void> _showBody(dynamic versionId, dynamic version) async {
    final v = await Api.get(
        '/api/admin/programs/$versionId?athleteId=$_athleteId');
    if (!mounted) return;
    final pretty = const JsonEncoder.withIndent('  ')
        .convert(jsonDecode(v['body'] as String));
    await showDialog(
      context: context,
      builder: (context) => AlertDialog(
        title: Text('Body v$version'),
        content: SizedBox(
            width: 640,
            height: 480,
            child: SingleChildScrollView(child: SelectableText(pretty))),
        actions: [
          FilledButton(
              onPressed: () => Navigator.pop(context),
              child: const Text('Закрыть')),
        ],
      ),
    );
  }
}

// ---------- 4. Метрики ----------

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

  @override
  State<MetricsPage> createState() => _MetricsPageState();
}

class _MetricsPageState extends State<MetricsPage> {
  int? _athleteId;

  @override
  Widget build(BuildContext context) => Column(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: [
          Padding(
            padding: const EdgeInsets.all(12),
            child: AthletePicker(
                selected: _athleteId, onChanged: (id) => setState(() => _athleteId = id)),
          ),
          Expanded(
            child: _athleteId == null
                ? const Center(child: Text('Выберите атлета'))
                : FutureBuilderJson(
                    Api.get('/api/admin/metrics?athleteId=$_athleteId'),
                    (data) {
                    final weeks = (data['weekly'] as List).cast<Json>();
                    final workouts = (data['workouts'] as List).cast<Json>();
                    return Column(children: [
                      if (weeks.isNotEmpty)
                        SizedBox(
                          height: 160,
                          child: CustomPaint(
                            painter: _WeeklyChartPainter(weeks),
                            size: Size.infinite,
                          ),
                        ),
                      Expanded(
                        child: DataTable(columns: const [
                          DataColumn(label: Text('Дата')),
                          DataColumn(label: Text('Adherence')),
                          DataColumn(label: Text('Тоннаж')),
                          DataColumn(label: Text('Флаги')),
                        ], rows: [
                          for (final m in workouts)
                            DataRow(cells: [
                              DataCell(Text('${m['date'] ?? '—'}')),
                              DataCell(Text('${m['adherence']}')),
                              DataCell(Text('${m['tonnage']}')),
                              DataCell(Text(_flags(m))),
                            ]),
                        ]),
                      ),
                    ]);
                  }),
          ),
        ],
      );

  String _flags(Json m) {
    final flags = m['redFlags'];
    if (flags is List) return flags.isEmpty ? '—' : '${flags.length}';
    return '—';
  }
}

class _WeeklyChartPainter extends CustomPainter {
  _WeeklyChartPainter(this.weeks);

  final List<Json> weeks;

  @override
  void paint(Canvas canvas, Size size) {
    if (weeks.isEmpty) return;
    final maxTonnage = weeks
        .map((w) => (w['tonnage'] as num).toDouble())
        .reduce((a, b) => a > b ? a : b);
    final barWidth = size.width / weeks.length * 0.6;
    final step = size.width / weeks.length;
    final barPaint = Paint()..color = const Color(0x804FC3F7);
    final tp = TextPainter(textDirection: TextDirection.ltr);
    for (var i = 0; i < weeks.length; i++) {
      final tonnage = (weeks[i]['tonnage'] as num).toDouble();
      final h = tonnage / maxTonnage * (size.height - 40);
      canvas.drawRect(
          Rect.fromLTWH(i * step + (step - barWidth) / 2,
              size.height - 24 - h, barWidth, h),
          barPaint);
      // подписи текстом (цвет дублируется значением — UI/UX-стандарт)
      tp.text = TextSpan(
          text: '${weeks[i]['week']}'.split('-').last,
          style: const TextStyle(color: Color(0xFFB0BEC5), fontSize: 11));
      tp.layout();
      tp.paint(canvas, Offset(i * step + step / 2 - tp.width / 2, size.height - 20));
      tp.text = TextSpan(
          text: '${weeks[i]['avgAdherence']}%',
          style: const TextStyle(color: Color(0xFF80CBC4), fontSize: 11));
      tp.layout();
      tp.paint(canvas, Offset(i * step + step / 2 - tp.width / 2, size.height - 40));
    }
  }

  @override
  bool shouldRepaint(covariant CustomPainter oldDelegate) => true;
}

// ---------- 5. План/факт ----------

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

  @override
  State<PlanPage> createState() => _PlanPageState();
}

class _PlanPageState extends State<PlanPage> {
  int? _athleteId;

  @override
  Widget build(BuildContext context) => Column(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: [
          Padding(
            padding: const EdgeInsets.all(12),
            child: AthletePicker(
                selected: _athleteId, onChanged: (id) => setState(() => _athleteId = id)),
          ),
          Expanded(
            child: _athleteId == null
                ? const Center(child: Text('Выберите атлета'))
                : FutureBuilderJson(
                    Api.get('/api/admin/plan?athleteId=$_athleteId'), (data) {
                    if (data['activeVersion'] == null) {
                      return const Center(child: Text('Активной версии нет'));
                    }
                    final weeks = (data['weeks'] as List).cast<Json>();
                    return ListView(children: [
                      for (final w in weeks)
                        Card(
                          child: ListTile(
                            title: Text(
                                'Неделя ${w['week']} (${w['from']} — ${w['to']})'),
                            subtitle: Text(
                                'запланировано ${w['planned']} · '
                                'выполнено ${w['performed']} · '
                                'пропущено ${w['missed']}'),
                            trailing: Text(
                              '${w['avgAdherence'] ?? '—'}%',
                              style: TextStyle(
                                color: (w['missed'] as int) > 0
                                    ? Colors.orangeAccent
                                    : Colors.greenAccent,
                              ),
                            ),
                          ),
                        ),
                    ]);
                  }),
          ),
        ],
      );
}