import 'package:flutter/material.dart';
import 'package:patbond_flutter/analytics/analytics_page_name.dart';
import 'package:patbond_flutter/core/navigation/fade_route.dart';
import 'package:patbond_flutter/core/network/api_exception.dart';
import 'package:patbond_flutter/core/theme/app_theme.dart';
import 'package:patbond_flutter/core/widgets/empty_state_illustration.dart';
import 'package:patbond_flutter/core/widgets/inline_error_banner.dart';
import 'package:patbond_flutter/core/widgets/record_type_dot.dart';
import 'package:patbond_flutter/features/pets/health_record_analytics.dart';
import 'package:patbond_flutter/features/pets/health_record_display.dart';
import 'package:patbond_flutter/features/pets/pet_display.dart';
import 'package:patbond_flutter/features/pets/pet_models.dart';
import 'package:patbond_flutter/features/pets/pets_repository.dart';
import 'package:patbond_flutter/features/pets/vaccination_form_page.dart';
import 'package:patbond_flutter/widgets/common.dart';

enum _ListPhase { loading, ready, error }

/// 疫苗记录列表页（T2-13）：契约不分页，服务端按
/// `series_key, dose_no, created_at, id` 排序，客户端按系列直接分组；
/// 含 cancelled 行原样展示（取消后同剂次可重新登记的事实留痕）。
/// 四态齐备；登记经 [VaccinationFormPage]。
///
/// 曝光埋点：每次进入首个成功加载上报一次
/// `health_record_viewed(recordType=vaccine, source=pet_detail)`。
class VaccinationRecordsPage extends StatefulWidget {
  const VaccinationRecordsPage({
    required this.repository,
    required this.petId,
    required this.petSpecies,
    required this.canWrite,
    super.key,
    this.analytics,
  });

  final PetsRepository repository;
  final String petId;

  /// 疫苗目录按宠物物种过滤（契约：疫苗 species 须与宠物一致）。
  final PetSpecies petSpecies;

  /// owner/caregiver 可写；viewer 隐藏登记入口。
  final bool canWrite;

  final HealthRecordAnalytics? analytics;

  @override
  State<VaccinationRecordsPage> createState() => _VaccinationRecordsPageState();
}

class _VaccinationRecordsPageState extends State<VaccinationRecordsPage> {
  _ListPhase _phase = _ListPhase.loading;
  List<Vaccination> _records = const [];
  ApiException? _error;
  bool _viewedFired = false;

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

  Future<void> _load() async {
    setState(() {
      _phase = _ListPhase.loading;
      _error = null;
    });
    try {
      final records = await widget.repository.listVaccinations(widget.petId);
      if (!mounted) return;
      setState(() {
        _records = records;
        _phase = _ListPhase.ready;
      });
      if (!_viewedFired) {
        _viewedFired = true;
        widget.analytics?.viewed(
          recordType: HealthRecordType.vaccine,
          source: HealthRecordViewSource.petDetail,
        );
      }
    } on ApiException catch (error) {
      if (!mounted) return;
      setState(() {
        _error = error;
        _phase = _ListPhase.error;
      });
    }
  }

  Future<void> _openCreate() async {
    final created = await Navigator.of(context).push<Vaccination>(
      fadePageRoute(
        VaccinationFormPage(
          repository: widget.repository,
          petId: widget.petId,
          petSpecies: widget.petSpecies,
          analytics: widget.analytics,
        ),
        settings: RouteSettings(name: AnalyticsPageName.recordForm.pageName),
      ),
    );
    if (created != null && mounted) {
      ScaffoldMessenger.of(
        context,
      ).showSnackBar(const SnackBar(content: Text('已登记疫苗')));
      // 排序键在服务端（series_key, dose_no），重新拉取而非本地猜位置。
      await _load();
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Colors.transparent,
        elevation: 0,
        foregroundColor: AppColors.ink,
        title: const Text('疫苗记录'),
        centerTitle: true,
        titleTextStyle: const TextStyle(
          color: AppColors.ink,
          fontSize: 16,
          fontWeight: FontWeight.w800,
        ),
        actions: [
          if (widget.canWrite && _phase == _ListPhase.ready)
            IconButton(
              tooltip: '登记疫苗',
              onPressed: _openCreate,
              icon: const Icon(Icons.add),
            ),
        ],
      ),
      body: switch (_phase) {
        _ListPhase.loading => const Center(child: CircularProgressIndicator()),
        _ListPhase.error => Center(
          child: Padding(
            padding: const EdgeInsets.all(24),
            child: Column(
              mainAxisAlignment: MainAxisAlignment.center,
              children: [
                InlineErrorBanner(message: petLoadErrorMessage(_error)),
                const SizedBox(height: 16),
                FilledButton(onPressed: _load, child: const Text('重试')),
              ],
            ),
          ),
        ),
        _ListPhase.ready when _records.isEmpty => Center(
          child: SingleChildScrollView(
            child: EmptyStateIllustration(
              icon: Icons.vaccines_outlined,
              title: '还没有疫苗记录',
              description: '登记接种计划与完成情况，不错过每一针',
              ctaLabel: widget.canWrite ? '登记第一针' : null,
              onCtaPressed: widget.canWrite ? _openCreate : null,
            ),
          ),
        ),
        _ListPhase.ready => _list(),
      },
    );
  }

  /// 按系列分组渲染：服务端排序保证同系列相邻，系列变化处插组头
  /// （疫苗名 · 系列键）。
  Widget _list() {
    final children = <Widget>[];
    String? currentSeries;
    for (final record in _records) {
      final seriesId = '${record.vaccineId}/${record.seriesKey}';
      if (seriesId != currentSeries) {
        currentSeries = seriesId;
        children.add(
          Padding(
            padding: EdgeInsets.only(top: children.isEmpty ? 0 : 14, bottom: 8),
            child: Text(
              '${record.vaccineName} · ${record.seriesKey}',
              style: const TextStyle(
                color: AppColors.inkSoft,
                fontSize: 12,
                fontWeight: FontWeight.w700,
              ),
            ),
          ),
        );
      }
      children
        ..add(_VaccinationTile(record: record))
        ..add(const SizedBox(height: 10));
    }
    return RefreshIndicator(
      onRefresh: _load,
      child: ListView(
        padding: const EdgeInsets.fromLTRB(16, 8, 16, 30),
        children: children,
      ),
    );
  }
}

/// 疫苗条目：RecordTypeDot(疫苗) + 剂次标题 + 日期副行 + 状态 TagPill
/// （图标+文字双通道，不单靠颜色区分）。
class _VaccinationTile extends StatelessWidget {
  const _VaccinationTile({required this.record});

  final Vaccination record;

  @override
  Widget build(BuildContext context) {
    return Card(
      child: Padding(
        padding: const EdgeInsets.all(14),
        child: Row(
          children: [
            const RecordTypeDot(
              type: RecordType.vaccine,
              size: RecordTypeDotSize.md,
            ),
            const SizedBox(width: 12),
            Expanded(
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text(
                    vaccinationDoseLabel(record),
                    style: Theme.of(context).textTheme.titleMedium,
                  ),
                  const SizedBox(height: 4),
                  Text(
                    vaccinationDateLine(record),
                    maxLines: 1,
                    overflow: TextOverflow.ellipsis,
                    style: const TextStyle(
                      color: AppColors.inkSoft,
                      fontSize: 12,
                    ),
                  ),
                ],
              ),
            ),
            const SizedBox(width: 8),
            TagPill(
              vaccinationStatusLabel(record.status),
              color: vaccinationStatusColor(record.status),
            ),
          ],
        ),
      ),
    );
  }
}