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/app_text_field.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_exceptions.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]。
///
/// T2-14 收尾（25 号报告 §7 遗留①②）：scheduled 行支持「标记完成 /
/// 取消登记」PATCH 流转；完成时可补录厂商/批号（契约可选字段）；
/// 挂 `health_record_edit_succeeded/failed`（recordType=vaccine）。
///
/// 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;
  bool _mutating = 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();
    }
  }

  void _trackEditFailed(HealthRecordFailureReason reason, [int? errorCode]) {
    widget.analytics?.editFailed(
      recordType: HealthRecordType.vaccine,
      reason: reason,
      errorCode: errorCode,
    );
  }

  /// 标记完成（25 号报告遗留①②）：接种日期必填、下次接种/厂商/批号可选
  /// （厂商/批号为契约可选字段的补录入口）。
  Future<void> _markCompleted(Vaccination record) async {
    final result = await showDialog<_CompleteVaccinationResult>(
      context: context,
      builder: (context) => _CompleteVaccinationDialog(record: record),
    );
    if (result == null || !mounted) return;
    await _mutate(
      record,
      UpdateVaccinationRequest(
        version: record.version,
        status: VaccinationStatus.completed,
        administeredOn: result.administeredOn,
        nextDueOn: result.nextDueOn,
        manufacturer: result.manufacturer,
        batchNo: result.batchNo,
      ),
      successText: '已标记完成',
    );
  }

  Future<void> _cancelRegistration(Vaccination record) async {
    final confirmed = await showDialog<bool>(
      context: context,
      builder: (context) => AlertDialog(
        title: const Text('取消这条登记？'),
        content: Text(
          '「${vaccinationDoseLabel(record)}」将标记为已取消；'
          '取消后同系列同剂次可重新登记。',
        ),
        actions: [
          TextButton(
            onPressed: () => Navigator.of(context).pop(false),
            child: const Text('返回'),
          ),
          FilledButton(
            onPressed: () => Navigator.of(context).pop(true),
            child: const Text('取消登记'),
          ),
        ],
      ),
    );
    if (confirmed != true || !mounted) return;
    await _mutate(
      record,
      UpdateVaccinationRequest(
        version: record.version,
        status: VaccinationStatus.cancelled,
      ),
      successText: '已取消登记',
    );
  }

  Future<void> _mutate(
    Vaccination record,
    UpdateVaccinationRequest request, {
    required String successText,
  }) async {
    if (_mutating) return;
    setState(() => _mutating = true);
    final messenger = ScaffoldMessenger.of(context);
    try {
      await widget.repository.updateVaccination(record.id, request);
      widget.analytics?.editSucceeded(
        recordType: HealthRecordType.vaccine,
        fieldCount: request.toJson().length - 1,
      );
      if (!mounted) return;
      messenger.showSnackBar(SnackBar(content: Text(successText)));
      await _load();
    } on PetVersionConflictException {
      if (!mounted) return;
      // 40902：并发修改抢先——刷新取新 version 后由用户重试动作。
      messenger.showSnackBar(
        const SnackBar(content: Text('记录已在其他设备被修改，已刷新，请重试')),
      );
      _trackEditFailed(HealthRecordFailureReason.conflict, 40902);
      await _load();
    } on VaccinationRuleException {
      if (!mounted) return;
      // 42201：状态机/状态-日期规则兜底（前端已按规则拦截主路径）。
      messenger.showSnackBar(
        const SnackBar(content: Text('接种状态与日期不符合规则，请核对后重试')),
      );
      _trackEditFailed(HealthRecordFailureReason.validationError, 42201);
    } on PetRecordNotFoundException {
      if (!mounted) return;
      messenger.showSnackBar(const SnackBar(content: Text('记录不存在或已被删除，已刷新')));
      _trackEditFailed(HealthRecordFailureReason.notFound, 40402);
      await _load();
    } on PetAccessDeniedException {
      if (!mounted) return;
      messenger.showSnackBar(const SnackBar(content: Text('你没有权限操作该记录')));
      _trackEditFailed(HealthRecordFailureReason.permissionDenied, 40300);
    } on ApiBusinessException catch (error) {
      if (!mounted) return;
      messenger.showSnackBar(const SnackBar(content: Text('操作失败，请稍后重试')));
      _trackEditFailed(HealthRecordFailureReason.serverError, error.code);
    } on ApiNetworkException {
      if (!mounted) return;
      messenger.showSnackBar(const SnackBar(content: Text('网络异常，请检查网络后重试')));
      _trackEditFailed(HealthRecordFailureReason.networkError);
    } on SessionExpiredException {
      // 会话失效：认证状态机自动回登录页。
    } finally {
      if (mounted) setState(() => _mutating = false);
    }
  }

  @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,
            // 流转动作仅 scheduled 行可用（终态由服务端状态机守卫）。
            onComplete:
                widget.canWrite &&
                    record.status == VaccinationStatus.scheduled &&
                    !_mutating
                ? () => _markCompleted(record)
                : null,
            onCancel:
                widget.canWrite &&
                    record.status == VaccinationStatus.scheduled &&
                    !_mutating
                ? () => _cancelRegistration(record)
                : null,
          ),
        )
        ..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）；scheduled 行附
/// 「标记完成 / 取消登记」流转动作。
class _VaccinationTile extends StatelessWidget {
  const _VaccinationTile({
    required this.record,
    this.onComplete,
    this.onCancel,
  });

  final Vaccination record;
  final VoidCallback? onComplete;
  final VoidCallback? onCancel;

  @override
  Widget build(BuildContext context) {
    return Card(
      child: Padding(
        padding: const EdgeInsets.all(14),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            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),
                ),
              ],
            ),
            if (onComplete != null || onCancel != null) ...[
              const SizedBox(height: 6),
              Row(
                mainAxisAlignment: MainAxisAlignment.end,
                children: [
                  TextButton.icon(
                    onPressed: onCancel,
                    icon: const Icon(Icons.close, size: 16),
                    style: TextButton.styleFrom(
                      foregroundColor: AppColors.inkSoft,
                    ),
                    label: const Text('取消登记'),
                  ),
                  const SizedBox(width: 4),
                  TextButton.icon(
                    onPressed: onComplete,
                    icon: const Icon(Icons.check_circle_outline, size: 16),
                    label: const Text('标记完成'),
                  ),
                ],
              ),
            ],
          ],
        ),
      ),
    );
  }
}

/// 标记完成对话框返回值。
class _CompleteVaccinationResult {
  const _CompleteVaccinationResult({
    required this.administeredOn,
    this.nextDueOn,
    this.manufacturer,
    this.batchNo,
  });

  final DateTime administeredOn;
  final DateTime? nextDueOn;
  final String? manufacturer;
  final String? batchNo;
}

/// 标记完成对话框：接种日期必填（默认今天）、下次接种可选；
/// 厂商/批号补录（契约可选字段，25 号报告遗留②的落地入口）。
/// 日期规则复用 [vaccinationDateRuleError]（42201 前置拦截）。
class _CompleteVaccinationDialog extends StatefulWidget {
  const _CompleteVaccinationDialog({required this.record});

  final Vaccination record;

  @override
  State<_CompleteVaccinationDialog> createState() =>
      _CompleteVaccinationDialogState();
}

class _CompleteVaccinationDialogState
    extends State<_CompleteVaccinationDialog> {
  final _manufacturerCtrl = TextEditingController();
  final _batchNoCtrl = TextEditingController();
  DateTime _administeredOn = DateTime.now();
  DateTime? _nextDueOn;
  String? _dateError;

  @override
  void initState() {
    super.initState();
    _manufacturerCtrl.text = widget.record.manufacturer ?? '';
    _batchNoCtrl.text = widget.record.batchNo ?? '';
  }

  @override
  void dispose() {
    _manufacturerCtrl.dispose();
    _batchNoCtrl.dispose();
    super.dispose();
  }

  void _confirm() {
    final error = vaccinationDateRuleError(
      status: VaccinationStatus.completed,
      administeredOn: _administeredOn,
      nextDueOn: _nextDueOn,
    );
    if (error != null) {
      setState(() => _dateError = error);
      return;
    }
    final manufacturer = _manufacturerCtrl.text.trim();
    final batchNo = _batchNoCtrl.text.trim();
    Navigator.of(context).pop(
      _CompleteVaccinationResult(
        administeredOn: _administeredOn,
        nextDueOn: _nextDueOn,
        manufacturer: manufacturer.isEmpty ? null : manufacturer,
        batchNo: batchNo.isEmpty ? null : batchNo,
      ),
    );
  }

  Widget _dateTile({
    required String label,
    required DateTime? value,
    required bool allowFuture,
    required ValueChanged<DateTime> onPicked,
  }) {
    return ListTile(
      contentPadding: EdgeInsets.zero,
      leading: const Icon(Icons.event_outlined, color: AppColors.muted),
      title: Text(label, style: const TextStyle(fontSize: 14)),
      subtitle: Text(
        value == null ? '未选择' : dateToJson(value),
        style: const TextStyle(color: AppColors.inkSoft, fontSize: 12),
      ),
      onTap: () async {
        final now = DateTime.now();
        final picked = await showDatePicker(
          context: context,
          initialDate: value ?? now,
          firstDate: DateTime(1990),
          lastDate: allowFuture ? DateTime(now.year + 5) : now,
        );
        if (picked != null && mounted) {
          setState(() {
            onPicked(picked);
            _dateError = null;
          });
        }
      },
    );
  }

  @override
  Widget build(BuildContext context) {
    return AlertDialog(
      title: const Text('标记完成'),
      content: SingleChildScrollView(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Text(
              '「${vaccinationDoseLabel(widget.record)}」',
              maxLines: 1,
              overflow: TextOverflow.ellipsis,
            ),
            const SizedBox(height: 8),
            _dateTile(
              label: '接种日期',
              value: _administeredOn,
              allowFuture: false,
              onPicked: (value) => _administeredOn = value,
            ),
            _dateTile(
              label: '下次接种日期（可选）',
              value: _nextDueOn,
              allowFuture: true,
              onPicked: (value) => _nextDueOn = value,
            ),
            if (_dateError != null) ...[
              const SizedBox(height: 4),
              Text(
                _dateError!,
                style: const TextStyle(color: AppColors.error, fontSize: 12),
              ),
            ],
            const SizedBox(height: 12),
            AppTextField(
              label: '厂商（可选）',
              controller: _manufacturerCtrl,
              textInputAction: TextInputAction.next,
            ),
            const SizedBox(height: 12),
            AppTextField(
              label: '批号（可选）',
              controller: _batchNoCtrl,
              textInputAction: TextInputAction.done,
              onSubmitted: (_) => _confirm(),
            ),
          ],
        ),
      ),
      actions: [
        TextButton(
          onPressed: () => Navigator.of(context).pop(),
          child: const Text('取消'),
        ),
        FilledButton(onPressed: _confirm, child: const Text('确认完成')),
      ],
    );
  }
}