import 'package:flutter/material.dart';
import 'package:flutter/semantics.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/inline_error_banner.dart';
import 'package:patbond_flutter/core/widgets/primary_button.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/money.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';

/// 健康事件录入表单页（T2-14）。
///
/// - 六类事件类型选择（05 §4.4 类型选择器形态：RecordTypeDot sm + 标签，
///   图标 + 文字双通道）；类型必选。
/// - 发生时间默认「现在」，可回选日期（非今日取当日 12:00，与体重表单
///   同一约定）；提交前转 UTC，ISO 8601 带 Z 上送。
/// - 金额可选：**UI 以元录入/展示，传输为整数分**（money.dart 换算，
///   最多两位小数，非法拦截）；后端提交小数 400/40000 兜底。
/// - 埋点：health_record_create_started/succeeded/failed
///   （recordType=health_event）。
class HealthEventFormPage extends StatefulWidget {
  const HealthEventFormPage({
    required this.repository,
    required this.petId,
    super.key,
    this.analytics,
    this.entryPoint = HealthRecordEntryPoint.recordList,
  });

  final PetsRepository repository;
  final String petId;
  final HealthRecordAnalytics? analytics;
  final HealthRecordEntryPoint entryPoint;

  @override
  State<HealthEventFormPage> createState() => _HealthEventFormPageState();
}

class _HealthEventFormPageState extends State<HealthEventFormPage> {
  final _titleCtrl = TextEditingController();
  final _amountCtrl = TextEditingController();
  final _notesCtrl = TextEditingController();

  HealthEventType? _type;
  DateTime _occurredDate = DateTime.now();
  String? _typeError;
  String? _titleError;
  String? _amountError;
  String? _formError;
  bool _submitting = false;

  bool _startedFired = false;
  int _attemptSeq = 0;
  late final DateTime _openedAt;

  @override
  void initState() {
    super.initState();
    _openedAt = DateTime.now();
  }

  @override
  void dispose() {
    _titleCtrl.dispose();
    _amountCtrl.dispose();
    _notesCtrl.dispose();
    super.dispose();
  }

  void _markStarted() {
    if (_startedFired) return;
    _startedFired = true;
    widget.analytics?.createStarted(
      recordType: HealthRecordType.healthEvent,
      entryPoint: widget.entryPoint,
    );
  }

  void _trackFailed(HealthRecordFailureReason reason, [int? errorCode]) {
    widget.analytics?.createFailed(
      recordType: HealthRecordType.healthEvent,
      reason: reason,
      attemptSeq: _attemptSeq,
      errorCode: errorCode,
    );
  }

  void _showFormError(String message) {
    setState(() => _formError = message);
    SemanticsService.sendAnnouncement(
      View.of(context),
      message,
      TextDirection.ltr,
    );
  }

  /// 发生时刻：今日取此刻，历史日期取当日 12:00（本地），提交前转 UTC
  /// （与体重表单同一约定，规避无时区后缀的解析歧义）。
  DateTime _occurredAt() {
    final now = DateTime.now();
    final sameDay =
        _occurredDate.year == now.year &&
        _occurredDate.month == now.month &&
        _occurredDate.day == now.day;
    final local = sameDay
        ? now
        : DateTime(
            _occurredDate.year,
            _occurredDate.month,
            _occurredDate.day,
            12,
          );
    return local.toUtc();
  }

  Future<void> _submit() async {
    if (_submitting) return;
    _attemptSeq++;
    final typeError = _type == null ? '请选择事件类型' : null;
    final titleError = _titleCtrl.text.trim().isEmpty ? '请输入标题' : null;
    final amountText = _amountCtrl.text.trim();
    final amountError =
        amountText.isNotEmpty && parseYuanToCents(amountText) == null
        ? '金额格式不正确，最多两位小数'
        : null;
    if (typeError != null || titleError != null || amountError != null) {
      setState(() {
        _typeError = typeError;
        _titleError = titleError;
        _amountError = amountError;
      });
      _trackFailed(HealthRecordFailureReason.validationError);
      return;
    }

    setState(() {
      _submitting = true;
      _formError = null;
    });
    try {
      final notes = _notesCtrl.text.trim();
      final record = await widget.repository.createHealthEvent(
        widget.petId,
        CreateHealthEventRequest(
          eventType: _type!,
          occurredAt: _occurredAt(),
          title: _titleCtrl.text.trim(),
          notes: notes.isEmpty ? null : notes,
          // 元 → 整数分换算，DTO 层保持整数分（开发计划 §4.3）。
          amountCents: amountText.isEmpty ? null : parseYuanToCents(amountText),
        ),
      );
      widget.analytics?.createSucceeded(
        recordType: HealthRecordType.healthEvent,
        durationMs: DateTime.now().difference(_openedAt).inMilliseconds,
      );
      if (mounted) Navigator.of(context).pop(record);
    } on PetAccessDeniedException {
      if (!mounted) return;
      _showFormError('你没有权限为该宠物添加记录');
      _trackFailed(HealthRecordFailureReason.permissionDenied, 40300);
    } on PetNotFoundException {
      if (!mounted) return;
      final navigator = Navigator.of(context);
      ScaffoldMessenger.of(
        context,
      ).showSnackBar(const SnackBar(content: Text('宠物不存在或已被删除')));
      _trackFailed(HealthRecordFailureReason.notFound, 40401);
      navigator.pop();
    } on ApiRateLimitException {
      if (!mounted) return;
      _showFormError('操作过于频繁，请稍后再试');
      _trackFailed(HealthRecordFailureReason.rateLimited);
    } on ApiBusinessException catch (error) {
      if (!mounted) return;
      final isParam = error.code == ApiCodes.paramError;
      _showFormError(isParam ? '请检查填写内容后重试' : '保存失败，请稍后重试');
      _trackFailed(
        isParam
            ? HealthRecordFailureReason.validationError
            : HealthRecordFailureReason.serverError,
        error.code,
      );
    } on ApiNetworkException {
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(
          content: const Text('网络异常，请检查网络后重试'),
          action: SnackBarAction(label: '重试', onPressed: _submit),
        ),
      );
      _trackFailed(HealthRecordFailureReason.networkError);
    } on SessionExpiredException {
      // 会话失效：认证状态机自动回登录页。
    } finally {
      if (mounted) setState(() => _submitting = false);
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Colors.transparent,
        elevation: 0,
        foregroundColor: AppColors.ink,
        title: const Text('记录健康事件'),
        centerTitle: true,
        titleTextStyle: const TextStyle(
          color: AppColors.ink,
          fontSize: 16,
          fontWeight: FontWeight.w800,
        ),
      ),
      body: SafeArea(
        child: ListView(
          padding: const EdgeInsets.fromLTRB(20, 8, 20, 30),
          children: [
            const Text(
              '事件类型',
              style: TextStyle(
                color: AppColors.inkSoft,
                fontSize: 13,
                fontWeight: FontWeight.w600,
              ),
            ),
            const SizedBox(height: 8),
            _typeSelector(),
            if (_typeError != null) ...[
              const SizedBox(height: 6),
              Text(
                _typeError!,
                style: const TextStyle(color: AppColors.error, fontSize: 12),
              ),
            ],
            const SizedBox(height: 18),
            AppTextField(
              label: '标题（如：皮肤检查）',
              controller: _titleCtrl,
              prefixIcon: Icons.title_outlined,
              errorText: _titleError,
              enabled: !_submitting,
              textInputAction: TextInputAction.next,
              onChanged: (_) {
                _markStarted();
                if (_titleError != null || _formError != null) {
                  setState(() {
                    _titleError = null;
                    _formError = null;
                  });
                }
              },
            ),
            const SizedBox(height: 14),
            ListTile(
              shape: RoundedRectangleBorder(
                side: const BorderSide(color: AppColors.border),
                borderRadius: BorderRadius.circular(AppRadius.lg),
              ),
              tileColor: AppColors.surface,
              leading: const Icon(Icons.event_outlined, color: AppColors.muted),
              title: const Text('发生日期', style: TextStyle(fontSize: 14)),
              subtitle: Text(
                dateToJson(_occurredDate),
                style: const TextStyle(color: AppColors.inkSoft, fontSize: 12),
              ),
              trailing: const Icon(
                Icons.calendar_month_outlined,
                color: AppColors.muted,
              ),
              enabled: !_submitting,
              onTap: () async {
                final now = DateTime.now();
                final value = await showDatePicker(
                  context: context,
                  initialDate: _occurredDate,
                  firstDate: DateTime(1990),
                  lastDate: now,
                );
                if (value != null && mounted) {
                  _markStarted();
                  setState(() => _occurredDate = value);
                }
              },
            ),
            const SizedBox(height: 14),
            AppTextField(
              label: '金额（元，可选）',
              controller: _amountCtrl,
              prefixIcon: Icons.payments_outlined,
              errorText: _amountError,
              helperText: '以元填写，最多两位小数，如 128.50',
              enabled: !_submitting,
              keyboardType: const TextInputType.numberWithOptions(
                decimal: true,
              ),
              textInputAction: TextInputAction.next,
              onChanged: (_) {
                _markStarted();
                if (_amountError != null || _formError != null) {
                  setState(() {
                    _amountError = null;
                    _formError = null;
                  });
                }
              },
            ),
            const SizedBox(height: 14),
            AppTextField(
              label: '备注（可选）',
              controller: _notesCtrl,
              prefixIcon: Icons.sticky_note_2_outlined,
              enabled: !_submitting,
              textInputAction: TextInputAction.done,
              onChanged: (_) => _markStarted(),
              onSubmitted: (_) => _submit(),
            ),
            if (_formError != null) ...[
              const SizedBox(height: 16),
              InlineErrorBanner(message: _formError!),
            ],
            const SizedBox(height: 24),
            PrimaryButton(
              label: '保存记录',
              isLoading: _submitting,
              onPressed: _submit,
            ),
          ],
        ),
      ),
    );
  }

  /// 六类类型选择器（05 §4.4：RecordTypeDot sm 上、标签下；
  /// 选中 surfaceTint 底 + primaryDark 标签，未选中 inkSoft）。
  Widget _typeSelector() {
    return Wrap(
      spacing: 8,
      runSpacing: 8,
      children: [
        for (final type in HealthEventType.values)
          _TypeUnit(
            type: type,
            selected: _type == type,
            enabled: !_submitting,
            onTap: () {
              _markStarted();
              setState(() {
                _type = type;
                _typeError = null;
                _formError = null;
              });
            },
          ),
      ],
    );
  }
}

class _TypeUnit extends StatelessWidget {
  const _TypeUnit({
    required this.type,
    required this.selected,
    required this.enabled,
    required this.onTap,
  });

  final HealthEventType type;
  final bool selected;
  final bool enabled;
  final VoidCallback onTap;

  @override
  Widget build(BuildContext context) {
    return Material(
      color: selected ? AppColors.surfaceTint : AppColors.surface,
      shape: RoundedRectangleBorder(
        side: BorderSide(
          color: selected ? AppColors.primaryStrong : AppColors.border,
        ),
        borderRadius: BorderRadius.circular(AppRadius.md),
      ),
      child: InkWell(
        onTap: enabled ? onTap : null,
        borderRadius: BorderRadius.circular(AppRadius.md),
        child: Container(
          constraints: const BoxConstraints(minWidth: 64, minHeight: 52),
          padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 6),
          child: Column(
            mainAxisSize: MainAxisSize.min,
            children: [
              RecordTypeDot(
                type: recordTypeForHealthEvent(type),
                size: RecordTypeDotSize.sm,
              ),
              const SizedBox(height: 4),
              Text(
                healthEventTypeLabel(type),
                style: TextStyle(
                  fontSize: 11,
                  fontWeight: selected ? FontWeight.w700 : FontWeight.w600,
                  color: selected ? AppColors.primaryDark : AppColors.inkSoft,
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }
}