import 'dart:async';

import 'package:flutter/material.dart';

import '../agent.dart';
import '../server/protocol.dart';

/// 饭卡打印机插件页：主状态一眼可懂，技术参数收进"技术详情"。
class CardPrinterPage extends StatefulWidget {
  const CardPrinterPage({super.key, required this.agent});

  final Agent agent;

  @override
  State<CardPrinterPage> createState() => _CardPrinterPageState();
}

class _CardPrinterPageState extends State<CardPrinterPage> {
  PrinterStatus? _status;
  String? _statusError;
  bool _loading = false;
  StreamSubscription<String>? _logSub;
  final _logs = <String>[];

  Agent get _agent => widget.agent;

  @override
  void initState() {
    super.initState();
    _logSub = _agent.log.stream.listen((line) {
      if (mounted) setState(() => _logs.add(line));
    });
    _logs.addAll(_agent.log.lines);
    _refreshStatus();
  }

  @override
  void dispose() {
    _logSub?.cancel();
    super.dispose();
  }

  Future<void> _refreshStatus() async {
    setState(() => _loading = true);
    try {
      final status = await _agent.backend.getStatus();
      if (!mounted) return;
      setState(() {
        _status = status;
        _statusError = null;
      });
    } catch (e) {
      if (!mounted) return;
      setState(() => _statusError = '$e');
    } finally {      if (mounted) setState(() => _loading = false);
    }
  }

  @override
  Widget build(BuildContext context) {
    final scheme = Theme.of(context).colorScheme;
    return Scaffold(
      backgroundColor: scheme.surface,
      body: SelectionArea(
        child: CustomScrollView(
          slivers: [
            SliverPadding(
              padding: const EdgeInsets.fromLTRB(28, 24, 28, 24),
              sliver: SliverList(
                delegate: SliverChildListDelegate([
                  _header(context),
                  const SizedBox(height: 20),
                  _statusHeroCard(context),
                  const SizedBox(height: 14),
                  _metricsRow(context),
                  const SizedBox(height: 14),
                  _techDetailsCard(context),
                ]),
              ),
            ),
          ],
        ),
      ),
    );
  }

  // ---------------- 头部：插件名 + 服务徽章 + 刷新 ----------------

  Widget _header(BuildContext context) {
    final scheme = Theme.of(context).colorScheme;
    final serviceOnline = _agent.port != null;
    return Row(
      children: [
        Expanded(
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Text('饭卡打印机', style: Theme.of(context).textTheme.headlineSmall),
              const SizedBox(height: 2),
              Text(
                '管理端开卡页提交的卡面会自动发送到本机打印机',
                style: Theme.of(context)
                    .textTheme
                    .bodyMedium
                    ?.copyWith(color: scheme.onSurfaceVariant),
              ),
            ],
          ),
        ),
        Container(
          padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 5),
          decoration: BoxDecoration(
            color: serviceOnline ? scheme.primaryContainer : scheme.errorContainer,
            borderRadius: BorderRadius.circular(999),
          ),
          child: Row(
            mainAxisSize: MainAxisSize.min,
            children: [
              Icon(
                serviceOnline ? Icons.check_circle : Icons.error_outline,
                size: 14,
                color: serviceOnline ? scheme.primary : scheme.error,
              ),
              const SizedBox(width: 6),
              Text(
                serviceOnline ? '服务运行中' : '服务未运行',
                style: Theme.of(context).textTheme.labelMedium?.copyWith(
                      color: serviceOnline ? scheme.onPrimaryContainer : scheme.onErrorContainer,
                    ),
              ),
            ],
          ),
        ),
        const SizedBox(width: 10),
        IconButton.filledTonal(
          onPressed: _loading ? null : _refreshStatus,
          tooltip: '刷新打印机状态',
          icon: _loading
              ? const SizedBox(
                  width: 16,
                  height: 16,
                  child: CircularProgressIndicator(strokeWidth: 2),
                )
              : const Icon(Icons.refresh),
        ),
      ],
    );
  }

  // ---------------- 状态主卡：一眼看懂 ----------------

  /// 主状态归纳：普通用户只需要知道"能不能用、现在干嘛"。
  _Headline _headline() {
    final s = _status;
    if (s == null) {
      if (_statusError != null) {
        return _Headline('状态读取失败', _StateColor.attention, Icons.help_outline_rounded);
      }
      return _Headline('正在获取状态…', _StateColor.idle, Icons.hourglass_empty);
    }
    if (!s.online) {
      return _Headline('打印机未连接', _StateColor.error, Icons.print_disabled);
    }
    if (s.status == 0) {
      return _Headline('打印机就绪', _StateColor.ok, Icons.print_rounded);
    }
    if (s.status == 0x00000002 || s.status == 0x00000005 || s.status == 0x00000006) {
      return _Headline('正在打印', _StateColor.ok, Icons.print_rounded);
    }
    return _Headline('需要处理', _StateColor.attention, Icons.report_problem_outlined);
  }

  Widget _statusHeroCard(BuildContext context) {
    final scheme = Theme.of(context).colorScheme;
    final head = _headline();
    final s = _status;
    final color = switch (head.color) {
      _StateColor.ok => scheme.primary,
      _StateColor.attention => const Color(0xFFD97706),
      _StateColor.error => scheme.error,
      _StateColor.idle => scheme.onSurfaceVariant,
    };
    return Card(
      margin: EdgeInsets.zero,
      elevation: 0,
      color: scheme.surfaceContainerLow,
      shape: RoundedRectangleBorder(
        borderRadius: BorderRadius.circular(12),
        side: BorderSide(color: scheme.outlineVariant),
      ),
      child: Padding(
        padding: const EdgeInsets.all(20),
        child: Row(
          crossAxisAlignment: CrossAxisAlignment.center,
          children: [
            Container(
              width: 64,
              height: 64,
              decoration: BoxDecoration(
                color: color.withValues(alpha: 0.14),
                borderRadius: BorderRadius.circular(16),
              ),
              child: Icon(head.icon, size: 34, color: color),
            ),
            const SizedBox(width: 18),
            Expanded(
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text(head.label, style: Theme.of(context).textTheme.titleLarge),
                  const SizedBox(height: 4),
                  Text(
                    s == null
                        ? (_statusError ?? '正在读取打印机状态')
                        : (s.statusText.isEmpty ? '—' : s.statusText),
                    style: Theme.of(context)
                        .textTheme
                        .bodyMedium
                        ?.copyWith(color: scheme.onSurfaceVariant),
                  ),
                  if (s != null && s.model.isNotEmpty) ...[
                    const SizedBox(height: 4),
                    Text(
                      s.model,
                      style: Theme.of(context).textTheme.bodySmall?.copyWith(
                            color: scheme.onSurfaceVariant,
                            fontWeight: FontWeight.w500,
                          ),
                    ),
                  ],
                ],
              ),
            ),
          ],
        ),
      ),
    );
  }

  // ---------------- 指标行：色带 / 卡量（生活化表述） ----------------

  Widget _metricsRow(BuildContext context) {
    // SliverList 内高度无界，stretch 需先经 IntrinsicHeight 拿到有界高度，
    // 否则子项会收到 h=Infinity 的约束直接布局断言失败
    return IntrinsicHeight(
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: [
          Expanded(child: _ribbonCard(context)),
          const SizedBox(width: 14),
          Expanded(child: _cardStockCard(context)),
        ],
      ),
    );
  }

  Widget _ribbonCard(BuildContext context) {
    final scheme = Theme.of(context).colorScheme;
    final s = _status;
    final remain = s?.ribbon.remain ?? -1;
    final known = remain >= 0;
    final color = !known
        ? scheme.onSurfaceVariant
        : remain <= 10
            ? scheme.error
            : remain <= 30
                ? const Color(0xFFD97706)
                : scheme.primary;
    return _MetricCard(
      icon: Icons.style_outlined,
      title: '色带余量',
      child: known
          ? Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(
                  '$remain%',
                  style: Theme.of(context)
                      .textTheme
                      .titleMedium
                      ?.copyWith(color: color, fontWeight: FontWeight.w700),
                ),
                const SizedBox(height: 8),
                ClipRRect(
                  borderRadius: BorderRadius.circular(4),
                  child: LinearProgressIndicator(
                    value: remain / 100,
                    minHeight: 6,
                    backgroundColor: scheme.surfaceContainerHighest,
                    color: color,
                  ),
                ),
                if (remain <= 10)
                  Padding(
                    padding: const EdgeInsets.only(top: 6),
                    child: Text(
                      '色带即将用尽，请准备更换',
                      style: Theme.of(context)
                          .textTheme
                          .bodySmall
                          ?.copyWith(color: color),
                    ),
                  ),
              ],
            )
          : _unknownText(context, '由打印机驱动提供，当前不可读'),
    );
  }

  Widget _cardStockCard(BuildContext context) {
    final scheme = Theme.of(context).colorScheme;
    final s = _status;
    final left = s?.cardLeft ?? -1;
    final low = s?.cardLow ?? false;
    final known = left >= 0;
    final color = low ? const Color(0xFFD97706) : scheme.onSurfaceVariant;
    return _MetricCard(
      icon: Icons.layers_outlined,
      title: '进卡仓卡量',
      child: known
          ? Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(
                  '剩余 $left 张',
                  style: Theme.of(context)
                      .textTheme
                      .titleMedium
                      ?.copyWith(fontWeight: FontWeight.w700),
                ),
                if (low)
                  Padding(
                    padding: const EdgeInsets.only(top: 6),
                    child: Text(
                      '卡量不足，请及时补充空白卡',
                      style: Theme.of(context).textTheme.bodySmall?.copyWith(color: color),
                    ),
                  ),
              ],
            )
          : _unknownText(context, '由打印机驱动提供，当前不可读'),
    );
  }

  Widget _unknownText(BuildContext context, String hint) => Builder(
        builder: (context) {
          final scheme = Theme.of(context).colorScheme;
          return Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Text(
                '未知',
                style: Theme.of(context)
                    .textTheme
                    .titleMedium
                    ?.copyWith(color: scheme.onSurfaceVariant),
              ),
              const SizedBox(height: 6),
              Text(
                hint,
                style: Theme.of(context).textTheme.bodySmall?.copyWith(
                      color: scheme.onSurfaceVariant,
                    ),
              ),
            ],
          );
        },
      );

  // ---------------- 技术详情（折叠收纳） ----------------

  Widget _techDetailsCard(BuildContext context) {
    final scheme = Theme.of(context).colorScheme;
    final s = _status;
    return Card(
      margin: EdgeInsets.zero,
      elevation: 0,
      color: scheme.surfaceContainerLow,
      shape: RoundedRectangleBorder(
        borderRadius: BorderRadius.circular(12),
        side: BorderSide(color: scheme.outlineVariant),
      ),
      clipBehavior: Clip.antiAlias,
      child: Theme(
        // 去掉 ExpansionTile 默认分割线密度，保持卡片内干净
        data: Theme.of(context).copyWith(dividerColor: Colors.transparent),
        child: ExpansionTile(
          tilePadding: const EdgeInsets.symmetric(horizontal: 20, vertical: 4),
          childrenPadding: const EdgeInsets.fromLTRB(20, 0, 20, 16),
          controlAffinity: ListTileControlAffinity.trailing,
          title: Text('技术详情', style: Theme.of(context).textTheme.titleSmall),
          subtitle: Text(
            '服务地址、后端模式、设备信息与运行日志',
            style: Theme.of(context).textTheme.bodySmall?.copyWith(
                  color: scheme.onSurfaceVariant,
                ),
          ),
          children: [
            Align(
              alignment: Alignment.centerLeft,
              child: ConstrainedBox(
                constraints: const BoxConstraints(maxWidth: 560),
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    _DetailSection(title: '本机服务', rows: [
                      ('运行状态', _agent.port != null ? '运行中' : '未运行'),
                      ('服务地址', _agent.port != null ? 'http://127.0.0.1:${_agent.port}' : '—'),
                      ('打印通道', _agent.options.mock ? '模拟（测试用）' : '系统打印通道'),
                    ]),
                    const SizedBox(height: 14),
                    _DetailSection(title: '设备信息', rows: [
                      ('型号', s == null || s.model.isEmpty ? '—' : s.model),
                      ('固件版本', s != null && s.firmware.isNotEmpty ? s.firmware : '—'),
                      ('连接方式', s?.connection ?? '—'),
                      ('状态码', s == null ? '—' : '0x${s.status.toRadixString(16).padLeft(8, '0').toUpperCase()}'),
                      ('色带类型', s != null && s.ribbon.type.isNotEmpty ? s.ribbon.type : '—'),
                      ('色带剩余张数', s != null && s.ribbon.remainCount >= 0 ? '${s.ribbon.remainCount} 张' : '—'),
                    ]),
                    const SizedBox(height: 14),
                    Text('运行日志（最近 50 条）',
                        style: Theme.of(context).textTheme.labelMedium?.copyWith(
                              color: scheme.onSurfaceVariant,
                            )),
                    const SizedBox(height: 6),
                    Container(
                      width: double.infinity,
                      constraints: const BoxConstraints(maxHeight: 220),
                      padding: const EdgeInsets.all(12),
                      decoration: BoxDecoration(
                        color: scheme.surfaceContainerHighest,
                        borderRadius: BorderRadius.circular(8),
                      ),
                      child: _logs.isEmpty
                          ? Text('（暂无日志）',
                              style: TextStyle(color: scheme.onSurfaceVariant, fontSize: 12))
                          : ListView(
                              children: [
                                for (final line in (_logs.length > 50 ? _logs.sublist(_logs.length - 50) : _logs))
                                  Text(
                                    line,
                                    style: TextStyle(
                                      fontFamily: 'monospace',
                                      fontSize: 11.5,
                                      height: 1.5,
                                      color: scheme.onSurfaceVariant,
                                    ),
                                  ),
                              ],
                            ),
                    ),
                  ],
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }
}

/// 指标小卡容器。
class _MetricCard extends StatelessWidget {
  const _MetricCard({required this.icon, required this.title, required this.child});

  final IconData icon;
  final String title;
  final Widget child;

  @override
  Widget build(BuildContext context) {
    final scheme = Theme.of(context).colorScheme;
    return Card(
      margin: EdgeInsets.zero,
      elevation: 0,
      color: scheme.surfaceContainerLow,
      shape: RoundedRectangleBorder(
        borderRadius: BorderRadius.circular(12),
        side: BorderSide(color: scheme.outlineVariant),
      ),
      child: Padding(
        padding: const EdgeInsets.all(16),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Row(
              children: [
                Icon(icon, size: 16, color: scheme.onSurfaceVariant),
                const SizedBox(width: 6),
                Text(title, style: Theme.of(context).textTheme.labelMedium),
              ],
            ),
            const SizedBox(height: 10),
            child,
          ],
        ),
      ),
    );
  }
}

/// 详情分组：标题 + 标签值行。
class _DetailSection extends StatelessWidget {
  const _DetailSection({required this.title, required this.rows});

  final String title;
  final List<(String, String)> rows;

  @override
  Widget build(BuildContext context) {
    final scheme = Theme.of(context).colorScheme;
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Text(title,
            style: Theme.of(context).textTheme.labelMedium?.copyWith(
                  color: scheme.onSurfaceVariant,
                )),
        const SizedBox(height: 6),
        Table(
          columnWidths: const {
            0: FixedColumnWidth(120),
            1: FlexColumnWidth(),
          },
          defaultVerticalAlignment: TableCellVerticalAlignment.middle,
          children: [
            for (final (label, value) in rows)
              TableRow(children: [
                Padding(
                  padding: const EdgeInsets.symmetric(vertical: 3),
                  child: Text(
                    label,
                    style: Theme.of(context).textTheme.bodySmall?.copyWith(
                          color: scheme.onSurfaceVariant,
                        ),
                  ),
                ),
                Padding(
                  padding: const EdgeInsets.symmetric(vertical: 3),
                  child: Text(value, style: Theme.of(context).textTheme.bodySmall),
                ),
              ]),
          ],
        ),
      ],
    );
  }
}

enum _StateColor { ok, attention, error, idle }

class _Headline {
  const _Headline(this.label, this.color, this.icon);

  final String label;
  final _StateColor color;
  final IconData icon;
}