import 'package:flutter/material.dart';
import 'package:go_router/go_router.dart';
import 'package:miaoji_zhang/features/chat/chat_page.dart';
import 'package:miaoji_zhang/shared/api/api_client.dart';
import 'package:miaoji_zhang/shared/api/auth_api.dart';
import 'package:miaoji_zhang/shared/api/business_api.dart';
import 'package:miaoji_zhang/shared/api/config_api.dart';
import 'package:miaoji_zhang/shared/services/current_ledger_store.dart';
import 'package:miaoji_zhang/shared/services/transaction_events.dart';
import 'package:miaoji_zhang/shared/theme/app_theme.dart';
import 'package:miaoji_zhang/shared/widgets/app_icons.dart';
import 'package:miaoji_zhang/shared/services/shanghai_time.dart';

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

  @override
  State<AiModePage> createState() => _AiModePageState();
}

class _AiModePageState extends State<AiModePage> {
  MonthSummary? _summary;
  BudgetsData? _budgets;
  String? _summaryError;
  String? _budgetError;
  bool _summaryLoading = true;
  bool _budgetLoading = true;
  int _loadRevision = 0;
  final _chatController = ChatPageController();

  @override
  void initState() {
    super.initState();
    CurrentLedgerStore.instance.addListener(_load);
    TransactionEvents.revision.addListener(_load);
    _load();
  }

  @override
  void dispose() {
    CurrentLedgerStore.instance.removeListener(_load);
    TransactionEvents.revision.removeListener(_load);
    super.dispose();
  }

  Future<void> _load() async {
    final revision = ++_loadRevision;
    if (mounted) {
      setState(() {
        _summaryLoading = true;
        _budgetLoading = true;
        _summaryError = null;
        _budgetError = null;
      });
    }
    final now = ShanghaiTime.now;
    await Future.wait([
      () async {
        try {
          final summary = await TxApi.month(now.year, now.month);
          if (!mounted || revision != _loadRevision) return;
          setState(() => _summary = summary);
        } catch (error) {
          if (!mounted || revision != _loadRevision) return;
          setState(() => _summaryError = apiErrorMessage(error));
        } finally {
          if (mounted && revision == _loadRevision) {
            setState(() => _summaryLoading = false);
          }
        }
      }(),
      () async {
        try {
          final budgets = await BudgetApi.get(now.year, now.month);
          if (!mounted || revision != _loadRevision) return;
          setState(() => _budgets = budgets);
        } catch (error) {
          if (!mounted || revision != _loadRevision) return;
          setState(() => _budgetError = apiErrorMessage(error));
        } finally {
          if (mounted && revision == _loadRevision) {
            setState(() => _budgetLoading = false);
          }
        }
      }(),
    ]);
  }

  Future<void> _openBudget() async {
    await context.push('/budget');
    await _load();
  }

  Future<void> _switchToNormal() async {
    try {
      await AuthApi.switchMode('normal');
      if (mounted) context.go('/home');
    } catch (error) {
      if (!mounted) return;
      ScaffoldMessenger.of(
        context,
      ).showSnackBar(SnackBar(content: Text(apiErrorMessage(error))));
    }
  }

  Widget _summarySection(MonthSummary? summary, double todayExpense) {
    if (_summaryLoading && summary == null) {
      return const _AiLoadCard(message: '正在加载本月收支', loading: true);
    }
    if (_summaryError != null && summary == null) {
      return _AiLoadCard(message: _summaryError!, onRetry: _load);
    }
    return Column(
      children: [
        if (_summaryError != null)
          _AiRefreshNotice(message: _summaryError!, onRetry: _load),
        Row(
          children: [
            _MiniCard(
              label: '今日支出',
              value: '¥${todayExpense.toStringAsFixed(2)}',
              color: AppTheme.red,
            ),
            SizedBox(width: 8),
            _MiniCard(
              label: '本月结余',
              value: '¥${summary!.balance.toStringAsFixed(0)}',
              color: AppTheme.primary,
            ),
            SizedBox(width: 8),
            _MiniCard(
              label: '本月支出',
              value: '¥${summary.expense.toStringAsFixed(0)}',
              color: context.jz.text,
            ),
          ],
        ),
      ],
    );
  }

  Widget _budgetSection() {
    if (_budgetLoading && _budgets == null) {
      return const _AiLoadCard(message: '正在加载本月预算', loading: true);
    }
    if (_budgetError != null && _budgets == null) {
      return _AiLoadCard(message: _budgetError!, onRetry: _load);
    }
    return Column(
      children: [
        if (_budgetError != null)
          _AiRefreshNotice(message: _budgetError!, onRetry: _load),
        AiBudgetStrip(data: _budgets!, onTap: _openBudget),
      ],
    );
  }

  @override
  Widget build(BuildContext context) {
    final s = _summary;
    final today = ShanghaiTime.now.day;
    final todayExpense =
        s?.days
            .where((d) => d.date.day == today)
            .fold<double>(0, (sum, d) => sum + d.expense) ??
        0;

    return Scaffold(
      body: Container(
        decoration: BoxDecoration(color: context.jz.background),
        child: SafeArea(
          bottom: false,
          child: Column(
            children: [
              ValueListenableBuilder<CompanionDisplay>(
                valueListenable: PublicConfigApi.companionNotifier,
                builder: (_, companion, __) {
                  return Padding(
                    padding: const EdgeInsets.symmetric(
                      horizontal: 16,
                      vertical: 8,
                    ),
                    child: Row(
                      children: [
                        CircleAvatar(
                          radius: 22,
                          backgroundColor: AppTheme.ai,
                          child: AppIcons.icon(
                            AppIcons.keyMap[companion.avatarKey] ??
                                AppIcons.cat,
                            size: 24,
                            color: Colors.white,
                          ),
                        ),
                        SizedBox(width: 10),
                        Expanded(
                          child: Column(
                            crossAxisAlignment: CrossAxisAlignment.start,
                            children: [
                              Text(
                                companion.name,
                                style: TextStyle(
                                  fontSize: 15,
                                  fontWeight: FontWeight.w700,
                                ),
                              ),
                              Text(
                                '全 AI 模式 · 说句话就能记账',
                                style: TextStyle(
                                  fontSize: 10,
                                  color: context.jz.text3,
                                ),
                              ),
                            ],
                          ),
                        ),
                        IconButton(
                          tooltip: '清理上下文',
                          onPressed: _chatController.clearContext,
                          icon: Icon(
                            Icons.restart_alt_rounded,
                            size: 21,
                            color: context.jz.text2,
                          ),
                        ),
                        GestureDetector(
                          onTap: _switchToNormal,
                          child: Container(
                            padding: const EdgeInsets.symmetric(
                              horizontal: 11,
                              vertical: 5,
                            ),
                            decoration: BoxDecoration(
                              color: context.jz.card,
                              borderRadius: BorderRadius.circular(14),
                              border: Border.all(
                                color: AppTheme.ai.withValues(alpha: 0.35),
                              ),
                            ),
                            child: Text(
                              '切换模式',
                              style: TextStyle(
                                fontSize: 10.5,
                                color: AppTheme.ai,
                              ),
                            ),
                          ),
                        ),
                      ],
                    ),
                  );
                },
              ),
              Padding(
                padding: const EdgeInsets.symmetric(horizontal: 16),
                child: _summarySection(s, todayExpense),
              ),
              SizedBox(height: 8),
              Padding(
                padding: const EdgeInsets.symmetric(horizontal: 16),
                child: _budgetSection(),
              ),
              SizedBox(height: 8),
              Expanded(
                child: ChatPage(aiMode: true, controller: _chatController),
              ),
            ],
          ),
        ),
      ),
    );
  }
}

class _AiLoadCard extends StatelessWidget {
  final String message;
  final bool loading;
  final Future<void> Function()? onRetry;
  const _AiLoadCard({
    required this.message,
    this.loading = false,
    this.onRetry,
  });

  @override
  Widget build(BuildContext context) {
    return Container(
      constraints: const BoxConstraints(minHeight: 58),
      padding: const EdgeInsets.symmetric(horizontal: 13, vertical: 10),
      decoration: BoxDecoration(
        color: context.jz.card,
        borderRadius: BorderRadius.circular(14),
        border: Border.all(
          color: loading
              ? context.jz.line
              : AppTheme.red.withValues(alpha: 0.22),
        ),
      ),
      child: Row(
        children: [
          if (loading)
            SizedBox(
              width: 17,
              height: 17,
              child: CircularProgressIndicator(
                strokeWidth: 2,
                color: AppTheme.primary,
              ),
            )
          else
            Icon(Icons.cloud_off_rounded, size: 18, color: AppTheme.red),
          SizedBox(width: 10),
          Expanded(
            child: Text(
              message,
              style: TextStyle(fontSize: 11.5, color: context.jz.text2),
            ),
          ),
          if (!loading && onRetry != null)
            TextButton(onPressed: onRetry, child: Text('重试')),
        ],
      ),
    );
  }
}

class _AiRefreshNotice extends StatelessWidget {
  final String message;
  final Future<void> Function() onRetry;
  const _AiRefreshNotice({required this.message, required this.onRetry});

  @override
  Widget build(BuildContext context) {
    return Container(
      margin: const EdgeInsets.only(bottom: 7),
      padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 7),
      decoration: BoxDecoration(
        color: context.jz.warningBackground,
        borderRadius: BorderRadius.circular(10),
      ),
      child: Row(
        children: [
          Icon(Icons.info_outline_rounded, size: 15, color: AppTheme.orange),
          SizedBox(width: 7),
          Expanded(
            child: Text(
              '刷新失败，当前显示上次数据：' + message,
              maxLines: 2,
              overflow: TextOverflow.ellipsis,
              style: TextStyle(fontSize: 10.5, color: context.jz.text2),
            ),
          ),
          TextButton(
            onPressed: onRetry,
            style: TextButton.styleFrom(
              minimumSize: const Size(0, 30),
              padding: const EdgeInsets.symmetric(horizontal: 7),
            ),
            child: Text('重试', style: TextStyle(fontSize: 10.5)),
          ),
        ],
      ),
    );
  }
}

class AiBudgetStrip extends StatelessWidget {
  final BudgetsData? data;
  final VoidCallback onTap;
  const AiBudgetStrip({super.key, required this.data, required this.onTap});

  @override
  Widget build(BuildContext context) {
    final total = data?.total;
    final categories = data?.categories ?? const <BudgetItem>[];
    final amount =
        total?.amount ??
        categories.fold<double>(0, (sum, item) => sum + item.amount);
    final spent =
        total?.spent ??
        categories.fold<double>(0, (sum, item) => sum + item.spent);
    final hasBudget = amount > 0;
    final ratio = hasBudget ? (spent / amount).clamp(0.0, 1.0) : 0.0;
    final over = hasBudget && spent > amount;

    return Semantics(
      button: true,
      label: hasBudget ? '查看本月预算' : '设置本月预算',
      child: InkWell(
        onTap: onTap,
        borderRadius: BorderRadius.circular(14),
        child: Container(
          padding: const EdgeInsets.fromLTRB(13, 10, 13, 9),
          decoration: BoxDecoration(
            color: context.jz.card,
            borderRadius: BorderRadius.circular(14),
            border: Border.all(color: context.jz.line),
          ),
          child: hasBudget
              ? Column(
                  children: [
                    Row(
                      children: [
                        AppIcons.icon(
                          AppIcons.target,
                          size: 16,
                          color: over ? AppTheme.red : AppTheme.primary,
                        ),
                        SizedBox(width: 7),
                        Text(
                          '本月预算',
                          style: TextStyle(
                            fontSize: 11.5,
                            fontWeight: FontWeight.w700,
                          ),
                        ),
                        Spacer(),
                        Text(
                          over
                              ? '已超 ¥${(spent - amount).toStringAsFixed(0)}'
                              : '剩余 ¥${(amount - spent).toStringAsFixed(0)}',
                          style: TextStyle(
                            fontSize: 11.5,
                            fontWeight: FontWeight.w700,
                            color: over ? AppTheme.red : AppTheme.primaryDeep,
                          ),
                        ),
                        SizedBox(width: 3),
                        Icon(
                          Icons.chevron_right_rounded,
                          size: 17,
                          color: context.jz.text3,
                        ),
                      ],
                    ),
                    SizedBox(height: 7),
                    ClipRRect(
                      borderRadius: BorderRadius.circular(3),
                      child: LinearProgressIndicator(
                        value: ratio,
                        minHeight: 5,
                        backgroundColor: context.jz.line,
                        color: over
                            ? AppTheme.red
                            : ratio > 0.8
                            ? AppTheme.orange
                            : AppTheme.primary,
                      ),
                    ),
                    SizedBox(height: 5),
                    Row(
                      children: [
                        Text(
                          '已用 ¥${spent.toStringAsFixed(0)}',
                          style: TextStyle(
                            fontSize: 9.5,
                            color: context.jz.text3,
                          ),
                        ),
                        Spacer(),
                        Text(
                          '总额 ¥${amount.toStringAsFixed(0)}',
                          style: TextStyle(
                            fontSize: 9.5,
                            color: context.jz.text3,
                          ),
                        ),
                      ],
                    ),
                  ],
                )
              : Row(
                  children: [
                    Container(
                      width: 30,
                      height: 30,
                      decoration: BoxDecoration(
                        color: context.jz.primaryBackground,
                        borderRadius: BorderRadius.circular(9),
                      ),
                      child: Center(
                        child: AppIcons.icon(
                          AppIcons.target,
                          size: 16,
                          color: AppTheme.primary,
                        ),
                      ),
                    ),
                    SizedBox(width: 10),
                    Expanded(
                      child: Column(
                        crossAxisAlignment: CrossAxisAlignment.start,
                        children: [
                          Text(
                            '本月还没设置预算',
                            style: TextStyle(
                              fontSize: 11.5,
                              fontWeight: FontWeight.w700,
                            ),
                          ),
                          SizedBox(height: 2),
                          Text(
                            '设个上限，让 AI 帮你一起盯住',
                            style: TextStyle(
                              fontSize: 9.5,
                              color: context.jz.text3,
                            ),
                          ),
                        ],
                      ),
                    ),
                    Text(
                      '去设置',
                      style: TextStyle(
                        fontSize: 11,
                        color: AppTheme.primaryDeep,
                        fontWeight: FontWeight.w700,
                      ),
                    ),
                    Icon(
                      Icons.chevron_right_rounded,
                      size: 17,
                      color: AppTheme.primary,
                    ),
                  ],
                ),
        ),
      ),
    );
  }
}

class _MiniCard extends StatelessWidget {
  final String label, value;
  final Color color;
  const _MiniCard({
    required this.label,
    required this.value,
    required this.color,
  });

  @override
  Widget build(BuildContext context) {
    return Expanded(
      child: Container(
        padding: const EdgeInsets.all(9),
        decoration: BoxDecoration(
          color: context.jz.card,
          borderRadius: BorderRadius.circular(12),
          border: Border.all(color: context.jz.line),
        ),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Text(label, style: TextStyle(fontSize: 9, color: context.jz.text3)),
            SizedBox(height: 2),
            Text(
              value,
              style: TextStyle(
                fontSize: 13.5,
                fontWeight: FontWeight.w700,
                color: color,
              ),
            ),
          ],
        ),
      ),
    );
  }
}