import 'dart:typed_data';
import 'package:flutter/material.dart';
import 'package:tdesign_flutter/tdesign_flutter.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';
import '../../shared/widgets/nav_bar_config.dart';
import '../../shared/widgets/loading_dialog.dart';
import '../../core/utils/date_utils.dart' as du;
import '../../shared/widgets/form_section.dart';
import '../../shared/widgets/form_field_row.dart';
import 'expense_model.dart';
import '../../core/i18n/app_localizations.dart';
import '../../shared/models/bill_attachment.dart';
import '../../core/theme/app_colors.dart';
import '../../core/theme/app_colors_extension.dart';
import 'expense_api.dart';
import 'dart:io';
import 'package:path_provider/path_provider.dart';
import 'package:open_filex/open_filex.dart';
import '../expense_apply/widgets/attachment_preview_page.dart';

class ExpenseDetailPage extends ConsumerStatefulWidget {
  final String billNo;
  final int queryId;
  const ExpenseDetailPage({super.key, required this.billNo, this.queryId = 0});

  @override
  ConsumerState<ExpenseDetailPage> createState() => _ExpenseDetailPageState();
}

class _ExpenseDetailPageState extends ConsumerState<ExpenseDetailPage>
    with WidgetsBindingObserver {
  ExpenseModel? _expense;
  List<BillAttachment> _attachments = [];
  bool _attachAvailable = false;
  bool _isLoading = true;
  String? _error;

  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addObserver(this);
    _loadData();
  }

  @override
  void dispose() {
    WidgetsBinding.instance.removeObserver(this);
    super.dispose();
  }

  bool _openingFile = false;

  @override
  void didChangeAppLifecycleState(AppLifecycleState state) {
    if (state == AppLifecycleState.resumed) {
      if (_openingFile) {
        _openingFile = false;
        return;
      }
      _attachments = [];
      _attachAvailable = false;
      _loadData();
    }
  }

  Future<void> _loadData() async {
    setState(() {
      _isLoading = true;
      _error = null;
    });
    try {
      final api = ref.read(expenseApiProvider);
      // 1. 加载报销详情（主表 + 明细）
      final expense = await api.fetchDetail(widget.billNo);
      setState(() => _expense = expense);

      // 2. 加载附件（非致命）
      try {
        _attachAvailable = await api.checkAttachHealth();
      } catch (_) {
        _attachAvailable = false;
      }
      if (_attachAvailable) {
        try {
          _attachments = await api.getAttachments('BX', widget.billNo);
        } catch (_) {
          _attachments = [];
        }
      }
    } catch (e) {
      setState(() => _error = e.toString());
    } finally {
      setState(() => _isLoading = false);
    }
  }

  @override
  Widget build(BuildContext context) {
    final colors = Theme.of(context).extension<AppColorsExtension>()!;
    final l10n = AppLocalizations.of(context);

    setNavBarTitle(context, ref, NavBarConfig(
      title: l10n.get('expenseDetail'),
      showBack: true,
      onBack: () => context.pop(),
    ));

    if (_isLoading) {
      return const Center(
        child: TDLoading(
          size: TDLoadingSize.large,
          icon: TDLoadingIcon.activity,
        ),
      );
    }

    if (_error != null) {
      return Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Icon(Icons.error_outline, size: 48, color: colors.danger),
            const SizedBox(height: 12),
            Text(
              _error!,
              style: TextStyle(fontSize: AppFontSizes.body, color: colors.danger),
              textAlign: TextAlign.center,
            ),
            const SizedBox(height: 16),
            TDButton(
              text: l10n.get('retry'),
              theme: TDButtonTheme.primary,
              onTap: _loadData,
            ),
          ],
        ),
      );
    }

    final expense = _expense!;

    return Expanded(
      child: SingleChildScrollView(
        physics: const AlwaysScrollableScrollPhysics(),
        padding: const EdgeInsets.all(16),
        child: Column(
          children: [
            _buildBasicInfoSection(expense, l10n, colors),
            const SizedBox(height: 16),
            _buildExpenseDetailSection(expense, l10n, colors),
            const SizedBox(height: 16),
            _buildAttachmentSection(l10n, colors),
            const SizedBox(height: 24),
            _buildPageFooter(colors),
          ],
        ),
      ),
    );
  }

  // ═══ 基本信息 ═══
  Widget _buildBasicInfoSection(
      ExpenseModel expense, AppLocalizations l10n, AppColorsExtension colors) {
    return FormSection(
      title: l10n.get('basicInfo'),
      leadingIcon: Icons.info_outline,
      children: [
        FormFieldRow(
            label: l10n.get('expenseNo'),
            value: expense.expenseNo,
            readOnly: true,
            showArrow: false),
        const SizedBox(height: 16),
        FormFieldRow(
            label: l10n.get('voucherNo'),
            value: expense.voucherNo.isNotEmpty ? expense.voucherNo : '-',
            readOnly: true,
            showArrow: false),
        const SizedBox(height: 16),
        FormFieldRow(
            label: l10n.get('expensePersonnel'),
            value: expense.applicantId.isNotEmpty
                ? '${expense.applicantId}/${expense.applicantName}'
                : expense.applicantName,
            readOnly: true,
            showArrow: false),
        const SizedBox(height: 16),
        FormFieldRow(
            label: l10n.get('expenseDept'),
            value: expense.deptId.isNotEmpty
                ? '${expense.deptId}/${expense.deptName}'
                : expense.deptName,
            readOnly: true,
            showArrow: false),
        const SizedBox(height: 16),
        FormFieldRow(
            label: l10n.get('date'),
            value: du.DateUtils.formatDateTime(expense.createTime),
            readOnly: true,
            showArrow: false),
        const SizedBox(height: 16),
        FormFieldRow(
            label: l10n.get('currency'),
            value: expense.currencyCode.isNotEmpty ? expense.currencyCode : '-',
            readOnly: true,
            showArrow: false),
        const SizedBox(height: 16),
        SizedBox(
          height: 24,
          child: Row(crossAxisAlignment: CrossAxisAlignment.center, children: [
            Text(l10n.get('feeReason'),
                style: TextStyle(fontSize: AppFontSizes.subtitle, color: colors.textSecondary)),
            const SizedBox(width: 8),
            Expanded(
              child: Text(expense.purpose.isNotEmpty ? expense.purpose : '-',
                  textAlign: TextAlign.end,
                  maxLines: 2,
                  overflow: TextOverflow.ellipsis,
                  style: TextStyle(fontSize: AppFontSizes.subtitle, fontWeight: FontWeight.w500, color: colors.textPrimary)),
            ),
          ]),
        ),
        const SizedBox(height: 16),
        FormFieldRow(
            label: l10n.get('paymentMethod'),
            value: expense.paymentMethod.isNotEmpty ? expense.paymentMethod : '-',
            readOnly: true,
            showArrow: false),
        const SizedBox(height: 16),
        SizedBox(
          height: 24,
          child: Row(crossAxisAlignment: CrossAxisAlignment.center, children: [
            Text(l10n.get('remark'),
                style: TextStyle(fontSize: AppFontSizes.subtitle, color: colors.textSecondary)),
            const SizedBox(width: 8),
            Expanded(
              child: Text(expense.remark.isNotEmpty ? expense.remark : '-',
                  textAlign: TextAlign.end,
                  maxLines: 2,
                  overflow: TextOverflow.ellipsis,
                  style: TextStyle(fontSize: AppFontSizes.subtitle, fontWeight: FontWeight.w500, color: colors.textPrimary)),
            ),
          ]),
        ),
      ],
    );
  }

  // ═══ 费用明细 ═══
  Widget _buildExpenseDetailSection(
      ExpenseModel expense, AppLocalizations l10n, AppColorsExtension colors) {
    final totalAmount = expense.details.fold<double>(
      0,
      (sum, d) => sum + d.totalAmount,
    );
    final totalApproved = expense.details.fold<double>(
      0,
      (sum, d) => sum + d.approvedAmount,
    );
    return FormSection(
      title: l10n.get('expenseDetails'),
      leadingIcon: Icons.receipt_long_outlined,
      children: [
        if (expense.details.isEmpty)
          Padding(
            padding: const EdgeInsets.symmetric(vertical: 8),
            child: Text(l10n.get('noDetailData'),
                style: TextStyle(fontSize: AppFontSizes.body, color: colors.textPlaceholder)),
          )
        else
          ...expense.details.asMap().entries.map((e) {
            final d = e.value;
            final title = d.categoryName.isNotEmpty
                ? '${d.expenseCategory}/${d.categoryName}'
                : (d.remark.isNotEmpty ? d.remark : (d.acctSubjectId.isNotEmpty ? d.acctSubjectId : '--'));
            return Container(
              margin: const EdgeInsets.symmetric(vertical: 6),
              padding: const EdgeInsets.all(12),
              decoration: BoxDecoration(color: colors.bgPage, borderRadius: BorderRadius.circular(8)),
              child: Row(
                children: [
                  Expanded(
                    child: Column(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: [
                        Row(
                          children: [
                            Expanded(
                              child: Text(title,
                                  style: TextStyle(fontSize: AppFontSizes.body, fontWeight: FontWeight.w500, color: colors.textPrimary)),
                            ),
                            Column(
                              crossAxisAlignment: CrossAxisAlignment.end,
                              children: [
                                Text('¥${d.totalAmount.toStringAsFixed(2)}',
                                    style: TextStyle(fontSize: AppFontSizes.body, fontWeight: FontWeight.w600, color: colors.amountPrimary)),
                                if (d.approvedAmount > 0)
                                  Text('¥${d.approvedAmount.toStringAsFixed(2)}',
                                      style: TextStyle(fontSize: AppFontSizes.body, fontWeight: FontWeight.w600, color: colors.success)),
                              ],
                            ),
                          ],
                        ),
                        const SizedBox(height: 2),
                        Text('${l10n.get('amountExcludingTax')}: ¥${d.amount.toStringAsFixed(2)}',
                            style: TextStyle(fontSize: AppFontSizes.caption, color: colors.textSecondary)),
                        if (d.taxAmount > 0)
                          Text('${l10n.get('taxAmount')}: ¥${d.taxAmount.toStringAsFixed(2)}',
                              style: TextStyle(fontSize: AppFontSizes.caption, color: colors.textSecondary)),
                        if (d.approvedAmount > 0)
                          Text('${l10n.get('approvedAmount')}: ¥${d.approvedAmount.toStringAsFixed(2)}',
                              style: TextStyle(fontSize: AppFontSizes.caption, fontWeight: FontWeight.w500, color: colors.success)),
                        if (d.acctSubjectName.isNotEmpty)
                          Text('${l10n.get('acctSubject')}: ${d.acctSubjectId}/${d.acctSubjectName}',
                              maxLines: 1, overflow: TextOverflow.ellipsis,
                              style: TextStyle(fontSize: AppFontSizes.caption, color: colors.textSecondary)),
                        if (d.aeNo.isNotEmpty)
                          Text('${l10n.get('expenseApplyNo')}: ${d.aeNo}',
                              maxLines: 1, overflow: TextOverflow.ellipsis,
                              style: TextStyle(fontSize: AppFontSizes.caption, color: colors.textSecondary)),
                        if (d.aeDd.isNotEmpty)
                          Text('${l10n.get('applyDate')}: ${d.aeDd}',
                              style: TextStyle(fontSize: AppFontSizes.caption, color: colors.textSecondary)),
                        if (d.projectName.isNotEmpty)
                          Text('${l10n.get('project')}: ${d.projectId}/${d.projectName}',
                              maxLines: 1, overflow: TextOverflow.ellipsis,
                              style: TextStyle(fontSize: AppFontSizes.caption, color: colors.textSecondary)),
                        if (d.costDeptName.isNotEmpty)
                          Text('${l10n.get('dept')}: ${d.costDeptId}/${d.costDeptName}',
                              maxLines: 1, overflow: TextOverflow.ellipsis,
                              style: TextStyle(fontSize: AppFontSizes.caption, color: colors.textSecondary)),
                        if (d.customerVendorName.isNotEmpty)
                          Text('${l10n.get('customerVendor')}: ${d.customerVendorName}',
                              maxLines: 1, overflow: TextOverflow.ellipsis,
                              style: TextStyle(fontSize: AppFontSizes.caption, color: colors.textSecondary)),
                        if (d.remark.isNotEmpty)
                          Text(d.remark,
                              maxLines: 2, overflow: TextOverflow.ellipsis,
                              style: TextStyle(fontSize: AppFontSizes.caption, color: colors.textSecondary)),
                      ],
                    ),
                  ),
                ],
              ),
            );
          }),
        if (expense.details.isNotEmpty) ...[
          const SizedBox(height: 8),
          Row(mainAxisAlignment: MainAxisAlignment.spaceBetween, children: [
            Text(l10n.get('total'),
                style: TextStyle(fontSize: AppFontSizes.body, fontWeight: FontWeight.w600, color: colors.textPrimary)),
            Column(
              crossAxisAlignment: CrossAxisAlignment.end,
              children: [
                Text('¥${totalAmount.toStringAsFixed(2)}',
                    style: TextStyle(fontSize: AppFontSizes.subtitle, fontWeight: FontWeight.w700, color: colors.amountPrimary)),
                if (totalApproved > 0)
                  Text('${l10n.get('approvedAmount')} ¥${totalApproved.toStringAsFixed(2)}',
                      style: TextStyle(fontSize: AppFontSizes.caption, fontWeight: FontWeight.w600, color: colors.success)),
              ],
            ),
          ]),
        ],
      ],
    );
  }

  // ═══ 附件 ═══
  Widget _buildAttachmentSection(AppLocalizations l10n, AppColorsExtension colors) {
    if (!_attachAvailable) {
      return FormSection(
        title: l10n.get('attachments'),
        leadingIcon: Icons.attach_file_outlined,
        children: [Text(l10n.get('attachServiceUnavailable'),
            style: TextStyle(fontSize: AppFontSizes.body, color: colors.textPlaceholder))],
      );
    }

    final headerAtts = _attachments.where((a) => a.isHeader).toList();
    final bodyGroups = <int, List<BillAttachment>>{};
    for (final a in _attachments.where((a) => a.isBody)) {
      bodyGroups.putIfAbsent(a.srcItm, () => []).add(a);
    }

    final children = <Widget>[];
    if (_attachments.isEmpty) {
      children.add(Text(l10n.get('noAttachment'),
          style: TextStyle(fontSize: AppFontSizes.body, color: colors.textPlaceholder)));
    } else {
      // 表头附件
      if (headerAtts.isNotEmpty) {
        children.add(Padding(
          padding: const EdgeInsets.only(bottom: 8),
          child: Text(l10n.get('headerAttachments'),
              style: TextStyle(fontSize: AppFontSizes.caption, fontWeight: FontWeight.w600, color: colors.textSecondary)),
        ));
        for (final a in headerAtts) {
          children.add(_buildAttachmentRow(a, colors));
        }
      }
      // 表身附件（按明细行分组）
      for (final entry in bodyGroups.entries) {
        children.add(const SizedBox(height: 8));
        children.add(Padding(
          padding: const EdgeInsets.only(bottom: 8),
          child: Text('${l10n.get('detailLine')} ${entry.key}',
              style: TextStyle(fontSize: AppFontSizes.caption, fontWeight: FontWeight.w600, color: colors.textSecondary)),
        ));
        for (final a in entry.value) {
          children.add(_buildAttachmentRow(a, colors));
        }
      }
    }

    return FormSection(
      title: l10n.get('attachments'),
      leadingIcon: Icons.attach_file_outlined,
      children: children,
    );
  }

  Widget _buildAttachmentRow(BillAttachment a, AppColorsExtension colors) {
    final isImage = ['jpg', 'jpeg', 'png', 'gif', 'bmp', 'webp'].contains(a.ext.toLowerCase());
    return GestureDetector(
      onTap: () => _openAttachment(a),
      child: Container(
        margin: const EdgeInsets.symmetric(vertical: 4),
        padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
        decoration: BoxDecoration(
          color: colors.bgPage,
          borderRadius: BorderRadius.circular(8),
        ),
        child: Row(children: [
          if (isImage)
            _ExpAttachmentThumbnail(api: ref.read(expenseApiProvider), attachment: a, size: 40)
          else
            Icon(_fileTypeIcon(a.ext), size: 40, color: colors.primary),
          const SizedBox(width: 10),
          Expanded(
            child: Text(a.fileName,
                maxLines: 1, overflow: TextOverflow.ellipsis,
                style: TextStyle(fontSize: AppFontSizes.body, color: colors.textPrimary)),
          ),
        ]),
      ),
    );
  }

  Future<void> _openAttachment(BillAttachment a) async {
    final l10n = AppLocalizations.of(context);
    final ext = a.ext.toLowerCase();
    final isImage = ['jpg', 'jpeg', 'png', 'gif', 'bmp', 'webp'].contains(ext);

    if (isImage) {
      // 图片 → 弹窗预览，内部自动下载并显示 loading
      final api = ref.read(expenseApiProvider);
      AttachmentPreview.show(context,
        loader: api.downloadAttachment(a.id),
        fileName: a.fileName,
        loadingText: l10n.get('loading'),
      );
      return;
    }

    // 非图片 → 下载后调用系统工具打开
    try {
      LoadingDialog.show(context, text: l10n.get('downloading'));
      final api = ref.read(expenseApiProvider);
      final bytes = await api.downloadAttachment(a.id);
      if (!mounted) return;
      LoadingDialog.hide(context);
      if (bytes == null) {
        TDToast.showText(l10n.get('downloadFailed'), context: context);
        return;
      }
      final dir = await getTemporaryDirectory();
      final file = File('${dir.path}/${a.fileName}');
      await file.writeAsBytes(bytes);
      _openingFile = true;
      await OpenFilex.open(file.path);
    } catch (_) {
      if (mounted) LoadingDialog.hide(context);
      if (mounted) TDToast.showText(l10n.get('openFailed'), context: context);
    }
  }

  IconData _fileTypeIcon(String ext) {
    switch (ext.toLowerCase()) {
      case 'pdf': return Icons.picture_as_pdf;
      case 'doc': case 'docx': return Icons.description;
      case 'xls': case 'xlsx': return Icons.table_chart;
      case 'jpg': case 'jpeg': case 'png': case 'gif': case 'bmp': return Icons.image_outlined;
      default: return Icons.insert_drive_file;
    }
  }

  Widget _buildPageFooter(AppColorsExtension colors) {
    final l10n = AppLocalizations.of(context);
    return Center(
      child: Padding(
        padding: const EdgeInsets.only(bottom: 16),
        child: Row(
          mainAxisSize: MainAxisSize.min,
          children: [
            Icon(Icons.rocket_launch_outlined, size: 16, color: colors.textPlaceholder),
            const SizedBox(width: 6),
            Text(l10n.get('pageFooter'),
                style: TextStyle(fontSize: AppFontSizes.caption, color: colors.textPlaceholder)),
          ],
        ),
      ),
    );
  }
}

/// 附件缩略图 — 自动调用 DownloadAttachment 加载图片
class _ExpAttachmentThumbnail extends StatefulWidget {
  final ExpenseApi api;
  final BillAttachment attachment;
  final double size;
  const _ExpAttachmentThumbnail({required this.api, required this.attachment, required this.size});
  @override
  State<_ExpAttachmentThumbnail> createState() => _ExpAttachmentThumbnailState();
}

class _ExpAttachmentThumbnailState extends State<_ExpAttachmentThumbnail> {
  Uint8List? _bytes;
  bool _loading = true;

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

  Future<void> _load() async {
    try {
      final bytes = await widget.api.downloadAttachment(widget.attachment.id);
      if (mounted) setState(() { _bytes = bytes; _loading = false; });
    } catch (_) {
      if (mounted) setState(() => _loading = false);
    }
  }

  @override
  Widget build(BuildContext context) {
    if (_loading) {
      return SizedBox(width: widget.size, height: widget.size,
          child: const Center(child: SizedBox(width: 16, height: 16, child: CircularProgressIndicator(strokeWidth: 2))));
    }
    if (_bytes != null) {
      return ClipRRect(
        borderRadius: BorderRadius.circular(4),
        child: Image.memory(_bytes!, width: widget.size, height: widget.size, fit: BoxFit.cover),
      );
    }
    return Icon(Icons.broken_image, size: widget.size * 0.6, color: Colors.grey);
  }
}