import 'package:flutter/material.dart';
import '../../../core/network/api_client.dart';
import '../../../core/theme/app_theme.dart';
import '../../../core/widgets/glass_container.dart';
import '../models/recent_setup_model.dart';
import '../models/watchlist_entry_model.dart';
import '../repositories/admin_repository.dart';

/// Card sitting next to "AUFSCHLÜSSELUNG NACH GRUND" showing how many assets
/// FinlyticTechnicals' background scanner is currently watching. Tapping opens
/// a dialog listing every entry — this directly answers "is anything even
/// being checked in the background right now", independent of whether any of
/// those checks have (yet) produced a proposal-worthy evaluation the engine
/// history tab above would show.
class WatchlistCard extends StatefulWidget {
  final ApiClient apiClient;

  const WatchlistCard({super.key, required this.apiClient});

  @override
  State<WatchlistCard> createState() => _WatchlistCardState();
}

class _WatchlistCardState extends State<WatchlistCard> {
  late final AdminRepository _repository = AdminRepository(apiClient: widget.apiClient);
  List<WatchlistEntryModel>? _entries;
  String? _error;

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

  Future<void> _load() async {
    try {
      final entries = await _repository.fetchWatchlist();
      if (!mounted) return;
      setState(() {
        _entries = entries;
        _error = null;
      });
    } catch (e) {
      if (!mounted) return;
      setState(() => _error = e.toString());
    }
  }

  void _showDialog() {
    showDialog(
      context: context,
      builder: (_) => _WatchlistDialog(repository: _repository, initialEntries: _entries ?? const []),
    );
  }

  @override
  Widget build(BuildContext context) {
    final count = _entries?.length;
    final value = _error != null ? '—' : (count?.toString() ?? '…');

    return GlassContainer(
      padding: const EdgeInsets.all(14),
      onTap: _showDialog,
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Row(
            children: [
              Text('WATCHLIST', style: TextStyle(color: AppTheme.textSecondary, fontSize: 11, fontWeight: FontWeight.w900, letterSpacing: 0.5)),
              const Spacer(),
              Icon(Icons.list_alt_rounded, size: 16, color: AppTheme.accentCyan),
            ],
          ),
          const SizedBox(height: 10),
          Row(
            crossAxisAlignment: CrossAxisAlignment.end,
            children: [
              Text(value, style: TextStyle(fontSize: 22, color: AppTheme.textPrimary, fontWeight: FontWeight.bold)),
              const SizedBox(width: 8),
              Padding(
                padding: const EdgeInsets.only(bottom: 4),
                child: Text('überwachte Assets', style: TextStyle(color: AppTheme.textMuted, fontSize: 12)),
              ),
            ],
          ),
          if (_error != null) ...[
            const SizedBox(height: 6),
            Text(_error!, style: TextStyle(color: AppTheme.accentRed, fontSize: 11)),
          ],
        ],
      ),
    );
  }
}

class _WatchlistDialog extends StatefulWidget {
  final AdminRepository repository;
  final List<WatchlistEntryModel> initialEntries;

  const _WatchlistDialog({required this.repository, required this.initialEntries});

  @override
  State<_WatchlistDialog> createState() => _WatchlistDialogState();
}

class _WatchlistDialogState extends State<_WatchlistDialog> {
  late List<WatchlistEntryModel> _entries = widget.initialEntries;
  bool _refreshing = false;

  Future<void> _refresh() async {
    setState(() => _refreshing = true);
    try {
      final fresh = await widget.repository.fetchWatchlist();
      if (!mounted) return;
      setState(() {
        _entries = fresh;
        _refreshing = false;
      });
    } catch (_) {
      if (!mounted) return;
      setState(() => _refreshing = false);
    }
  }

  String _formatTimestamp(DateTime utc) {
    final local = utc.toLocal();
    final d = local.day.toString().padLeft(2, '0');
    final m = local.month.toString().padLeft(2, '0');
    final h = local.hour.toString().padLeft(2, '0');
    final min = local.minute.toString().padLeft(2, '0');
    return '$d.$m.${local.year} $h:$min';
  }

  @override
  Widget build(BuildContext context) {
    final activeTheme = AppTheme.activePreset;

    return Dialog(
      backgroundColor: activeTheme.cardSurface,
      insetPadding: const EdgeInsets.symmetric(horizontal: 20, vertical: 24),
      child: ConstrainedBox(
        constraints: const BoxConstraints(maxWidth: 560, maxHeight: 640),
        child: GlassContainer(
          borderRadius: 20,
          padding: const EdgeInsets.all(20),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            mainAxisSize: MainAxisSize.min,
            children: [
              Row(
                children: [
                  Icon(Icons.list_alt_rounded, color: AppTheme.accentCyan, size: 20),
                  const SizedBox(width: 10),
                  Expanded(
                    child: Text('Watchlist (${_entries.length})', style: const TextStyle(color: Colors.white, fontSize: 17, fontWeight: FontWeight.bold)),
                  ),
                  IconButton(
                    onPressed: _refreshing ? null : _refresh,
                    icon: _refreshing
                        ? const SizedBox(width: 16, height: 16, child: CircularProgressIndicator(strokeWidth: 2))
                        : const Icon(Icons.refresh_rounded, color: Colors.white70),
                    tooltip: 'Neu laden',
                  ),
                  IconButton(
                    onPressed: () => Navigator.of(context).pop(),
                    icon: const Icon(Icons.close_rounded, color: Colors.white70),
                  ),
                ],
              ),
              Text(
                'Assets, die FinlyticTechnicals derzeit im Hintergrund fortlaufend überprüft. Eintrag antippen für die letzten Bewertungen.',
                style: TextStyle(color: AppTheme.textMuted, fontSize: 12),
              ),
              const SizedBox(height: 12),
              if (_entries.isEmpty)
                Padding(
                  padding: const EdgeInsets.symmetric(vertical: 24),
                  child: Center(
                    child: Text('Die Watchlist ist derzeit leer.', style: TextStyle(color: AppTheme.textMuted, fontSize: 13)),
                  ),
                )
              else
                Flexible(
                  child: ListView.separated(
                    shrinkWrap: true,
                    itemCount: _entries.length,
                    separatorBuilder: (_, __) => const Divider(height: 1, color: Colors.white12),
                    itemBuilder: (context, index) => _WatchlistEntryTile(
                      entry: _entries[index],
                      repository: widget.repository,
                      formatTimestamp: _formatTimestamp,
                    ),
                  ),
                ),
            ],
          ),
        ),
      ),
    );
  }
}

class _WatchlistEntryTile extends StatefulWidget {
  final WatchlistEntryModel entry;
  final AdminRepository repository;
  final String Function(DateTime) formatTimestamp;

  const _WatchlistEntryTile({required this.entry, required this.repository, required this.formatTimestamp});

  @override
  State<_WatchlistEntryTile> createState() => _WatchlistEntryTileState();
}

class _WatchlistEntryTileState extends State<_WatchlistEntryTile> {
  List<RecentSetupModel>? _history;
  bool _loading = false;
  String? _error;

  Future<void> _loadHistory() async {
    if (_history != null || _loading) return;
    setState(() => _loading = true);
    try {
      final history = await widget.repository.fetchWatchlistEntryHistory(widget.entry.isin);
      if (!mounted) return;
      setState(() {
        _history = history;
        _loading = false;
      });
    } catch (e) {
      if (!mounted) return;
      setState(() {
        _error = e.toString();
        _loading = false;
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    final entry = widget.entry;

    return Theme(
      data: Theme.of(context).copyWith(dividerColor: Colors.transparent),
      child: ExpansionTile(
        onExpansionChanged: (expanded) {
          if (expanded) _loadHistory();
        },
        tilePadding: EdgeInsets.zero,
        title: Row(
          children: [
            Expanded(
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text(
                    entry.symbol?.isNotEmpty == true ? entry.symbol! : entry.isin,
                    style: TextStyle(color: AppTheme.textPrimary, fontWeight: FontWeight.bold, fontSize: 14),
                  ),
                  Text(entry.isin, style: TextStyle(color: AppTheme.textMuted, fontSize: 11)),
                ],
              ),
            ),
            if (entry.source != null)
              Container(
                padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
                margin: const EdgeInsets.only(right: 8),
                decoration: BoxDecoration(
                  color: AppTheme.accentCyan.withValues(alpha: 0.15),
                  borderRadius: BorderRadius.circular(6),
                  border: Border.all(color: AppTheme.accentCyan.withValues(alpha: 0.4)),
                ),
                child: Text(entry.source!.label, style: TextStyle(color: AppTheme.accentCyan, fontSize: 10, fontWeight: FontWeight.bold)),
              ),
          ],
        ),
        subtitle: Text(
          'Seit ${widget.formatTimestamp(entry.addedAtUtc)}'
          '${entry.expiresAtUtc != null ? ' · Läuft ab ${widget.formatTimestamp(entry.expiresAtUtc!)}' : ''}',
          style: TextStyle(color: AppTheme.textMuted, fontSize: 11),
        ),
        children: [
          Padding(
            padding: const EdgeInsets.only(bottom: 12),
            child: _buildHistoryBody(),
          ),
        ],
      ),
    );
  }

  Widget _buildHistoryBody() {
    if (_loading) {
      return const Padding(
        padding: EdgeInsets.symmetric(vertical: 8),
        child: Center(child: SizedBox(width: 18, height: 18, child: CircularProgressIndicator(strokeWidth: 2))),
      );
    }
    if (_error != null) {
      return Text(_error!, style: TextStyle(color: AppTheme.accentRed, fontSize: 12));
    }
    final history = _history ?? const [];
    if (history.isEmpty) {
      return Text(
        'Noch keine technische Bewertung für dieses Asset erfasst.',
        style: TextStyle(color: AppTheme.textMuted, fontSize: 12),
      );
    }

    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Text('LETZTE BEWERTUNGEN', style: TextStyle(color: AppTheme.textSecondary, fontSize: 10, fontWeight: FontWeight.w900, letterSpacing: 0.5)),
        const SizedBox(height: 6),
        ...history.map((setup) => Padding(
              padding: const EdgeInsets.symmetric(vertical: 3),
              child: Row(
                children: [
                  SizedBox(
                    width: 90,
                    child: Text(widget.formatTimestamp(setup.createdAt), style: TextStyle(color: AppTheme.textMuted, fontSize: 11)),
                  ),
                  Expanded(
                    child: Text(setup.strategyName, style: TextStyle(color: AppTheme.textPrimary, fontSize: 11), overflow: TextOverflow.ellipsis),
                  ),
                  Container(
                    padding: const EdgeInsets.symmetric(horizontal: 6, vertical: 2),
                    decoration: BoxDecoration(
                      color: (setup.isTopPick ? AppTheme.primaryEmerald : Colors.amber).withValues(alpha: 0.15),
                      borderRadius: BorderRadius.circular(6),
                    ),
                    child: Text(
                      setup.qualityScore.toStringAsFixed(1),
                      style: TextStyle(
                        color: setup.isTopPick ? AppTheme.primaryEmerald : Colors.amber,
                        fontSize: 11,
                        fontWeight: FontWeight.bold,
                      ),
                    ),
                  ),
                ],
              ),
            )),
      ],
    );
  }
}