import 'package:flutter/material.dart';
import 'package:flutter/services.dart';

import '../../../fly/state/alert_state.dart';
import '../../../theme.dart';
import '../../pv_icons.dart';
import '../hud_kit.dart';

/// The error stack (plan P3, GO 4's `fpv_error_pop_item`): the aircraft's
/// live diagnostics as up to [maxCards] dismissible cards, most severe first.
///
/// [AlertState] already de-duplicates by code and keeps a dismissed card hidden
/// until its fault clears; this widget adds the haptic buzz when a new warning
/// or critical fault appears. Info-level messages stay in the tip marquee only.
///
/// It shows as many cards as fit the height it is given; what does not fit
/// collapses into a "+N more" pill ([onMore], the Aircraft Status sheet).
class AlertStack extends StatefulWidget {
  const AlertStack({super.key, required this.alerts, this.width = 280, this.onMore});

  final AlertState alerts;
  final double width;
  final VoidCallback? onMore;

  static const int maxCards = 6;

  /// A two-line card plus its gap, for working out how many fit.
  static const double cardExtent = 41;

  @override
  State<AlertStack> createState() => _AlertStackState();
}

class _AlertStackState extends State<AlertStack> {
  DateTime? _seen;

  @override
  void initState() {
    super.initState();
    _seen = widget.alerts.updatedAt;
    widget.alerts.addListener(_onAlerts);
  }

  @override
  void didUpdateWidget(AlertStack old) {
    super.didUpdateWidget(old);
    if (old.alerts != widget.alerts) {
      old.alerts.removeListener(_onAlerts);
      widget.alerts.addListener(_onAlerts);
    }
  }

  @override
  void dispose() {
    widget.alerts.removeListener(_onAlerts);
    super.dispose();
  }

  /// Buzzes once per bridge update that added a warning or worse — not on a
  /// dismissal, which notifies too but leaves [AlertState.updatedAt] alone.
  void _onAlerts() {
    final AlertState a = widget.alerts;
    if (a.updatedAt == _seen) return;
    _seen = a.updatedAt;
    AlertSeverity? worst;
    for (final DiagnosticAlert d in a.all) {
      if (!a.lastAdded.contains(d.key)) continue;
      if (worst == null || d.severity.index > worst.index) worst = d.severity;
    }
    if (worst == AlertSeverity.critical) {
      HapticFeedback.heavyImpact();
    } else if (worst == AlertSeverity.warning) {
      HapticFeedback.mediumImpact();
    }
  }

  @override
  Widget build(BuildContext context) {
    return ListenableBuilder(
      listenable: widget.alerts,
      builder: (BuildContext context, _) {
        final List<DiagnosticAlert> all = <DiagnosticAlert>[
          for (final DiagnosticAlert a in widget.alerts.active)
            if (a.severity != AlertSeverity.info) a,
        ];
        return LayoutBuilder(builder: (BuildContext context, BoxConstraints box) {
          final int room = box.maxHeight.isFinite ? (box.maxHeight / AlertStack.cardExtent).floor() : AlertStack.maxCards;
          final int fit = room.clamp(1, AlertStack.maxCards);
          // When some must go, the last slot becomes the "+N more" pill.
          final int shown = all.length <= fit ? all.length : fit - 1;
          final int hidden = all.length - shown;
          return SizedBox(
            width: widget.width,
            child: Column(mainAxisSize: MainAxisSize.min, crossAxisAlignment: CrossAxisAlignment.start, children: <Widget>[
              for (final DiagnosticAlert a in all.take(shown))
                Padding(
                  padding: const EdgeInsets.only(bottom: 4),
                  child: AlertCard(
                    key: ValueKey<String>('alert-${a.key}'),
                    alert: a,
                    onClose: () => widget.alerts.dismiss(a.key),
                  ),
                ),
              if (hidden > 0)
                GlassPill(
                  key: const ValueKey<String>('alert-more'),
                  height: 24,
                  color: const Color(0xCC0B1426),
                  onTap: widget.onMore,
                  child: Text('+$hidden more', style: HudText.sans.copyWith(fontSize: 11, color: AlertCard.colorOf(all[shown].severity))),
                ),
            ]),
          );
        });
      },
    );
  }
}

class AlertCard extends StatelessWidget {
  const AlertCard({super.key, required this.alert, required this.onClose});

  final DiagnosticAlert alert;
  final VoidCallback onClose;

  static Color colorOf(AlertSeverity s) => switch (s) {
        AlertSeverity.critical => HudColors.danger,
        AlertSeverity.warning => HudColors.caution,
        AlertSeverity.info => Glass.ink,
      };

  @override
  Widget build(BuildContext context) {
    final Color c = colorOf(alert.severity);
    return Container(
      decoration: BoxDecoration(
        color: const Color(0xCC0B1426),
        borderRadius: BorderRadius.circular(8),
        border: Border(left: BorderSide(color: c, width: 3)),
      ),
      padding: const EdgeInsets.fromLTRB(8, 5, 2, 5),
      child: Row(crossAxisAlignment: CrossAxisAlignment.start, children: <Widget>[
        Padding(padding: const EdgeInsets.only(top: 1), child: PVIcon('alert', size: 13, color: c)),
        const SizedBox(width: 6),
        Expanded(
          child: Column(crossAxisAlignment: CrossAxisAlignment.start, mainAxisSize: MainAxisSize.min, children: <Widget>[
            Text(alert.reason,
                maxLines: 1,
                overflow: TextOverflow.ellipsis,
                style: HudText.sans.copyWith(fontSize: 11.5, fontWeight: FontWeight.w700, color: c)),
            if (alert.solution != null)
              Text(alert.solution!,
                  maxLines: 1,
                  overflow: TextOverflow.ellipsis,
                  style: HudText.sans.copyWith(fontSize: 10.5, fontWeight: FontWeight.w400, color: HudText.dim)),
          ]),
        ),
        GestureDetector(
          behavior: HitTestBehavior.opaque,
          onTap: onClose,
          child: const Padding(padding: EdgeInsets.fromLTRB(6, 0, 6, 4), child: PVIcon('close', size: 13, color: HudText.dim)),
        ),
      ]),
    );
  }
}