import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';
import '../../../core/pairing/pairing_notifier.dart';
import '../../../core/theme/halo_tokens.dart';
import '../../../core/theme/widgets/widgets.dart';

/// Phase 4 Stage 5 — `SWaitingBestie` overlay.
///
/// Entry route: `/chat/waiting-targeted/:mitraId` — pushed from the chat
/// history "Curhat lagi" CTA after the targeted payment session is confirmed.
///
/// Three sub-states mapped from `pairingProvider`:
///
/// - `waiting` (PairingTargetedWaitingData) — orb + 20s countdown + cancel.
///   The countdown is purely cosmetic; the server owns the auto-reject timer.
/// - `accepted` (PairingBestieFoundData / PairingActiveData) — routes into
///   the chat screen immediately.
/// - `declined` (PairingTargetedUnavailableData) — shows the bestie-offline
///   popup. TODO(stage8): swap this stub for the proper BestieOfflinePopup
///   component once Stage 8 lands.
class TargetedWaitingScreen extends ConsumerStatefulWidget {
  final String mitraId;
  const TargetedWaitingScreen({super.key, required this.mitraId});

  @override
  ConsumerState<TargetedWaitingScreen> createState() =>
      _TargetedWaitingScreenState();
}

class _TargetedWaitingScreenState extends ConsumerState<TargetedWaitingScreen> {
  bool _popupShown = false;

  @override
  void initState() {
    super.initState();
    ref.listenManual<PairingData>(pairingProvider, _onPairingState);
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (!mounted) return;
      _onPairingState(null, ref.read(pairingProvider));
    });
  }

  void _onPairingState(PairingData? prev, PairingData next) {
    if (!mounted) return;

    if (next is PairingBestieFoundData) {
      context.go('/chat/session/${next.sessionId}', extra: next.mitraName);
      return;
    }
    if (next is PairingActiveData) {
      context.go('/chat/session/${next.sessionId}', extra: next.mitraName);
      return;
    }
    if (next is PairingCancelledData) {
      context.go('/home');
      return;
    }
    if (next is PairingTargetedUnavailableData && !_popupShown) {
      _popupShown = true;
      // TODO(stage8): replace stub with the production BestieOfflinePopup
      // (Stage 8 owns the proper variant + fallback-to-blast surface).
      // ignore: discarded_futures
      HaloPopup.show(
        context,
        title: '${next.mitraName} lagi nggak online',
        body:
            'bestie kamu belum bisa nerima chat sekarang. coba bestie lain atau balik ke beranda dulu ya.',
        primary: HaloPopupAction(
          label: 'kembali ke home',
          onPressed: () {
            ref.read(pairingProvider.notifier).reset();
            if (mounted) context.go('/home');
          },
        ),
      ).then((_) {
        if (mounted) _popupShown = false;
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    final state = ref.watch(pairingProvider);

    final waiting = state is PairingTargetedWaitingData ? state : null;
    final mitraName = waiting?.mitraName ?? 'bestie';
    final secondsRemaining = waiting?.secondsRemaining ?? 0;

    return PopScope(
      // Targeted-wait is reachable directly from chat history; per the
      // deep-link pop-fallback rule (project memory), we drop the user
      // back to home if they swipe back rather than into a stale stack.
      canPop: false,
      onPopInvokedWithResult: (didPop, _) {
        if (didPop) return;
        ref.read(pairingProvider.notifier).cancelSearch();
      },
      child: Scaffold(
        backgroundColor: HaloTokens.bg,
        body: SafeArea(
          child: Padding(
            padding: const EdgeInsets.fromLTRB(
              HaloSpacing.s24,
              HaloSpacing.s24,
              HaloSpacing.s24,
              HaloSpacing.s24,
            ),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.stretch,
              children: [
                Expanded(
                  child: Center(
                    child: Column(
                      mainAxisSize: MainAxisSize.min,
                      children: [
                        HaloOrb(
                          size: 120,
                          seed: mitraName.hashCode,
                          label: mitraName,
                        ),
                        const SizedBox(height: HaloSpacing.s20),
                        const Text(
                          '◦ MENUNGGU JAWABAN ◦',
                          style: TextStyle(
                            fontFamily: HaloTokens.fontBody,
                            fontSize: 12,
                            fontWeight: FontWeight.w700,
                            letterSpacing: 1.6,
                            color: HaloTokens.brand,
                          ),
                        ),
                        const SizedBox(height: HaloSpacing.s8),
                        Text(
                          'lagi nungguin $mitraName',
                          textAlign: TextAlign.center,
                          style: const TextStyle(
                            fontFamily: HaloTokens.fontDisplay,
                            fontSize: 24,
                            height: 30 / 24,
                            fontWeight: FontWeight.w700,
                            color: HaloTokens.brandDark,
                          ),
                        ),
                        const SizedBox(height: HaloSpacing.s12),
                        Container(
                          padding: const EdgeInsets.symmetric(
                            horizontal: HaloSpacing.s16,
                            vertical: HaloSpacing.s8,
                          ),
                          decoration: BoxDecoration(
                            color: HaloTokens.brandSofter,
                            borderRadius: BorderRadius.circular(999),
                            border: Border.all(color: HaloTokens.brandSoft),
                          ),
                          child: Text(
                            '${secondsRemaining}d',
                            style: const TextStyle(
                              fontFamily: HaloTokens.fontDisplay,
                              fontSize: 22,
                              fontWeight: FontWeight.w700,
                              color: HaloTokens.brandDark,
                            ),
                          ),
                        ),
                        const SizedBox(height: HaloSpacing.s12),
                        ConstrainedBox(
                          constraints: const BoxConstraints(maxWidth: 280),
                          child: const Text(
                            'kalau bestie nggak respon dalam 20 detik, kami bantu cariin yang lain.',
                            textAlign: TextAlign.center,
                            style: TextStyle(
                              fontFamily: HaloTokens.fontBody,
                              fontSize: 13,
                              height: 20 / 13,
                              color: HaloTokens.inkSoft,
                            ),
                          ),
                        ),
                      ],
                    ),
                  ),
                ),
                HaloButton(
                  label: 'batalkan',
                  variant: HaloButtonVariant.ghost,
                  fullWidth: true,
                  onPressed: () =>
                      ref.read(pairingProvider.notifier).cancelSearch(),
                ),
              ],
            ),
          ),
        ),
      ),
    );
  }
}