import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import '../../../core/chat/chat_opening_provider.dart';
import '../../../core/chat/session_closure_notifier.dart';
import '../../../core/constants.dart';
import '../../../core/pairing/pairing_notifier.dart';

class PricingBottomSheet extends ConsumerWidget {
  /// If set, the bottom sheet is in "extension" mode — selecting a tier extends the session.
  final String? extensionSessionId;

  /// Required when starting a new pairing. Null when in extension mode.
  final TopicSensitivity? topicSensitivity;

  const PricingBottomSheet({super.key, this.extensionSessionId, this.topicSensitivity});

  /// Show for new pairing (from home screen)
  static Future<void> show(BuildContext context, {required TopicSensitivity topicSensitivity}) {
    return showModalBottomSheet(
      context: context,
      isScrollControlled: true,
      builder: (_) => PricingBottomSheet(topicSensitivity: topicSensitivity),
    );
  }

  /// Show for session extension (from chat screen)
  static Future<void> showForExtension(BuildContext context, {required String sessionId}) {
    return showModalBottomSheet(
      context: context,
      isScrollControlled: true,
      builder: (_) => PricingBottomSheet(extensionSessionId: sessionId),
    );
  }

  String _formatPrice(int price) {
    final str = price.toString();
    final buffer = StringBuffer();
    for (var i = 0; i < str.length; i++) {
      if (i > 0 && (str.length - i) % 3 == 0) buffer.write('.');
      buffer.write(str[i]);
    }
    return 'Rp $buffer';
  }

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final isExtension = extensionSessionId != null;
    final pricingAsync = ref.watch(chatPricingProvider);

    return pricingAsync.when(
      loading: () => const SizedBox(
        height: 200,
        child: Center(child: CircularProgressIndicator()),
      ),
      error: (error, _) => SizedBox(
        height: 200,
        child: Center(child: Text('Gagal memuat harga. Coba lagi.')),
      ),
      data: (pricing) => DraggableScrollableSheet(
        initialChildSize: 0.6,
        minChildSize: 0.4,
        maxChildSize: 0.8,
        expand: false,
        builder: (_, scrollController) {
          return Padding(
            padding: const EdgeInsets.all(24),
            child: ListView(
              controller: scrollController,
              children: [
                Text(
                  isExtension ? 'Perpanjang Durasi' : 'Pilih Durasi Curhat',
                  style: const TextStyle(fontSize: 20, fontWeight: FontWeight.bold),
                  textAlign: TextAlign.center,
                ),
                const SizedBox(height: 16),
                if (!isExtension && pricing.freeTrialEligible) ...[
                  Card(
                    color: Colors.green.shade50,
                    child: ListTile(
                      leading: const Icon(Icons.card_giftcard, color: Colors.green),
                      title: Text('Free Trial (${pricing.freeTrialDurationMinutes} Menit)'),
                      subtitle: const Text('Gratis untuk pertama kali!'),
                      trailing: const Icon(Icons.arrow_forward_ios, size: 16),
                      onTap: () {
                        Navigator.of(context).pop();
                        _startPairing(ref, isFreeTrial: true);
                      },
                    ),
                  ),
                  const Divider(height: 24),
                ],
                ...pricing.tiers.map((tier) => Card(
                  child: ListTile(
                    title: Text(tier.label),
                    trailing: Text(
                      _formatPrice(tier.price),
                      style: const TextStyle(fontWeight: FontWeight.bold, fontSize: 16),
                    ),
                    onTap: () {
                      Navigator.of(context).pop();
                      if (isExtension) {
                        _requestExtension(
                          ref,
                          sessionId: extensionSessionId!,
                          durationMinutes: tier.durationMinutes,
                          price: tier.price,
                        );
                      } else {
                        _startPairing(
                          ref,
                          durationMinutes: tier.durationMinutes,
                          price: tier.price,
                        );
                      }
                    },
                  ),
                )),
              ],
            ),
          );
        },
      ),
    );
  }

  void _startPairing(WidgetRef ref, {bool isFreeTrial = false, int? durationMinutes, int? price}) {
    ref.read(pairingProvider.notifier).requestPairingWithTier(
      durationMinutes: durationMinutes,
      price: price,
      isFreeTrial: isFreeTrial,
      topicSensitivity: topicSensitivity ?? TopicSensitivity.regular,
    );
  }

  void _requestExtension(WidgetRef ref, {required String sessionId, required int durationMinutes, required int price}) {
    ref.read(sessionClosureProvider.notifier).requestExtension(
      sessionId,
      durationMinutes: durationMinutes,
      price: price,
    );
  }
}
