import 'package:flutter/material.dart';
import 'package:font_awesome_flutter/font_awesome_flutter.dart';
import 'package:provider/provider.dart';
import 'package:simplecloudnotifier/api/api_client.dart';
import 'package:simplecloudnotifier/models/channel.dart';
import 'package:simplecloudnotifier/models/scan_result.dart';
import 'package:simplecloudnotifier/models/subscription.dart';
import 'package:simplecloudnotifier/models/user.dart';
import 'package:simplecloudnotifier/pages/channel_view/channel_view.dart';
import 'package:simplecloudnotifier/state/app_auth.dart';
import 'package:simplecloudnotifier/state/application_log.dart';
import 'package:simplecloudnotifier/utils/navi.dart';
import 'package:simplecloudnotifier/utils/toaster.dart';
import 'package:simplecloudnotifier/utils/ui.dart';

class ChannelScannerResultChannelSubscribe extends StatefulWidget {
  final ScanResultChannelSubscribe value;

  const ChannelScannerResultChannelSubscribe({required this.value}) : super();

  @override
  State<ChannelScannerResultChannelSubscribe> createState() => _ChannelScannerResultChannelSubscribeState();
}

class _ChannelScannerResultChannelSubscribeState extends State<ChannelScannerResultChannelSubscribe> {
  Future<(ChannelPreview, UserPreview)?> _fetchDataFuture;

  _ChannelScannerResultChannelSubscribeState() : _fetchDataFuture = Future.value(null); // Initial dummy future

  Subscription? overrideSubscription = null;

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

    final auth = Provider.of<AppAuth>(context, listen: false);
    setState(() {
      _fetchDataFuture = _fetchData(auth);
    });
  }

  Future<(ChannelPreview, UserPreview)?> _fetchData(AppAuth auth) async {
    ChannelPreview? channel = null;
    try {
      channel = await APIClient.getChannelPreview(auth, widget.value.channelID);
    } catch (e, stackTrace) {
      Toaster.error("Error", 'Failed to fetch channel preview: ${e.toString()}');
      ApplicationLog.error('Failed to fetch channel (preview) for ${widget.value.channelID}', trace: stackTrace);
      return null;
    }

    UserPreview? user = null;
    try {
      user = await APIClient.getUserPreview(auth, widget.value.ownerUserID);
    } catch (e, stackTrace) {
      Toaster.error("Error", 'Failed to fetch user preview: ${e.toString()}');
      ApplicationLog.error('Failed to fetch user (preview) for ${widget.value.ownerUserID}', trace: stackTrace);
      return null;
    }

    return (channel, user);
  }

  @override
  Widget build(BuildContext context) {
    return FutureBuilder<(ChannelPreview, UserPreview)?>(
      future: _fetchDataFuture,
      builder: (context, snapshot) {
        final auth = Provider.of<AppAuth>(context, listen: false);

        if (snapshot.connectionState == ConnectionState.waiting) {
          return const Center(child: CircularProgressIndicator());
        }

        if (snapshot.hasError) {
          return Text('Error: ${snapshot.error}'); //TODO better error display
        }

        if (snapshot.data == null) {
          return Column(
            spacing: 32,
            children: [
              Icon(FontAwesomeIcons.solidTriangleExclamation, size: 64, color: Colors.red[900]),
              Text("Failed to parse QR", textAlign: TextAlign.center),
            ],
          );
        }

        final (channel, user) = snapshot.data!;

        final sub = overrideSubscription ?? channel.subscription;

        return Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            Text("SCN Channel", style: const TextStyle(fontWeight: FontWeight.bold, fontSize: 20), textAlign: TextAlign.center),
            const SizedBox(height: 16),
            Row(
              children: [
                ConstrainedBox(child: Text("Name: ", style: const TextStyle(fontWeight: FontWeight.bold)), constraints: const BoxConstraints(minWidth: 100)),
                Expanded(child: SingleChildScrollView(child: Text(channel.displayName), scrollDirection: Axis.horizontal)),
              ],
            ),
            Row(
              children: [
                ConstrainedBox(child: Text("InternalName: ", style: const TextStyle(fontWeight: FontWeight.bold)), constraints: const BoxConstraints(minWidth: 100)),
                Expanded(child: SingleChildScrollView(child: Text(channel.internalName, style: const TextStyle(fontStyle: FontStyle.italic)), scrollDirection: Axis.horizontal)),
              ],
            ),
            Row(
              children: [
                ConstrainedBox(child: Text("ChannelID: ", style: const TextStyle(fontWeight: FontWeight.bold)), constraints: const BoxConstraints(minWidth: 100)),
                Expanded(child: SingleChildScrollView(child: Text(channel.channelID, style: const TextStyle(fontStyle: FontStyle.italic)), scrollDirection: Axis.horizontal)),
              ],
            ),
            Row(
              children: [
                ConstrainedBox(child: Text("Messages: ", style: const TextStyle(fontWeight: FontWeight.bold)), constraints: const BoxConstraints(minWidth: 100)),
                Expanded(child: SingleChildScrollView(child: Text(channel.messagesSent.toString()), scrollDirection: Axis.horizontal)),
              ],
            ),
            if (channel.descriptionName != null && channel.descriptionName!.isNotEmpty)
              Row(
                children: [
                  ConstrainedBox(child: Text("Description:", style: const TextStyle(fontWeight: FontWeight.bold)), constraints: const BoxConstraints(minWidth: 100)),
                  Expanded(child: SingleChildScrollView(child: Text(channel.descriptionName!), scrollDirection: Axis.horizontal)),
                ],
              ),
            const SizedBox(height: 16),
            Row(
              children: [
                ConstrainedBox(child: Text("Owner:", style: const TextStyle(fontWeight: FontWeight.bold)), constraints: const BoxConstraints(minWidth: 100)),
                Expanded(child: SingleChildScrollView(child: Text((user.username ?? user.userID) + ((auth.userID != null && auth.userID! == user.userID) ? "\n(you)" : "")), scrollDirection: Axis.horizontal)),
              ],
            ),
            Row(
              children: [
                ConstrainedBox(child: Text("UserID:", style: const TextStyle(fontWeight: FontWeight.bold)), constraints: const BoxConstraints(minWidth: 100)),
                Expanded(child: SingleChildScrollView(child: Text(user.userID, style: const TextStyle(fontStyle: FontStyle.italic)), scrollDirection: Axis.horizontal)),
              ],
            ),
            const SizedBox(height: 16),
            Row(
              children: [
                ConstrainedBox(child: Text("Status:", style: const TextStyle(fontWeight: FontWeight.bold)), constraints: const BoxConstraints(minWidth: 100)),
                Expanded(child: SingleChildScrollView(child: Text(_formatSubscriptionStatus(sub)), scrollDirection: Axis.horizontal)),
              ],
            ),
            const SizedBox(height: 48),
            if (sub == null)
              UI.button(
                text: 'Request Subscription',
                onPressed: _onSubscribe,
                color: Theme.of(context).colorScheme.primary,
                textColor: Theme.of(context).colorScheme.onPrimary,
              ),
            if (sub != null && sub.confirmed)
              UI.button(
                text: 'Go to channel',
                onPressed: () {
                  Navi.pushOnRoot(context, () => ChannelViewPage(channelID: widget.value.channelID, preloadedData: null, needsReload: null));
                },
                color: Theme.of(context).colorScheme.primary,
                textColor: Theme.of(context).colorScheme.onPrimary,
              ),
          ],
        );
      },
    );
  }

  void _onSubscribe() async {
    final auth = Provider.of<AppAuth>(context, listen: false);
    try {
      var sub = await APIClient.subscribeToChannelbyID(auth, widget.value.channelID, subscribeKey: widget.value.subscribeKey);
      if (sub.confirmed) {
        Toaster.success("Success", "Subscription request sent and auto-confirmed");
      } else {
        Toaster.success("Success", "Subscription request sent - pending confirmation");
      }
      setState(() {
        overrideSubscription = sub;
      });
    } catch (e) {
      Toaster.error("Error", 'Failed to send subscription-request: ${e.toString()}');
    }
  }

  String _formatSubscriptionStatus(Subscription? sub) {
    if (sub == null) {
      return "Not Subscribed";
    } else if (sub.confirmed) {
      if (sub.active) {
        return "Already Subscribed";
      } else {
        return "Already Subscribed (inactive)";
      }
    } else {
      return "Unconfirmed Subscription";
    }
  }
}