import 'package:flutter/foundation.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:supabase_flutter/supabase_flutter.dart';

import '../models/pass_slip.dart';
import 'profile_provider.dart';
import 'supabase_provider.dart';
import 'stream_recovery.dart';
import 'realtime_controller.dart';

/// All visible pass slips (own for staff, all for admin/dispatcher).
final passSlipsProvider = StreamProvider<List<PassSlip>>((ref) {
  final client = ref.watch(supabaseClientProvider);
  final profileAsync = ref.watch(currentProfileProvider);
  final profile = profileAsync.valueOrNull;
  if (profile == null) return Stream.value(const <PassSlip>[]);

  final isAdmin = profile.role == 'admin' || profile.role == 'dispatcher';
  final hasFullAccess = isAdmin || profile.role == 'programmer';

  final wrapper = StreamRecoveryWrapper<PassSlip>(
    stream: hasFullAccess
        ? client
              .from('pass_slips')
              .stream(primaryKey: ['id'])
              .order('requested_at', ascending: false)
        : client
              .from('pass_slips')
              .stream(primaryKey: ['id'])
              .eq('user_id', profile.id)
              .order('requested_at', ascending: false),
    onPollData: () async {
      final query = client.from('pass_slips').select();
      final data = hasFullAccess
          ? await query.order('requested_at', ascending: false)
          : await query
                .eq('user_id', profile.id)
                .order('requested_at', ascending: false);
      return data.map(PassSlip.fromMap).toList();
    },
    fromMap: PassSlip.fromMap,
    channelName: 'pass_slips',
    onStatusChanged: ref.read(realtimeControllerProvider).handleChannelStatus,
  );

  ref.onDispose(wrapper.dispose);
  return wrapper.stream.map((result) => result.data);
});

/// Currently active pass slip for the logged-in user (approved, not completed).
final activePassSlipProvider = Provider<PassSlip?>((ref) {
  final slips = ref.watch(passSlipsProvider).valueOrNull ?? [];
  final userId = ref.watch(currentUserIdProvider);
  if (userId == null) return null;
  try {
    return slips.firstWhere((s) => s.userId == userId && s.isActive);
  } catch (_) {
    return null;
  }
});

/// Active pass slips for all users (for dashboard IT Staff Pulse).
final activePassSlipsProvider = Provider<List<PassSlip>>((ref) {
  final slips = ref.watch(passSlipsProvider).valueOrNull ?? [];
  return slips.where((s) => s.isActive).toList();
});

final passSlipControllerProvider = Provider<PassSlipController>((ref) {
  final client = ref.watch(supabaseClientProvider);
  return PassSlipController(client);
});

class PassSlipController {
  PassSlipController(this._client);

  final SupabaseClient _client;

  Future<void> requestSlip({
    required String dutyScheduleId,
    required String reason,
    DateTime? requestedStart,
  }) async {
    final userId = _client.auth.currentUser?.id;
    if (userId == null) throw Exception('Not authenticated');
    final payload = {
      'user_id': userId,
      'duty_schedule_id': dutyScheduleId,
      'reason': reason,
      'status': 'pending',
      'requested_at': DateTime.now().toUtc().toIso8601String(),
      if (requestedStart != null)
        'requested_start': requestedStart.toUtc().toIso8601String(),
    };

    final insertedRaw = await _client
        .from('pass_slips')
        .insert(payload)
        .select()
        .maybeSingle();
    final Map<String, dynamic>? inserted = insertedRaw is Map<String, dynamic>
        ? insertedRaw
        : null;

    // Notify admins for approval
    try {
      final adminIds = await _fetchRoleUserIds(
        roles: const ['admin'],
        excludeUserId: userId,
      );
      if (adminIds.isEmpty) return;

      // Resolve actor display name for nice push text
      String actorName = 'Someone';
      try {
        final p = await _client
            .from('profiles')
            .select('full_name,display_name,name')
            .eq('id', userId)
            .maybeSingle();
        if (p != null) {
          if (p['full_name'] != null) {
            actorName = p['full_name'].toString();
          } else if (p['display_name'] != null) {
            actorName = p['display_name'].toString();
          } else if (p['name'] != null) {
            actorName = p['name'].toString();
          }
        }
      } catch (_) {}

      final slipId = (inserted ?? <String, dynamic>{})['id']?.toString() ?? '';
      final title = 'Pass Slip Filed for Approval';
      final body = '$actorName filed a pass slip that requires approval.';
      final notificationId = (inserted ?? <String, dynamic>{})['id']
          ?.toString();

      final dataPayload = <String, dynamic>{
        'type': 'pass_slip_filed',
        'pass_slip_id': slipId,
        ...?(notificationId != null
            ? {'notification_id': notificationId}
            : null),
      };

      await _client
          .from('notifications')
          .insert(
            adminIds
                .map(
                  (adminId) => {
                    'user_id': adminId,
                    'actor_id': userId,
                    'type': 'pass_slip_filed',
                    'pass_slip_id': slipId,
                  },
                )
                .toList(),
          );

      final res = await _client.functions.invoke(
        'send_fcm',
        body: {
          'user_ids': adminIds,
          'title': title,
          'body': body,
          'data': dataPayload,
        },
      );
      debugPrint('pass slip send_fcm result: $res');
    } catch (e) {
      debugPrint('pass slip send_fcm error: $e');
      // Non-fatal: keep slip request working even if send_fcm fails
    }
  }

  Future<void> approveSlip(String slipId) async {
    final userId = _client.auth.currentUser?.id;
    if (userId == null) throw Exception('Not authenticated');

    // Determine slip start time based on requested_start
    final nowUtc = DateTime.now().toUtc();
    String slipStartIso = nowUtc.toIso8601String();

    final row = await _client
        .from('pass_slips')
        .select('requested_start')
        .eq('id', slipId)
        .maybeSingle();
    if (row != null && row['requested_start'] != null) {
      final requestedStart = DateTime.parse(row['requested_start'] as String);
      if (requestedStart.isAfter(nowUtc)) {
        slipStartIso = requestedStart.toIso8601String();
      }
    }

    await _client
        .from('pass_slips')
        .update({
          'status': 'approved',
          'approved_by': userId,
          'approved_at': nowUtc.toIso8601String(),
          'slip_start': slipStartIso,
        })
        .eq('id', slipId);

    await _notifyRequester(slipId: slipId, actorId: userId, approved: true);
  }

  Future<void> rejectSlip(String slipId) async {
    final userId = _client.auth.currentUser?.id;
    if (userId == null) throw Exception('Not authenticated');

    await _client
        .from('pass_slips')
        .update({
          'status': 'rejected',
          'approved_by': userId,
          'approved_at': DateTime.now().toUtc().toIso8601String(),
        })
        .eq('id', slipId);

    await _notifyRequester(slipId: slipId, actorId: userId, approved: false);
  }

  Future<void> _notifyRequester({
    required String slipId,
    required String actorId,
    required bool approved,
  }) async {
    try {
      final row = await _client
          .from('pass_slips')
          .select('user_id')
          .eq('id', slipId)
          .maybeSingle();
      // ignore: unnecessary_cast
      final rowMap = row as Map<String, dynamic>?;
      final userId = rowMap?['user_id']?.toString();
      if (userId == null || userId.isEmpty) return;

      String actorName = 'Someone';
      try {
        final p = await _client
            .from('profiles')
            .select('full_name,display_name,name')
            .eq('id', actorId)
            .maybeSingle();
        if (p != null) {
          if (p['full_name'] != null) {
            actorName = p['full_name'].toString();
          } else if (p['display_name'] != null) {
            actorName = p['display_name'].toString();
          } else if (p['name'] != null) {
            actorName = p['name'].toString();
          }
        }
      } catch (_) {}

      final title = approved ? 'Pass Slip Approved' : 'Pass Slip Rejected';
      final body = approved
          ? '$actorName approved your pass slip.'
          : '$actorName rejected your pass slip.';

      final dataPayload = <String, dynamic>{
        'type': approved ? 'pass_slip_approved' : 'pass_slip_rejected',
        'pass_slip_id': slipId,
      };

      await _client.from('notifications').insert({
        'user_id': userId,
        'actor_id': actorId,
        'type': approved ? 'pass_slip_approved' : 'pass_slip_rejected',
        'pass_slip_id': slipId,
      });

      await _client.functions.invoke(
        'send_fcm',
        body: {
          'user_ids': [userId],
          'title': title,
          'body': body,
          'data': dataPayload,
        },
      );
    } catch (_) {
      // non-fatal
    }
  }

  Future<void> completeSlip(String slipId) async {
    await _client
        .from('pass_slips')
        .update({
          'status': 'completed',
          'slip_end': DateTime.now().toUtc().toIso8601String(),
        })
        .eq('id', slipId);
  }

  Future<List<String>> _fetchRoleUserIds({
    required List<String> roles,
    required String? excludeUserId,
  }) async {
    try {
      final data = await _client
          .from('profiles')
          .select('id, role')
          .inFilter('role', roles);
      final rows = data as List<dynamic>;
      final ids = rows
          .map((row) => row['id'] as String?)
          .whereType<String>()
          .where((id) => id.isNotEmpty && id != excludeUserId)
          .toList();
      return ids;
    } catch (_) {
      return [];
    }
  }
}