import 'package:flutter/material.dart';
import '../models/channel.dart';
import '../models/group_member.dart';
import '../services/api_service.dart';
import '../services/auth_service.dart';

class GroupMembersScreen extends StatefulWidget {
  final Channel channel;
  final String? currentUserId;

  const GroupMembersScreen({
    super.key,
    required this.channel,
    this.currentUserId,
  });

  @override
  State<GroupMembersScreen> createState() => _GroupMembersScreenState();
}

class _GroupMembersScreenState extends State<GroupMembersScreen> {
  late final ApiService _api;
  List<GroupMember> _members = [];
  bool _loading = true;
  bool _isManager = false;

  @override
  void initState() {
    super.initState();
    _api = ApiService(AuthService());
    _load();
  }

  Future<void> _load() async {
    setState(() => _loading = true);
    final list = await _api.getGroupMembers(widget.channel.id);
    if (!mounted) return;
    final isManager = list.any(
      (m) => m.userId == widget.currentUserId && m.isManager,
    );
    setState(() {
      _members = list;
      _isManager = isManager;
      _loading = false;
    });
  }

  Future<void> _showInviteDialog() async {
    String username = '';
    final confirmed = await showDialog<bool>(
      context: context,
      builder: (ctx) => _InviteDialog(
        onUsernameChanged: (v) => username = v,
      ),
    );
    if (confirmed == true && username.trim().isNotEmpty) {
      final err = await _api.inviteMember(widget.channel.id, username.trim());
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(
          content: Text(
            err ?? 'دعوت‌نامه ارسال شد',
            style: const TextStyle(fontSize: 11),
            textAlign: TextAlign.center,
          ),
          backgroundColor: err == null ? const Color(0xFF1C1C1E) : const Color(0xFF333333),
          behavior: SnackBarBehavior.floating,
          duration: const Duration(seconds: 2),
          margin: const EdgeInsets.symmetric(horizontal: 16, vertical: 40),
          shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(20)),
        ),
      );
    }
  }

  Future<void> _removeMember(GroupMember member) async {
    final confirmed = await showDialog<bool>(
      context: context,
      builder: (ctx) => AlertDialog(
        backgroundColor: const Color(0xFF1C1C1E),
        shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(16)),
        contentPadding: const EdgeInsets.all(16),
        content: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            const Icon(Icons.person_remove_outlined, color: Colors.red, size: 28),
            const SizedBox(height: 8),
            Text(
              'حذف ${member.username}؟',
              style: const TextStyle(color: Colors.white, fontSize: 12, fontWeight: FontWeight.bold),
              textAlign: TextAlign.center,
            ),
            const SizedBox(height: 12),
            Row(
              children: [
                Expanded(
                  child: TextButton(
                    onPressed: () => Navigator.pop(ctx, false),
                    child: const Text('انصراف', style: TextStyle(color: Colors.white54, fontSize: 11)),
                  ),
                ),
                Expanded(
                  child: TextButton(
                    onPressed: () => Navigator.pop(ctx, true),
                    child: const Text('حذف', style: TextStyle(color: Colors.red, fontSize: 11)),
                  ),
                ),
              ],
            ),
          ],
        ),
      ),
    );

    if (confirmed == true) {
      final err = await _api.removeMember(widget.channel.id, member.userId);
      if (!mounted) return;
      if (err != null) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(
            content: Text(err, style: const TextStyle(fontSize: 11), textAlign: TextAlign.center),
            backgroundColor: const Color(0xFF333333),
            behavior: SnackBarBehavior.floating,
            duration: const Duration(seconds: 2),
            margin: const EdgeInsets.symmetric(horizontal: 16, vertical: 40),
            shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(20)),
          ),
        );
      } else {
        _load();
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Colors.black,
      body: SafeArea(
        child: Column(
          children: [
            // Header
            Padding(
              padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 6),
              child: Row(
                children: [
                  IconButton(
                    onPressed: () => Navigator.pop(context),
                    padding: EdgeInsets.zero,
                    constraints: const BoxConstraints(minWidth: 28, minHeight: 28),
                    icon: const Icon(Icons.arrow_back_ios_new, color: Colors.white70, size: 14),
                  ),
                  const SizedBox(width: 4),
                  const Icon(Icons.group_outlined, color: Color(0xFF00C853), size: 14),
                  const SizedBox(width: 4),
                  const Expanded(
                    child: Text(
                      'اعضا',
                      style: TextStyle(color: Colors.white, fontSize: 12, fontWeight: FontWeight.bold),
                    ),
                  ),
                  // Invite button
                  IconButton(
                    onPressed: _showInviteDialog,
                    padding: EdgeInsets.zero,
                    constraints: const BoxConstraints(minWidth: 28, minHeight: 28),
                    icon: const Icon(Icons.person_add_outlined, color: Color(0xFF00C853), size: 16),
                  ),
                  IconButton(
                    onPressed: _loading ? null : _load,
                    padding: EdgeInsets.zero,
                    constraints: const BoxConstraints(minWidth: 28, minHeight: 28),
                    icon: const Icon(Icons.refresh, color: Colors.white54, size: 16),
                  ),
                ],
              ),
            ),

            // Group name chip
            Padding(
              padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 2),
              child: Row(
                children: [
                  Container(
                    padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 3),
                    decoration: BoxDecoration(
                      color: const Color(0xFF00C853).withValues(alpha: 0.12),
                      borderRadius: BorderRadius.circular(20),
                    ),
                    child: Row(
                      mainAxisSize: MainAxisSize.min,
                      children: [
                        Icon(
                          widget.channel.type == 'PUBLIC'
                              ? Icons.public
                              : Icons.lock_outline,
                          color: const Color(0xFF00C853),
                          size: 10,
                        ),
                        const SizedBox(width: 4),
                        Text(
                          widget.channel.name,
                          style: const TextStyle(color: Color(0xFF00C853), fontSize: 10),
                        ),
                      ],
                    ),
                  ),
                  if (!_loading) ...[
                    const SizedBox(width: 6),
                    Text(
                      '${_members.length} عضو',
                      style: const TextStyle(color: Colors.white38, fontSize: 10),
                    ),
                  ],
                ],
              ),
            ),
            const SizedBox(height: 4),

            // Content
            Expanded(
              child: _loading
                  ? const Center(
                      child: CircularProgressIndicator(color: Color(0xFF00C853), strokeWidth: 2),
                    )
                  : _members.isEmpty
                      ? const Center(
                          child: Text('عضوی یافت نشد',
                              style: TextStyle(color: Colors.white38, fontSize: 11)),
                        )
                      : ListView.builder(
                          padding: const EdgeInsets.only(bottom: 4),
                          itemCount: _members.length,
                          itemBuilder: (ctx, i) {
                            final m = _members[i];
                            final isMe = m.userId == widget.currentUserId;
                            return _MemberTile(
                              member: m,
                              isMe: isMe,
                              canRemove: _isManager && !isMe && !m.isManager,
                              onRemove: () => _removeMember(m),
                            );
                          },
                        ),
            ),
          ],
        ),
      ),
    );
  }
}

class _MemberTile extends StatelessWidget {
  final GroupMember member;
  final bool isMe;
  final bool canRemove;
  final VoidCallback onRemove;

  const _MemberTile({
    required this.member,
    required this.isMe,
    required this.canRemove,
    required this.onRemove,
  });

  @override
  Widget build(BuildContext context) {
    return Container(
      margin: const EdgeInsets.symmetric(horizontal: 8, vertical: 2),
      height: 40,
      decoration: BoxDecoration(
        color: const Color(0xFF1C1C1E),
        borderRadius: BorderRadius.circular(12),
      ),
      padding: const EdgeInsets.symmetric(horizontal: 10),
      child: Row(
        children: [
          // Online indicator
          Container(
            width: 7,
            height: 7,
            decoration: BoxDecoration(
              shape: BoxShape.circle,
              color: member.isOnline ? const Color(0xFF00C853) : Colors.white24,
            ),
          ),
          const SizedBox(width: 8),
          // Username
          Expanded(
            child: Text(
              member.username + (isMe ? ' (من)' : ''),
              style: TextStyle(
                color: isMe ? const Color(0xFF00C853) : Colors.white,
                fontSize: 11,
                fontWeight: member.isManager ? FontWeight.bold : FontWeight.normal,
              ),
              overflow: TextOverflow.ellipsis,
            ),
          ),
          // Role badge
          if (member.isManager)
            Container(
              padding: const EdgeInsets.symmetric(horizontal: 5, vertical: 2),
              decoration: BoxDecoration(
                color: const Color(0xFF00C853).withValues(alpha: 0.15),
                borderRadius: BorderRadius.circular(8),
              ),
              child: const Text(
                'مدیر',
                style: TextStyle(color: Color(0xFF00C853), fontSize: 9),
              ),
            ),
          // Remove button
          if (canRemove) ...[
            const SizedBox(width: 4),
            GestureDetector(
              onTap: onRemove,
              child: const Icon(Icons.remove_circle_outline, color: Colors.red, size: 16),
            ),
          ],
        ],
      ),
    );
  }
}

// ── Invite Dialog ──────────────────────────────────────────────────────────

class _InviteDialog extends StatefulWidget {
  final ValueChanged<String> onUsernameChanged;

  const _InviteDialog({required this.onUsernameChanged});

  @override
  State<_InviteDialog> createState() => _InviteDialogState();
}

class _InviteDialogState extends State<_InviteDialog> {
  final _ctrl = TextEditingController();

  @override
  void dispose() {
    _ctrl.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return AlertDialog(
      backgroundColor: const Color(0xFF1C1C1E),
      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(16)),
      contentPadding: const EdgeInsets.all(16),
      content: Column(
        mainAxisSize: MainAxisSize.min,
        children: [
          const Icon(Icons.person_add_outlined, color: Color(0xFF00C853), size: 26),
          const SizedBox(height: 8),
          const Text(
            'دعوت عضو',
            style: TextStyle(color: Colors.white, fontSize: 12, fontWeight: FontWeight.bold),
          ),
          const SizedBox(height: 10),
          TextField(
            controller: _ctrl,
            autofocus: true,
            textAlign: TextAlign.center,
            style: const TextStyle(color: Colors.white, fontSize: 12),
            decoration: InputDecoration(
              hintText: 'نام کاربری',
              hintStyle: const TextStyle(color: Colors.white38, fontSize: 11),
              filled: true,
              fillColor: Colors.white.withValues(alpha: 0.05),
              border: OutlineInputBorder(
                borderRadius: BorderRadius.circular(10),
                borderSide: BorderSide.none,
              ),
              contentPadding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
            ),
            onChanged: widget.onUsernameChanged,
          ),
          const SizedBox(height: 12),
          Row(
            children: [
              Expanded(
                child: TextButton(
                  onPressed: () => Navigator.pop(context, false),
                  child: const Text('انصراف', style: TextStyle(color: Colors.white54, fontSize: 11)),
                ),
              ),
              Expanded(
                child: TextButton(
                  onPressed: () => Navigator.pop(context, true),
                  child: const Text('ارسال', style: TextStyle(color: Color(0xFF00C853), fontSize: 11, fontWeight: FontWeight.bold)),
                ),
              ),
            ],
          ),
        ],
      ),
    );
  }
}