bindmanager/app.py

from flask import Flask, render_template, request, redirect, flash, url_for, jsonify, send_file, session
from werkzeug.security import check_password_hash, generate_password_hash
from functools import wraps
import subprocess, os, re, time, json, zipfile, io, datetime, urllib.request

import config
from core import file_manager as fm
from core import dns_manager as dns
from core import adblock_manager as ab
from core import cluster_manager as cm
from core import stats_manager as stats

app = Flask(__name__)
app.secret_key = "bind_pro_v108_modular_masterpiece"

# Εκκίνηση του Background Daemon για τα Analytics
stats.start_stats_daemon()

# --- DECORATORS & AUTH ---
def login_required(f):
    @wraps(f)
    def dec(*args, **kwargs):
        if 'username' not in session: return redirect(url_for('login'))
        return f(*args, **kwargs)
    return dec

def admin_required(f):
    @wraps(f)
    def dec(*args, **kwargs):
        if session.get('role') != 'admin': return redirect(url_for('dashboard'))
        return f(*args, **kwargs)
    return dec

def api_required(f):
    @wraps(f)
    def dec(*args, **kwargs):
        key = request.headers.get('X-API-Key')
        if not key or key != fm.load_panel_settings().get('api_key'): 
            return jsonify({"status": "error", "message": "Unauthorized"}), 401
        return f(*args, **kwargs)
    return dec

def check_zone_access(domain):
    if session.get('role') == 'admin': return True
    return fm.load_panel_settings().get('zone_owners', {}).get(domain) == session.get('username')

# --- AUTH ROUTES ---
@app.route('/login', methods=['GET', 'POST'])
def login():
    if request.method == 'POST':
        u, p = request.form.get('username'), request.form.get('password')
        users = fm.load_users()
        if u in users and check_password_hash(users[u]['password'], p):
            session.update({'username': u, 'role': users[u]['role']})
            return redirect(url_for('dashboard'))
        flash("Invalid Credentials", "error")
    return render_template('login.html')

@app.route('/logout')
def logout():
    session.clear()
    return redirect(url_for('login'))

# --- MAIN DASHBOARD & ZONES ---
@app.route('/')
@login_required
def dashboard():
    conf = fm.read_file(config.LOCAL_CONF)
    zones_raw = re.findall(r'zone\s+"([^"]+)"\s*\{.*?type\s+(master|slave|forward|hint);', conf, re.DOTALL)
    zones_raw = [z for z in zones_raw if z[0] != "rpz.blacklist"]
    
    settings = fm.load_panel_settings()
    owners, users = settings.get('zone_owners', {}), fm.load_users()
    
    if session['role'] == 'admin': 
        zones = zones_raw
    else: 
        zones = [z for z in zones_raw if owners.get(z[0]) == session['username']]
        
    try: status = subprocess.check_output(["systemctl", "is-active", config.BIND_SERVICE]).decode().strip()
    except: status = "inactive"
    
    view_mode = users.get(session['username'], {}).get('view_mode', 'cards')
    return render_template('dashboard.html', zones=zones, status=status, templates=settings['templates'], 
                           owners=owners, all_usernames=list(users.keys()), view_mode=view_mode)

@app.route('/zones/add', methods=['POST'])
@login_required
def add_zone():
    raw_domain = request.form.get('domain', '').strip()
    domain = re.sub(r'[^a-zA-Z0-9\.\-\/]', '', raw_domain).replace('../', '') 
    z_type, direction = request.form.get('type'), request.form.get('direction', 'forward')
    
    if z_type != "hint" and direction == 'reverse' and not domain.endswith('.arpa'):
        domain = re.sub(r'/.*$', '', domain)
        parts = domain.strip('.').split('.')
        if len(parts) == 4 and parts[3] == '0': parts = parts[:3]
        domain = ".".join(reversed(parts)) + ".in-addr.arpa"
        
    if z_type == "hint": domain = "."
    conf = fm.read_file(config.LOCAL_CONF)
    default_zones = fm.read_file(os.path.join(config.BIND_PATH, "named.conf.default-zones"))
    
    if f'zone "{domain}"' in conf or f'zone "{domain}"' in default_zones: 
        flash(f"Zone '{domain}' exists!", "error")
        return redirect(url_for('dashboard'))

    if z_type == "hint":
        hint_path = os.path.join(config.BIND_PATH, "db.root")
        try: 
            urllib.request.urlretrieve("https://www.internic.net/domain/named.root", hint_path)
            subprocess.run(["chown", "bind:bind", hint_path])
        except: 
            fm.write_file(hint_path, ". 3600000 IN NS A.ROOT-SERVERS.NET.\nA.ROOT-SERVERS.NET. 3600000 A 198.41.0.4")
        conf += f'\nzone "." {{\n    type hint;\n    file "{hint_path}";\n}};\n'
        
    elif z_type == "master":
        path = os.path.join(config.BIND_PATH, f"db.{domain}")
        conf += f'\nzone "{domain}" {{\n    type master;\n    file "{path}";\n}};\n'
        t_name = request.form.get('template_name')
        if t_name:
            t = fm.load_panel_settings()['templates'].get(t_name)
            if t: fm.write_file(path, dns.apply_template(t['content'], domain, t))
        else:
            s_ip = fm.load_panel_settings().get('server_public_ip', '') or '127.0.0.1'
            fm.write_file(path, f"$TTL 86400\n@ IN SOA ns1.{domain}. admin.{domain}. (\n {time.strftime('%Y%m%d01')}\n 3600\n 1800\n 604800\n 86400\n)\n@ IN NS ns1.{domain}.\nns1 IN A {s_ip}\n")
            
    elif z_type == "forward":
        ips = "".join([f" {x.strip()};" for x in request.form.getlist('forwarders[]') if x.strip()])
        conf += f'\nzone "{domain}" {{\n    type forward;\n    forwarders {{{ips} }};\n}};\n'
        
    else:
        path = os.path.join(config.CACHE_PATH, f"db.{domain}")
        ips = "".join([f" {x.strip()};" for x in request.form.getlist('master_ips[]') if x.strip()])
        conf += f'\nzone "{domain}" {{\n    type slave;\n    file "{path}";\n    masters {{{ips} }};\n    masterfile-format text;\n}};\n'

    fm.write_file(config.LOCAL_CONF, conf)
    s = fm.load_panel_settings()
    s['zone_owners'][domain] = session['username']
    fm.save_panel_settings(s)
    subprocess.run(["rndc", "reconfig"])
    
    if z_type == "master": cm.broadcast_to_cluster('add_slave', domain)
    flash(f"Zone '{domain}' created!", "success")
    return redirect(url_for('dashboard'))

@app.route('/zones/manage/<path:domain>')
@login_required
def manage_zone(domain):
    clean = "." if domain == "root_zone" else domain.strip('/')
    if not check_zone_access(clean): return redirect(url_for('dashboard'))
    
    conf = fm.read_file(config.LOCAL_CONF)
    block = dns.get_zone_block(conf, clean)
    if not block: return redirect(url_for('dashboard'))
    
    path = dns.get_zone_file_path(clean)
    try:
        cmd = f"tail -n 5000 {config.QUERY_LOG_PATH} | grep -iE '({clean}|transfer|notify|axfr)' | tail -n 30"
        logs = subprocess.check_output(cmd, shell=True, text=True).strip().split('\n')
    except: logs = []
    
    records = dns.parse_zone_file(path, clean)
    has_records = any(len(r)>0 for r in records.values())
    
    m_ips = (re.search(r'masters\s*\{\s*(.*?)\s*\};', block, re.S | re.I) or type('m',(),{'group':lambda x,y:''})()).group(1).replace(';',' ')
    f_ips = (re.search(r'forwarders\s*\{\s*(.*?)\s*\};', block, re.S | re.I) or type('m',(),{'group':lambda x,y:''})()).group(1).replace(';',' ')
    
    z_type = "hint" if "type hint" in block else "slave" if "type slave" in block else "forward" if "type forward" in block else "master"
    
    audit_logs = fm.get_audit_log(clean)
    backups = dns.get_backups(clean)
    dnssec_enabled = "dnssec-policy default" in block
    ds_records = dns.get_ds_records(clean) if dnssec_enabled else []
    
    return render_template('manage_zone.html', domain=clean, type=z_type, records=records, has_records=has_records, 
                           path=path, logs=[l for l in logs if l], master_ips=m_ips, forwarders=f_ips, 
                           audit_logs=audit_logs, backups=backups, dnssec_enabled=dnssec_enabled, ds_records=ds_records)

@app.route('/zones/delete/<path:domain>')
@login_required
def delete_zone(domain):
    clean = "." if domain == "root_zone" else domain.strip('/')
    if not check_zone_access(clean): return redirect(url_for('dashboard'))
    
    conf = fm.read_file(config.LOCAL_CONF)
    path = dns.get_zone_file_path(clean)
    block = dns.get_zone_block(conf, clean)
    
    if block:
        fm.write_file(config.LOCAL_CONF, conf.replace(block, ""))
        s = fm.load_panel_settings()
        s['zone_owners'].pop(clean, None)
        fm.save_panel_settings(s)
        subprocess.run(["rndc", "reconfig"])
        try: os.remove(path)
        except: pass
        if "type master" in block: cm.broadcast_to_cluster('delete_zone', clean)
        
    flash("Zone Deleted", "success")
    return redirect(url_for('dashboard'))

# --- ZONE ACTIONS (RECORDS, IP, DNSSEC) ---
@app.route('/zones/manage/<path:domain>/add_record', methods=['POST'])
@login_required
def add_record(domain):
    clean = "." if domain == "root_zone" else domain
    if not check_zone_access(clean): return redirect(url_for('dashboard'))
    path, rtype = dns.get_zone_file_path(clean), request.form.get('rtype')
    name = dns.sanitize_record_name(request.form.get('name'), clean)
    val = dns.construct_record_value(request.form, rtype)
    
    new_content = dns.increment_serial(fm.read_file(path)) + f"{name}\tIN\t{rtype}\t{val}\n"
    is_valid, err = dns.check_zone_syntax(clean, new_content)
    if not is_valid: 
        flash(f"Linter Error: {err}", "error")
        return redirect(url_for('manage_zone', domain=domain))
        
    dns.backup_zone(clean, fm.read_file(path))
    fm.write_file(path, new_content)
    subprocess.run(["rndc", "reload", clean])
    fm.log_audit(session['username'], clean, f"Added record {rtype} {name}")
    flash("Record added", "success")
    return redirect(url_for('manage_zone', domain=domain))

@app.route('/zones/manage/<path:domain>/delete_record', methods=['POST'])
@login_required
def delete_record(domain):
    clean = "." if domain == "root_zone" else domain
    if not check_zone_access(clean): return redirect(url_for('dashboard'))
    path, raw = dns.get_zone_file_path(clean), request.form.get('raw_line').strip()
    lines = fm.read_file(path).split('\n')
    
    for i, l in enumerate(lines):
        if l.strip() == raw: 
            del lines[i]
            break
            
    new_content = dns.increment_serial('\n'.join(lines))
    is_valid, err = dns.check_zone_syntax(clean, new_content)
    if not is_valid: 
        flash(f"Linter Error: {err}", "error")
        return redirect(url_for('manage_zone', domain=domain))
        
    dns.backup_zone(clean, fm.read_file(path))
    fm.write_file(path, new_content)
    subprocess.run(["rndc", "reload", clean])
    fm.log_audit(session['username'], clean, "Deleted a record")
    flash("Record deleted", "success")
    return redirect(url_for('manage_zone', domain=domain))

@app.route('/zones/manage/<path:domain>/edit_record', methods=['POST'])
@login_required
def edit_record(domain):
    clean = "." if domain == "root_zone" else domain
    if not check_zone_access(clean): return redirect(url_for('dashboard'))
    path, old_raw, rtype = dns.get_zone_file_path(clean), request.form.get('old_raw').strip(), request.form.get('rtype')
    name = dns.sanitize_record_name(request.form.get('name'), clean)
    val = dns.construct_record_value(request.form, rtype)
    
    lines = fm.read_file(path).split('\n')
    for i, l in enumerate(lines):
        if l.strip() == old_raw: 
            lines[i] = f"{name}\tIN\t{rtype}\t{val}"
            break
            
    new_content = dns.increment_serial('\n'.join(lines))
    is_valid, err = dns.check_zone_syntax(clean, new_content)
    if not is_valid: 
        flash(f"Linter Error: {err}", "error")
        return redirect(url_for('manage_zone', domain=domain))
        
    dns.backup_zone(clean, fm.read_file(path))
    fm.write_file(path, new_content)
    subprocess.run(["rndc", "reload", clean])
    fm.log_audit(session['username'], clean, f"Edited record {rtype} {name}")
    flash("Record updated", "success")
    return redirect(url_for('manage_zone', domain=domain))

@app.route('/zones/manage/<path:domain>/rollback/<ts>', methods=['POST'])
@login_required
def rollback_zone(domain, ts):
    clean = "." if domain == "root_zone" else domain
    if not check_zone_access(clean): return redirect(url_for('dashboard'))
    backup_file = os.path.join(config.BACKUP_DIR, f"{clean}_{ts}.db")
    if os.path.exists(backup_file):
        path = dns.get_zone_file_path(clean)
        dns.backup_zone(clean, fm.read_file(path))
        fm.write_file(path, fm.read_file(backup_file))
        subprocess.run(["rndc", "reload", clean])
        fm.log_audit(session['username'], clean, f"Rolled back to {ts}")
        flash("Zone rolled back", "success")
    else: 
        flash("Backup not found", "error")
    return redirect(url_for('manage_zone', domain=domain))

@app.route('/zones/manage/<path:domain>/dnssec', methods=['POST'])
@login_required
def toggle_dnssec(domain):
    clean = "." if domain == "root_zone" else domain
    if not check_zone_access(clean): return redirect(url_for('dashboard'))
    
    conf = fm.read_file(config.LOCAL_CONF)
    block = dns.get_zone_block(conf, clean)
    
    # BUG FIX: Αν δεν βρει τη ζώνη, να μην κρασάρει, αλλά να γυρίσει πίσω
    if not block:
        flash("Zone configuration block not found!", "error")
        return redirect(url_for('manage_zone', domain=domain))
        
    if "dnssec-policy" in block:
        new_block = re.sub(r'\s*dnssec-policy default;\s*inline-signing yes;', '', block)
        fm.log_audit(session['username'], clean, "Disabled DNSSEC")
    else:
        new_block = block.replace('type master;', 'type master;\n    dnssec-policy default;\n    inline-signing yes;')
        subprocess.run(["chown", "-R", "bind:bind", config.BIND_PATH])
        fm.log_audit(session['username'], clean, "Enabled DNSSEC")
        
    fm.write_file(config.LOCAL_CONF, conf.replace(block, new_block))
    subprocess.run(["rndc", "reconfig"])
    subprocess.run(["rndc", "reload", clean])
    return redirect(url_for('manage_zone', domain=domain))

@app.route('/zones/manage/<path:domain>/edit_ips', methods=['POST'])
@login_required
def edit_zone_ips(domain):
    clean = "." if domain == "root_zone" else domain
    if not check_zone_access(clean): return redirect(url_for('dashboard'))
    conf, block = fm.read_file(config.LOCAL_CONF), dns.get_zone_block(fm.read_file(config.LOCAL_CONF), clean)
    ips = "".join([f" {x.strip()};" for x in request.form.getlist('ips[]') if x.strip()]) or " none;"
    if "type slave" in block: new_block = re.sub(r'masters\s*\{.*?\};', f'masters {{{ips} }};', block, flags=re.S|re.I)
    elif "type forward" in block: new_block = re.sub(r'forwarders\s*\{.*?\};', f'forwarders {{{ips} }};', block, flags=re.S|re.I)
    fm.write_file(config.LOCAL_CONF, conf.replace(block, new_block))
    subprocess.run(["rndc", "reconfig"])
    return redirect(url_for('manage_zone', domain=domain))

@app.route('/zones/assign', methods=['POST'])
@admin_required
def assign_zone():
    d, o = request.form.get('domain'), request.form.get('owner')
    s = fm.load_panel_settings()
    s['zone_owners'][d] = o
    fm.save_panel_settings(s)
    flash("Assigned", "success")
    return redirect(url_for('dashboard'))

@app.route('/zones/manage/<path:domain>/cluster_sync', methods=['POST'])
@login_required
def cluster_sync_zone(domain):
    clean = "." if domain == "root_zone" else domain.strip('/')
    if not check_zone_access(clean): return redirect(url_for('dashboard'))
    conf, block = fm.read_file(config.LOCAL_CONF), dns.get_zone_block(fm.read_file(config.LOCAL_CONF), clean)
    if block and "type master" in block:
        cm.broadcast_to_cluster('add_slave', clean)
        time.sleep(1.5)
        subprocess.run(["rndc", "notify", clean])
        flash(f"Cluster Sync triggered for {clean}!", "success")
    else: 
        flash("Only Master zones can be synced.", "error")
    return redirect(url_for('dashboard'))

@app.route('/zones/manage/<path:domain>/sync')
@login_required
def sync_zone(domain):
    clean = "." if domain == "root_zone" else domain
    if not check_zone_access(clean): return redirect(url_for('dashboard'))
    try: 
        subprocess.run(["rndc", "retransfer", clean], check=True)
        flash(f"Sync initiated", "success")
    except: 
        flash("Sync failed", "error")
    return redirect(url_for('manage_zone', domain=domain))

@app.route('/zones/manage/<path:domain>/convert_to_master')
@login_required
def convert_to_master(domain):
    clean = "." if domain == "root_zone" else domain
    if not check_zone_access(clean): return redirect(url_for('dashboard'))
    conf, block = fm.read_file(config.LOCAL_CONF), dns.get_zone_block(fm.read_file(config.LOCAL_CONF), clean)
    if not block or "type slave" not in block: return redirect(url_for('dashboard'))
    
    path_old = dns.get_zone_file_path(clean)
    res = subprocess.run(["named-compilezone", "-f", "raw", "-F", "text", "-o", "-", clean, path_old], capture_output=True, text=True)
    records_text = res.stdout if res.returncode == 0 else fm.read_file(path_old)
    path_new = os.path.join(config.BIND_PATH, f"db.{clean}" if clean != "." else "db.root")
    
    fm.write_file(config.LOCAL_CONF, conf.replace(block, f'zone "{clean}" {{\n    type master;\n    file "{path_new}";\n}};'))
    fm.write_file(path_new, records_text)
    subprocess.run(["rndc", "reconfig"])
    fm.log_audit(session['username'], clean, "Converted to Master")
    return redirect(url_for('manage_zone', domain=domain))

@app.route('/zones/manage/<path:domain>/convert_to_slave', methods=['POST'])
@login_required
def convert_to_slave(domain):
    clean = "." if domain == "root_zone" else domain
    if not check_zone_access(clean): return redirect(url_for('dashboard'))
    conf, block = fm.read_file(config.LOCAL_CONF), dns.get_zone_block(fm.read_file(config.LOCAL_CONF), clean)
    if not block or "type master" not in block: return redirect(url_for('dashboard'))
    
    path_old = dns.get_zone_file_path(clean)
    path_new = os.path.join(config.CACHE_PATH, f"db.{clean}" if clean != "." else "db.root")
    ips = "".join([f" {x.strip()};" for x in request.form.getlist('master_ips[]') if x.strip()])
    
    fm.write_file(config.LOCAL_CONF, conf.replace(block, f'zone "{clean}" {{\n    type slave;\n    file "{path_new}";\n    masters {{{ips} }};\n    masterfile-format text;\n}};'))
    try: os.remove(path_old)
    except: pass
    subprocess.run(["rndc", "reconfig"])
    fm.log_audit(session['username'], clean, "Converted to Slave")
    return redirect(url_for('manage_zone', domain=domain))

# --- ADBLOCK & ANALYTICS VIEWS ---
@app.route('/adanalytics')
@admin_required
def adanalytics_page():
    s = fm.load_panel_settings()
    return render_template('adanalytics.html', log_enabled=(s.get('query_log_enabled') == 'yes'))

@app.route('/adblock')
@admin_required
def adblock_dashboard():
    settings = fm.load_panel_settings()
    adblock_lists = fm.load_adblock_lists()
    custom_rules = fm.load_custom_rules()
    rpz_enabled = 'zone "rpz.blacklist"' in fm.read_file(config.LOCAL_CONF) and 'response-policy' in fm.read_file(config.OPTIONS_FILE)
    return render_template('adblock.html', settings=settings, adblock_lists=adblock_lists, custom_rules=custom_rules, rpz_enabled=rpz_enabled)

@app.route('/analytics')
@admin_required
def analytics(): 
    return render_template('analytics.html')

# --- CLUSTER & SETTINGS VIEWS ---
@app.route('/cluster', methods=['GET', 'POST'])
@admin_required
def cluster_management():
    settings = fm.load_panel_settings()
    if request.method == 'POST':
        action = request.form.get('action')
        if action == 'save_ip':
            settings['server_public_ip'] = request.form.get('server_public_ip', '').strip()
            flash("Master IP Configuration Saved", "success")
        elif action == 'add_node':
            node_url = request.form.get('node_url', '').strip()
            if node_url and not node_url.startswith('http'): node_url = 'http://' + node_url
            node_url = node_url.rstrip('/')
            new_node = {"name": request.form.get('node_name', '').strip(), "url": node_url, "api_key": request.form.get('node_api_key', '').strip()}
            if new_node['name'] and new_node['url'] and new_node['api_key']:
                settings['cluster_nodes'] = [n for n in settings.get('cluster_nodes', []) if n['name'].strip() != new_node['name']]
                settings.setdefault('cluster_nodes', []).append(new_node)
                flash("Cluster Node Added Successfully!", "success")
        elif action == 'delete_node':
            try:
                node_idx = int(request.form.get('node_index'))
                settings['cluster_nodes'].pop(node_idx)
                flash("Cluster Node Removed", "success")
            except: flash("Failed to remove node", "error")
        elif action == 'regenerate_api':
            settings['api_key'] = secrets.token_hex(32)
            flash("API Key Regenerated. Update your nodes!", "success")
        elif action == 'save_master':
            m_url = request.form.get('master_url', '').strip()
            if m_url and not m_url.startswith('http'): m_url = 'http://' + m_url
            m_url = m_url.rstrip('/')
            settings['master_node'] = {"name": request.form.get('master_name', '').strip(), "url": m_url}
            flash("Master Node Linked", "success")
        elif action == 'unlink_master':
            settings['master_node'] = {}
            flash("Master Node Unlinked", "success")
        fm.save_panel_settings(settings)
        return redirect(url_for('cluster_management'))
    return render_template('cluster.html', settings=settings)

@app.route('/settings')
@admin_required
def settings():
    conf = fm.read_file(config.OPTIONS_FILE)
    def parse_opt(regex, default='any'):
        m = re.search(regex, conf, re.DOTALL | re.I)
        return [x.strip() for x in m.group(1).split(';') if x.strip()] if m else [default]
    b_opt = {
        'listen_v4': parse_opt(r'listen-on\s*port\s+53\s*\{\s*(.*?)\s*\};'),
        'allow_query': parse_opt(r'allow-query\s*\{\s*(.*?)\s*\};'),
        'allow_transfer': parse_opt(r'allow-transfer\s*\{\s*(.*?)\s*\};', 'none'),
        'also_notify': parse_opt(r'also-notify\s*\{\s*(.*?)\s*\};', ''),
        'dnssec': (re.search(r'dnssec-validation\s+(.*?);', conf) or type('m',(),{'group':lambda x,y:'auto'})()).group(1)
    }
    return render_template('general_config.html', b_opt=b_opt, p_data=fm.load_panel_settings())

@app.route('/settings/save', methods=['POST'])
@admin_required
def save_settings():
    def join_ips(field): 
        vals = [x.strip() for x in request.form.getlist(field) if x.strip()]
        return "".join([f" {x};" for x in vals]) if vals else ""
        
    lv4 = join_ips('listen_v4[]') or " any;"
    aq = join_ips('allow_query[]') or " any;"
    at = join_ips('allow_transfer[]') or " none;"
    an_raw = join_ips('also_notify[]')
    an_line = f"    also-notify {{{an_raw} }};\n" if an_raw else ""
    dnssec = request.form.get('dnssec', 'auto')
    query_log = request.form.get('query_log_enabled', 'no')
    
    log_block = ""
    if query_log == 'yes':
        subprocess.run(["mkdir", "-p", "/var/log/named"])
        subprocess.run(["touch", "/var/log/named/queries.log"])
        subprocess.run(["chown", "-R", "bind:bind", "/var/log/named"])
        log_block = """
logging {
    channel queries_log {
        file "/var/log/named/queries.log" versions 3 size 5m;
        severity info;
        print-time yes;
        print-category yes;
        print-severity yes;
    };
    category queries { queries_log; };
    category xfer-in { queries_log; };
    category xfer-out { queries_log; };
    category notify { queries_log; };
    category rpz { queries_log; };
};"""
    
    old_opts = fm.read_file(config.OPTIONS_FILE)
    rpz_line = '    response-policy { zone "rpz.blacklist"; };\n' if 'response-policy' in old_opts else ''
    
    opt_content = f"options {{\n    directory \"/var/cache/bind\";\n    listen-on port 53 {{{lv4} }};\n    allow-query {{{aq} }};\n    allow-transfer {{{at} }};\n{an_line}{rpz_line}    dnssec-validation {dnssec};\n    querylog {'yes' if query_log=='yes' else 'no'};\n    auth-nxdomain no;\n}};\n{log_block}"
    fm.write_file(config.OPTIONS_FILE, opt_content.strip())
    
    t_names, t_refresh, t_retry, t_expire, t_ttl, t_content = request.form.getlist('t_name[]'), request.form.getlist('t_refresh[]'), request.form.getlist('t_retry[]'), request.form.getlist('t_expire[]'), request.form.getlist('t_ttl[]'), request.form.getlist('t_content[]')
    new_templates = {}
    for idx, name in enumerate(t_names):
        name = name.strip()
        if not name: continue
        keys, vals = request.form.getlist(f'custom_key_{idx}[]'), request.form.getlist(f'custom_val_{idx}[]')
        custom_vars = {keys[i].strip().upper(): vals[i] for i in range(len(keys)) if keys[i].strip()}
        new_templates[name] = {"refresh": t_refresh[idx], "retry": t_retry[idx], "expire": t_expire[idx], "ttl": t_ttl[idx], "content": t_content[idx], "custom_vars": custom_vars}
        
    s = fm.load_panel_settings()
    s.update({"templates": new_templates, "stats_retention": int(request.form.get('stats_retention', 30)), "query_log_enabled": query_log})
    fm.save_panel_settings(s)
    subprocess.run(["systemctl", "restart", config.BIND_SERVICE])
    flash("Settings Saved", "success")
    return redirect(url_for('settings'))

@app.route('/settings/view_mode', methods=['POST'])
@login_required
def update_view_mode():
    mode = request.json.get('mode', 'cards')
    users = fm.load_users()
    if session['username'] in users: 
        users[session['username']]['view_mode'] = mode
        fm.save_users(users)
    return jsonify({"status": "success"})

# --- USERS VIEWS ---
@app.route('/users')
@admin_required
def manage_users(): 
    return render_template('users.html', users=fm.load_users(), all_templates=list(fm.load_panel_settings()['templates'].keys()))

@app.route('/users/save', methods=['POST'])
@admin_required
def save_user():
    action, old_u, u, p, r = request.form.get('action'), request.form.get('old_username'), request.form.get('username'), request.form.get('password'), request.form.get('role')
    assigned = request.form.getlist('assigned_templates[]')
    users = fm.load_users()
    if action == 'add':
        if u in users: flash("User exists", "error")
        else: users[u] = {"password": generate_password_hash(p), "role": r, "assigned_templates": assigned, "view_mode": "cards"}
    elif action == 'edit' and old_u in users:
        pw = generate_password_hash(p) if p else users[old_u]['password']
        users[old_u] = {"password": pw, "role": r, "assigned_templates": assigned, "view_mode": users[old_u].get('view_mode','cards')}
        if u != old_u: users[u] = users.pop(old_u)
    fm.save_users(users)
    flash("User saved", "success")
    return redirect(url_for('manage_users'))

@app.route('/users/delete/<username>')
@admin_required
def delete_user(username):
    users = fm.load_users()
    if username != 'admin' and username in users:
        del users[username]
        fm.save_users(users)
        flash("User deleted", "success")
    return redirect(url_for('manage_users'))

# --- ADBLOCK API (MASTER) ---
@app.route('/api/adblock/update', methods=['POST'])
@admin_required
def route_update_adblock():
    result = ab.generate_and_apply_rpz()
    if result.get("status") == "success":
        # BUG FIX: Ειδοποιούμε το Cluster ότι κάναμε update!
        cm.broadcast_adblock_to_cluster('enable')
        return jsonify(result)
    else:
        return jsonify(result), 500

@app.route('/api/adblock/disable', methods=['POST'])
@admin_required
def route_disable_adblock():
    result = ab.disable_rpz()
    cm.broadcast_adblock_to_cluster('disable')
    return jsonify(result)

@app.route('/api/adblock/sync_cluster', methods=['POST'])
@admin_required
def route_sync_adblock_cluster():
    rpz_enabled = 'zone "rpz.blacklist"' in fm.read_file(config.LOCAL_CONF)
    action = 'enable' if rpz_enabled else 'disable'
    
    settings = fm.load_panel_settings()
    nodes = settings.get('cluster_nodes', [])
    lists = fm.load_adblock_lists()
    rules = fm.load_custom_rules()
    count = settings.get('adblock_domains_count', 0)
    update_time = settings.get('adblock_last_update', 'Never')
    
    success_count = 0
    for node in nodes:
        try:
            url = f"{node['url'].rstrip('/')}/api/v1/cluster/adblock"
            headers = {"X-API-Key": node['api_key'], "Content-Type": "application/json"}
            payload = {"action": action, "lists": lists, "rules": rules, "count": count, "time": update_time}
            
            proxy_handler = urllib.request.ProxyHandler({})
            opener = urllib.request.build_opener(proxy_handler)
            req = urllib.request.Request(url, data=json.dumps(payload).encode('utf-8'), headers=headers, method='POST')
            with opener.open(req, timeout=10) as response:
                if response.status == 200: success_count += 1
        except Exception as e:
            print(f"Cluster AdBlock Sync FAIL: {node['name']} -> {e}")
            
    return jsonify({"status": "success", "message": f"Sent AdBlock config to {success_count}/{len(nodes)} cluster nodes."})

@app.route('/api/adblock/toggle_list', methods=['POST'])
@admin_required
def toggle_adblock_list():
    list_id = request.json.get('id')
    state = request.json.get('state')
    lists = fm.load_adblock_lists()
    for l in lists:
        if l['id'] == list_id:
            l['enabled'] = state
            break
    fm.save_adblock_lists(lists)
    return jsonify({"status": "success"})

@app.route('/api/adblock/add_custom', methods=['POST'])
@admin_required
def add_custom_adblock():
    name = request.form.get('name', '').strip()
    url = request.form.get('url', '').strip()
    desc = request.form.get('desc', 'Custom User Blocklist').strip()
    if not name or not url: return redirect(url_for('adblock_dashboard'))
    lists = fm.load_adblock_lists()
    new_id = "custom_" + str(int(time.time()))
    lists.append({"id": new_id, "name": name, "desc": desc, "url": url, "enabled": True, "category": "Custom", "is_custom": True, "info": url})
    fm.save_adblock_lists(lists)
    flash("Custom list added", "success")
    return redirect(url_for('adblock_dashboard'))

@app.route('/api/adblock/edit_custom', methods=['POST'])
@admin_required
def edit_custom_adblock():
    list_id = request.form.get('list_id')
    name = request.form.get('name', '').strip()
    url = request.form.get('url', '').strip()
    desc = request.form.get('desc', '').strip()
    lists = fm.load_adblock_lists()
    for l in lists:
        if l['id'] == list_id and l.get('is_custom'):
            l['name'], l['desc'], l['url'], l['info'] = name, desc, url, url
            break
    fm.save_adblock_lists(lists)
    flash("Custom list updated", "success")
    return redirect(url_for('adblock_dashboard'))

@app.route('/api/adblock/delete_list/<list_id>', methods=['GET'])
@admin_required
def delete_adblock_list(list_id):
    lists = [l for l in fm.load_adblock_lists() if l['id'] != list_id or not l['is_custom']]
    fm.save_adblock_lists(lists)
    flash("List deleted", "success")
    return redirect(url_for('adblock_dashboard'))

@app.route('/api/adblock/rules/add', methods=['POST'])
@admin_required
def add_adblock_rule():
    rtype, domain = request.form.get('type'), request.form.get('domain', '').strip().lower()
    domain = re.sub(r'^https?://', '', domain).rstrip('/')
    rules = fm.load_custom_rules()
    if domain not in rules[rtype]: rules[rtype].append(domain)
    fm.save_custom_rules(rules)
    return jsonify({"status": "success"})

@app.route('/api/adblock/rules/edit', methods=['POST'])
@admin_required
def edit_adblock_rule():
    rtype = request.form.get('type')
    old_domain = request.form.get('old_domain', '').strip()
    new_domain = re.sub(r'^https?://', '', request.form.get('new_domain', '').strip().lower()).rstrip('/')
    rules = fm.load_custom_rules()
    if old_domain in rules.get(rtype, []):
        rules[rtype][rules[rtype].index(old_domain)] = new_domain
    fm.save_custom_rules(rules)
    return jsonify({"status": "success"})

@app.route('/api/adblock/rules/delete', methods=['POST'])
@admin_required
def delete_adblock_rule():
    rtype, domain = request.form.get('type'), request.form.get('domain', '').strip()
    rules = fm.load_custom_rules()
    rules[rtype] = [d for d in rules.get(rtype, []) if d != domain]
    fm.save_custom_rules(rules)
    return jsonify({"status": "success"})

# --- STATS API ---
@app.route('/api/adblock/stats_live')
@admin_required
def api_adblock_stats_live():
    with stats.stats_lock:
        try:
            with open(config.STATS_FILE, "r") as f: st = json.load(f)
        except: st = {}
        
    now = datetime.datetime.now().strftime("%Y-%m-%d")
    day_data = st.get(now, {})
    
    total_q = day_data.get("queries", 0)
    total_b = day_data.get("blocked_queries", 0)
    
    top_domains = sorted(day_data.get("blocked_domains", {}).items(), key=lambda x: x[1], reverse=True)[:10]
    top_clients = sorted(day_data.get("blocked_clients", {}).items(), key=lambda x: x[1], reverse=True)[:10]
    percentage = round((total_b / total_q * 100), 2) if total_q > 0 else 0
    
    return jsonify({
        "total_queries": total_q,
        "total_blocked": total_b,
        "percentage": percentage,
        "top_domains": top_domains,
        "top_clients": top_clients,
        "timeline": day_data.get("timeline", {}),
        "block_timeline": day_data.get("block_timeline", {})
    })

@app.route('/api/stats')
@admin_required
def api_stats():
    with stats.stats_lock: return fm.read_file(config.STATS_FILE) or "{}"

@app.route('/api/ip_queries/<ip>')
@admin_required
def get_ip_queries(ip):
    if not re.match(r'^[\d\.\:a-fA-F]+$', ip): return jsonify({"error": "Invalid IP format"})
    try:
        cmd = f"grep -i '{ip}#' {config.QUERY_LOG_PATH} | tail -n 50"
        proc = subprocess.run(cmd, shell=True, capture_output=True, text=True)
        lines = proc.stdout.strip().split('\n')
        queries = []
        for line in reversed(lines):
            if not line: continue
            m = re.search(r'query:\s+([^\s]+)\s+IN\s+([A-Z0-9]+)', line, re.I)
            if m:
                time_str = " ".join(line.split()[:2]) if len(line.split()) > 2 else ""
                queries.append({"time": time_str, "domain": m.group(1), "type": m.group(2)})
        return jsonify({"ip": ip, "queries": queries})
    except Exception as e: return jsonify({"error": str(e)})

# --- UTILS API ---
@app.route('/api/zones/test_dig', methods=['POST'])
@login_required
def test_dig_transfer():
    domain, target_ip = request.json.get('domain'), request.json.get('target_ip', '127.0.0.1')
    if not domain: return jsonify({"error": "No domain provided"}), 400
    
    block = dns.get_zone_block(fm.read_file(config.LOCAL_CONF), domain)
    if block:
        m = re.search(r'masters\s*\{\s*([^;]+);', block)
        if m: target_ip = m.group(1).strip()

    try:
        output = subprocess.run(["dig", f"@{target_ip}", domain, "AXFR"], capture_output=True, text=True, timeout=8).stdout
        if "Transfer failed" in output or "connection refused" in output.lower() or not output.strip():
            return jsonify({"success": False, "raw": output, "message": f"Transfer failed from Master ({target_ip})"})

        analysis, total_count = {}, 0
        for line in output.split('\n'):
            if not line or line.startswith((';', '\n')): continue
            for p in line.split():
                if p in ['A', 'AAAA', 'MX', 'TXT', 'CNAME', 'NS', 'SOA', 'SRV', 'PTR']:
                    analysis[p] = analysis.get(p, 0) + 1
                    total_count += 1
                    break
        return jsonify({"success": True, "total": total_count, "analysis": analysis, "raw": output, "target": target_ip})
    except Exception as e: return jsonify({"success": False, "message": str(e)})

@app.route('/api/service/status')
@admin_required
def get_service_status():
    try:
        res = subprocess.run(["systemctl", "is-active", config.BIND_SERVICE], capture_output=True, text=True)
        is_active = res.stdout.strip() == "active"
        uptime = "Unknown"
        if is_active:
            res_up = subprocess.run(["systemctl", "show", config.BIND_SERVICE, "--property=ActiveEnterTimestamp"], capture_output=True, text=True)
            uptime = res_up.stdout.replace("ActiveEnterTimestamp=", "").strip()
        return jsonify({"status": "active" if is_active else "inactive", "uptime": uptime})
    except: return jsonify({"status": "error", "uptime": "N/A"})

@app.route('/service/<action>')
@admin_required
def service_control(action):
    try:
        if action == 'reload': subprocess.run(["rndc", "reload"], check=True)
        else: subprocess.run(["systemctl", action, config.BIND_SERVICE], check=True)
    except: pass
    return redirect(request.referrer or url_for('dashboard'))

@app.route('/backup/export')
@admin_required
def export_backup():
    memory_file = io.BytesIO()
    zip_f = zipfile.ZipFile(memory_file, 'w', zipfile.ZIP_DEFLATED)
    
    core_files = [
        config.LOCAL_CONF, config.OPTIONS_FILE, config.PANEL_SETTINGS, 
        config.USERS_FILE, config.STATS_FILE, config.ADBLOCK_LISTS_FILE, 
        config.ADBLOCK_CUSTOM_RULES_FILE
    ]
    for f in core_files:
        if os.path.exists(f): 
            zip_f.write(f, os.path.basename(f))
            
    # BUG FIX: Διπλός έλεγχος os.path.exists() για να μην κρασάρει το zip
    for f in os.listdir(config.BIND_PATH):
        if f.startswith("db.") and f != "db.rpz.blacklist": 
            full_path = os.path.join(config.BIND_PATH, f)
            if os.path.exists(full_path):
                zip_f.write(full_path, f)
            
    zip_f.close()
    memory_file.seek(0)
    return send_file(memory_file, download_name=f"bind_backup_{time.strftime('%Y%m%d_%H%M%S')}.zip", as_attachment=True)

@app.route('/backup/import', methods=['POST'])
@admin_required
def import_backup():
    file = request.files.get('backup_file')
    if file and file.filename.endswith('.zip'):
        with zipfile.ZipFile(file, 'r') as zf: zf.extractall(config.BIND_PATH)
        subprocess.run(["systemctl", "restart", config.BIND_SERVICE])
        flash("Restored", "success")
    return redirect(url_for('dashboard'))

# --- CLUSTER SLAVE RECEIVERS (V1 API) ---
@app.route('/api/v1/cluster/adblock', methods=['POST'])
@api_required
def api_cluster_adblock():
    data = request.json
    action = data.get('action')
    master_ip = request.headers.get('X-Forwarded-For', request.remote_addr).split(',')[0].strip()

    if 'lists' in data: fm.save_adblock_lists(data['lists'])
    if 'rules' in data: fm.save_custom_rules(data['rules'])
    s = fm.load_panel_settings()
    if 'count' in data: s['adblock_domains_count'] = data['count']
    if 'time' in data: s['adblock_last_update'] = data['time']
    fm.save_panel_settings(s)

    conf, opts = fm.read_file(config.LOCAL_CONF), fm.read_file(config.OPTIONS_FILE)

    if action == 'enable':
        if 'zone "rpz.blacklist"' not in conf:
            path = os.path.join(config.CACHE_PATH, "db.rpz.blacklist")
            conf += f'\nzone "rpz.blacklist" {{\n    type slave;\n    file "{path}";\n    masters {{ {master_ip}; }};\n    allow-query {{ any; }};\n}};\n'
            fm.write_file(config.LOCAL_CONF, conf)
        if "response-policy" not in opts:
            opts = re.sub(r'(options\s*\{)', r'\1\n    response-policy { zone "rpz.blacklist"; };', opts)
            fm.write_file(config.OPTIONS_FILE, opts)
    else:
        block = dns.get_zone_block(conf, "rpz.blacklist")
        if block: fm.write_file(config.LOCAL_CONF, conf.replace(block, ""))
        opts = re.sub(r'\s*response-policy\s*\{\s*zone\s*"rpz\.blacklist";\s*\};\s*', '\n', opts)
        fm.write_file(config.OPTIONS_FILE, opts)

    subprocess.run(["systemctl", "restart", config.BIND_SERVICE])
    return jsonify({"status": "success", "message": "RPZ synced on slave."})

# Στο app.py του SLAVE
@app.route('/api/v1/cluster/zone', methods=['POST'])
@api_required
def api_add_slave():
    # force=True για να διαβάσει το JSON ακόμα κι αν το content-type λείπει
    data = request.get_json(force=True, silent=True) or {}
    domain = data.get('domain')
    if not domain:
        return jsonify({"status": "error", "message": "No domain provided"}), 400

    # Καθαρισμός domain
    domain = re.sub(r'[^a-zA-Z0-9\.\-\/]', '', domain).replace('../', '')
    
    # Λήψη των Masters (είτε από το payload είτε από την IP του Master)
    masters_list = data.get('masters', [])
    if not masters_list:
        master_ip = request.headers.get('X-Forwarded-For', request.remote_addr).split(',')[0].strip()
        masters_list = [master_ip]
    
    masters_string = "".join([f" {ip};" for ip in masters_list])
    
    conf = fm.read_file(config.LOCAL_CONF)
    # Αν υπάρχει ήδη, δεν την ξαναφτιάχνουμε
    if f'zone "{domain}"' in conf:
        return jsonify({"status": "success", "message": "Already exists"}), 200
        
    path = os.path.join(config.CACHE_PATH, f"db.{domain}")
    new_zone = f'\nzone "{domain}" {{\n    type slave;\n    file "{path}";\n    masters {{{masters_string} }};\n    masterfile-format text;\n}};\n'
    
    fm.write_file(config.LOCAL_CONF, conf + new_zone)
    subprocess.run(["rndc", "reconfig"])
    return jsonify({"status": "success", "message": f"Zone {domain} added"})

@app.route('/api/v1/cluster/zone/<domain>', methods=['DELETE'])
@api_required
def api_delete_zone(domain):
    clean = re.sub(r'[^a-zA-Z0-9\.\-\/]', '', domain).replace('../', '')
    conf = fm.read_file(config.LOCAL_CONF)
    block = dns.get_zone_block(conf, clean)
    if not block: return jsonify({"status": "error", "message": "Zone not found"}), 404
        
    path = dns.get_zone_file_path(clean)
    fm.write_file(config.LOCAL_CONF, conf.replace(block, ""))
    subprocess.run(["rndc", "reconfig"])
    try: os.remove(path)
    except: pass
    
    fm.log_audit("API_SYNC", clean, "Auto-deleted via Cluster Sync")
    return jsonify({"status": "success", "message": f"Zone {clean} deleted."})

@app.route('/api/v1/cluster/ping', methods=['GET'])
@api_required
def api_ping():
    # ΑΦΑΙΡΕΘΗΚΕ ΤΟ AUTO-LINKING! Το Ping πλέον απλά επιβεβαιώνει ότι το API Key είναι σωστό.
    return jsonify({"status": "success", "message": "Node is synchronized"})

@app.route('/cluster/check_node', methods=['POST'])
@login_required
def check_cluster_node():
    node_name = request.json.get('node_name')
    node = next((n for n in fm.load_panel_settings().get('cluster_nodes', []) if n['name'] == node_name), None)
    if not node: return jsonify({"status": "error"})
    
    try:
        url = f"{node['url'].rstrip('/')}/api/v1/cluster/ping"
        proxy_handler = urllib.request.ProxyHandler({})
        opener = urllib.request.build_opener(proxy_handler)
        req = urllib.request.Request(url, headers={"X-API-Key": node['api_key']})
        with opener.open(req, timeout=10) as response:
            if response.status == 200: return jsonify({"status": "online"})
            
    except urllib.error.HTTPError as e:
        print(f"\n[CLUSTER HTTP ERROR] Node: {node_name} -> Κωδικός: {e.code}\n")
        if e.code == 401: return jsonify({"status": "auth_error"})
    except Exception as e:
        print(f"\n[CLUSTER NETWORK ERROR] Node: {node_name} -> Αιτία: {str(e)}\n")
        
    return jsonify({"status": "offline"})
# --- REMOTE SERVICE CONTROL (SLAVE RECEIVER) ---
@app.route('/api/v1/cluster/service', methods=['POST'])
@api_required
def api_cluster_service():
    # Fix: Ασφαλής ανάγνωση του JSON, χωρίς να σκάει
    data = request.get_json(force=True, silent=True) or {}
    action = data.get('action')
    
    if action in ['start', 'stop', 'restart', 'reload']:
        try:
            # Fix: Πιάνουμε το πραγματικό error του systemctl αν αποτύχει
            res = subprocess.run(["systemctl", action, config.BIND_SERVICE], capture_output=True, text=True)
            if res.returncode == 0:
                return jsonify({"status": "success", "message": f"Service {action}ed successfully"})
            else:
                return jsonify({"status": "error", "message": f"Systemctl failed: {res.stderr.strip()}"})
        except Exception as e:
            return jsonify({"status": "error", "message": str(e)})
            
    elif action == 'status':
        try:
            res = subprocess.run(["systemctl", "is-active", config.BIND_SERVICE], capture_output=True, text=True)
            is_active = res.stdout.strip() == "active"
            return jsonify({"status": "success", "service_status": "active" if is_active else "inactive"})
        except:
            return jsonify({"status": "error", "service_status": "unknown"})
            
    return jsonify({"status": "error", "message": "Invalid action provided"})

# --- REMOTE SERVICE PROXY (MASTER TO SLAVE) ---
@app.route('/cluster/node_service', methods=['POST'])
@login_required
def cluster_node_service():
    import urllib.request, urllib.error
    try:
        data = request.get_json(force=True, silent=True) or {}
        node = next((n for n in fm.load_panel_settings().get('cluster_nodes', []) if n['name'] == data.get('node_name')), None)
        if not node: return jsonify({"status": "error", "message": "Node not found."})
        
        url = f"{node['url'].rstrip('/')}/api/v1/cluster/service"
        req = urllib.request.Request(url, data=json.dumps({"action": data.get('action')}).encode('utf-8'), headers={"X-API-Key": node['api_key'], "Content-Type": "application/json"}, method='POST')
        
        proxy_handler = urllib.request.ProxyHandler({})
        https_handler = urllib.request.HTTPSHandler(context=config.ssl_ctx)
        opener = urllib.request.build_opener(proxy_handler, https_handler)
        
        with opener.open(req, timeout=15) as response:
            return jsonify(json.loads(response.read().decode('utf-8')))
            
    except urllib.error.HTTPError as e:
        return jsonify({"status": "error", "message": f"Slave HTTP Error {e.code}."})
    except Exception as e:
        return jsonify({"status": "error", "message": f"Connection failed: {str(e)}"})

# --- GLOBAL CLUSTER SYNC (MASTER ACTION) ---
@app.route('/api/cluster/sync_all', methods=['POST'])
@admin_required
def sync_all_cluster():
    conf = fm.read_file(config.LOCAL_CONF)
    import re
    zones = re.findall(r'zone\s+"([^"]+)"', conf)
    
    ignore = ["rpz.blacklist", ".", "localhost", "127.in-addr.arpa", "0.in-addr.arpa", "255.in-addr.arpa"]
    valid_zones = [z for z in zones if z not in ignore]
    
    if not valid_zones:
        return jsonify({"status": "error", "message": "No zones found to sync."})

    def bulk_sync():
        import urllib.request, json, ssl, time
        settings = fm.load_panel_settings()
        nodes = settings.get('cluster_nodes', [])
        
        ctx = ssl.create_default_context()
        ctx.check_hostname = False
        ctx.verify_mode = ssl.CERT_NONE

        for node in nodes:
            for z in valid_zones:
                masters = dns.get_zone_masters_list(z)
                if not masters:
                    master_ip = settings.get('server_public_ip', '').strip()
                    if master_ip: masters = [master_ip]
                
                try:
                    url = f"{node['url'].rstrip('/')}/api/v1/cluster/zone"
                    headers = {"X-API-Key": node['api_key'], "Content-Type": "application/json"}
                    payload = {"domain": z, "masters": masters}
                    
                    req = urllib.request.Request(url, data=json.dumps(payload).encode('utf-8'), headers=headers, method='POST')
                    urllib.request.urlopen(req, timeout=5, context=ctx)
                    print(f"Cluster Sync OK: {node['name']} -> {z}")
                except Exception as e:
                    print(f"Cluster Sync FAIL: {node['name']} -> {z} ({e})")
                
                # ΠΟΛΥ ΣΗΜΑΝΤΙΚΟ: Περιμένουμε μισό δευτερόλεπτο για να προλάβει ο Slave να γράψει το αρχείο!
                time.sleep(0.5)

    import threading
    threading.Thread(target=bulk_sync, daemon=True).start()
    return jsonify({"status": "success", "message": f"Sync started! Sending {len(valid_zones)} zones in the background. Please wait ~10 seconds."})
    
if __name__ == '__main__':
    # Είναι σημαντικό το threaded=True για να μην κάνει "block" το UI στο self-ping
    app.run(host='0.0.0.0', port=5000, debug=False, threaded=True)