import os
import re
import time
import datetime
import subprocess
import secrets
import config
from core.file_manager import read_file, write_file

def backup_zone(domain, content):
    ts = int(time.time())
    write_file(os.path.join(config.BACKUP_DIR, f"{domain}_{ts}.db"), content)
    return ts

def get_backups(domain):
    if not os.path.exists(config.BACKUP_DIR): return []
    files = [f for f in os.listdir(config.BACKUP_DIR) if f.startswith(f"{domain}_") and f.endswith(".db")]
    backups = []
    for f in sorted(files, reverse=True):
        ts = f.replace(f"{domain}_", "").replace(".db", "")
        dt = datetime.datetime.fromtimestamp(int(ts)).strftime("%Y-%m-%d %H:%M:%S")
        backups.append({"file": f, "time": dt, "ts": ts})
    return backups

def check_zone_syntax(domain, content):
    # FIX 3: Μοναδικό temp file για να μην υπάρξει ποτέ σύγκρουση (Race Condition)
    tmp_path = os.path.join("/tmp", f"bind_check_{domain}_{secrets.token_hex(4)}.db")
    write_file(tmp_path, content)
    res = subprocess.run(["named-checkzone", domain, tmp_path], capture_output=True, text=True)
    try: os.remove(tmp_path)
    except: pass
    
    if res.returncode == 0: return True, ""
    else: return False, res.stdout.replace(tmp_path, 'zone_file').strip()

def get_ds_records(domain):
    try:
        res = subprocess.run(["rndc", "dnssec", "-status", domain], capture_output=True, text=True)
        if res.returncode == 0: return [line for line in res.stdout.split('\n') if line]
    except: pass
    return []

def apply_template(content, domain, t_data):
    replacements = {
        "{DOMAIN}": domain, "{SERIAL}": time.strftime('%Y%m%d01'),
        "{TTL}": str(t_data.get('ttl', '86400')), "{REFRESH}": str(t_data.get('refresh', '3600')),
        "{RETRY}": str(t_data.get('retry', '1800')), "{EXPIRE}": str(t_data.get('expire', '604800'))
    }
    for k, v in t_data.get('custom_vars', {}).items(): replacements[f"{{{k.upper()}}}"] = str(v)
    loops = 0
    while loops < 10:
        old_content = content
        for k, v in replacements.items(): content = content.replace(k, v)
        if old_content == content: break
        loops += 1
    return content

def sanitize_record_name(name, domain):
    name = name.strip()
    if name.endswith('.'): return name
    if domain.endswith('.in-addr.arpa'):
        base_ip = ".".join(reversed(domain.replace('.in-addr.arpa', '').split('.')))
        if name.startswith(base_ip + "."):
            remainder = name[len(base_ip)+1:] 
            rem_reversed = ".".join(reversed(remainder.split('.'))) 
            return f"{rem_reversed}.{domain}."
        elif re.match(r'^\d+(?:\.\d+)*$', name):
            rem_reversed = ".".join(reversed(name.split('.')))
            return f"{rem_reversed}.{domain}."
    if name != '@' and not name.endswith('.'): return f"{name}.{domain}."
    return name

def get_zone_block(conf, domain):
    parts = conf.split('zone "')
    for p in parts[1:]:
        if p.startswith(domain + '"'):
            block = 'zone "' + p
            open_braces = 0
            in_block = False
            for i, char in enumerate(block):
                if char == '{': 
                    open_braces += 1
                    in_block = True
                elif char == '}': 
                    open_braces -= 1
                    if in_block and open_braces == 0:
                        if i + 1 < len(block) and block[i+1] == ';': return block[:i+2]
                        return block[:i+1]
            return block
    return None

def get_zone_file_path(domain):
    conf = read_file(config.LOCAL_CONF)
    block = get_zone_block(conf, domain)
    if block:
        m = re.search(r'file\s+"([^"]+)";', block)
        if m:
            p = m.group(1)
            return p if p.startswith('/') else os.path.join(config.CACHE_PATH if "type slave" in block else config.BIND_PATH, p)
    if domain == ".": return os.path.join(config.BIND_PATH, "db.root")
    return os.path.join(config.BIND_PATH, f"db.{domain}")

def parse_zone_file(path, domain=None):
    records = {"A":[], "AAAA":[], "CNAME":[], "MX":[], "TXT":[], "NS":[], "SRV":[], "PTR":[]}
    content = read_file(path)
    if domain and domain != "." and ('\0' in content or 'SOA' not in content.upper()):
        try:
            res = subprocess.run(["named-compilezone", "-q", "-f", "raw", "-F", "text", "-o", "-", domain, path], capture_output=True, text=True)
            if res.returncode == 0: content = res.stdout
        except: pass
    if not content: return records
    
    is_reverse = domain and domain.endswith('.in-addr.arpa')
    for line in content.split('\n'):
        clean = line.split(';')[0].strip()
        if not clean or (domain != "." and 'SOA' in clean) or clean.startswith('$'): continue
        tokens = clean.split()
        ridx = -1
        for i, t in enumerate(tokens):
            if t.upper() in records: ridx = i; break
            
        if ridx != -1:
            rtype = tokens[ridx].upper()
            name = re.sub(r'\.{2,}', '.', tokens[0])
            if name.upper() in ['IN', '@'] or name.isdigit(): name = "@"
            
            # FIX 2: Αλεξίσφαιρη ανάγνωση της τιμής χωρίς να σπάει αν το name περιέχει "TXT" ή "A"
            match = re.search(rf'\s+(?:IN\s+)?{rtype}\s+(.*)', clean, re.IGNORECASE)
            val = match.group(1).strip() if match else " ".join(tokens[ridx+1:])
            
            friendly_name = name
            if is_reverse and name != '@':
                clean_name = name.lower().replace('.in-addr.arpa.', '')
                parts = clean_name.split('.')
                if all(p.isdigit() for p in parts): friendly_name = ".".join(reversed(parts))
                    
            records[rtype].append({"name": name, "friendly_name": friendly_name, "value": val, "raw": line})
    return records

def increment_serial(content):
    # FIX 1 (CRITICAL): Έξυπνος SOA Serial Parser
    # Αντί να ψάχνει σχόλια, βρίσκει το "SOA", ανοίγει την παρένθεση "(" και αρπάζει τον 1ο αριθμό που θα βρει!
    match = re.search(r'(SOA\s+.*?\(\s*)(\d+)', content, re.IGNORECASE | re.DOTALL)
    
    if match:
        prefix = match.group(1)
        old_serial = match.group(2)
        
        today_prefix = time.strftime('%Y%m%d')
        # Αν το serial είναι ήδη σημερινό (π.χ. 2026042001), του προσθέτουμε +1
        if old_serial.startswith(today_prefix):
            new_serial = str(int(old_serial) + 1)
        else:
            # Αλλιώς ξεκινάμε με σημερινή ημερομηνία + 01
            new_serial = today_prefix + "01"
            
        return content[:match.start()] + prefix + new_serial + content[match.end():]
        
    return content

def construct_record_value(req_form, rtype):
    v = req_form.get('value', '').strip()
    if not v: return ""
    if rtype == 'TXT':
        v = v.strip('"') 
        return f'"{v}"'
    if rtype in ['PTR', 'CNAME', 'NS'] and not v.endswith('.'): v = f"{v}."
    elif rtype in ['MX', 'SRV']:
        parts = v.split()
        if len(parts) >= 2 and not parts[-1].endswith('.'):
            parts[-1] = f"{parts[-1]}."
            v = " ".join(parts)
    return v
    
def get_zone_masters_list(domain):
    conf = read_file(config.LOCAL_CONF)
    block = get_zone_block(conf, domain)
    if not block: return []
    if "type slave" in block or "type forward" in block:
        import re
        m = re.search(r'(?:masters|forwarders)\s*\{\s*(.*?)\s*\};', block, re.S | re.I)
        if m:
            ips_raw = m.group(1).replace('\n', ' ')
            return [ip.strip() for ip in ips_raw.split(';') if ip.strip()]
    return []