from .ssh import SSHClient

class DNSManager:
    def __init__(self, config):
        # DNS is on la-vmh-11 (dnsmasq_lxc_id)
        node = config.get_node('la-vmh-11')
        if not node:
            raise ValueError("Node 'la-vmh-11' not found in config")
        
        self.pve_host = node['host']
        self.pve_user = config.get('proxmox.user', 'root')
        self.lxc_id = config.get('proxmox.dnsmasq_lxc_id')
        self.ssh_key = config.get('proxmox.ssh_key_path')
        self.client = SSHClient(self.pve_host, self.pve_user, self.ssh_key)
        
        self.hosts_file = "/etc/dnsmasq.d/dynamic-hosts.conf"
        self.dns_file = "/etc/dnsmasq.d/dynamic-dns.conf"

    def exec_lxc(self, cmd):
        return self.client.run(f"pct exec {self.lxc_id} -- {cmd}")

    def add_host(self, mac, ip, hostname):
        self.exec_lxc(f"touch {self.hosts_file}")
        # Check for duplicates
        res = self.exec_lxc(f"grep -q -F '{mac}' {self.hosts_file}")
        if res.returncode == 0:
            raise ValueError(f"MAC {mac} already exists")
        
        cmd = f"sh -c \"echo 'dhcp-host={mac},{hostname},{ip}' >> {self.hosts_file}\""
        self.exec_lxc(cmd)
        self.reload()

    def remove_host(self, mac):
        self.exec_lxc(f"sed -i '/{mac}/d' {self.hosts_file}")
        self.reload()

    def add_dns(self, domain, ip):
        self.exec_lxc(f"touch {self.dns_file}")
        cmd = f"sh -c \"echo 'address=/{domain}/{ip}' >> {self.dns_file}\""
        self.exec_lxc(cmd)
        self.reload()

    def remove_dns(self, domain):
        cmd = f"sh -c \"sed -i '\#address=/{domain}/#d' {self.dns_file}\""
        self.exec_lxc(cmd)
        self.reload()

    def reload(self):
        res = self.exec_lxc("dnsmasq --test")
        if res.returncode == 0:
            self.exec_lxc("systemctl reload dnsmasq")
        else:
            raise RuntimeError(f"Dnsmasq config test failed: {res.stderr}")

    def list(self):
        hosts = self.exec_lxc(f"cat {self.hosts_file}").stdout
        dns = self.exec_lxc(f"cat {self.dns_file}").stdout
        return {"hosts": hosts, "dns": dns}

        def get_free_ips(self, start_subnet=70, end_subnet=80):

            """Finds free IPs in the range 10.32.[70-80].1-254 by checking both static and dynamic leases"""

            # 1. Get all static IPs from dhcp-hosts.conf and dynamic-hosts.conf

            static_configs = self.exec_lxc(f"cat /etc/dnsmasq.d/dhcp-hosts.conf {self.hosts_file} 2>/dev/null").stdout

            import re

            used_ips = set(re.findall(r'10\.32\.[0-9]{1,3}\.[0-9]{1,3}', static_configs))

            

            # 2. Get all active dynamic leases

            leases = self.exec_lxc("cat /var/lib/misc/dnsmasq.leases 2>/dev/null").stdout

            used_ips.update(set(re.findall(r'10\.32\.[0-9]{1,3}\.[0-9]{1,3}', leases)))

    

            # 3. Find first available in the expanded agent range

            free_ips = []

            for subnet_idx in range(start_subnet, end_subnet + 1):

                for host_idx in range(1, 255):

                    candidate = f"10.32.{subnet_idx}.{host_idx}"

                    if candidate not in used_ips:

                        free_ips.append(candidate)

                    if len(free_ips) >= 10: # Return top 10

                        return free_ips

            return free_ips