import pulumi
import pulumi_libvirt as libvirt
import yaml

# function to convert GB to bytes for disk size stated in stack config
def gb_to_bytes(gb: int) -> int:
   """Converts gigabytes to bytes for resource capacity."""
   return int(gb) * 1024 * 1024 * 1024


config = pulumi.Config("kvm")

ssh_user = config.get("ssh_user") or "root"
base_image_path = config.require("base_image_path")
nodes = config.require_object("nodes") 
secret_hash = config.require_secret("password_hash")

# Load user data once outside the loop
try:
    with open(config.require("user_data_path"), "r") as f:
       user_data = pulumi.Output.format(f.read(), password_hash=secret_hash)
except Exception as e:
     # Handle case where file path is wrong or secret fails to resolve
     print(f"Warning: Could not process user_data. Skipping node deployment. Error: {e}")

# Dictionary to cache providers per target host
providers = {} 

for node in nodes:
   name = node["name"]
   target_host = node["host"]
   bridge_interface = node["bridge"]
   disk_gb = node["disk_gb"]
   memory_mb = node["memory_mb"]
   vcpu = node["vcpu"]

   # Get or cache providers in providers dictionary
   if target_host not in providers:
       providers[target_host] = libvirt.Provider(
           f"prov-{target_host}",
           uri=f"qemu+sshcmd://{ssh_user}@{target_host}/system"
       )
   host_provider = providers[target_host]

   meta_data_yaml = yaml.dump({"instance-id": f"i-{name}", "local-hostname": name})

   # Initialize network payload in V1 format
   network_config_payload = {
       "version": 1,
       "config": [] # Start with an empty list of configurations (The list container)
   }


   # physical interface
   physical_interface = {
       "type": "physical",
       "name": "eth0",
       "subnets": [
           {
               "type": "static",
               "address": node["static_ip"],
               "gateway": node["gateway"],
           }
       ]
   }
   network_config_payload["config"].append(physical_interface)


   # Append the nameservers to network_config_payload (solves missing nameserver issues)
   if "dns_servers" in node:
        nameserver_block = {
            "type": "nameserver",
            "address": [str(ip) for ip in node["dns_servers"]] # Create clean python list of strings
        }
        network_config_payload["config"].append(nameserver_block)


   if "dns_search" in node and node["dns_search"]:
       network_config_payload["config"][0]["subnets"][0]["dns_search"] = [str(s) for s in node["dns_search"]] # Create clean python list of strings

   # complete network config yaml 
   network_config_yaml = yaml.dump(network_config_payload)


   # cloud image backing store
   base_volume = libvirt.Volume(
       f"base-vol-{name}",
       name=f"{name}-base",
       pool=pool_target,
       capacity=gb_to_bytes(10),
       target={
           "format": {"type": "qcow2"}
       },
       create={
           "content": {
               "url": base_image_path
           }
       },
       opts=pulumi.ResourceOptions(provider=host_provider)
   )

   guest_volume = libvirt.Volume(
       f"{name}",
       name=f"{name}",
       pool=pool_target,
       capacity=gb_to_bytes(disk_gb),
       target={
           "format": {"type": "qcow2"}
       },
       backing_store={
           "path": base_volume.id,
           "format": {
               "type": "qcow2"
           }
       },
       opts=pulumi.ResourceOptions(provider=host_provider)
   )

   cloud_init_disk = libvirt.CloudinitDisk(
       f"ci-disk-{name}",
       meta_data=meta_data_yaml,
       user_data=user_data,
       network_config=network_config_yaml,  # Passes the fully constructed network payload
       opts=pulumi.ResourceOptions(provider=host_provider)
   )

   cloud_init_volume = libvirt.Volume(
       f"ci-vol-{name}",
       pool=pool_target,
       target={
           "format": {"type": "raw"}
       },
       create={
           "content": {
               "url": cloud_init_disk.path
           }
       },
       opts=pulumi.ResourceOptions(provider=host_provider)
   )

   guest = libvirt.Domain(
       f"dom-{name}",
       name=name,
       type="kvm",
       autostart=True,
       cpu={
           "mode": "host-passthrough"
       },
       memory=memory_mb,
       memory_unit="MiB",
       vcpu=vcpu,
       os={
           "type": "hvm",
           "type_arch": "x86_64",
           "type_machine": "q35",
           "firmware": "efi",
           "boot_devices": []
       },
       features={
           "acpi": True
       },
       devices={
           "disks": [
               {
                   "source": {
                       "volume": {
                           "pool": guest_volume.pool,
                           "volume": guest_volume.name
                       }
                   },
                   "target": {
                       "dev": "vda",
                       "bus": "virtio"
                   },
                   "driver": {
                       "type": "qcow2"
                   },
                   "boot": {
                       "order": 1
                   }
               },
               {
                   "device": "cdrom",
                   "source": {
                       "volume": {
                           "pool": cloud_init_volume.pool,
                           "volume": cloud_init_volume.name
                       }
                   },
                   "target": {
                       "dev": "sda",
                       "bus": "sata"
                   },
                   "driver": {
                       "type": "raw"
                   }
               }
           ],
           "interfaces": [
               {
                   "type": "bridge",
                   "model": {
                       "type": "virtio"
                   },
                   "source": {
                       "bridge": {
                           "bridge": bridge_interface
                       }
                   },
                   "wait_for_ip": {
                       "timeout": 300,
                       "source": "lease"
                   }
               }
           ],
           "graphics": [
               {
                   "type": "vnc",
                   "vnc": {
                       "autoport": True,
                       "listen": "127.0.0.1"
                   }
               }
           ]
       },
       opts=pulumi.ResourceOptions(provider=host_provider)
)

pulumi.export("deployed_node", guest.name)