"""
LED driver registry persisted in ``db/device.json``.

Storage key and **id** field are the device **MAC**: 12 lowercase hex characters
(no colons). **name** is for ``select`` / tabs (not unique). **address** is the
reachability hint: same as MAC for ESP-NOW, or IP/hostname for Wi-Fi.
"""

from models.model import Model

DEVICE_TYPES = frozenset({"led"})
DEVICE_TRANSPORTS = frozenset({"wifi", "espnow"})


def validate_device_type(value):
    t = (value or "led").strip().lower()
    if t not in DEVICE_TYPES:
        raise ValueError(f"type must be one of: {', '.join(sorted(DEVICE_TYPES))}")
    return t


def validate_device_transport(value):
    tr = (value or "espnow").strip().lower()
    if tr not in DEVICE_TRANSPORTS:
        raise ValueError(
            f"transport must be one of: {', '.join(sorted(DEVICE_TRANSPORTS))}"
        )
    return tr


def normalize_mac(mac):
    """Normalise to 12-char lowercase hex or None."""
    if mac is None:
        return None
    s = str(mac).strip().lower().replace(":", "").replace("-", "")
    if len(s) == 12 and all(c in "0123456789abcdef" for c in s):
        return s
    return None


def derive_device_mac(mac=None, address=None, transport="espnow"):
    """
    Resolve the device MAC used as storage id.

    Explicit ``mac`` wins. For ESP-NOW, ``address`` is the peer MAC. For Wi-Fi,
    ``mac`` must be supplied (``address`` is typically an IP).
    """
    m = normalize_mac(mac)
    if m:
        return m
    tr = validate_device_transport(transport)
    if tr == "espnow":
        return normalize_mac(address)
    return None


def normalize_address_for_transport(addr, transport):
    """ESP-NOW → 12 hex or None; Wi-Fi → trimmed string or None."""
    tr = validate_device_transport(transport)
    if tr == "espnow":
        return normalize_mac(addr)
    if addr is None:
        return None
    s = str(addr).strip()
    return s if s else None


class Device(Model):
    def __init__(self):
        super().__init__()

    def load(self):
        super().load()
        changed = False
        for sid, doc in list(self.items()):
            if not isinstance(doc, dict):
                continue
            if self._migrate_record(str(sid), doc):
                changed = True
        if self._rekey_legacy_ids():
            changed = True
        if changed:
            self.save()

    def _migrate_record(self, storage_id, doc):
        changed = False
        if doc.get("type") not in DEVICE_TYPES:
            doc["type"] = "led"
            changed = True
        if doc.get("transport") not in DEVICE_TRANSPORTS:
            doc["transport"] = "espnow"
            changed = True
        raw_list = doc.get("addresses")
        if isinstance(raw_list, list) and raw_list:
            picked = None
            for item in raw_list:
                n = normalize_mac(item)
                if n:
                    picked = n
                    break
            if picked:
                doc["address"] = picked
            del doc["addresses"]
            changed = True
        elif "addresses" in doc:
            del doc["addresses"]
            changed = True
        tr = doc["transport"]
        norm = normalize_address_for_transport(doc.get("address"), tr)
        if doc.get("address") != norm:
            doc["address"] = norm
            changed = True
        mac_key = normalize_mac(storage_id)
        if mac_key and mac_key == storage_id and str(doc.get("id") or "") != mac_key:
            doc["id"] = mac_key
            changed = True
        elif str(doc.get("id") or "").strip() != storage_id:
            doc["id"] = storage_id
            changed = True
        doc.pop("mac", None)
        return changed

    def _rekey_legacy_ids(self):
        """Move numeric-keyed rows to MAC keys when ESP-NOW MAC is known."""
        changed = False
        moves = []
        for sid in list(self.keys()):
            doc = self.get(sid)
            if not isinstance(doc, dict):
                continue
            if normalize_mac(sid) == sid:
                continue
            if not str(sid).isdigit():
                continue
            tr = doc.get("transport", "espnow")
            cand = None
            if tr == "espnow":
                cand = normalize_mac(doc.get("address"))
            if not cand:
                continue
            moves.append((sid, cand))
        for old, mac in moves:
            if old not in self:
                continue
            doc = self.pop(old)
            if mac in self:
                existing = dict(self[mac])
                for k, v in doc.items():
                    if k not in existing or existing[k] in (None, "", []):
                        existing[k] = v
                doc = existing
            doc["id"] = mac
            self[mac] = doc
            changed = True
        return changed

    def create(
        self,
        name="",
        address=None,
        mac=None,
        default_pattern=None,
        tabs=None,
        device_type="led",
        transport="espnow",
    ):
        dt = validate_device_type(device_type)
        tr = validate_device_transport(transport)
        mac_hex = derive_device_mac(mac=mac, address=address, transport=tr)
        if not mac_hex:
            raise ValueError(
                "mac is required (12 hex characters); for Wi-Fi pass mac separately from IP address"
            )
        if mac_hex in self:
            raise ValueError("device with this mac already exists")
        addr = normalize_address_for_transport(address, tr)
        if tr == "espnow":
            addr = mac_hex
        self[mac_hex] = {
            "id": mac_hex,
            "name": name,
            "type": dt,
            "transport": tr,
            "address": addr,
            "default_pattern": default_pattern if default_pattern else None,
            "tabs": list(tabs) if tabs else [],
        }
        self.save()
        return mac_hex

    def read(self, id):
        m = normalize_mac(id)
        if m is not None and m in self:
            return self.get(m)
        return self.get(str(id), None)

    def update(self, id, data):
        id_str = normalize_mac(id)
        if id_str is None:
            id_str = str(id)
        if id_str not in self:
            return False
        incoming = dict(data)
        incoming.pop("id", None)
        incoming.pop("addresses", None)
        in_mac = normalize_mac(incoming.get("mac"))
        if in_mac is not None and in_mac != id_str:
            raise ValueError("cannot change device mac; delete and re-add")
        incoming.pop("mac", None)
        merged = dict(self[id_str])
        merged.update(incoming)
        merged["type"] = validate_device_type(merged.get("type"))
        merged["transport"] = validate_device_transport(merged.get("transport"))
        tr = merged["transport"]
        merged["address"] = normalize_address_for_transport(merged.get("address"), tr)
        if tr == "espnow":
            merged["address"] = id_str
        merged["id"] = id_str
        self[id_str] = merged
        self.save()
        return True

    def delete(self, id):
        id_str = normalize_mac(id)
        if id_str is None:
            id_str = str(id)
        if id_str not in self:
            return False
        self.pop(id_str)
        self.save()
        return True

    def list(self):
        return list(self.keys())

    def upsert_wifi_tcp_client(self, device_name, peer_ip, mac, device_type=None):
        """
        Register or update a Wi-Fi client by **MAC** (storage id). Updates **name**,
        **address** (peer IP), and optionally **type** from the client hello when valid.
        """
        mac_hex = normalize_mac(mac)
        if not mac_hex:
            return None
        name = (device_name or "").strip()
        if not name:
            return None
        ip = normalize_address_for_transport(peer_ip, "wifi")
        if not ip:
            return None
        resolved_type = None
        if device_type is not None:
            try:
                resolved_type = validate_device_type(device_type)
            except ValueError:
                resolved_type = None
        if mac_hex in self:
            merged = dict(self[mac_hex])
            merged["name"] = name
            if resolved_type is not None:
                merged["type"] = resolved_type
            else:
                merged["type"] = validate_device_type(merged.get("type"))
            merged["transport"] = "wifi"
            merged["address"] = ip
            merged["id"] = mac_hex
            self[mac_hex] = merged
            self.save()
            return mac_hex
        self[mac_hex] = {
            "id": mac_hex,
            "name": name,
            "type": resolved_type or "led",
            "transport": "wifi",
            "address": ip,
            "default_pattern": None,
            "tabs": [],
        }
        self.save()
        return mac_hex