"""Data models for Sidecar V2 — backend-centric, Canonical Name routing."""

from dataclasses import dataclass, field, asdict
from typing import Optional
import json


@dataclass
class ModelMapping:
    """A single model mapping within a backend: Canonical Name → native_id + properties."""

    native_id: str
    reasoning: bool = False
    reasoning_effort: bool = False
    input_modalities: list[str] = field(default_factory=lambda: ["text"])
    cost: dict = field(default_factory=lambda: {
        "input": 0.0, "output": 0.0, "cacheRead": 0.0, "cacheWrite": 0.0
    })
    context_window: int = 128000
    max_tokens: int = 65536
    compat: dict = field(default_factory=dict)

    def to_dict(self) -> dict:
        return asdict(self)

    @classmethod
    def from_dict(cls, d: dict) -> "ModelMapping":
        defaults = {
            "native_id": "",
            "reasoning": False,
            "reasoning_effort": False,
            "input_modalities": ["text"],
            "cost": {"input": 0.0, "output": 0.0, "cacheRead": 0.0, "cacheWrite": 0.0},
            "context_window": 128000,
            "max_tokens": 65536,
            "compat": {},
        }
        defaults.update(d)
        return cls(**{k: v for k, v in defaults.items() if k in cls.__dataclass_fields__})


@dataclass
class Backend:
    """A physical API backend (API Key + URL).

    Represents a single API key endpoint. Multiple backends can serve the same
    Canonical Models through their model_mappings.
    """

    id: str = ""
    name: str = ""
    label: str = ""  # e.g., "nvidia", "siliconflow" — WebUI tag only
    api_base_url: str = ""
    api_key_encrypted: str = ""
    api: str = "openai-completions"
    timeout_seconds: int = 120
    rpm_limit: int = 40
    pool: str = "primary"  # primary | fallback
    enabled: bool = True
    status: str = "healthy"  # healthy | cooling | error | disabled
    model_mappings: dict[str, ModelMapping] = field(default_factory=dict)
    source: str = "webui"  # webui | env | import
    cooldown_until: Optional[str] = None
    consecutive_429_count: int = 0
    metadata: dict = field(default_factory=dict)
    created_at: str = ""
    updated_at: str = ""

    # Runtime fields (not persisted)
    api_key_plain: str = ""  # decrypted at load time, not serialized to DB

    def has_model(self, canonical_name: str) -> bool:
        """Check if backend supports a given Canonical Model."""
        return canonical_name in self.model_mappings

    def get_native_id(self, canonical_name: str) -> str:
        """Get this backend's native model ID for a Canonical Name."""
        mm = self.model_mappings.get(canonical_name)
        return mm.native_id if mm else canonical_name

    def get_model_cost(self, canonical_name: str) -> dict:
        """Get cost info for a Canonical Model on this backend."""
        mm = self.model_mappings.get(canonical_name)
        return mm.cost if mm else {"input": 0.0, "output": 0.0, "cacheRead": 0.0, "cacheWrite": 0.0}

    def to_dict(self, mask_key: bool = True) -> dict:
        """Convert to dict for API responses."""
        d = asdict(self)
        # Remove runtime-only fields
        d.pop("api_key_plain", None)
        d.pop("api_key_encrypted", None)

        # Mask API key
        if mask_key and self.api_key_plain:
            d["api_key"] = _mask_key(self.api_key_plain)
        elif self.api_key_plain:
            d["api_key"] = self.api_key_plain
        else:
            d["api_key"] = ""

        # Convert model_mappings to dict for serialization
        d["model_mappings"] = {
            k: v.to_dict() for k, v in self.model_mappings.items()
        }
        return d


def _mask_key(key: str) -> str:
    if len(key) <= 10:
        return key[:2] + "****"
    return key[:6] + "****" + key[-4:]


@dataclass
class CooldownEvent:
    id: str = ""
    backend_id: str = ""
    consecutive_count: int = 1
    cooldown_seconds: int = 60
    response_summary: str = ""
    started_at: str = ""
    ended_at: Optional[str] = None


@dataclass
class BackendHealth:
    backend_id: str = ""
    state: str = "healthy"  # healthy | degraded | down
    last_latency_ms: int = 0
    last_status_code: int = 200
    success_rate_5m: float = 1.0
    consecutive_failures: int = 0
    last_check_at: str = ""


@dataclass
class UsageLog:
    id: str = ""
    backend_id: str = ""
    model: str = "unknown"
    prompt_tokens: int = 0
    completion_tokens: int = 0
    total_tokens: int = 0
    cost: float = 0.0
    request_count: int = 0
    error_count: int = 0
    avg_latency_ms: int = 0
    ttft_ms: int = 0
    hour_bucket: str = ""


@dataclass
class DailyStats:
    id: str = ""
    date: str = ""
    pool: str = "primary"
    total_requests: int = 0
    total_errors: int = 0
    total_tokens: int = 0
    total_cost: float = 0.0
    unique_backends: int = 0