from typing import Dict, Any, List, Optional
from datetime import datetime

# Lightweight fallback if pydantic is not installed in the test environment.
try:
    from pydantic import BaseModel, Field
except Exception:
    class Field:
        def __init__(self, default=None, default_factory=None):
            self.default = default
            self.default_factory = default_factory

    class BaseModel:
        def __init__(self, **data):
            # populate annotated fields with provided values or defaults
            for name, _typ in getattr(self, "__annotations__", {}).items():
                if name in data:
                    setattr(self, name, data[name])
                    continue

                val = getattr(self.__class__, name, None)
                if isinstance(val, Field):
                    if val.default_factory is not None:
                        setattr(self, name, val.default_factory())
                    else:
                        setattr(self, name, val.default)
                else:
                    setattr(self, name, val)

        def dict(self):
            return {k: getattr(self, k) for k in getattr(self, "__annotations__", {})}


class LocalPlan(BaseModel):
    id: str
    service: str
    pipeline: Dict[str, Any]
    canary: Optional[Dict[str, Any]] = None
    metadata: Dict[str, Any] = Field(default_factory=dict)


class SharedSignals(BaseModel):
    timestamp: datetime = Field(default_factory=datetime.utcnow)
    service: str
    metrics: Dict[str, float] = Field(default_factory=dict)
    # exposure controls: per-signal metadata (allowlist, retention seconds)
    exposure: Dict[str, Dict[str, Any]] = Field(default_factory=dict)


class PlanDelta(BaseModel):
    id: str
    plan_id: str
    delta: Dict[str, Any]
    author_id: str
    timestamp: datetime = Field(default_factory=datetime.utcnow)
    signature: Optional[str] = None  # placeholder for signed deltas


class AuditEntry(BaseModel):
    id: str
    event: str
    actor: str
    detail: Dict[str, Any] = Field(default_factory=dict)
    timestamp: datetime = Field(default_factory=datetime.utcnow)


class AuditLog(BaseModel):
    entries: List[AuditEntry] = Field(default_factory=list)