from __future__ import annotations

from datetime import datetime, timezone
from typing import Optional

from sqlmodel import Field, SQLModel


def _now() -> datetime:
    return datetime.now(timezone.utc)


class Template(SQLModel, table=True):
    """User-saved custom template (bundled ones live on disk)."""

    id: Optional[int] = Field(default=None, primary_key=True)
    slug: str = Field(index=True, unique=True)
    name: str
    description: Optional[str] = None
    tags: str = ""  # comma separated
    yaml: str = ""
    created_at: datetime = Field(default_factory=_now)


# --- API schemas ---


class TemplateVariable(SQLModel):
    name: str
    description: str = ""
    default: str = ""


class TemplateSummary(SQLModel):
    id: str
    name: str
    description: Optional[str] = None
    tags: list[str] = []
    gpu: Optional[str] = None
    source: str = "bundled"  # "bundled" | "custom"


class TemplateDetail(TemplateSummary):
    yaml: str
    variables: list[TemplateVariable] = []


class TemplateSaveRequest(SQLModel):
    name: str
    description: Optional[str] = None
    tags: list[str] = []
    yaml: str


class TemplateInstantiateRequest(SQLModel):
    name: str  # new stack name
    values: dict[str, str] = {}
    agent_id: int | None = None  # None = local host; otherwise deploy to a remote agent