"""Shared factory for building runtime :class:`~core.agent.Agent` instances.

Each agent harness surface (action, evidence, gateway) assembles its per-turn
configuration in a surface-specific factory and hands it to :func:`build_agent`,
the single construction site for :class:`~core.agent.Agent` across surfaces.
"""

from __future__ import annotations

from dataclasses import dataclass, field
from typing import Any, Generic, TypeVar

from core.agent import Agent
from core.events import RuntimeEventCallback
from core.execution import ToolExecutionHooks
from core.llm.types import AgentLLMClient, ResolvedIntegrations
from core.types import RuntimeTool

RuntimeToolT = TypeVar("RuntimeToolT", bound=RuntimeTool)


@dataclass(frozen=True)
class AgentConfig(Generic[RuntimeToolT]):  # noqa: UP046
    """Immutable per-turn config the runtime :class:`Agent` needs to construct.

    Surfaces assemble one of these and hand it to :func:`build_agent`.
    """

    llm: AgentLLMClient
    system: str
    tools: tuple[RuntimeToolT, ...]
    resolved_integrations: ResolvedIntegrations
    max_iterations: int
    tool_resources: dict[str, Any] = field(default_factory=dict)
    tool_hooks: ToolExecutionHooks | None = None
    on_runtime_event: RuntimeEventCallback | None = None


def build_agent(  # noqa: UP047
    config: AgentConfig[RuntimeToolT],
) -> Agent[RuntimeToolT]:
    """Construct a runtime :class:`Agent` from an :class:`AgentConfig`.

    This is the single place :class:`Agent` is instantiated across the
    harness — surfaces call it after building their config.
    """
    return Agent[RuntimeToolT](
        llm=config.llm,
        system=config.system,
        tools=config.tools,
        resolved_integrations=config.resolved_integrations,
        max_iterations=config.max_iterations,
        tool_resources=config.tool_resources,
        tool_hooks=config.tool_hooks,
        on_runtime_event=config.on_runtime_event,
    )


__all__ = ["AgentConfig", "build_agent"]