"""Scene routing configuration (架构文档 §8.1: 改模型不改代码)."""

from __future__ import annotations

import pytest

from packages.llm.errors import SceneNotRoutedError
from packages.llm.routing import SceneRouter, build_scene_configs
from packages.llm.types import Scene


def test_defaults_put_the_primary_first_and_the_backup_second() -> None:
    configs = build_scene_configs(primary_provider="deepseek", backup_provider="zhipu")
    assert configs[Scene.AGENT_CHAT].providers == ("deepseek", "zhipu")


def test_a_missing_backup_yields_a_single_provider_chain() -> None:
    configs = build_scene_configs(primary_provider="deepseek", backup_provider=None)
    assert configs[Scene.AGENT_CHAT].providers == ("deepseek",)


def test_every_scene_is_routed_and_bound_to_a_prompt_version() -> None:
    configs = build_scene_configs(primary_provider="deepseek")
    assert set(configs) == set(Scene)
    for config in configs.values():
        assert config.prompt_id
        assert config.prompt_version


def test_intent_classification_is_critical_so_budget_pressure_cannot_disable_it() -> None:
    configs = build_scene_configs(primary_provider="deepseek")
    assert configs[Scene.INTENT_CLASSIFY].critical is True
    assert configs[Scene.AGENT_CHAT].critical is False


def test_agent_chat_output_budget_matches_the_token_plan() -> None:
    # 架构文档 §7.2: 输出 ≤ 800
    assert build_scene_configs(primary_provider="x")[Scene.AGENT_CHAT].max_tokens <= 800


def test_overrides_change_routing_without_a_code_change() -> None:
    configs = build_scene_configs(
        primary_provider="deepseek",
        backup_provider="zhipu",
        overrides={
            "agent_chat": {
                "max_tokens": 1200,
                "prompt_version": "v2",
                "models": {"deepseek": "deepseek-v4-pro"},
                "providers": ["zhipu", "deepseek"],
            }
        },
    )
    config = configs[Scene.AGENT_CHAT]
    assert config.max_tokens == 1200
    assert config.prompt_version == "v2"
    assert config.providers == ("zhipu", "deepseek")
    assert config.model_for("deepseek", "fallback") == "deepseek-v4-pro"
    assert config.model_for("zhipu", "fallback") == "fallback"
    # Untouched scenes keep their defaults.
    assert configs[Scene.REPORT_COPY].max_tokens == 3000


def test_structured_retry_budget_is_configurable() -> None:
    configs = build_scene_configs(primary_provider="x", structured_max_retries=5)
    assert configs[Scene.AGENT_CHAT].structured_max_retries == 5


def test_router_raises_for_an_unconfigured_scene() -> None:
    router = SceneRouter({})
    with pytest.raises(SceneNotRoutedError):
        router.resolve(Scene.AGENT_CHAT)


def test_router_lists_configured_scenes() -> None:
    router = SceneRouter(build_scene_configs(primary_provider="x"))
    assert set(router.scenes()) == set(Scene)