"""运行时配置 API：GET/PUT /api/v1/settings、GET /api/v1/settings/schema、POST /api/v1/settings/reset

GET 任何登录用户可读；PUT/reset 需 admin。PUT 后会清空 LLM 客户端 / 解析插件 /
去重策略三处进程级缓存，使新配置立即对后续请求生效。
"""

from typing import Any

import structlog
from fastapi import APIRouter, Depends
from pydantic import BaseModel

from app.api.response import ApiError, ok
from app.core.auth import AuthUser, get_current_user, require_admin
from app.core.dedup import invalidate_dedup_strategy_cache
from app.core.file_parser import (
    list_docx_plugins,
    list_ocr_plugins,
    list_pdf_plugins,
    invalidate_parser_plugin_cache,
)
from app.core.runtime_settings import (
    RuntimeSettings,
    get_runtime_settings,
    reset_runtime_settings,
    update_runtime_settings,
)
from app.services.llm import invalidate_llm_client_cache

logger = structlog.get_logger()

router = APIRouter(prefix="/api/v1", tags=["settings"])


class SettingsUpdateRequest(BaseModel):
    """Settings PATCH body：任意子树可缺省，缺省字段保留原值

    例：{"models": {"summarize": {"model": "qwen2.5:3b"}}}、
        {"parsers": {"ocr": {"plugin": "tesseract"}}}、
        {"dedup": {"strategy": "simhash", "simhash_threshold": 5}}
    """

    models: dict[str, Any] | None = None
    parsers: dict[str, Any] | None = None
    dedup: dict[str, Any] | None = None


@router.get("/settings")
async def get_settings(user: AuthUser = Depends(get_current_user)) -> dict[str, Any]:
    """返回当前 RuntimeSettings（任何登录用户可读）"""
    cfg = get_runtime_settings()
    return ok(cfg.model_dump(mode="json"))


@router.put("/settings")
async def update_settings(
    body: SettingsUpdateRequest,
    user: AuthUser = Depends(require_admin),
) -> dict[str, Any]:
    """部分更新 RuntimeSettings（仅 admin）

    更新成功后清空 LLM 客户端 / 解析插件 / 去重策略三处进程级缓存，
    使新配置立即对后续请求生效。
    """
    patch = body.model_dump(exclude_none=True)
    if not patch:
        raise ApiError(1001, "请求体为空，未提供任何待更新字段")

    try:
        cfg = update_runtime_settings(patch)
    except Exception as exc:
        logger.error("RuntimeSettings 更新失败", error=str(exc), exc_info=True)
        raise ApiError(2000, f"配置更新失败: {exc}") from exc

    # 清缓存：让后续读取拿到新配置
    invalidate_llm_client_cache()
    invalidate_parser_plugin_cache()
    invalidate_dedup_strategy_cache()
    logger.info("RuntimeSettings 已更新并清理缓存", operator=user.username)
    return ok(cfg.model_dump(mode="json"))


@router.get("/settings/schema")
async def get_settings_schema(
    user: AuthUser = Depends(get_current_user),
) -> dict[str, Any]:
    """返回可选插件与策略列表（前端 Settings 页渲染选项用）"""
    return ok(
        {
            "llm_providers": ["ollama", "openai_compatible"],
            "pdf_plugins": list_pdf_plugins(),
            "docx_plugins": list_docx_plugins(),
            "ocr_plugins": list_ocr_plugins(),
            "dedup_strategies": ["none", "sha256", "simhash"],
        }
    )


@router.post("/settings/reset")
async def reset_settings(
    user: AuthUser = Depends(require_admin),
) -> dict[str, Any]:
    """重置 RuntimeSettings 为默认值（仅 admin），同时清缓存"""
    try:
        cfg = reset_runtime_settings()
    except Exception as exc:
        logger.error("RuntimeSettings 重置失败", error=str(exc), exc_info=True)
        raise ApiError(2000, f"配置重置失败: {exc}") from exc

    invalidate_llm_client_cache()
    invalidate_parser_plugin_cache()
    invalidate_dedup_strategy_cache()
    logger.info("RuntimeSettings 已重置为默认值", operator=user.username)
    return ok(cfg.model_dump(mode="json"))