meijiaka-zy/python-api/app/api/v1/script.py

"""
脚本生成 API
============

提供脚本生成、润色、模型健康检查等功能。
"""

from __future__ import annotations

import asyncio
import logging

from fastapi import APIRouter

from app.ai.model_router import get_model_router
from app.ai.prompts import list_categories, load_prompt, render_template
from app.schemas.common import ApiResponse, success_response
from app.schemas.script import (
    CategoryItem,
    GenerateTitleRequest,
    GenerateTitleResponse,
    ModelHealthResponse,
    PolishRequest,
    TestModelRequest,
    TestModelResponse,
)
from app.services.script_service import get_script_service

router = APIRouter()
logger = logging.getLogger(__name__)


@router.get("/categories", response_model=ApiResponse[list[CategoryItem]])
async def get_categories():
    """
    获取提示词分类列表

    返回所有大类和小类结构，供前端选择。
    """
    categories = list_categories()
    return success_response(
        data=categories,
        message="获取分类列表成功",
    )


@router.post("/polish", response_model=ApiResponse[str])
async def polish_content(request: PolishRequest):
    """
    AI 润色文案/画面描述

    - `polishType=scene`: 润色画面描述（根据 shot_type 自动区分分镜/空镜）
    - `polishType=voiceover`: 润色配音文案

    参数:
    - `shot_type`: "segment"（分镜）或 "empty_shot"（空镜），画面润色时必填
    """
    service = get_script_service()
    type_name = "画面" if request.polish_type == "scene" else "文案"

    try:
        polished = await service.polish_content(
            content=request.content,
            polish_type=request.polish_type,
            shot_type=request.shot_type or "segment",
        )

        return success_response(
            data=polished,
            message=f"{type_name}润色完成",
        )
    except ValueError as e:
        logger.warning(f"[Polish] 润色失败: {e}")
        return success_response(
            code=500,
            message="润色失败，请检查输入内容后重试",
            data=None,
        )
    except Exception as e:
        logger.error(f"[Polish] 润色异常: {e}")
        return success_response(
            code=500,
            message=f"{type_name}润色失败，请稍后重试",
            data=None,
        )


@router.get("/model-health", response_model=ApiResponse[ModelHealthResponse])
async def check_model_health():
    """
    检查 AI 模型健康状态

    返回所有配置的模型及其可用性状态。
    """
    service = get_script_service()
    health_data = await service.check_model_health()

    return success_response(
        data=ModelHealthResponse(**health_data),
        message="模型健康检查完成",
    )


@router.post("/test-model", response_model=ApiResponse[TestModelResponse])
async def test_model(request: TestModelRequest):
    """
    测试指定模型连接

    发送一个简单的测试请求，验证模型是否可用。
    """
    service = get_script_service()
    result = await service.test_model(request.model_id)

    return success_response(
        data=TestModelResponse(**result),
        message="模型测试完成" if result["success"] else f"模型测试失败: {result.get('error')}",
    )


@router.post("/generate-title", response_model=ApiResponse[GenerateTitleResponse])
async def generate_title(request: GenerateTitleRequest):
    """
    根据脚本内容智能生成标题

    调用 LLM 根据脚本内容生成大标题或小标题。
    提示词从文件加载，支持热更新。
    """
    model_router = await get_model_router()

    # 加载提示词
    system_prompt = load_prompt("user/title_system")
    user_template = load_prompt("user/title")

    if not system_prompt or not user_template:
        return success_response(
            code=500,
            message="标题生成提示词文件缺失",
            data=None,
        )

    # 根据使用场景确定描述
    if request.usage == "cover":
        usage_desc = "视频封面标题——用于封面图设计，是决定用户是否点击的第一要素"
        style_requirement = "极具冲击力、抓眼球，适合静态封面大图展示，善用爆款句式"
        usage_note = "- 封面主标题必须极度吸睛，让用户一眼就想点进去，善用数字、疑问、痛点、冲突\n- 封面副标题要补充悬念或细节，激发点击欲望"
    else:
        usage_desc = "视频画面标题——直接叠加在视频画面上，与动态视频内容共存"
        style_requirement = "口语化、精炼有力，适合视频内展示，避免遮挡画面主体"
        usage_note = "- 视频画面上的标题需要精炼，聚焦核心关键词\n- 副标题与主标题形成呼应，补充说明但不喧宾夺主"

    # 渲染用户提示词
    title_type_desc = "大标题（主标题，提炼核心卖点，吸睛）" if request.title_type == "main" else "小标题（副标题，补充说明或制造悬念）"
    user_prompt = render_template(
        user_template,
        title_type=request.title_type,
        title_type_desc=title_type_desc,
        script_content=request.script_content,
        max_length=request.max_length,
        usage=request.usage,
        usage_desc=usage_desc,
        style_requirement=style_requirement,
        usage_note=usage_note,
    )

    try:
        async with asyncio.timeout(15):
            result = await model_router.generate(
                prompt=user_prompt,
                system_prompt=system_prompt,
                task_type="script",
                temperature=0.8,
                max_tokens=64,
            )

        title = result.content.strip() if result.content else ""
        # 去除可能的引号
        title = title.strip('"').strip("'").strip('「」').strip('『』').strip('《》')
        # 截断到最大长度
        if len(title) > request.max_length:
            title = title[:request.max_length]

        return success_response(
            data=GenerateTitleResponse(title=title),
            message="标题生成成功",
        )
    except TimeoutError:
        logger.warning("[generate_title] 标题生成超时")
        return success_response(
            code=500,
            message="标题生成超时，请重试",
            data=None,
        )
    except Exception as e:
        logger.error(f"[generate_title] 标题生成失败: {e}")
        return success_response(
            code=500,
            message=f"标题生成失败: {str(e)}",
            data=None,
        )