"""
Video Flow API - FastAPI Backend
前后端分离架构的后端服务
端口：8000（与 Streamlit 8503 共存；8502 为历史 runtime/素材目录标识）
"""
import os
import sys
import logging
from pathlib import Path
from contextlib import asynccontextmanager

from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware
from fastapi.staticfiles import StaticFiles

# 确保项目根目录在 path 中
PROJECT_ROOT = Path(__file__).parent.parent
sys.path.insert(0, str(PROJECT_ROOT))

import config
from api.routes import projects, editor, assets, compose

# 配置日志
logging.basicConfig(
    level=logging.INFO,
    format='%(asctime)s - %(name)s - %(levelname)s - %(message)s'
)
logger = logging.getLogger(__name__)


@asynccontextmanager
async def lifespan(app: FastAPI):
    """应用生命周期管理"""
    logger.info("Video Flow API 启动中...")
    logger.info(f"项目根目录: {PROJECT_ROOT}")
    logger.info(f"输出目录: {config.OUTPUT_DIR}")
    logger.info(f"临时目录: {config.TEMP_DIR}")
    yield
    logger.info("Video Flow API 关闭中...")


# 创建 FastAPI 应用
app = FastAPI(
    title="Video Flow API",
    description="视频工作流后端 API - 支持项目管理、素材处理、视频编辑与合成",
    version="1.0.0",
    lifespan=lifespan,
    docs_url="/api/docs",
    redoc_url="/api/redoc",
    openapi_url="/api/openapi.json"
)

# CORS 配置 - 允许 React 前端访问
app.add_middleware(
    CORSMiddleware,
    allow_origins=[
        "http://localhost:3000",      # React dev server
        "http://localhost:5173",      # Vite dev server
        "http://127.0.0.1:3000",
        "http://127.0.0.1:5173",
    ],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# 挂载静态文件目录（用于访问生成的视频/图片）
app.mount("/static/output", StaticFiles(directory=str(config.OUTPUT_DIR)), name="output")
app.mount("/static/temp", StaticFiles(directory=str(config.TEMP_DIR)), name="temp")
app.mount("/static/assets", StaticFiles(directory=str(config.ASSETS_DIR)), name="assets")

# Legacy mounts（8502 runtime 产物，宿主机目录通过 docker-compose 挂载到容器内）
try:
    app.mount("/static/legacy-temp", StaticFiles(directory="/legacy/temp"), name="legacy-temp")
    app.mount("/static/legacy-output", StaticFiles(directory="/legacy/output"), name="legacy-output")
except Exception:
    # 本地非 docker 环境可能不存在这些目录
    pass

# 注册路由
app.include_router(projects.router, prefix="/api/projects", tags=["Projects"])
app.include_router(editor.router, prefix="/api/editor", tags=["Editor"])
app.include_router(assets.router, prefix="/api/assets", tags=["Assets"])
app.include_router(compose.router, prefix="/api/compose", tags=["Compose"])


@app.get("/api/health")
async def health_check():
    """健康检查"""
    return {
        "status": "ok",
        "service": "video-flow-api",
        "version": "1.0.0"
    }


@app.get("/api/config")
async def get_config():
    """获取前端所需的配置信息"""
    return {
        "video_settings": config.VIDEO_SETTINGS,
        "available_voices": [
            {"id": config.VOLC_TTS_DEFAULT_VOICE, "name": "三通永 (默认)"},
            {"id": "zh_female_meilinvyou_saturn_bigtts", "name": "美丽女友"},
        ],
        "available_bgm": _list_bgm_files(),
    }


def _list_bgm_files():
    """列出可用的 BGM 文件"""
    bgm_dir = config.ASSETS_DIR / "bgm"
    if not bgm_dir.exists():
        return []
    
    bgm_files = []
    for f in bgm_dir.iterdir():
        if f.suffix.lower() in ['.mp3', '.mp4', '.m4a', '.wav']:
            bgm_files.append({
                "id": f.name,
                "name": f.stem,
                "path": f"/static/assets/bgm/{f.name}"
            })
    return bgm_files


if __name__ == "__main__":
    import uvicorn
    uvicorn.run(
        "api.main:app",
        host="0.0.0.0",
        port=8000,
        reload=True,
        log_level="info"
    )