"""Application implementation - ASGI."""

import os

from fastapi import FastAPI, Request
from fastapi.exceptions import RequestValidationError
from fastapi.responses import JSONResponse
from loguru import logger
from fastapi.staticfiles import StaticFiles
from fastapi.middleware.cors import CORSMiddleware

from app.config import config
from app.models.exception import HttpException
from app.router import root_api_router
from app.utils import utils
from app.utils import ffmpeg_utils


def exception_handler(request: Request, e: HttpException):
    return JSONResponse(
        status_code=e.status_code,
        content=utils.get_response(e.status_code, e.data, e.message),
    )


def validation_exception_handler(request: Request, e: RequestValidationError):
    return JSONResponse(
        status_code=400,
        content=utils.get_response(
            status=400, data=e.errors(), message="field required"
        ),
    )


def get_application() -> FastAPI:
    """Initialize FastAPI application.

    Returns:
       FastAPI: Application object instance.

    """
    instance = FastAPI(
        title=config.project_name,
        description=config.project_description,
        version=config.project_version,
        debug=False,
    )
    instance.include_router(root_api_router)
    instance.add_exception_handler(HttpException, exception_handler)
    instance.add_exception_handler(RequestValidationError, validation_exception_handler)
    return instance


app = get_application()

# Configures the CORS middleware for the FastAPI app
cors_allowed_origins_str = os.getenv("CORS_ALLOWED_ORIGINS", "")
origins = cors_allowed_origins_str.split(",") if cors_allowed_origins_str else ["*"]
app.add_middleware(
    CORSMiddleware,
    allow_origins=origins,
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

task_dir = utils.task_dir()
app.mount(
    "/tasks", StaticFiles(directory=task_dir, html=True, follow_symlink=True), name=""
)

public_dir = utils.public_dir()
app.mount("/", StaticFiles(directory=public_dir, html=True), name="")


@app.on_event("shutdown")
def shutdown_event():
    logger.info("shutdown event")


@app.on_event("startup")
def startup_event():
    logger.info("startup event")

    # 检测FFmpeg硬件加速
    hwaccel_info = ffmpeg_utils.detect_hardware_acceleration()
    if hwaccel_info["available"]:
        logger.info(f"FFmpeg硬件加速检测结果: 可用 | 类型: {hwaccel_info['type']} | 编码器: {hwaccel_info['encoder']} | 独立显卡: {hwaccel_info['is_dedicated_gpu']} | 参数: {hwaccel_info['hwaccel_args']}")
    else:
        logger.warning(f"FFmpeg硬件加速不可用: {hwaccel_info['message']}, 将使用CPU软件编码")