"""通用文件上传路由 - 腾讯云COS"""
import uuid
import os
from datetime import datetime
from fastapi import APIRouter, UploadFile, File, Depends, HTTPException
from sqlalchemy.orm import Session
from routers.auth import get_current_user
from models.user import User
from models.system_config import SystemConfig
from database import get_db
from config import MAX_UPLOAD_SIZE, MAX_ATTACHMENT_SIZE, UPLOAD_DIR
from models.attachment import Attachment

router = APIRouter()

ALLOWED_IMAGE_TYPES = ["image/jpeg", "image/png", "image/gif", "image/webp"]

ALLOWED_ATTACHMENT_TYPES = [
    "application/pdf",
    "application/msword",
    "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
    "application/vnd.ms-excel",
    "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
    "application/vnd.ms-powerpoint",
    "application/vnd.openxmlformats-officedocument.presentationml.presentation",
    "application/zip",
    "application/x-zip-compressed",
    "application/x-rar-compressed",
    "application/vnd.rar",
]
ALLOWED_ATTACHMENT_EXTS = {
    "pdf", "doc", "docx", "xls", "xlsx", "ppt", "pptx", "zip", "rar",
}


def _get_cos_config(db: Session) -> dict:
    """从数据库读取COS配置"""
    keys = ["cos_secret_id", "cos_secret_key", "cos_bucket", "cos_region", "cos_custom_domain"]
    config = {}
    for k in keys:
        row = db.query(SystemConfig).filter(SystemConfig.key == k).first()
        config[k] = row.value if row else ""
    return config


def _get_cos_client(db: Session):
    """获取COS客户端实例，未配置则返回None"""
    config = _get_cos_config(db)
    secret_id = config.get("cos_secret_id", "")
    secret_key = config.get("cos_secret_key", "")
    bucket = config.get("cos_bucket", "")
    region = config.get("cos_region", "")
    if not all([secret_id, secret_key, bucket, region]):
        return None, config
    try:
        from qcloud_cos import CosConfig, CosS3Client
        cos_config = CosConfig(Region=region, SecretId=secret_id, SecretKey=secret_key)
        client = CosS3Client(cos_config)
        return client, config
    except ImportError:
        return None, config


def _build_cos_url(config: dict, object_key: str) -> str:
    """构建COS访问URL"""
    custom_domain = config.get("cos_custom_domain", "")
    if custom_domain:
        return f"https://{custom_domain}/{object_key}"
    bucket = config.get("cos_bucket", "")
    region = config.get("cos_region", "")
    return f"https://{bucket}.cos.{region}.myqcloud.com/{object_key}"


@router.post("/image")
async def upload_image(
    file: UploadFile = File(...),
    current_user: User = Depends(get_current_user),
    db: Session = Depends(get_db),
):
    """上传图片，优先OSS，未配置则本地存储"""
    # 验证文件类型
    if file.content_type not in ALLOWED_IMAGE_TYPES:
        raise HTTPException(status_code=400, detail="不支持的文件类型，仅支持 JPG/PNG/GIF/WEBP")

    # 读取文件内容
    content = await file.read()

    # 验证文件大小
    if len(content) > MAX_UPLOAD_SIZE:
        raise HTTPException(status_code=400, detail=f"文件过大，最大支持 {MAX_UPLOAD_SIZE // (1024*1024)}MB")

    # 生成唯一文件名
    ext = file.filename.split(".")[-1].lower() if "." in file.filename else "png"
    date_prefix = datetime.now().strftime("%Y/%m")
    filename = f"{uuid.uuid4().hex}.{ext}"
    object_key = f"images/{date_prefix}/{filename}"

    # 尝试COS上传（从数据库读取配置）
    client, config = _get_cos_client(db)
    if client:
        try:
            client.put_object(
                Bucket=config.get("cos_bucket", ""),
                Body=content,
                Key=object_key,
                ContentType=file.content_type,
            )
            url = _build_cos_url(config, object_key)
            return {"url": url, "storage": "cos"}
        except Exception as e:
            raise HTTPException(status_code=500, detail=f"COS上传失败: {str(e)}")
    else:
        # 降级到本地存储
        os.makedirs(UPLOAD_DIR, exist_ok=True)
        filepath = os.path.join(UPLOAD_DIR, filename)
        with open(filepath, "wb") as f:
            f.write(content)
        return {"url": f"/uploads/{filename}", "storage": "local"}


@router.post("/attachment")
async def upload_attachment(
    file: UploadFile = File(...),
    post_id: int = 0,
    current_user: User = Depends(get_current_user),
    db: Session = Depends(get_db),
):
    """上传附件到COS，支持 PDF/Word/Excel/PPT/ZIP/RAR"""
    # 验证文件扩展名
    ext = file.filename.split(".")[-1].lower() if "." in file.filename else ""
    if ext not in ALLOWED_ATTACHMENT_EXTS:
        raise HTTPException(
            status_code=400,
            detail=f"不支持的文件类型，仅支持: {', '.join(sorted(ALLOWED_ATTACHMENT_EXTS))}",
        )

    # 读取文件内容
    content = await file.read()
    if len(content) > MAX_ATTACHMENT_SIZE:
        raise HTTPException(
            status_code=400,
            detail=f"文件过大，最大支持 {MAX_ATTACHMENT_SIZE // (1024*1024)}MB",
        )

    # 生成唯一文件名
    date_prefix = datetime.now().strftime("%Y/%m")
    unique_name = f"{uuid.uuid4().hex}.{ext}"
    object_key = f"attachments/{date_prefix}/{unique_name}"

    # 上传到COS
    client, config = _get_cos_client(db)
    if not client:
        raise HTTPException(status_code=500, detail="对象存储未配置，无法上传附件")

    try:
        client.put_object(
            Bucket=config.get("cos_bucket", ""),
            Body=content,
            Key=object_key,
            ContentType=file.content_type or "application/octet-stream",
        )
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"COS上传失败: {str(e)}")

    url = _build_cos_url(config, object_key)

    # 写入数据库
    attachment = Attachment(
        post_id=post_id if post_id else None,
        user_id=current_user.id,
        filename=file.filename,
        storage_key=object_key,
        url=url,
        file_size=len(content),
        file_type=file.content_type or "application/octet-stream",
    )
    db.add(attachment)
    db.commit()
    db.refresh(attachment)

    return {
        "id": attachment.id,
        "filename": attachment.filename,
        "url": attachment.url,
        "file_size": attachment.file_size,
        "file_type": attachment.file_type,
    }


@router.put("/attachment/{attachment_id}/post")
async def update_attachment_post(
    attachment_id: int,
    post_id: int = 0,
    current_user: User = Depends(get_current_user),
    db: Session = Depends(get_db),
):
    """将附件关联到帖子（新建帖子后回填 post_id）"""
    attachment = db.query(Attachment).filter(
        Attachment.id == attachment_id,
        Attachment.user_id == current_user.id,
    ).first()
    if not attachment:
        raise HTTPException(status_code=404, detail="附件不存在")
    attachment.post_id = post_id
    db.commit()
    return {"message": "ok"}