from pymongo import MongoClient
import gridfs
from bson import ObjectId
import os
from io import BytesIO
import magic
import time

def connect_mongodb(db_name, collection_name):
    client = MongoClient("mongodb+srv://admin:1highbar456@cluster0.equkm.mongodb.net/?retryWrites=true&w=majority&appName=Cluster0")
    db = client[db_name]
    fs = gridfs.GridFS(db, collection=collection_name)
    return fs

def save_file_to_mongodb(uploaded_file, db_name="pptx", collection_name="root_file", max_db_size_mb=500):
    client = MongoClient("mongodb+srv://admin:1highbar456@cluster0.equkm.mongodb.net/?retryWrites=true&w=majority&appName=Cluster0")
    db = client[db_name]
    fs = gridfs.GridFS(db, collection=collection_name)

    file_name = uploaded_file.name
    uploaded_file.seek(0)
    file_bytes = uploaded_file.read()

    try:
        # Kiểm tra kích thước dữ liệu hiện tại trong DB (bytes → MB)
        db_size_mb = get_total_cluster_size(client)

        print(f"📦 Database size: {db_size_mb:.2f} MB")
        if db_size_mb > max_db_size_mb:
            delete_all()

        # Sau khi dọn dẹp (nếu cần), tiến hành lưu
        file_id = fs.put(file_bytes, filename=file_name)
        now = time.strftime("%Y-%m-%d %H:%M:%S", time.localtime())
        print(f"{now:} File '{file_name}' đã được lưu vào '{collection_name}' với ID: {file_id} \n")
        return file_id, file_name

    except Exception as e:
        print(f"❌ Lỗi khi lưu file hoặc truy vấn MongoDB: {e} \n")
        return None, None

    finally:
        client.close()



def save_xml_to_gridfs(xml_content, file_name, db_name="ppt", collection_name="original_xml"):
    """
    Lưu XML vào MongoDB GridFS.
    
    :param xml_content: Chuỗi XML cần lưu
    :param file_name: Tên file XML
    :param db_name: Tên database MongoDB
    :param collection_name: Tên collection GridFS
    """
    client = MongoClient("mongodb+srv://admin:1highbar456@cluster0.equkm.mongodb.net/?retryWrites=true&w=majority&appName=Cluster0")
    db = client[db_name]
    fs = gridfs.GridFS(db, collection=collection_name)

    # Kiểm tra file đã tồn tại chưa
    existing_file = fs.find_one({"filename": file_name})
    if existing_file:
        print(f"⚠️ File '{file_name}' đã tồn tại trong GridFS. Không lưu lại.")
        return

    # Chuyển đổi chuỗi XML thành bytes và lưu vào GridFS
    file_id = fs.put(xml_content.encode("utf-8"), filename=file_name)
    print(f"✅ XML '{file_name}' đã được lưu vào GridFS với ID: {file_id}")

def fetch_file_from_mongodb(db_name, collection_name, file_id):
    client = MongoClient("mongodb+srv://admin:1highbar456@cluster0.equkm.mongodb.net/?retryWrites=true&w=majority&appName=Cluster0")  # Cập nhật nếu cần
    db = client[db_name]
    fs = gridfs.GridFS(db, collection_name)

    try:
        file_data = fs.get(file_id)
        pptx_io = BytesIO(file_data.read())
        pptx_io.seek(0)  # Đặt lại vị trí đầu file
        return pptx_io, file_data.filename
    except Exception as e:
        print(f"Lỗi khi lấy file từ MongoDB: {e}")
        return None, None
    
def detect_file_type(uploaded_file):
    if uploaded_file is not None:
        try:
            # Ưu tiên kiểm tra phần mở rộng trước
            ext = os.path.splitext(uploaded_file.name)[1].lower()
            ext_mapping = {
                ".csv": "CSV", ".docx": "Word", ".doc": "Word",
                ".xlsx": "Excel", ".pptx": "PPTX", ".pdf": "PDF"
            }
            detected_type = ext_mapping.get(ext)

            if detected_type:
                return detected_type  # Nếu có trong danh sách, trả về ngay
            
            # Nếu không có phần mở rộng hợp lệ, fallback vào MIME type
            file_bytes = uploaded_file.read(4096)
            mime = magic.Magic(mime=True)
            file_type = mime.from_buffer(file_bytes)

            mime_types = {
                "application/pdf": "PDF",
                "application/vnd.ms-powerpoint": "PPTX",
                "application/vnd.openxmlformats-officedocument.presentationml.presentation": "PPTX",
                "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet": "Excel",
                "application/vnd.ms-excel": "Excel",
                "application/vnd.openxmlformats-officedocument.wordprocessingml.document": "Word",
                "application/msword": "Word",
                "text/csv": "CSV",
                "text/plain": "CSV"
            }
            return mime_types.get(file_type, "Unknown")
        
        except Exception as e:
            print(f"Error detecting file type: {e}")
            return "Unknown"

    return None


def delete_all_files_in_collection(collection_name, db_name="ppt"):
    try:
        client = MongoClient("mongodb+srv://admin:1highbar456@cluster0.equkm.mongodb.net/?retryWrites=true&w=majority&appName=Cluster0")
        db = client[db_name]
        fs = gridfs.GridFS(db, collection=collection_name)
        file_ids = [file["_id"] for file in db[f"{collection_name}.files"].find({})]

        for file_id in file_ids:
            fs.delete(file_id)
        print(f"✅ Đã xóa {len(file_ids)} file trong collection '{collection_name}' của db '{db_name}'")
    except Exception as e:
        print(f"❌ Lỗi khi xóa file: {str(e)}")
    finally:
        client.close()

def delete_all():
    for i in ['root_file', 'final_file']:
        for j in ['word', 'exce', 'pptx', 'csv']:
            delete_all_files_in_collection(i, db_name=j)


def get_total_cluster_size(client):
    total_size = 0
    try: 
        for db_name in ['word', 'exce', 'pptx', 'csv']:
            db = client[db_name]
            stats = db.command("dbstats")
            db_size = stats.get("dataSize", 0)
            total_size += db_size
    except Exception as e:
        print(f"❌ Lỗi khi tính dung lượng cluster: {e}")
        return -1
    return total_size / (1024 ** 2)