from fastapi import FastAPI, UploadFile, File, HTTPException
from fastapi.responses import FileResponse
from pathlib import Path
import psutil
import shutil
import os

app = FastAPI()

# Directory where files will be uploaded
UPLOAD_DIRECTORY = Path("uploads")
UPLOAD_DIRECTORY.mkdir(parents=True, exist_ok=True)

# Hugging Face Spaces has a 50GB limit
TOTAL_SPACE_GB = 50

# Helper function to calculate the size of a directory
def get_directory_size(directory: Path) -> int:
    total_size = 0
    for dirpath, dirnames, filenames in os.walk(directory):
        for f in filenames:
            fp = os.path.join(dirpath, f)
            total_size += os.path.getsize(fp)
    return total_size

# Health check endpoint
@app.get("/health")
def health_check():
    return {
        "status": "healthy"
    }

# System metrics endpoint: CPU, RAM, and disk usage for uploads folder (in GB and percentage of 50GB limit)
@app.get("/metrics")
def get_metrics():
    # CPU percentage (rounded to the nearest whole number)
    cpu_percent = round(psutil.cpu_percent(interval=1))

    # Memory stats in GB
    memory = psutil.virtual_memory()
    memory_total_gb = memory.total / (1024 ** 3)
    memory_available_gb = memory.available / (1024 ** 3)

    # Disk stats for uploads directory
    uploads_size_bytes = get_directory_size(UPLOAD_DIRECTORY)
    uploads_size_gb = uploads_size_bytes / (1024 ** 3)
    uploads_percent = (uploads_size_gb / TOTAL_SPACE_GB) * 100

    return {
        "cpu_percent": cpu_percent,  # Rounded CPU percentage
        "memory": {
            "total_gb": round(memory_total_gb, 2),
            "available_gb": round(memory_available_gb, 2),
            "percent": memory.percent
        },
        "disk": {
            "uploads_folder_size_gb": round(uploads_size_gb, 2),
            "uploads_usage_percent_of_50gb": round(uploads_percent, 2),
            "total_space_gb": TOTAL_SPACE_GB
        }
    }

# File upload endpoint
@app.post("/uploadfile/")
async def upload_file(file: UploadFile = File(...)):
    file_location = UPLOAD_DIRECTORY / file.filename

    with file_location.open("wb") as buffer:
        shutil.copyfileobj(file.file, buffer)

    return {"info": f"file '{file.filename}' saved at '{file_location}'"}

# File download endpoint
@app.get("/downloadfile/{filename}")
def download_file(filename: str):
    file_location = UPLOAD_DIRECTORY / filename

    if not file_location.exists():
        raise HTTPException(status_code=404, detail="File not found")

    return FileResponse(path=file_location, filename=filename)

# Show current files endpoint
@app.get("/files/")
def list_files():
    files = [f for f in os.listdir(UPLOAD_DIRECTORY) if os.path.isfile(UPLOAD_DIRECTORY / f)]
    return {"files": files}