"""
Utility — File & Job Directory Manager
Creates/cleans temp directories, tracks disk usage, handles expiry.
"""

import logging
import shutil
import uuid
import time
from pathlib import Path
from config import TEMP_DIR, JOB_EXPIRY_HOURS

logger = logging.getLogger(__name__)


def create_job_directory() -> tuple:
    """Create a unique job directory. Returns (job_id, job_dir)."""
    job_id = str(uuid.uuid4())[:8]
    job_dir = TEMP_DIR / job_id
    job_dir.mkdir(parents=True, exist_ok=True)
    logger.info(f"Created job directory: {job_dir}")
    return job_id, job_dir


def get_job_directory(job_id: str) -> Path:
    """Get the directory for a given job ID."""
    job_dir = TEMP_DIR / job_id
    if not job_dir.exists():
        raise FileNotFoundError(f"Job directory not found: {job_id}")
    return job_dir


def cleanup_job(job_id: str):
    """Remove all temp files for a job."""
    job_dir = TEMP_DIR / job_id
    if job_dir.exists():
        shutil.rmtree(job_dir)
        logger.info(f"Cleaned up job: {job_id}")


def cleanup_expired_jobs():
    """Remove job directories older than JOB_EXPIRY_HOURS."""
    if not TEMP_DIR.exists():
        return

    now = time.time()
    expiry_seconds = JOB_EXPIRY_HOURS * 3600
    cleaned = 0

    for job_dir in TEMP_DIR.iterdir():
        if job_dir.is_dir():
            age = now - job_dir.stat().st_mtime
            if age > expiry_seconds:
                shutil.rmtree(job_dir)
                logger.info(f"Expired job cleaned: {job_dir.name}")
                cleaned += 1

    if cleaned:
        logger.info(f"Cleaned {cleaned} expired jobs")


def get_job_disk_usage(job_id: str) -> str:
    """Get human-readable disk usage for a job."""
    job_dir = TEMP_DIR / job_id
    if not job_dir.exists():
        return "0 B"

    total = sum(f.stat().st_size for f in job_dir.rglob("*") if f.is_file())

    if total > 1e9:
        return f"{total / 1e9:.1f} GB"
    elif total > 1e6:
        return f"{total / 1e6:.1f} MB"
    elif total > 1e3:
        return f"{total / 1e3:.1f} KB"
    return f"{total} B"