#!/usr/bin/env python3
"""Check the latest backup date.

Usage:
    checkBackup <uuid>   print latest backup date for one container
    checkBackup -a       check all containers returned by activeContainers;
                         status is OK if the latest backup is at most 2 days
                         old, NOK if older or missing
"""

import subprocess
import sys
from datetime import date, datetime
from pathlib import Path

BACKUP_ROOT = Path("/BACKUP")
MAX_AGE_DAYS = 2
ACTIVE_CONTAINERS = Path(__file__).resolve().parent / "activeContainers"


def check_backup(uuid):
    """Return (ok, message) for the given UUID."""
    directory = BACKUP_ROOT / uuid

    if not directory.is_dir():
        return False, f"ERROR: directory not found for UUID {uuid}"

    latest_date = None
    latest_file = None

    for zip_file in directory.rglob("*.zip"):
        date_part = zip_file.name.split("_")[0]
        if len(date_part) != 8 or not date_part.isdigit():
            continue

        if latest_date is None or date_part > latest_date:
            latest_date = date_part
            latest_file = zip_file

    if latest_date is None:
        return False, "NO BACKUPS"

    if latest_file.stat().st_size < 1000:
        return True, "01-01-2000"

    # Format as yyyy-mm-dd
    return True, f"{latest_date[:4]}-{latest_date[4:6]}-{latest_date[6:8]}"


def is_recent(ok, message):
    """True if the backup date in message is at most MAX_AGE_DAYS old."""
    if not ok:
        return False
    try:
        backup_date = datetime.strptime(message, "%Y-%m-%d").date()
    except ValueError:
        # e.g. the "01-01-2000" placeholder for too-small backup files
        return False
    return (date.today() - backup_date).days <= MAX_AGE_DAYS


def active_uuids():
    """UUIDs printed by activeContainers (skips header and separator lines)."""
    result = subprocess.run(
        [str(ACTIVE_CONTAINERS)], capture_output=True, text=True
    )
    if result.returncode != 0:
        print(
            f"ERROR: activeContainers failed: {result.stderr.strip()}",
            file=sys.stderr,
        )
        sys.exit(1)

    lines = result.stdout.splitlines()
    uuids = []
    for line in lines[2:]:  # line 0 = header, line 1 = "----" separator
        fields = line.split()
        if fields:
            uuids.append(fields[0])
    return uuids


def main():
    if len(sys.argv) < 2:
        print("Usage: checkBackup <uuid> | -a")
        sys.exit(1)

    if sys.argv[1] == "-a":
        rows = [("uuid", "latest", "status")]
        failed = False
        for uuid in active_uuids():
            ok, message = check_backup(uuid)
            recent = is_recent(ok, message)
            rows.append((uuid, message, "OK" if recent else "NOK"))
            failed = failed or not recent

        widths = [max(len(row[i]) for row in rows) for i in range(2)]
        for uuid, message, status in rows:
            print(f"{uuid:<{widths[0]}}  {message:<{widths[1]}}  {status}")
        sys.exit(1 if failed else 0)

    ok, message = check_backup(sys.argv[1])
    print(message)
    sys.exit(0 if ok else 1)


if __name__ == "__main__":
    main()