#!/usr/bin/env python3
import fcntl
import os
import shutil
import subprocess
import time
from datetime import datetime
from pathlib import Path

PYTHON = '/opt/intranet-venv/bin/python'
ROOT = Path('/opt/intranet/worker')
STATE_DIR = Path('/data/state')
PDF_OUTPUT = Path(os.getenv('PDF_OUTPUT', '/data/pdf/terminuebersicht.pdf'))
INTERVAL = int(os.getenv('CALENDAR_INTERVAL_SECONDS', '60'))


def required(name: str) -> str:
    value = os.getenv(name, '').strip()
    if not value:
        raise RuntimeError(f'Missing environment variable: {name}')
    return value


def run(cmd, cwd=None):
    print('+', ' '.join(map(str, cmd)), flush=True)
    subprocess.run(cmd, cwd=cwd, check=True, env=os.environ.copy())


def prepare_ssh_key() -> Path:
    source = Path(os.getenv('STRATO_SSH_KEY_FILE', '/run/secrets/strato_ed25519'))
    if not source.is_file():
        raise RuntimeError(f'SSH key file missing: {source}')
    target = Path('/tmp/strato_ed25519')
    shutil.copyfile(source, target)
    target.chmod(0o600)
    return target


def calendar_sync():
    # CKalender-XLSX verarbeiten
    run(
        [PYTHON, str(ROOT / 'ckal_upload_client/client.py')],
        cwd=ROOT / 'ckal_upload_client'
    )

    # PDF erzeugen
    run(
        [PYTHON, str(ROOT / 'pdf_python/create_pdf.py')],
        cwd=ROOT / 'pdf_python'
    )

    # PDF in Dashboard-PNGs umwandeln
    run(
        ['/bin/bash', str(ROOT / 'pdf_python/pdf_to_png.sh')],
        cwd=ROOT / 'pdf_python'
    )

    # STRATO-Synchronisation kann z. B. im DEV deaktiviert werden
    strato_sync_enabled = os.getenv(
        'STRATO_SYNC_ENABLED',
        'true'
    ).strip().lower() in ('1', 'true', 'yes', 'on')

    if not strato_sync_enabled:
        print('STRATO Sync deaktiviert', flush=True)
        print('Calendar Sync erfolgreich (ohne STRATO)', flush=True)
        return

    required('STRATO_SSH_USER')
    required('STRATO_REMOTE_PATH')

    host = os.getenv('STRATO_SSH_HOST', 'ssh.strato.de')
    port = os.getenv('STRATO_SSH_PORT', '22')

    known_hosts = Path(
        os.getenv(
            'STRATO_KNOWN_HOSTS_FILE',
            '/run/secrets/known_hosts'
        )
    )

    if not known_hosts.is_file():
        raise RuntimeError(
            f'known_hosts missing: {known_hosts}'
        )

    key = prepare_ssh_key()

    if not PDF_OUTPUT.is_file() or PDF_OUTPUT.stat().st_size == 0:
        raise RuntimeError(
            f'PDF missing/empty: {PDF_OUTPUT}'
        )

    run([
        '/usr/bin/scp',
        '-O',
        '-q',
        '-P', port,
        '-i', str(key),
        '-o', 'IdentitiesOnly=yes',
        '-o', 'BatchMode=yes',
        '-o', 'StrictHostKeyChecking=yes',
        '-o', f'UserKnownHostsFile={known_hosts}',
        str(PDF_OUTPUT),
        f"{required('STRATO_SSH_USER')}@{host}:{required('STRATO_REMOTE_PATH')}",
    ])

    print('Calendar Sync erfolgreich', flush=True)


def brandschutz_once_per_month():
    now = datetime.now()

    if now.day != 1 or now.hour < 8:
        return

    brandschutz_enabled = os.getenv(
        'BRANDSCHUTZ_MAIL_ENABLED',
        'true'
    ).strip().lower() in ('1', 'true', 'yes', 'on')

    if not brandschutz_enabled:
        print('Brandschutz-Mail deaktiviert', flush=True)
        return

    marker = STATE_DIR / 'brandschutz-last-attempt'
    month = now.strftime('%Y-%m')

    if marker.exists() and marker.read_text().strip() == month:
        return

    # At-most-once: erst markieren, dann ausführen
    marker.write_text(month + '\n')

    print(f'Brandschutz-Lauf {month}', flush=True)

    run([
        '/usr/local/bin/php',
        '/var/www/html/intranet_repo/projects/brandschutz/brandschutz_cron.php'
    ])
    

def main():
    STATE_DIR.mkdir(parents=True, exist_ok=True)
    lock_handle = (STATE_DIR / 'scheduler.lock').open('w')
    try:
        fcntl.flock(lock_handle.fileno(), fcntl.LOCK_EX | fcntl.LOCK_NB)
    except BlockingIOError as exc:
        raise RuntimeError('Ein anderer Scheduler läuft bereits.') from exc

    if INTERVAL < 30:
        raise RuntimeError('CALENDAR_INTERVAL_SECONDS muss >= 30 sein.')
    for name in ('CKAL_USERNAME', 'CKAL_PASSWORD', 'CKAL_CALENDAR_URL'):
        required(name)
    PDF_OUTPUT.parent.mkdir(parents=True, exist_ok=True)

    next_run = 0.0
    while True:
        try:
            brandschutz_once_per_month()
        except Exception as exc:
            print(f'FEHLER Brandschutz: {exc}', flush=True)

        now_mono = time.monotonic()
        if now_mono >= next_run:
            try:
                calendar_sync()
            except Exception as exc:
                print(f'FEHLER Calendar Sync: {exc}', flush=True)
            next_run = time.monotonic() + INTERVAL

        (STATE_DIR / 'heartbeat').write_text(str(int(time.time())) + '\n')
        time.sleep(1)


if __name__ == '__main__':
    main()