"""PiCopy – Konfiguration, Pfade, Konstanten, Logging."""

import os
import json
import logging
from pathlib import Path

RAW_BASE = 'https://git.leuschner.dev/Tobias/PiCopy/raw/branch/main'
VERSION_FILE = Path(__file__).parent.parent / 'version.txt'


def load_installed_version():
    try:
        return VERSION_FILE.read_text(encoding='utf-8').strip() or '1.0.4'
    except Exception:
        return 'X.X.X'


VERSION = load_installed_version()

BASE_DIR = Path('/opt/picopy')
CONFIG_FILE = BASE_DIR / 'config.json'
STATE_FILE  = BASE_DIR / 'state.json'
LOG_DIR     = BASE_DIR / 'logs'
LOG_FILE    = LOG_DIR  / 'picopy.log'
INTERNAL_DEST_DIR = BASE_DIR / 'internal'
LOG_DIR.mkdir(parents=True, exist_ok=True)
HISTORY_FILE = BASE_DIR / 'history.json'
MAX_HISTORY  = 100

logging.basicConfig(
    level=logging.INFO,
    format='%(asctime)s %(levelname)s %(message)s',
    handlers=[logging.FileHandler(LOG_FILE), logging.StreamHandler()]
)
log = logging.getLogger('picopy')

NM_AP_CON     = 'PiCopy-AP'
NM_CLIENT_CON = 'PiCopy-WiFi'
WIFI_BOOT_WAIT = 25  # Sekunden warten beim Start bevor AP gestartet wird

DEFAULT_CONFIG = {
    # USB
    'source_ports': [],          # [{port, label}, ...]
    'source_port': None, 'source_label': '',  # Migration legacy
    'dest_port': None,   'dest_label': '',
    'dest_type': 'usb', 'internal_dest_label': 'Interner Speicher',
    'internal_share_enabled': False,
    'folder_format': '%Y-%m-%d', 'add_time': True,
    'subfolder': True, 'auto_copy': True,
    'file_filter': '', 'exclude_system': True,
    'duplicate_handling': 'skip',
    'verify_checksum': False, 'delete_source': False,
    # WiFi
    'wifi_ssid': '', 'wifi_password': '',
    'ap_ssid': 'PiCopy', 'ap_password': 'PiCopy,',
    # WireGuard
    'wireguard_auto': False,
}


def load_cfg():
    cfg = DEFAULT_CONFIG.copy()
    try:
        if CONFIG_FILE.exists():
            cfg.update(json.loads(CONFIG_FILE.read_text(encoding='utf-8')))
    except (json.JSONDecodeError, ValueError) as e:
        log.error(f'config.json korrupt ({e}), verwende Standardwerte')
        try: CONFIG_FILE.rename(CONFIG_FILE.with_suffix('.corrupt'))
        except Exception: pass
    except Exception as e:
        log.warning(f'config.json nicht lesbar: {e}')
    return cfg


def save_cfg(cfg):
    _atomic_write(CONFIG_FILE, json.dumps(cfg, indent=2))


def _atomic_write(path: Path, content: str) -> None:
    """Schreibt atomar: erst .tmp, dann os.replace() - sicher bei Stromausfall."""
    tmp = path.with_suffix(path.suffix + '.tmp')
    try:
        tmp.write_text(content, encoding='utf-8')
        with open(tmp, 'rb') as fh:
            os.fsync(fh.fileno())      # Daten wirklich auf Datenträger schreiben
        os.replace(str(tmp), str(path))  # Atomares Umbenennen (POSIX-Garantie)
    except Exception:
        try: tmp.unlink(missing_ok=True)
        except Exception: pass
        raise


def _fmt_bytes(b):
    if b < 1024: return f'{b} B'
    if b < 1024**2: return f'{b/1024:.1f} KB'
    if b < 1024**3: return f'{b/1024**2:.1f} MB'
    return f'{b/1024**3:.2f} GB'