"""
collect_pictures_windows.py
---------------------------
Windows verze zálohovacího skriptu.
Prochází všechny lokální disky (ne síťové, ne CD), hledá JPG/JPEG,
kopíruje (deduplikace BLAKE3) na Tower1 přes UNC cestu a zapisuje do PostgreSQL.

Cesta zálohy:  \\Tower1\ZalohaVsechObrazku\{hostname}\{písmeno_disku}\{cesta}
Příklad:        \\Tower1\ZalohaVsechObrazku\JMENO-PC\D\Foto\2023\img.jpg

Bezpečné pro opakované spuštění (pokračuje tam kde skončilo).
Bezpečné pro souběžný běh na více strojích (ON CONFLICT v SQL).
"""

import os
import sys
import shutil
import socket
import string
import ctypes
import logging
from pathlib import Path
from datetime import datetime

import blake3
import psycopg2
from psycopg2.extras import execute_values

# ── Konfigurace ───────────────────────────────────────────────────────────────

DB_CONFIG = {
    "host": "192.168.1.76",
    "port": 5432,
    "user": "vladimir.buzalka",
    "password": "Vlado7309208104++",
    "database": "fotky_buzalkovi",
}

ZALOHA_DIR = Path(r"\\Tower1\ZalohaVsechObrazku")

JPEG_EXTENSIONS = {".jpg", ".jpeg"}

EXCLUDED_DIR_NAMES_LOWER = {
    "zalohavsechobrazku",
    "zálohavsechobrázku",
    "zálohavsechobrazku",
    "$recycle.bin",
    "system volume information",
    "recovery",
}

EXCLUDED_FULL_PATHS = {
    Path(os.environ.get("WINDIR", r"C:\Windows")),
}

BATCH_SIZE = 500

LOG_FILE = Path(__file__).parent / "collect_pictures_windows.log"

# ── Logging ───────────────────────────────────────────────────────────────────

logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s  %(levelname)-7s  %(message)s",
    datefmt="%Y-%m-%d %H:%M:%S",
    handlers=[
        logging.StreamHandler(sys.stdout),
        logging.FileHandler(LOG_FILE, encoding="utf-8"),
    ],
)
log = logging.getLogger(__name__)

# ── SQL ───────────────────────────────────────────────────────────────────────

SQL_INSERT_ZALOHA = """
INSERT INTO zaloha_obrazku (blake3_hash, cesta_zalohy, nazev_souboru, velikost)
VALUES (%s, %s, %s, %s)
ON CONFLICT (blake3_hash) DO NOTHING
RETURNING id
"""

SQL_INSERT_ZDROJ = """
INSERT INTO zdrojove_soubory (hostname, cesta_zdroje, nazev_souboru, velikost, blake3_hash, zaloha_id)
VALUES (%s, %s, %s, %s, %s, %s)
ON CONFLICT (hostname, cesta_zdroje) DO NOTHING
"""

SQL_GET_ZALOHA_ID = "SELECT id FROM zaloha_obrazku WHERE blake3_hash = %s"

# ── Pomocné funkce ────────────────────────────────────────────────────────────

def get_local_drives() -> list[Path]:
    DRIVE_FIXED = 3
    drives = []
    bitmask = ctypes.windll.kernel32.GetLogicalDrives()
    for letter in string.ascii_uppercase:
        if bitmask & 1:
            drive = Path(f"{letter}:\\")
            drive_type = ctypes.windll.kernel32.GetDriveTypeW(str(drive))
            if drive_type == DRIVE_FIXED:
                drives.append(drive)
        bitmask >>= 1
    return drives


def is_excluded_path(path: Path) -> bool:
    for excl in EXCLUDED_FULL_PATHS:
        try:
            path.relative_to(excl)
            return True
        except ValueError:
            pass
    return False


def compute_blake3(path: Path, chunk: int = 1 << 20) -> str:
    h = blake3.blake3()
    with open(path, "rb") as f:
        while data := f.read(chunk):
            h.update(data)
    return h.hexdigest()


def dest_path_for(source: Path, hostname: str) -> Path:
    drive_letter = source.drive.rstrip(":")
    relative = source.relative_to(source.drive + "\\")
    return ZALOHA_DIR / hostname / drive_letter / relative


def copy_to_backup(source: Path, dest: Path) -> None:
    dest.parent.mkdir(parents=True, exist_ok=True)
    if dest.exists():
        return
    shutil.copy2(source, dest)


def iter_jpeg_files(drives: list[Path]):
    for drive in drives:
        log.info(f"Skenuji disk: {drive}")
        for root, dirs, files in os.walk(drive, followlinks=False):
            root_path = Path(root)

            if is_excluded_path(root_path):
                dirs.clear()
                continue

            dirs[:] = [
                d for d in dirs
                if d.lower() not in EXCLUDED_DIR_NAMES_LOWER
                and not is_excluded_path(root_path / d)
            ]

            for fname in files:
                if Path(fname).suffix.lower() in JPEG_EXTENSIONS:
                    yield root_path / fname


def load_known_sources(conn, hostname: str) -> set[str]:
    with conn.cursor("src_cursor") as cur:
        cur.itersize = 10000
        cur.execute("SELECT cesta_zdroje FROM zdrojove_soubory WHERE hostname = %s", (hostname,))
        return {row[0] for row in cur}


def load_known_hashes(conn) -> dict[str, int]:
    with conn.cursor("hash_cursor") as cur:
        cur.itersize = 10000
        cur.execute("SELECT blake3_hash, id FROM zaloha_obrazku")
        return {row[0]: row[1] for row in cur}

# ── Hlavní logika ─────────────────────────────────────────────────────────────

def process(conn, hostname, drives):
    log.info(f"Hostname zdroje: {hostname}")

    log.info("Načítám známé zdroje z DB...")
    known_sources = load_known_sources(conn, hostname)
    log.info(f"Známých zdrojů v DB: {len(known_sources)}")

    log.info("Načítám známé hashe z DB...")
    known_hashes = load_known_hashes(conn)
    log.info(f"Známých hashů v DB: {len(known_hashes)}")

    stats = {"nalezeno": 0, "kopirovano": 0, "duplicit": 0, "chyb": 0, "preskoceno": 0}
    pending_zdroje = []

    def flush_zdroje():
        if not pending_zdroje:
            return
        cur = conn.cursor()
        execute_values(
            cur,
            """INSERT INTO zdrojove_soubory
               (hostname, cesta_zdroje, nazev_souboru, velikost, blake3_hash, zaloha_id)
               VALUES %s
               ON CONFLICT (hostname, cesta_zdroje) DO NOTHING""",
            pending_zdroje,
        )
        conn.commit()
        cur.close()
        pending_zdroje.clear()

    for source in iter_jpeg_files(drives):
        stats["nalezeno"] += 1
        src_str = str(source)

        if src_str in known_sources:
            stats["preskoceno"] += 1
            if stats["preskoceno"] % 5000 == 0:
                log.info(f"Přeskočeno (již v DB): {stats['preskoceno']}")
            continue

        try:
            velikost = source.stat().st_size
            hash_val = compute_blake3(source)
        except (OSError, PermissionError) as e:
            log.warning(f"CHYBA čtení: {source}  →  {e}")
            stats["chyb"] += 1
            continue

        zaloha_id = known_hashes.get(hash_val)

        if zaloha_id is not None:
            stats["duplicit"] += 1
        else:
            dest = dest_path_for(source, hostname)
            try:
                copy_to_backup(source, dest)
            except (OSError, shutil.Error) as e:
                log.warning(f"CHYBA kopírování: {source}  →  {e}")
                stats["chyb"] += 1
                continue

            cur = conn.cursor()
            cur.execute(SQL_INSERT_ZALOHA, (hash_val, str(dest), source.name, velikost))
            row = cur.fetchone()
            if row:
                zaloha_id = row[0]
            else:
                cur.execute(SQL_GET_ZALOHA_ID, (hash_val,))
                zaloha_id = cur.fetchone()[0]
            cur.close()
            conn.commit()

            known_hashes[hash_val] = zaloha_id
            stats["kopirovano"] += 1
            log.info(f"ZKOPÍROVÁNO  [{stats['kopirovano']:>6}]  {source}")

        pending_zdroje.append((hostname, src_str, source.name, velikost, hash_val, zaloha_id))
        known_sources.add(src_str)

        if len(pending_zdroje) >= BATCH_SIZE:
            flush_zdroje()

        if stats["nalezeno"] % 5000 == 0:
            log.info(
                f"Průběh: nalezeno={stats['nalezeno']}  "
                f"nových={stats['kopirovano']}  duplikátů={stats['duplicit']}  "
                f"chyb={stats['chyb']}  přeskočeno={stats['preskoceno']}"
            )

    flush_zdroje()
    return stats


def main():
    hostname = socket.gethostname()
    drives = get_local_drives()

    log.info("=" * 60)
    log.info(f"Spuštění: {datetime.now().strftime('%Y-%m-%d %H:%M:%S')}")
    log.info(f"Hostname: {hostname}")
    log.info(f"Disky:    {[str(d) for d in drives]}")
    log.info(f"Záloha:   {ZALOHA_DIR}\\{hostname}\\")

    try:
        conn = psycopg2.connect(**DB_CONFIG)
        conn.autocommit = False
        log.info("PostgreSQL: připojeno")
    except Exception as e:
        log.error(f"Nelze se připojit k DB: {e}")
        sys.exit(1)

    stats = {"nalezeno": 0, "kopirovano": 0, "duplicit": 0, "chyb": 0, "preskoceno": 0}
    try:
        stats = process(conn, hostname, drives)
    except KeyboardInterrupt:
        log.warning("Přerušeno uživatelem — dosavadní záznamy jsou uloženy.")
        conn.rollback()
    except Exception as e:
        log.error(f"Neočekávaná chyba: {e}", exc_info=True)
        conn.rollback()
    finally:
        conn.close()

    log.info("-" * 60)
    log.info(f"Nalezeno JPG/JPEG:  {stats['nalezeno']}")
    log.info(f"Zkopírováno nových: {stats['kopirovano']}")
    log.info(f"Duplikátů (hash):   {stats['duplicit']}")
    log.info(f"Přeskočeno (v DB):  {stats['preskoceno']}")
    log.info(f"Chyb:               {stats['chyb']}")
    log.info("Hotovo.")


if __name__ == "__main__":
    main()