import hashlib
import logging
import shutil
from pathlib import Path

import requests

log = logging.getLogger(__name__)


def compute_sha256(path: Path) -> str:
    h = hashlib.sha256()
    with path.open("rb") as f:
        for chunk in iter(lambda: f.read(65536), b""):
            h.update(chunk)
    return h.hexdigest()


def _is_in_grimmory(filename: str, url: str, user: str, password: str) -> bool:
    """Search Grimmory Komga-compatible API by filename stem. Non-fatal on error."""
    stem = Path(filename).stem
    try:
        r = requests.get(
            url.rstrip("/") + "/komga/api/v1/books",
            params={"search": stem},
            auth=(user, password),
            timeout=10,
        )
        if r.status_code == 200:
            return r.json().get("totalElements", 0) > 0
        log.warning("Grimmory search returned HTTP %s for '%s'", r.status_code, stem)
    except Exception as e:
        log.warning("Grimmory duplicate check failed for '%s': %s", filename, e)
    return False


class PlacementResult:
    __slots__ = ("status", "sha256", "error_msg")

    def __init__(self, status: str, sha256: str = "", error_msg: str = ""):
        self.status = status
        self.sha256 = sha256
        self.error_msg = error_msg


def place_book(
    book_path: Path,
    bookdrop_path: str,
    url: str,
    user: str,
    password: str,
    sha256: str | None = None,
) -> PlacementResult:
    if sha256 is None:
        sha256 = compute_sha256(book_path)

    if _is_in_grimmory(book_path.name, url, user, password):
        log.info("Skipping '%s' — already in Grimmory", book_path.name)
        return PlacementResult("skipped", sha256)

    dest_dir = Path(bookdrop_path)
    dest_dir.mkdir(parents=True, exist_ok=True)
    dest = dest_dir / book_path.name
    counter = 1
    while dest.exists():
        dest = dest_dir / f"{book_path.stem}_{counter}{book_path.suffix}"
        counter += 1

    shutil.copy2(book_path, dest)
    log.info("Placed '%s' → %s", book_path.name, dest)
    return PlacementResult("success", sha256)


def test_connection(url: str, user: str, password: str) -> tuple[bool, str]:
    base = url.rstrip("/")
    try:
        # Health check (no auth required)
        r = requests.get(base + "/api/v1/healthcheck", timeout=10)
        if r.status_code != 200:
            return False, f"Grimmory not reachable (HTTP {r.status_code})"
        # Verify credentials against Komga-compatible API
        r2 = requests.get(base + "/komga/api/v1/books", params={"size": 1},
                          auth=(user, password), timeout=10)
        if r2.status_code == 200:
            return True, "Connected to Grimmory successfully"
        if r2.status_code == 401:
            return False, "Grimmory reachable but credentials rejected — check username and password"
        return True, f"Grimmory reachable (API returned HTTP {r2.status_code})"
    except requests.exceptions.ConnectionError:
        return False, "Could not connect — check the URL"
    except Exception as e:
        return False, str(e)