"""Nextcloud WebDAV inbox sync.

Polls a Nextcloud folder via WebDAV (PROPFIND/GET) for new files,
downloads them for processing, and moves processed files to a processed/ subfolder.
"""

import logging
import xml.etree.ElementTree as ET
from pathlib import Path
from urllib.parse import unquote, urljoin

import httpx

from ingestion.config import IngestionConfig

logger = logging.getLogger(__name__)

# WebDAV XML namespace
DAV_NS = "DAV:"


class NextcloudInboxSync:
    """Sync files from a Nextcloud WebDAV folder."""

    def __init__(self, config: IngestionConfig):
        self.base_url = config.nextcloud_inbox_url.rstrip("/") + "/"
        self.user = config.nextcloud_inbox_user
        self.password = config.nextcloud_inbox_password
        self.local_inbox = Path(config.inbox_dir)
        self.local_inbox.mkdir(parents=True, exist_ok=True)

        self._client = httpx.Client(
            auth=(self.user, self.password),
            timeout=30.0,
        )

    def poll(self) -> list[Path]:
        """Poll Nextcloud inbox for files and download them.

        Returns:
            List of local paths to downloaded files.
        """
        try:
            filenames = self._list_files()
        except Exception as e:
            logger.error("Failed to list Nextcloud inbox: %s", e)
            return []

        if not filenames:
            logger.info("Nextcloud inbox is empty.")
            return []

        downloaded: list[Path] = []
        for filename in filenames:
            local_path = self.download(filename)
            if local_path:
                downloaded.append(local_path)

        logger.info("Downloaded %d file(s) from Nextcloud.", len(downloaded))
        return downloaded

    def _list_files(self) -> list[str]:
        """PROPFIND to list files in the inbox folder."""
        propfind_body = """<?xml version="1.0" encoding="UTF-8"?>
        <d:propfind xmlns:d="DAV:">
            <d:prop>
                <d:resourcetype/>
                <d:getcontentlength/>
            </d:prop>
        </d:propfind>"""

        response = self._client.request(
            "PROPFIND",
            self.base_url,
            content=propfind_body,
            headers={
                "Content-Type": "application/xml",
                "Depth": "1",
            },
        )
        response.raise_for_status()

        # Parse WebDAV XML response
        root = ET.fromstring(response.text)
        filenames: list[str] = []

        for resp_elem in root.findall(f"{{{DAV_NS}}}response"):
            href = resp_elem.findtext(f"{{{DAV_NS}}}href", "")
            # Skip the folder itself (collections)
            resourcetype = resp_elem.find(
                f".//{{{DAV_NS}}}resourcetype/{{{DAV_NS}}}collection"
            )
            if resourcetype is not None:
                continue

            # Extract filename from href
            filename = unquote(href.rstrip("/").split("/")[-1])
            if filename and not filename.startswith("."):
                filenames.append(filename)

        return filenames

    def download(self, filename: str) -> Path | None:
        """Download a file from Nextcloud inbox.

        Args:
            filename: Name of the file to download.

        Returns:
            Local path to the downloaded file, or None on failure.
        """
        url = urljoin(self.base_url, filename)
        try:
            response = self._client.get(url)
            response.raise_for_status()

            local_path = self.local_inbox / filename
            local_path.write_bytes(response.content)
            logger.info("Downloaded: %s", filename)
            return local_path

        except Exception as e:
            logger.error("Failed to download %s: %s", filename, e)
            return None

    def mark_processed(self, filename: str) -> bool:
        """Move a processed file to the processed/ subfolder on Nextcloud.

        Args:
            filename: Name of the file to move.

        Returns:
            True if move succeeded, False otherwise.
        """
        source_url = urljoin(self.base_url, filename)
        dest_url = urljoin(self.base_url, f"processed/{filename}")

        try:
            # Ensure processed/ folder exists (MKCOL)
            processed_url = urljoin(self.base_url, "processed/")
            self._client.request("MKCOL", processed_url)

            # MOVE the file
            response = self._client.request(
                "MOVE",
                source_url,
                headers={"Destination": dest_url, "Overwrite": "T"},
            )
            if response.status_code in (201, 204):
                logger.info("Marked processed: %s", filename)
                return True
            else:
                logger.warning(
                    "MOVE returned %d for %s", response.status_code, filename
                )
                return False

        except Exception as e:
            logger.warning("Failed to mark %s as processed: %s", filename, e)
            return False