"""Support for functionality to download files."""

from __future__ import annotations

from http import HTTPStatus
import os
import re
import threading

import requests
import voluptuous as vol

from homeassistant.config_entries import ConfigEntry
from homeassistant.core import HomeAssistant, ServiceCall
from homeassistant.helpers import config_validation as cv
from homeassistant.helpers.service import async_register_admin_service
from homeassistant.util import raise_if_invalid_filename, raise_if_invalid_path

from .const import (
    _LOGGER,
    ATTR_FILENAME,
    ATTR_OVERWRITE,
    ATTR_SUBDIR,
    ATTR_URL,
    CONF_DOWNLOAD_DIR,
    DOMAIN,
    DOWNLOAD_COMPLETED_EVENT,
    DOWNLOAD_FAILED_EVENT,
    SERVICE_DOWNLOAD_FILE,
)


async def async_setup_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
    """Listen for download events to download files."""
    download_path = entry.data[CONF_DOWNLOAD_DIR]

    # If path is relative, we assume relative to Home Assistant config dir
    if not os.path.isabs(download_path):
        download_path = hass.config.path(download_path)

    if not await hass.async_add_executor_job(os.path.isdir, download_path):
        _LOGGER.error(
            "Download path %s does not exist. File Downloader not active", download_path
        )
        return False

    def download_file(service: ServiceCall) -> None:
        """Start thread to download file specified in the URL."""

        def do_download() -> None:
            """Download the file."""
            try:
                url = service.data[ATTR_URL]

                subdir = service.data.get(ATTR_SUBDIR)

                filename = service.data.get(ATTR_FILENAME)

                overwrite = service.data.get(ATTR_OVERWRITE)

                if subdir:
                    # Check the path
                    raise_if_invalid_path(subdir)

                final_path = None

                req = requests.get(url, stream=True, timeout=10)

                if req.status_code != HTTPStatus.OK:
                    _LOGGER.warning(
                        "Downloading '%s' failed, status_code=%d", url, req.status_code
                    )
                    hass.bus.fire(
                        f"{DOMAIN}_{DOWNLOAD_FAILED_EVENT}",
                        {"url": url, "filename": filename},
                    )

                else:
                    if filename is None and "content-disposition" in req.headers:
                        match = re.findall(
                            r"filename=(\S+)", req.headers["content-disposition"]
                        )

                        if match:
                            filename = match[0].strip("'\" ")

                    if not filename:
                        filename = os.path.basename(url).strip()

                    if not filename:
                        filename = "ha_download"

                    # Check the filename
                    raise_if_invalid_filename(filename)

                    # Do we want to download to subdir, create if needed
                    if subdir:
                        subdir_path = os.path.join(download_path, subdir)

                        # Ensure subdir exist
                        os.makedirs(subdir_path, exist_ok=True)

                        final_path = os.path.join(subdir_path, filename)

                    else:
                        final_path = os.path.join(download_path, filename)

                    path, ext = os.path.splitext(final_path)

                    # If file exist append a number.
                    # We test filename, filename_2..
                    if not overwrite:
                        tries = 1
                        final_path = path + ext
                        while os.path.isfile(final_path):
                            tries += 1

                            final_path = f"{path}_{tries}.{ext}"

                    _LOGGER.debug("%s -> %s", url, final_path)

                    with open(final_path, "wb") as fil:
                        for chunk in req.iter_content(1024):
                            fil.write(chunk)

                    _LOGGER.debug("Downloading of %s done", url)
                    hass.bus.fire(
                        f"{DOMAIN}_{DOWNLOAD_COMPLETED_EVENT}",
                        {"url": url, "filename": filename},
                    )

            except requests.exceptions.ConnectionError:
                _LOGGER.exception("ConnectionError occurred for %s", url)
                hass.bus.fire(
                    f"{DOMAIN}_{DOWNLOAD_FAILED_EVENT}",
                    {"url": url, "filename": filename},
                )

                # Remove file if we started downloading but failed
                if final_path and os.path.isfile(final_path):
                    os.remove(final_path)
            except ValueError:
                _LOGGER.exception("Invalid value")
                hass.bus.fire(
                    f"{DOMAIN}_{DOWNLOAD_FAILED_EVENT}",
                    {"url": url, "filename": filename},
                )

                # Remove file if we started downloading but failed
                if final_path and os.path.isfile(final_path):
                    os.remove(final_path)

        threading.Thread(target=do_download).start()

    async_register_admin_service(
        hass,
        DOMAIN,
        SERVICE_DOWNLOAD_FILE,
        download_file,
        schema=vol.Schema(
            {
                vol.Optional(ATTR_FILENAME): cv.string,
                vol.Optional(ATTR_SUBDIR): cv.string,
                vol.Required(ATTR_URL): cv.url,
                vol.Optional(ATTR_OVERWRITE, default=False): cv.boolean,
            }
        ),
    )

    return True
