import os
import secrets
import urllib.parse

import slugify

from ows_text_campaigns.config import settings

# https://www.twilio.com/docs/messaging/guides/accepted-mime-types#media-file-name-guidelines
HASH_LENGTH = 4
FILENAME_MAX_LENGTH = 20


def unique_hash(size: int | None = HASH_LENGTH) -> str:
    return secrets.token_urlsafe(size)


def get_assets_url(path: str) -> str:
    return urllib.parse.urljoin(
        f"https://{settings.assets_cdn_domain}/",
        urllib.parse.quote_plus(path, safe="/"),
    )


def create_asset_filename(filename: str) -> str:
    name, ext = os.path.splitext(filename)
    slug_part = slugify.slugify(name, max_length=FILENAME_MAX_LENGTH - HASH_LENGTH)
    return f"{slug_part}__{unique_hash(HASH_LENGTH)}{ext}"


def update_asset_key(
    key: str, *, size: tuple[int, int] | None = None, extension: str | None = None
) -> str:
    dir_path, filename = os.path.split(key)
    name, ext = os.path.splitext(filename)
    slug_part, *_ = name.rsplit("__", 1)
    slug_part = slugify.slugify(slug_part, lowercase=True)
    size_suffix = ""
    if size is not None:
        width, height = size
        size_suffix = f"-{width}x{height}"
    hash_reserved = HASH_LENGTH + 2  # "__"
    max_slug_len = FILENAME_MAX_LENGTH - len(size_suffix) - hash_reserved
    slug_part = slug_part[:max_slug_len]
    if extension is not None:
        ext = extension
    if not ext.startswith("."):
        ext = f".{ext}"
    return os.path.join(
        dir_path, f"{slug_part}{size_suffix}__{unique_hash(HASH_LENGTH)}{ext}"
    )