from jinja2_simple_tags import StandaloneTag
import jinja2
from copy import deepcopy
from mkdocs.structure.files import File, Files
from mkdocs.plugins import event_priority, get_plugin_logger
import hashlib
from concurrent.futures import ThreadPoolExecutor
from pathlib import Path

logger = get_plugin_logger("static")


def transform_file_url(url: str, hash: str):
    url_path = Path(url)
    return str(url_path.with_stem(url_path.stem + "." + hash[:10]))

def hash_file(file: File) -> File:
    logger.debug("Hashing %s", file.url)

    hashed_file = deepcopy(file)

    with open(file.abs_src_path, "rb") as f:
        digest = hashlib.file_digest(f, "md5").hexdigest()

    hashed_file.abs_dest_path = transform_file_url(hashed_file.abs_dest_path, digest)
    hashed_file.dest_uri = transform_file_url(hashed_file.dest_uri, digest)
    hashed_file.url = transform_file_url(hashed_file.url, digest)

    return hashed_file

@event_priority(-100)
def on_files(files: Files, config):
    with ThreadPoolExecutor() as executor:
        for hashed_file in executor.map(hash_file, files.media_files()):
            files.append(hashed_file)

            # HACK: Add a fake file with a `src_uri` of the hashed path so other integrations can find the right file
            hashed_src_file = deepcopy(hashed_file)
            hashed_src_file.src_uri = hashed_src_file.dest_uri
            files.append(hashed_src_file)

    return files

def on_env(env: jinja2.Environment, config, files):
    env.add_extension(make_static_extension(files))
    env.add_extension(make_sri_extension(files))

    return env

def make_static_extension(files: Files):
    class StaticExtension(StandaloneTag):
        tags = {"static"}

        def render(self, filename):
            file = files.get_file_from_path(filename)

            if file is None:
                raise ValueError(f"Unable to find static file for {filename!r}")

            return f"/{file.url}"

    return StaticExtension


def make_sri_extension(files: Files):
    class SRIExtension(StandaloneTag):
        tags = {"sri_integrity"}

        def render(self, filename):
            file = files.get_file_from_path(filename)

            if file is None:
                raise ValueError(f"Unable to find static file for {filename!r}")

            with open(file.abs_src_path, "rb") as f:
                digest = hashlib.file_digest(f, "sha256").hexdigest()

            return f"sha256-{digest}"

    return SRIExtension