import os
import re
from pathlib import Path
from typing import List
from .templating import jinja
import glob

DOMAINS_RE = re.compile(
    r"^(((?!-))(xn--|_)?[a-z0-9-]{0,61}[a-z0-9]{1,1}\.)*(xn--)?([a-z0-9][a-z0-9\-]{0,60}|[a-z0-9-]{1,30}\.[a-z]{2,})$"
)


def _walk_nginx_conf(nginx_conf: Path):
    """Recursively finds all configuration files of a nginx config"""

    # this path is not necessarily correct... someone could have a weird prefix and
    # conf file combination
    conf_dir = nginx_conf.parent

    stack = [nginx_conf]

    while len(stack):
        file = stack.pop()
        conf = file.read_text()

        yield file, conf

        for include in re.finditer(r"(?:^|\n\s*|[{;]\s*)include (.+);", conf):
            pattern = include.group(1)
            for file in glob.glob(
                pattern if pattern.startswith("/") else f"{conf_dir}/pattern"
            ):
                stack.append(Path(file))


def gather_autossl_directives(nginx_conf: Path):
    """
    Finds #AUTOSSL directives inside an nginx configuration. The server_name
    must be on a separate line. (which it usually is)
    """
    directives = []
    for _, conf in _walk_nginx_conf(nginx_conf):
        for directive in re.finditer(
            r"(?:^|\n\s*|[{;]\s*)server_name (.*); *# *AUTOSSL *> *(\S+)", conf
        ):
            domains, alias = directive.groups()
            domains = domains.split()

            if any(not re.match(DOMAINS_RE, domain) for domain in domains):
                raise ValueError(
                    f"Cannot get SSL cert for \"{''.join(domains)}\". Invalid domains."
                )

            if not re.match(r"^[a-zA-Z0-9-_]+$", alias):
                raise ValueError(f'Invalid cert alias "{alias}"')

            directives.append((domains, alias))

    return directives


def get_site_files(nginx_dir: Path) -> List[Path]:
    names = []
    for file in (nginx_dir / "sites").iterdir():
        if file.is_file() and re.match(r"\d+-.+\.conf", file.name):
            names.append(file)

    return names


def build_domains_txt(directives):
    return (
        "\n".join(" ".join(domains) + " > " + alias for domains, alias in directives)
        + "\n"
    )


def generate_ssl_configs(dir: Path, cert_aliases: List[str]):
    for alias in cert_aliases:
        file = dir / (alias + ".conf")
        template = jinja.get_template("ssl.conf")
        file.write_text(template.render(alias=alias))