#!/usr/bin/env python3

"""
Update Mailman 2 lists via a json API of the form {"LIST": ["ADDRESS", ...]}
"""

import argparse
from dataclasses import dataclass
import os
from pathlib import Path
import secrets
import string
import subprocess
import tempfile

import requests

PASSWORD_CHARS = string.ascii_letters + string.digits + string.punctuation
PASSWORD_LEN = 18


@dataclass
class ListManager:
    mailman_bin: Path
    list_name: str
    dry_run: bool

    def newlist(self, urlhost: str, admin: str):
        password = "".join(secrets.choice(PASSWORD_CHARS) for i in range(PASSWORD_LEN))

        output = subprocess.run(
            [
                self.mailman_bin / "newlist",
                "--quiet",
                f"--urlhost={urlhost}",
                self.list_name,
                admin,
                password,
            ],
            encoding="ascii",
            capture_output=True,
            check=True,
        )
        for line in output.stdout.splitlines():
            print(f"[Creating {self.list_name}] {line}")

    def config_list(self):
        config_changes = """
# TODO: set real_name, moderator, subject prefix, and reply-to address
from_is_list = 1
anonymous_list = 1
first_strip_reply_to = 1
reply_goes_to_list = 2

# quiet member management
send_reminders = 0
send_welcome_msg = 0
send_goodbye_msg = 0

new_member_options = 272
advertised = 0
private_roster = 2  # only admins can view the roster
default_member_moderation = 1

generic_nonmember_action = 3  # discard non-member emails
forward_auto_discards = 0  # don't notify admin about discards
"""

        with tempfile.NamedTemporaryFile("w", suffix=".py") as config_file:
            config_file.write(config_changes)
            config_file.flush()

            command = [
                self.mailman_bin / "config_list",
                "--inputfile",
                config_file.name,
                self.list_name,
            ]
            if self.dry_run:
                command.append("--checkonly")

            output = subprocess.run(
                command,
                encoding="ascii",
                capture_output=True,
                check=True,
            )
            for line in output.stdout.splitlines():
                print(f"[Configuring {self.list_name}] {line}")

    def sync_members(self, members: list[str]):
        command = [
            self.mailman_bin / "sync_members",
            "--welcome-msg=no",
            "--goodbye-msg=no",
            "--notifyadmin=no",
            "--file",
            "-",
            self.list_name,
        ]
        if self.dry_run:
            command.append("--no-change")

        members_data = "\n".join(members)
        output = subprocess.run(
            command,
            input=members_data,
            encoding="ascii",
            capture_output=True,
            check=True,
        )
        for line in output.stdout.splitlines():
            print(f"[Syncing {self.list_name}] {line}")


def main(
    mailman_bin: Path,
    api: str,
    api_auth: str,
    list_suffix: str,
    dry_run: bool,
    urlhost: str,
    admin: str,
):
    r = requests.get(api, headers={"Authorization": api_auth})
    if not r.ok:
        print(f"Failed to get mailing list data from api: {r.status_code} {r.text}")
        return

    existing_lists = subprocess.run(
        [mailman_bin / "list_lists", "-b"],
        encoding="ascii",
        capture_output=True,
        check=True,
    ).stdout.split("\n")
    certification_lists = r.json()
    for name, members in certification_lists.items():
        list_name = name + list_suffix
        list_manager = ListManager(mailman_bin, list_name, dry_run)
        if list_name not in existing_lists:
            if dry_run:
                print(f"Skipping non-existing list {list_name} in dry run mode")
                continue
            else:
                list_manager.newlist(urlhost, admin)

        print(f"Configuring/syncing {list_name}...")
        list_manager.config_list()
        list_manager.sync_members(members)


def parse_arguments():
    argp = argparse.ArgumentParser(description=__doc__)
    argp.add_argument(
        "--bin",
        default="/usr/local/mailman",
        type=Path,
        help="Path to Mailman site admin scripts (default %(default)s)",
    )
    argp.add_argument("--api", required=True, help="API endpoint to retrieve JSON from")
    argp.add_argument("--list-suffix", help="Suffix for mailing lists")
    argp.add_argument("--urlhost", help="Urlhost to use when creating new lists")
    argp.add_argument(
        "--admin", help="Admin email address to use when creating new lists"
    )
    argp.add_argument(
        "-n",
        "--dry-run",
        action="store_true",
        help="Don't make changes, just print what would happen",
    )
    return argp.parse_args()


if __name__ == "__main__":
    args = parse_arguments()

    if "API_AUTH" in os.environ:
        api_auth = os.environ.get("API_AUTH")
    else:
        print("Missing API_AUTH environment variable")
        exit(-1)

    try:
        main(
            args.bin,
            args.api,
            api_auth,
            args.list_suffix,
            args.dry_run,
            args.urlhost,
            args.admin,
        )
    except subprocess.CalledProcessError as e:
        print(e.stderr)
        raise