"""
Provides the `cmdeploy` entry point function,
along with command line option and subcommand parsing.
"""
import argparse
import datetime
import shutil
import subprocess
import importlib
import os
import sys
from pathlib import Path


from termcolor import colored
from chatmaild.config import read_config, write_initial_config


class Out:
    """Convenience print output printer providing coloring."""

    def red(self, msg, file=sys.stderr):
        print(colored(msg, "red"), file=file)

    def green(self, msg, file=sys.stderr):
        print(colored(msg, "green"), file=file)

    def __call__(self, msg, red=False, green=False, file=sys.stdout):
        color = "red" if red else ("green" if green else None)
        print(colored(msg, color), file=file)


description = """\
Setup your chatmail server configuration and
deploy it via SSH to your remote location.
"""


def add_config_option(parser):
    parser.add_argument(
        "--config",
        dest="inipath",
        action="store",
        default=Path("chatmail.ini"),
        type=Path,
        help="path to the chatmail.ini file",
    )


def add_subcommand(subparsers, func):
    name = func.__name__
    assert name.endswith("_cmd")
    name = name[:-4]
    doc = func.__doc__.strip()
    p = subparsers.add_parser(name, description=doc, help=doc)
    p.set_defaults(func=func)
    add_config_option(p)
    return p


def get_parser():
    """Return an ArgumentParser for the 'cmdeploy' CLI."""
    parser = argparse.ArgumentParser(description=description)
    subparsers = parser.add_subparsers(
        title="subcommands",
    )

    init_parser = add_subcommand(subparsers, init_cmd)
    init_parser.add_argument(
        "chatmail_domain",
        action="store",
        help="fully qualified DNS domain name for your chatmail instance",
    )

    install_parser = add_subcommand(subparsers, run_cmd)
    install_parser.add_argument(
        "--dry-run",
        dest="dry_run",
        action="store_true",
        help="don't actually modify the server",
    )

    add_subcommand(subparsers, webdev_cmd)

    add_subcommand(subparsers, test_cmd)

    add_subcommand(subparsers, dns_cmd)

    return parser


def init_cmd(args, out):
    """Initialize chatmail config file."""
    if args.inipath.exists():
        out.red(f"Path exists, not modifying: {args.inipath}")
        raise SystemExit(1)
    write_initial_config(args.inipath, args.chatmail_domain)
    out.green(f"created config file for {args.chatmail_domain} in {args.inipath}")


def run_cmd(args, out, config):
    """Deploy chatmail services on the remote server."""

    popen_args = ["pyinfra"]
    if args.dry_run:
        popen_args.append("--dry")
    popen_args.extend(["--ssh-user", "root", config.mailname])
    popen_args.append("deploy-chatmail/src/deploy_chatmail/deploy.py")

    out(f"{os.getcwd()} $ {' '.join(popen_args)}")
    env = os.environ.copy()
    env["CHATMAIL_DOMAIN"] = config.mailname
    subprocess.check_call(popen_args, env=env)


def webdev_cmd(args, out, config):
    """Run web development loop for static local web pages."""
    from .www import main

    main()


def test_cmd(args, out, config):
    """run Run web development loop for static local web pages."""

    tox = shutil.which("tox")
    subprocess.check_call([tox, "-c", "chatmaild"])
    subprocess.check_call([tox, "-c", "deploy-chatmail"])

    pytest_path = shutil.which("pytest")
    subprocess.check_call(
        [pytest_path, "tests/online", "-rs", "-x", "-vrx", "--durations=5"]
    )


def read_dkim_entries(entry):
    lines = []
    for line in entry.split("\n"):
        if line.startswith(";") or not line.strip():
            continue
        line = line.replace("\t", " ")
        lines.append(line)
    return "\n".join(lines)


def dns_cmd(args, out, config):
    """generate dns zone file."""
    template = importlib.resources.files(__package__).joinpath("chatmail.zone.f")
    ssh = f"ssh root@{config.mailname}"

    def shell_output(arg):
        return subprocess.check_output(arg, shell=True).decode()

    out(f"[retrieving info by invoking {ssh}]", file=sys.stderr)
    acme_account_url = shell_output(f"{ssh} -- acmetool account-url")
    dkim_entry = read_dkim_entries(shell_output(f"{ssh} -- opendkim-genzone -F"))

    out(
        f"[writing {config.mailname} zone data (using space as separator) to stdout output]",
        green=True,
    )
    print(
        template.read_text()
        .format(
            acme_account_url=acme_account_url,
            email=f"root@{config.mailname}",
            sts_id=datetime.datetime.now().strftime("%Y%m%d%H%M"),
            chatmail_domain=config.mailname,
            dkim_entry=dkim_entry,
        )
        .strip()
    )


def main(args=None):
    """Provide main entry point for 'xdcget' CLI invocation."""
    parser = get_parser()
    args = parser.parse_args(args=args)
    if not hasattr(args, "func"):
        return parser.parse_args(["-h"])
    out = Out()
    if args.func.__name__ != "init_cmd":
        if not args.inipath.exists():
            out.red(f"expecting {args.inipath} to exist, run init first?")
            raise SystemExit(1)
        try:
            config = read_config(args.inipath)
        except Exception as ex:
            out.red(ex)
            raise SystemExit(2)
        args.func(args, out, config)
    else:
        args.func(args, out)


if __name__ == "__main__":
    main()