# Creates a Droplet on DigitalOcean for remote Zulip development.
# Particularly useful for sprints/hackathons, interns, and other
# situation where one wants to quickly onboard new contributors.
#
# This script takes one argument: the name of the GitHub user for whom you want
# to create a Zulip developer environment. Requires Python 3.
#
# Requires python-digitalocean library:
# https://github.com/koalalorenzo/python-digitalocean
#
# Also requires DigitalOcean team membership for Zulip and API token:
# https://cloud.digitalocean.com/settings/api/tokens
#
# Copy conf.ini-template to conf.ini and populate with your API token.
#
# usage: python3 create.py <username>
import argparse
import configparser
import json
import os
import sys
import time
import urllib.error
import urllib.request
from typing import Any, Dict, List

import digitalocean

# initiation argument parser
parser = argparse.ArgumentParser(description="Create a Zulip devopment VM DigitalOcean droplet.")
parser.add_argument(
    "username", help="GitHub username for whom you want to create a Zulip dev droplet"
)
parser.add_argument("--tags", nargs="+", default=[])
parser.add_argument("-f", "--recreate", action="store_true")


def get_config() -> configparser.ConfigParser:
    config = configparser.ConfigParser()
    config.read(os.path.join(os.path.dirname(os.path.abspath(__file__)), "conf.ini"))
    return config


def assert_github_user_exists(github_username: str) -> bool:
    print(f"Checking to see if GitHub user {github_username} exists...")
    user_api_url = f"https://api.github.com/users/{github_username}"
    try:
        response = urllib.request.urlopen(user_api_url)
        json.load(response)
        print("...user exists!")
        return True
    except urllib.error.HTTPError as err:
        print(err)
        print(f"Does the GitHub user {github_username} exist?")
        sys.exit(1)


def get_keys(username: str) -> List[Dict[str, Any]]:
    print("Checking to see that GitHub user has available public keys...")
    apiurl_keys = f"https://api.github.com/users/{username}/keys"
    try:
        response = urllib.request.urlopen(apiurl_keys)
        userkeys = json.load(response)
        if not userkeys:
            print(f"No keys found. Has user {username} added SSH keys to their GitHub account?")
            sys.exit(1)
        print("...public keys found!")
        return userkeys
    except urllib.error.HTTPError as err:
        print(err)
        print(f"Has user {username} added SSH keys to their GitHub account?")
        sys.exit(1)


def fork_exists(username: str) -> bool:
    print("Checking to see GitHub user has forked zulip/zulip...")
    apiurl_fork = f"https://api.github.com/repos/{username}/zulip"
    try:
        response = urllib.request.urlopen(apiurl_fork)
        json.load(response)
        print("...fork found!")
        return True
    except urllib.error.HTTPError as err:
        print(err)
        print(f"Has user {username} forked zulip/zulip?")
        sys.exit(1)


def assert_droplet_does_not_exist(my_token: str, droplet_name: str, recreate: bool) -> None:
    print(f"Checking to see if droplet {droplet_name} already exists...")
    manager = digitalocean.Manager(token=my_token)
    my_droplets = manager.get_all_droplets()
    for droplet in my_droplets:
        if droplet.name.lower() == droplet_name:
            if not recreate:
                print(
                    "Droplet {} already exists. Pass --recreate if you "
                    "need to recreate the droplet.".format(droplet_name)
                )
                sys.exit(1)
            else:
                print(f"Deleting existing droplet {droplet_name}.")
                droplet.destroy()
                return
    print("...No droplet found...proceeding.")


def get_ssh_keys_string_from_github_ssh_key_dicts(userkey_dicts: List[Dict[str, Any]]) -> str:
    return "\n".join([userkey_dict["key"] for userkey_dict in userkey_dicts])


def set_user_data(username: str, userkey_dicts: List[Dict[str, Any]]) -> str:
    ssh_keys_string = get_ssh_keys_string_from_github_ssh_key_dicts(userkey_dicts)
    setup_root_ssh_keys = f"printf '{ssh_keys_string}' > /root/.ssh/authorized_keys"
    setup_zulipdev_ssh_keys = f"printf '{ssh_keys_string}' > /home/zulipdev/.ssh/authorized_keys"

    # We pass the hostname as username.zulipdev.org to the DigitalOcean API.
    # But some droplets (eg on 18.04) are created with with hostname set to just username.
    # So we fix the hostname using cloud-init.
    hostname_setup = f"hostnamectl set-hostname {username}.zulipdev.org"

    setup_repo = (
        "cd /home/zulipdev/{1} && "
        "git remote add origin https://github.com/{0}/{1}.git && "
        "git fetch origin && "
        "git clean -f"
    )

    server_repo_setup = setup_repo.format(username, "zulip")
    python_api_repo_setup = setup_repo.format(username, "python-zulip-api")

    cloudconf = f"""\
#!/bin/bash

{setup_zulipdev_ssh_keys}
{setup_root_ssh_keys}
sed -i "s/PasswordAuthentication yes/PasswordAuthentication no/g" /etc/ssh/sshd_config
service ssh restart
{hostname_setup}
su -c '{server_repo_setup}' zulipdev
su -c '{python_api_repo_setup}' zulipdev
su -c 'git config --global core.editor nano' zulipdev
su -c 'git config --global pull.rebase true' zulipdev
"""
    print("...returning cloud-config data.")
    return cloudconf


def create_droplet(
    my_token: str, template_id: str, name: str, tags: List[str], user_data: str
) -> str:
    droplet = digitalocean.Droplet(
        token=my_token,
        name=name,
        region="nyc3",
        image=template_id,
        size_slug="s-1vcpu-2gb",
        user_data=user_data,
        tags=tags,
        backups=False,
    )

    print("Initiating droplet creation...")
    droplet.create()

    incomplete = True
    while incomplete:
        actions = droplet.get_actions()
        for action in actions:
            action.load()
            print(f"...[{action.type}]: {action.status}")
            if action.type == "create" and action.status == "completed":
                incomplete = False
                break
        if incomplete:
            time.sleep(15)
    print("...droplet created!")
    droplet.load()
    print(f"...ip address for new droplet is: {droplet.ip_address}.")
    return droplet.ip_address


def delete_existing_records(records: List[digitalocean.Record], record_name: str) -> None:
    count = 0
    for record in records:
        if record.name == record_name and record.domain == "zulipdev.org" and record.type == "A":
            record.destroy()
            count = count + 1
    if count:
        print(f"Deleted {count} existing A records for {record_name}.zulipdev.org.")


def create_dns_record(my_token: str, record_name: str, ip_address: str) -> None:
    domain = digitalocean.Domain(token=my_token, name="zulipdev.org")
    domain.load()
    records = domain.get_records()

    delete_existing_records(records, record_name)
    wildcard_name = "*." + record_name
    delete_existing_records(records, wildcard_name)

    print(f"Creating new A record for {record_name}.zulipdev.org that points to {ip_address}.")
    domain.create_new_domain_record(type="A", name=record_name, data=ip_address)
    print(f"Creating new A record for *.{record_name}.zulipdev.org that points to {ip_address}.")
    domain.create_new_domain_record(type="A", name=wildcard_name, data=ip_address)


def print_completion(droplet_domain_name: str) -> None:
    print(
        """
COMPLETE! Droplet for GitHub user {0} is available at {0}.zulipdev.org.

Instructions for use are below. (copy and paste to the user)

------
Your remote Zulip dev server has been created!

- Connect to your server by running
  `ssh zulipdev@{0}` on the command line
  (Terminal for macOS and Linux, Bash for Git on Windows).
- There is no password; your account is configured to use your SSH keys.
- Once you log in, you should see `(zulip-py3-venv) ~$`.
- To start the dev server, `cd zulip` and then run `./tools/run-dev.py`.
- While the dev server is running, you can see the Zulip server in your browser at
  http://{0}:9991.
""".format(
            droplet_domain_name
        )
    )

    print(
        "See [Developing remotely](https://zulip.readthedocs.io/en/latest/development/remote.html) "
        "for tips on using the remote dev instance and "
        "[Git & GitHub Guide](https://zulip.readthedocs.io/en/latest/git/index.html) "
        "to learn how to use Git with Zulip.\n"
    )
    print(
        "Note that this droplet will automatically be deleted after a month of inactivity. "
        "If you are leaving Zulip for more than a few weeks, we recommend pushing all of your "
        "active branches to GitHub."
    )
    print("------")


if __name__ == "__main__":
    # define id of image to create new droplets from
    # You can get this with something like the following. You may need to try other pages.
    # Broken in two to satisfy linter (line too long)
    # curl -X GET -H "Content-Type: application/json" -u <API_KEY>: "https://api.digitaloc
    # ean.com/v2/images?page=5" | grep --color=always base.zulipdev.org
    template_id = "63219191"

    # get command line arguments
    args = parser.parse_args()
    username = args.username.lower()
    print(f"Creating Zulip developer environment for GitHub user {username}...")

    subdomain = username
    droplet_domain_name = f"{subdomain}.zulipdev.org"

    # get config details
    config = get_config()

    assert_github_user_exists(github_username=username)

    # grab user's public keys
    public_keys = get_keys(username=username)

    # now make sure the user has forked zulip/zulip
    fork_exists(username=username)

    api_token = config["digitalocean"]["api_token"]
    assert_droplet_does_not_exist(
        my_token=api_token, droplet_name=droplet_domain_name, recreate=args.recreate
    )

    # set user_data
    user_data = set_user_data(username=username, userkey_dicts=public_keys)

    # create droplet
    ip_address = create_droplet(
        my_token=api_token,
        template_id=template_id,
        name=droplet_domain_name,
        tags=args.tags,
        user_data=user_data,
    )

    create_dns_record(my_token=api_token, record_name=subdomain, ip_address=ip_address)

    print_completion(droplet_domain_name=droplet_domain_name)

    sys.exit(1)