import datetime
import os
import shutil

import yaml
from django.conf import settings
from django.utils import timezone

from common.db.utils import safe_db_connection
from common.utils import get_logger, random_string
from ops.ansible import PlaybookRunner, JMSInventory
from terminal.models import Applet, AppletHostDeployment

logger = get_logger(__name__)
CURRENT_DIR = os.path.dirname(os.path.abspath(__file__))


class DeployAppletHostManager:
    def __init__(self, deployment: AppletHostDeployment, applet: Applet = None):
        self.deployment = deployment
        self.applet = applet
        self.run_dir = self.get_run_dir()

    @staticmethod
    def get_run_dir():
        base = os.path.join(settings.ANSIBLE_DIR, "applet_host_deploy")
        now = datetime.datetime.now().strftime("%Y%m%d%H%M%S")
        return os.path.join(base, now)

    def run(self, **kwargs):
        self._run(self._run_initial_deploy, **kwargs)

    def install_applet(self, **kwargs):
        self._run(self._run_install_applet, **kwargs)

    def _run_initial_deploy(self, **kwargs):
        playbook = self.generate_initial_playbook
        return self._run_playbook(playbook, **kwargs)

    def _run_install_applet(self, **kwargs):
        if self.applet:
            generate_playbook = self.generate_install_applet_playbook
        else:
            generate_playbook = self.generate_install_all_playbook
        return self._run_playbook(generate_playbook, **kwargs)

    def generate_initial_playbook(self):
        site_url = settings.SITE_URL
        download_host = settings.APPLET_DOWNLOAD_HOST
        bootstrap_token = settings.BOOTSTRAP_TOKEN
        host_id = str(self.deployment.host.id)
        if not site_url:
            site_url = "http://localhost:8080"
        options = self.deployment.host.deploy_options
        core_host = options.get("CORE_HOST", site_url)
        core_host = core_host.rstrip("/")
        if not download_host:
            download_host = core_host
        download_host = download_host.rstrip("/")

        def handler(plays):
            applet_host_name = self.deployment.host.name
            hostname = '{}-{}'.format(applet_host_name, random_string(7))
            for play in plays:
                play["vars"].update(options)
                play["vars"]["APPLET_DOWNLOAD_HOST"] = download_host
                play["vars"]["CORE_HOST"] = core_host
                play["vars"]["BOOTSTRAP_TOKEN"] = bootstrap_token
                play["vars"]["HOST_ID"] = host_id
                play["vars"]["HOST_NAME"] = hostname
            return plays

        return self._generate_playbook("playbook.yml", handler)

    def generate_install_all_playbook(self):
        return self._generate_playbook("install_all.yml")

    def generate_install_applet_playbook(self):
        applet_name = self.applet.name
        options = self.deployment.host.deploy_options

        def handler(plays):
            for play in plays:
                play["vars"].update(options)
                play["vars"]["applet_name"] = applet_name
            return plays

        return self._generate_playbook("install_applet.yml", handler)

    def generate_inventory(self):
        inventory = JMSInventory(
            [self.deployment.host], account_policy="privileged_only"
        )
        inventory_dir = os.path.join(self.run_dir, "inventory")
        inventory_path = os.path.join(inventory_dir, "hosts.yml")
        inventory.write_to_file(inventory_path)
        return inventory_path

    def _generate_playbook(self, playbook_template_name, plays_handler: callable = None):
        playbook_src = os.path.join(CURRENT_DIR, playbook_template_name)
        with open(playbook_src) as f:
            plays = yaml.safe_load(f)
        if plays_handler:
            plays = plays_handler(plays)
        playbook_dir = os.path.join(self.run_dir, "playbook")
        playbook_dst = os.path.join(playbook_dir, "main.yml")
        os.makedirs(playbook_dir, exist_ok=True)
        with open(playbook_dst, "w") as f:
            yaml.safe_dump(plays, f)
        return playbook_dst

    def _run_playbook(self, generate_playbook: callable, **kwargs):
        inventory = self.generate_inventory()
        playbook = generate_playbook()
        runner = PlaybookRunner(
            inventory=inventory, playbook=playbook, project_dir=self.run_dir
        )
        return runner.run(**kwargs)

    def delete_runtime_dir(self):
        if settings.DEBUG_DEV:
            return
        shutil.rmtree(self.run_dir)

    def _run(self, cb_func: callable, **kwargs):
        try:
            self.deployment.date_start = timezone.now()
            cb = cb_func(**kwargs)
            self.deployment.status = cb.status
        except Exception as e:
            logger.error("Error: {}".format(e))
            self.deployment.status = "error"
        finally:
            self.deployment.date_finished = timezone.now()
            with safe_db_connection():
                self.deployment.save()
        self.delete_runtime_dir()