import asyncio
import socket
import time
from collections import namedtuple
from urllib.parse import urlparse

import aiohttp
import psutil
from aiohttp import ClientConnectorError
from bs4 import BeautifulSoup
from django.views.generic import TemplateView
from humanize import naturalsize

from sdbs_infra.dashboard.models import Service, ServiceStatus, Link


class IndexView(TemplateView):
    template_name = "index.html"

    def get_context_data(self, **kwargs):

        return {
            'links': asyncio.run(self.process_links(list(Link.objects.all()))),
            'services': asyncio.run(self.process_services(list(Service.objects.all()))),
            'vps_stats': self.vps_stats()
        }

    async def process_links(self, links):
        result = []

        session = aiohttp.ClientSession(timeout=aiohttp.ClientTimeout(total=5, sock_connect=1))

        for link in links:
            index_text = None
            if not link.image:
                try:
                    async with session.get(link.url) as response:
                        index_status, index_text = response.status, await response.text()
                except (asyncio.TimeoutError, ClientConnectorError):
                    pass

            image = link.image.url if link.image else self.extract_favicon(link.url, index_text)

            result.append({
                'image_url': image,
                **vars(link)
            })

        await session.close()
        return result

    async def process_services(self, services):
        result = []

        session = aiohttp.ClientSession(timeout=aiohttp.ClientTimeout(total=5, sock_connect=1))

        for service in services:
            index_status, index_text = None, None
            if not service.port or not service.image:
                try:
                    async with session.get(service.url) as response:
                        index_status, index_text = response.status, await response.text()
                except (asyncio.TimeoutError, ClientConnectorError):
                    pass

            if service.port:
                a_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
                location = ("localhost", service.port)
                result_of_check = a_socket.connect_ex(location)
                if result_of_check == 0:
                    status = ServiceStatus.OK
                else:
                    status = ServiceStatus.DOWN
            elif index_status:
                status = ServiceStatus.OK if index_status == 200 else ServiceStatus.DOWN
            else:
                status = ServiceStatus.UNKNOWN

            image = service.image.url if service.image else self.extract_favicon(service.url, index_text)

            result.append({
                'status': status.value,
                'image_url': image,
                **vars(service)
            })

        await session.close()
        return result

    @staticmethod
    def extract_favicon(url, index_text):
        if not index_text:
            return None

        scheme, netloc, *_ = urlparse(url)
        base_url = (f"{scheme}://" if scheme else "") + netloc

        parsed_html = BeautifulSoup(index_text, features="html.parser")
        link_tags = parsed_html.find_all('link')
        for rel in ['apple-touch-icon', 'shortcut', 'icon']:
            for link_tag in link_tags:
                if rel in link_tag.attrs['rel']:
                    href = link_tag.attrs['href']
                    if netloc not in href and not (href.startswith("//") or href.startswith("http")):
                        image = base_url + (href if href.startswith("/") else f"/{href}")
                    else:
                        image = href
                    return image

    # noinspection PyListCreation
    @staticmethod
    def vps_stats():
        stats = []

        stats.append(f"<em>LOAD AVG:</em> {', '.join(map(str, psutil.getloadavg()))}")

        memory = psutil.virtual_memory()
        stats.append(
            f"<em>MEM:</em> {naturalsize(memory.used)}/{naturalsize(memory.total)} ({memory.percent}% USED)"
        )

        disk = psutil.disk_usage('/')
        stats.append(
            f"<em>DISK:</em> {naturalsize(disk.used)}/{naturalsize(disk.total)} ({disk.percent}% USED)"
        )

        uptime = normalize_seconds(time.time() - psutil.boot_time())

        stats.append(
            f"<em>UPTIME:</em> {int(uptime.days)} days, {int(uptime.hours)} hours, {int(uptime.minutes)} minutes"
        )

        return " / ".join(map(lambda stat: stat.replace(" ", "&nbsp;"), stats))


def normalize_seconds(seconds: int):
    (days, remainder) = divmod(seconds, 86400)
    (hours, remainder) = divmod(remainder, 3600)
    (minutes, seconds) = divmod(remainder, 60)

    return namedtuple("_", ("days", "hours", "minutes", "seconds"))(days, hours, minutes, seconds)