import os
import socket

from django.views import View
from django.shortcuts import render

"""
RedisActiveConnections
RedisCommands
RedisConnects
RedisUsedMemory
RedisSize
"""


class RedisGrafanaMetric(View):
    category = "Redis"

    def autoconf(self):
        try:
            self.get_info()
        except socket.error:
            return False
        return True

    def get_info(self):
        host = os.environ.get("REDIS_HOST") or "127.0.0.1"
        port = int(os.environ.get("REDIS_PORT") or "6379")
        if host.startswith("/"):
            s = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
            s.connect(host)
        else:
            s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
            s.connect((host, port))
        s.send("*1\r\n$4\r\ninfo\r\n")
        buf = ""
        while "\r\n" not in buf:
            buf += s.recv(1024)
        l, buf = buf.split("\r\n", 1)
        if l[0] != "$":
            s.close()
            raise Exception("Protocol error")
        remaining = int(l[1:]) - len(buf)
        if remaining > 0:
            buf += s.recv(remaining)
        s.close()
        return dict(x.split(":", 1) for x in buf.split("\r\n") if ":" in x)

    def execute(self):
        stats = self.get_info()
        values = {}
        for k, v in self.get_fields():
            try:
                value = stats[k]
            except KeyError:
                value = "U"
            values[k] = value
        return values

    def get_fields(self):
        raise NotImplementedError("You must implement the get_fields function")

    def get_context(self):
        raise NotImplementedError("You must implement the get_context function")

    def get(self, request):
        context = self.get_context()
        return render(request, "monitor/prometheus_data.html", context, content_type="text/plain")


class RedisActiveConnection(RedisGrafanaMetric):
    def get_fields(self):
        return (
            (
                "connected_clients",
                dict(
                    label="connections",
                    info="connections",
                    type="GAUGE",
                ),
            ),
        )

    def get_context(self):
        raise NotImplementedError("You must implement the get_context function")