"""Custom topology example

Three directly connected switches plus a host for each switch:

   host --- switch --- switch --- switch --- host

Adding the 'topos' dict with a key/value pair to generate our newly defined
topology enables one to pass in '--topo=mytopo' from the command line.
"""

from mininet.topo import Topo


class PathpolicyTopo(Topo):
    """Simple topology example."""

    def __init__(self):

        # Initialize topology
        Topo.__init__(self)

        # Add hosts and switches
        leftHost = self.addHost("h1")
        rightHost = self.addHost("h2")
        leftSwitch = self.addSwitch("s1")
        middleSwitch = self.addSwitch("s2")
        middleSwitch2 = self.addSwitch("s4")
        rightSwitch = self.addSwitch("s3")

        # Add links
        self.addLink(leftHost, leftSwitch)
        self.addLink(leftSwitch, middleSwitch)
        self.addLink(leftSwitch, middleSwitch2)
        self.addLink(middleSwitch, rightSwitch)
        self.addLink(middleSwitch2, rightSwitch)
        self.addLink(rightSwitch, rightHost)


topos = {"pathpolicytopo": (lambda: PathpolicyTopo())}