Casper.py

from CasperNode import CasperNode
import random
# each block will bet against a block using its stake. If they are selected to add the block they will
# earn a reward proportional to their stake.

# if however they are seen to misbehave their stake is slashed

# Author: Glenn Dollard

class Casper:
    stake = 0;

    nodes = []

    def bootstrap(self):
        num_nodes = input("Enter the number of Nodes: ")
        try:
            num_nodes = int(num_nodes)
        except ValueError:
            print("Invalid argument supplied, quitting.")
            # quit the program if we have invalid data
            exit()
        for counter in range(num_nodes):
            new_node = CasperNode(random.randrange(1, 101), "Casper_node_" + str(counter))
            self.nodes.append(new_node)

        for node in self.nodes:
            node.register(self.nodes)

    def get_tickets_for_nodes(self):
        tickets = []
        for node in self.nodes:
            print("Node stake: ", node.stake)
            for index in range(int(node.stake)):
                tickets.append(node)
        return tickets

    # Kicks off the proposal
    def begin(self, block):

        # select the leader, this leader will be the one determining whether to add the block or not
        # Pick a proposer weighted on their stake
        tickets_for_nodes = self.get_tickets_for_nodes()
        random_leader_index = random.randrange(len(tickets_for_nodes))
        leader = tickets_for_nodes[random_leader_index]
        block.bet_stake(leader.get_stake_to_bet())


        # implement the functions below in the Casper Node

        # let the first node propose (for now)
        for node in self.nodes:
            node.prepare(block, leader)

        for node in self.nodes:
            node.commit()

        # simulated end-of-rounds, get the result from the leader
        # if should be added then reward the leader with a fee proportional to their stake
        return leader.should_block_be_added()