# -*- coding: utf-8 -*-
import hashlib
import json
import time


class Blockchain(object):

    def __init__(self):
        self.chain = []
        self.memPool = []
        self.createGenesisBlock()

    def createGenesisBlock(self):
        self.createBlock()

    def createBlock(self, nonce=0, previousHash=0):
        # Lembre que o hash do bloco anterior é o hash na verdade do CABEÇALHO do bloco anterior.


        if(len(self.chain)==0):
            Block = dict(
            index=0,
            timestamp=(int(time.time())),
            nonce=0,
            merkleRoot=0,
            previousHash=0,
            transactions=self.memPool)
        else:
            header = self.chain[-1].copy()
            header.pop("transactions")

            Block = dict(
            index=(len(self.chain))+1,
            timestamp=(int(time.time())),
            nonce=0,
            merkleRoot=0,
            previousHash=self.generateHash(header),
            transactions=self.memPool)

        self.chain.append(Block)



    @staticmethod
    def generateHash(data):
        blkSerial = json.dumps(data, sort_keys=True).encode()
        return hashlib.sha256(blkSerial).hexdigest()

    def printChain(self):
        for i in self.chain:
            header = self.chain[-1].copy()
            header.pop("transactions")
            print(header["previousHash"])
            print(json.dumps(i, sort_keys=True).encode())


blockchain = Blockchain()
for x in range(1, 4):
    blockchain.createBlock()
    blockchain.printChain()