main.py

from flask import Flask, jsonify, request, render_template, redirect, url_for 
from backend import Blockchain
import json


# Web App named app
app = Flask(__name__)

# Initializing class here
blockchain = Blockchain()

# Registered Voters with unique Identity
voterID_array = [
    'VOID001', 'VOID002', 'VOID003', 
    'VOID004', 'VOID005', 'VOID006', 
    'VOID007', 'VOID008', 'VOID009', 
    'VOID010', 'VOID011', 'VOID012',
    'VOID013', 'VOID014', 'VOID015']  
    
# For Reference
vote_see_chain = voterID_array.copy() 
vote_check = voterID_array.copy() 
minerID_array = [
  'MOID001', 'MOID002', 'MOID003']

@app.route('/', methods=['GET', 'POST'])
def start():
  # Miners Home Page
  if request.method == 'POST':
    user = request.form["minerID"]
    if user in minerID_array and request.form['submit'] == 'mine':
      return redirect(url_for('mine'))
    if request.form['submit'] == 'vote':
      return redirect(url_for('initial'))
    if user in minerID_array and request.form['submit'] == 'vote':
      return '<h3>A miner with Miner ID cannot vote</h3>'
    else:
      return redirect(url_for("control", User="Miner", ID=user))
  else:
    return render_template('index.html')

# For Better User Interface
@app.route('/voter', methods=['POST', 'GET']) 
def initial():
  # Voters Home Page
  if request.method == 'POST':
    user = request.form["voterID"]
    if user in vote_see_chain and request.form["submit"] == 'see_chain':
        return redirect(url_for('full_chain'))
    if user in voterID_array and request.form["submit"] == 'new_vote':
        return redirect(url_for("put_vote", name=user))           
    else:
      return redirect(url_for("control", User="Voter", ID=user))
  else:
    return render_template('initial.html')


@app.route('/<User>_repeat/<ID>') 
def control(User, ID):
  # CONTROL Reload and Back Reference After Vote
  return render_template("repeat.html", User=User, ID=ID)

@app.route('/put_vote/<name>', methods=['POST', 'GET']) 
def put_vote(name):
  # POLL vote by Voter
  if request.method == 'POST' and name in voterID_array:
    voterID_array.remove(name)
    option = request.form['vote']
    return redirect(url_for("new_transaction", name=name, option=option))
  else:
    return render_template("fillup.html")

# The process of Mining
# This takes up the transactions done recently
# and put all into a block and append to the chain 
@app.route('/mine/', methods=['GET'])
def mine():
  last_block = blockchain.last_block
  last_proof = last_block['proof']
  proof = blockchain.proof_of_work(last_proof)

  block = blockchain.new_block(proof) 
  data = {
    'message': "New Block Mined",
    'index': block['index'],
    'transactions': block['transactions'], 'proof': block['proof'],
    'previous_hash': block['previous_hash'],
  }
  response = app.response_class(
    response=json.dumps(data, indent=2), status=200,
    mimetype='application/json'
  )
  return response

# New Votes are done here
@app.route('/vote/new/<name>/<option>', methods=['GET', 'POST'])
def new_transaction(name, option): 
  if request.method == "POST":
    values = request.get_json()
    # Check that the required fields are in the POST'ed data 
    required = ['Party_A', 'Party_B'] 
    required = [name, option]
    
    # Part_A is the nominee participating in the elections 
    # Party_B is the voter who votes
    if not all(k in values for k in required):
      return 'Missing values', 400
    
    # Create a new Transaction
    """name=values['Party_B']
    option=values['Party_A']"""
  if name not in vote_check:
    return redirect(url_for("control", User="Voter", ID=name)) 
  else:
    vote_check.remove(name)


  index = blockchain.new_transaction(name, option) 
  data = {
    'message': f'Transaction(The vote) will be added to Block {index}'} 
  response = app.response_class(
    response=json.dumps(data, indent=2),
    status=201,
    mimetype='application/json'
  )
  return response

@app.route('/chain/', methods=['GET'])
def full_chain():
  # Displays the whole block chain 
  data = {
    'chain': blockchain.chain, 
    'length': len(blockchain.chain),
  }
  response = app.response_class(
    response = json.dumps(data, indent=2),
    status = 200,
    mimetype = 'application/json'
  )
  return response

@app.route('/result', methods=['GET'])
def see_result():
    result = blockchain.see_result()
    return jsonify(result)


if __name__ == '__main__':
  # App starts
  app.run(host = 'localhost', port = 5000, debug = True)