artFi/app/dispatch.py

# Dispatches data to hasher and adds to database tables

import sqlalchemy
import os

from datetime import datetime
from flask import flash
from flask_login import current_user

from .models import Hashchain, Art, List, TX , User, Bids, List
from . import db

from app.lib import clean_file as cf
from app.lib import hasher as hsh 

def mint(designated_fn, art_name, art_desc, min_price, buyout_price, close_date):
    # gen filehash
    filehash = hsh.hashfile(f'{cf.UPLOAD_FOLDER}/{designated_fn}')
    # gen txhash (if exchanged or minted)
    ddt = datetime.utcnow().strftime("%Y-%m-%d %H:%M:%S")
    dt = sqlalchemy.func.now()
    txstring = f'[{filehash}, {ddt}, {current_user.id}, {current_user.id}, 0.0]' # minting
    txhash = hsh.gen_txhash(txstring)
    # fetch prev block hash OR GEN HASH
    try:
        prev_bhash = db.session.query(Hashchain).order_by(Hashchain.id.desc()).first().blockhash
        if prev_bhash is None:
            prev_bhash = hsh.GENESIS_HASH
    except:
        prev_bhash = hsh.GENESIS_HASH
    # gen block hash add to hashchain
    new_bhash = hsh.append_tx(txhash, prev_bhash)
    new_block = Hashchain(blockhash = new_bhash)
    db.session.add(new_block)
    # move the file into external secure storage (NOT DONE)
    os.rename(f'{cf.UPLOAD_FOLDER}/{designated_fn}', f'{cf.REPO_FOLDER}/{designated_fn}')
    # add to TX table (mint)
    new_tx = TX(
            filehash = filehash,
            datetime = dt,
            source_id = current_user.id,
            destination_id = current_user.id,
            price = 0.0,
            txhash = txhash
            )
    db.session.add(new_tx)
    # add to Art table
    new_art = Art(
            name = art_name,
            description = art_desc,
            filehash = filehash,
            owner = current_user.id,
            creator = current_user.id,
            dname = designated_fn
            )
    db.session.add(new_art)
    # add to List table
    new_listing = List(
            filehash = filehash,
            seller = current_user.id,
            min_price = min_price,
            out_price = buyout_price,
            timeout = close_date,
            )
    db.session.add(new_listing)

    try:
        db.session.commit() 
        flash('Minted & Listed!', category='success')
    except Exception:
        flash('Error Minting! Cannot Add an Already Existing File!', category='error')


def list_item(designated_fn, art_name, art_desc, min_price, buyout_price, close_date, filehash):
    # gen txhash
    ddt = datetime.utcnow().strftime("%Y-%m-%d %H:%M:%S")
    dt = sqlalchemy.func.now()
    txstring = f'[{filehash}, {ddt}, {current_user.id}, {current_user.id}, 0.0]' # listing
    txhash = hsh.gen_txhash(txstring)
    # fetch prev block hash OR GEN HASH
    try:
        prev_bhash = db.session.query(Hashchain).order_by(Hashchain.id.desc()).first().blockhash
        if prev_bhash is None:
            prev_bhash = hsh.GENESIS_HASH
    except:
        prev_bhash = hsh.GENESIS_HASH
    # gen block hash add to hashchain
    new_bhash = hsh.append_tx(txhash, prev_bhash)
    new_block = Hashchain(blockhash = new_bhash)
    db.session.add(new_block)
    # add to TX table (list)
    new_tx = TX(
            filehash = filehash,
            datetime = dt,
            source_id = current_user.id,
            destination_id = current_user.id,
            price = 0.0,
            txhash = txhash
            )
    db.session.add(new_tx)
    # add to List table
    new_listing = List(
            filehash = filehash,
            seller = current_user.id,
            min_price = min_price,
            out_price = buyout_price,
            timeout = close_date,
            )
    db.session.add(new_listing)

    db.session.commit() 

def tx_exchange(filehash, source_id, price, dest_id=None):
    if not dest_id:
        if current_user.is_authenticated:
            dest_id = current_user.id
            
    # create tx hash
    dt = sqlalchemy.func.now()
    ddt = datetime.utcnow().strftime("%Y-%m-%d %H:%M:%S")
    txstring = f'[{filehash}, {ddt}, {source_id}, {dest_id}, {price}]' # exchange
    txhash = hsh.gen_txhash(txstring)
    # fetch prev block hash OR GEN HASH
    try:
        prev_bhash = db.session.query(Hashchain).order_by(Hashchain.id.desc()).first().blockhash
        if prev_bhash is None:
            prev_bhash = hsh.GENESIS_HASH
    except:
        prev_bhash = hsh.GENESIS_HASH
    # gen block hash add to hashchain
    new_bhash = hsh.append_tx(txhash, prev_bhash)
    new_block = Hashchain(blockhash = new_bhash)
    db.session.add(new_block)

    new_tx = TX(
        filehash = filehash,
        datetime = dt,
        source_id = source_id,
        destination_id = dest_id,
        price = price,
        txhash = txhash
        )

    # add to TX table (exchange)
    db.session.add(new_tx)

    # remove from List table
    List.query.filter_by(filehash = filehash).delete()

    # change owner at Art table
    dbcall = Art.query.filter_by(filehash = filehash).first()
    dbcall.owner = dest_id

    db.session.commit()

def clean_bid_table(filehash):
    # cleans Bid table when Artwork is bought
    old_bids = Bids.query.filter_by(filehash = filehash).all()
    for bid in old_bids:
        db.session.delete(bid)
    db.session.commit()

def enter_bid(user_bid, focus):
    # add to Bids table
    new_bid = Bids(
        filehash = current_user.focus,
        buyer = current_user.id,
        bid_price = user_bid
            )
    db.session.add(new_bid)
    # update List table
    dbcall = List.query.filter_by(filehash = current_user.focus).first()
    dbcall.min_price = user_bid
    dbcall.cur_bid = user_bid
    db.session.commit()

def save_pp(pp_path):
    new_pppath =  User.query.filter_by(id=current_user.id).first()
    new_pppath.profile_image = pp_path
    db.session.commit()

def check_auction_end():
    # background scheduler runs this daily
    # to check for Auction end
    all_listings = List.query.all()

    # go through List table and check for timeout
    for listing in all_listings:
        # if close_date and min bid reached
        ddt = datetime.utcnow().strftime("%Y-%m-%d")
        if listing.timeout == ddt and listing.cur_bid > listing.min_price:
            print(f'DEBUG: scheduler >>> EXCHANGING!!') ##
            # transaction for the last bid made
            # get buyer id from Bids table using filehash
            buyer_bid = Bids.query.filter_by(filehash = listing.filehash).order_by(desc(Bids.id)).first()
            # initiate exchange transaction and clean bid table
            tx_exchange(listing.filehash, listing.seller, buyer_bid.bid_price, buyer_bid.buyer)
            clean_bid_table(listing.filehash)
        # if close_date and min bid not reached (no one made a qualifying bid)
        elif listing.timeout == ddt and not listing.cur_bid > listing.min_price:
            print(f'DEBUG: scheduler >>> DE-LISTING!!') ##
            # remove from List table
            List.query.filter_by(filehash = filehash).delete()