import hashlib
import json
import random
import binascii
import os
import xcat.trades as trades

ROOT_DIR = os.path.dirname(os.path.dirname(os.path.realpath(__file__)))


############################################
########### Data conversion utils ##########
############################################


def b(string):
    """Convert a string to bytes"""
    return str.encode(string)


def x(h):
    """Convert a hex string to bytes"""
    return binascii.unhexlify(h.encode('utf8'))


def b2x(b):
    """Convert bytes to a hex string"""
    return binascii.hexlify(b).decode('utf8')


def x2s(hexstring):
    """Convert hex to a utf-8 string"""
    return binascii.unhexlify(hexstring).decode('utf-8')


def s2x(string):
    """Convert a utf-8 string to hex"""
    return b2x(b(string))


def hex2dict(hexstr):
    jsonstr = x2s(hexstr)
    print(hexstr['fund_tx'])
    print(jsonstr)
    return json.loads(jsonstr)


def jsonformat(trade):
    return {
        'sell': trade.sell.__dict__,
        'buy': trade.buyContract.__dict__
    }


############################################
########### Preimage utils #################
############################################


def generate_password():
    s = ("1234567890abcdefghijklmnopqrstuvwxyz"
         "01234567890ABCDEFGHIJKLMNOPQRSTUVWXYZ")
    passlen = 32
    p = "".join(random.sample(s, passlen))
    return p


def sha256(secret):
    preimage = secret.encode('utf8')
    h = hashlib.sha256(preimage).digest()
    return h


############################################
######## Error handling for CLI ############
############################################


def throw(err):
    print(err)
    exit()


#############################################
#########  xcat.json temp file  #############
#############################################


tmp_dir = os.path.join(ROOT_DIR, '.tmp')
if not os.path.exists(tmp_dir):
    os.makedirs(tmp_dir)
xcatjson = os.path.join(tmp_dir, 'xcat.json')


def get_trade():
    with open(xcatjson) as data_file:
        xcatdb = json.load(data_file)
        sell = trades.Contract(xcatdb['sell'])
        buy = trades.Contract(xcatdb['buy'])
        trade = trades.Trade(sell, buy, commitment=xcatdb['commitment'])
        return trade


def erase_trade():
    try:
        with open(xcatjson, 'w') as outfile:
            outfile.write('')
    except:
        pass

# Dumping trade to json file for development and debugging
def save(trade):
    # print("Saving trade")
    trade = {
    'sell': trade.sell.__dict__,
    'buy': trade.buy.__dict__,
    'commitment': trade.commitment
    }
    save_trade(trade)

def save_trade(trade):
    with open(xcatjson, 'w+') as outfile:
        json.dump(trade, outfile)

# Remove tmp files when trade is complete
def cleanup(tradeid):
    try:
        os.remove(os.path.join(ROOT_DIR, '.tmp/{0}'.format(tradeid)))
    except:
        pass