from typing import Optional, Union
from urllib.parse import urlparse
from fastapi import FastAPI, Request
from fastapi.responses import JSONResponse
import time, socket
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker
from sqlalchemy.pool import QueuePool
import uvicorn

#local
from rpcs import RPCHost, RPCXMR
from models import Return
from meta import Queue
from functions import checksumCheck, validDns
import config

class ErrorException(Exception):
    def __init__(self, code: str, status: str, status_message: str):
        self.status = status
        self.code = code
        self.status_message = status_message

app = FastAPI()

@app.get("/")
def root():
    return

@app.exception_handler(ErrorException)
def unicorn_exception_handler(request: Request, exc: ErrorException):
    return JSONResponse(
        status_code=exc.code,
        content={
            "status": f"{exc.status}",
            "message": f"{exc.status_message}"
            },
    )

@app.get("/api/receive")
def receive(method: str, address: str, callback: Union[str, None] = None):
    if not method:
        raise ErrorException(code=422,status="error",status_message='Empty method used')
    if not address:
        raise ErrorException(code=422,status="error",status_message='Empty destination address')
    if method.lower() not in ['btc', 'btct', 'ltc', 'doge', 'zec', 'bch', 'xmr']:
        raise ErrorException(code=422,status="error",status_message='Invalid method used')
    if checksumCheck(method.lower(), address) == False:
        raise ErrorException(code=422,status="error",status_message='Invalid Destination Address')

    if callback:
        try:
            data = urlparse(callback)
            #scheme validation
            if data.scheme == 'http' or data.scheme == 'https':
                #domain validation
                if validDns(data.netloc) != True:
                    raise ErrorException(code=422,status="error",status_message='Invalid callback: domain name does not resolve')
            else:
                raise ErrorException(code=422,status="error",status_message='Invalid callback: wrong url scheme, we accept http or https only')
        except:
            callback = 'None'
        callback_req_n = 0
    else:
        callback = 'None'
        callback_req_n = 1
   
    ## RPC connection to Demons
    match method.upper():
        case 'BTC' | 'LTC' | 'ZEC' | 'BCH' | 'BTCT' | 'DOGE':
            rpc = RPCHost("http://%s:%s@%s:%s" % (config.rpcs[method.upper()]['user'], config.rpcs[method.upper()]['pass'], config.rpcs[method.upper()]['host'], config.rpcs[method.upper()]['port']))
        case 'XMR':
            rpc = RPCXMR(config.rpcs[method.upper()]['host'], config.rpcs[method.upper()]['user'], config.rpcs[method.upper()]['pass'])
        case _:
            raise ErrorException(code=422,status="error",status_message='RPC undergoing maintenance')
    
    ## checking if wallet is loaded
    # wallet = rpc.call('createwallet','test',False,False,'exdTHnRJ1BxZfBvU',False,True,True,False)

    try:
        match method.upper():
            case 'XMR':
                wallet = rpc.call('create_address',{"account_index": 0})
                wallet = wallet['address']
            case 'LTC' | 'ZEC' | 'DOGE':
                #wallet = rpc.call('createwallet','test',False,False,'exdTHnRJ1BxZfBvU',False,False,True)
                wallet = rpc.call('getnewaddress')
            case 'BTC' | 'BTCT':
                #wallet = rpc.call('createwallet','test',False,False,'exdTHnRJ1BxZfBvU',False,True,True,False)
                wallet = rpc.call('getnewaddress','', 'p2sh-segwit')
            case 'BCH':
                wallet = rpc.call('getnewaddress')
                wallet = wallet.replace('bitcoincash:', '')
            case _:
                ## notify admin about the error
                raise ErrorException(code=422, status="error", status_message='RPC unavailable')
    except Exception as error:
        ## notify admin about the error
        # Failed to connect for remote procedure call.
        raise ErrorException(code=422, status="error", status_message='Failed to connect for remote procedure call.')
    

    ## SQL Connection with SQLAlchemy
    engine = create_engine(
    "mysql+pymysql://%s:%s@%s:%s/dev" % (config.DB['user'], config.DB['pass'], config.DB['host'], config.DB['port']),
    poolclass=QueuePool,
    #echo=True, #debug sqlalchemy
    pool_size=4,
    max_overflow=0,
    pool_timeout=15,  # Wait 15s for a connection
    )
    Session = sessionmaker(bind = engine)
    session = Session()

    if wallet:
        try:
            q = Queue(txhash = 'None', time = int(time.time()), account = method.upper(), fee = config.fee['REGULAR'][method.upper()], ready = 0, confirmations =0, callbackurl = callback, generated_address = wallet, destination = address, balance_received = '0.00000000', callback_req = callback_req_n, ip = socket.gethostbyname(socket.gethostname()) , hostname = socket.gethostname(), merchantId = 'None', dateTime = time.strftime("%Y-%m-%d %H:%M:%S", time.localtime()))
            session.add(q)
            session.commit()
            session.close()
        except Exception as error:
            ## notify admin about the error
            raise ErrorException(code=422,status="error",status_message='Invalid response from dbServer')
    else:
        ## notify admin about the error
        raise ErrorException(code=422,status="error",status_message='Invalid response from rpcServer')

    return Return(
        address = wallet,
        destination = address,
        callback_url = callback,
        fee = config.fee['REGULAR'][method.upper()],
        status = 'success'
    )
 
# Run
if __name__ == '__main__':
    uvicorn.run('main:app', host='0.0.0.0')
    #workers=4 (doesn't work with reload)