from __future__ import print_function
import os, sys, json
from wormhole.blocking.transcribe import Initiator, WrongPasswordError
from wormhole.blocking.transit import TransitSender
from .progress import start_progress, update_progress, finish_progress

APPID = "lothar.com/wormhole/file-xfer"

def send_file(so):
    # we're sending
    filename = so["filename"]
    assert os.path.isfile(filename)
    transit_sender = TransitSender(transit_relay=so.parent["transit-helper"])

    filesize = os.stat(filename).st_size
    data = json.dumps({
        "file": {
            "filename": os.path.basename(filename),
            "filesize": filesize,
            },
        "transit": {
            "direct_connection_hints": transit_sender.get_direct_hints(),
            "relay_connection_hints": transit_sender.get_relay_hints(),
            },
        }).encode("utf-8")

    i = Initiator(APPID, data, so.parent["relay-url"])
    code = i.get_code()
    print("On the other computer, please run: wormhole receive-file")
    print("Wormhole code is '%s'" % code)
    print()
    try:
        them_bytes = i.get_data()
    except WrongPasswordError as e:
        print("ERROR: " + e.explain(), file=sys.stderr)
        return 1
    them_d = json.loads(them_bytes.decode("utf-8"))
    #print("them: %r" % (them_d,))


    tdata = them_d["transit"]
    transit_key = i.derive_key(APPID+"/transit-key")
    transit_sender.set_transit_key(transit_key)
    transit_sender.add_their_direct_hints(tdata["direct_connection_hints"])
    transit_sender.add_their_relay_hints(tdata["relay_connection_hints"])
    record_pipe = transit_sender.connect()

    print("Sending (%s).." % transit_sender.describe())

    CHUNKSIZE = 64*1024
    with open(filename, "rb") as f:
        sent = 0
        next_update = start_progress(filesize)
        while sent < filesize:
            plaintext = f.read(CHUNKSIZE)
            record_pipe.send_record(plaintext)
            sent += len(plaintext)
            next_update = update_progress(next_update, sent, filesize)
        finish_progress(filesize)

    print("File sent.. waiting for confirmation")
    ack = record_pipe.receive_record()
    if ack == "ok\n":
        print("Confirmation received. Transfer complete.")
        return 0
    else:
        print("Transfer failed (remote says: %r)" % ack)
        return 1