import dbm.gnu as dbm
import os
import sys
from pathlib import Path
from typing import List, Tuple, Iterator

sys.path.insert(0, os.path.dirname(os.path.dirname((os.path.abspath(__file__)))))  # magic import-fixer
from silverstream.bittorrent.database import TorrentDatabase
from silverstream.bittorrent.peer import TorrentPeer
from silverstream.util import grouper


class OldPeerDatabaseStub:
    def __init__(self, filepath) -> None:
        self.dbm = dbm.open(filepath, "rf")  # read/fast mode

    def __iter__(self) -> Iterator[Tuple[bytes, List[TorrentPeer]]]:
        info_hash = self.dbm.firstkey()
        while info_hash is not None:
            yield info_hash, self.get(info_hash)
            info_hash = self.dbm.nextkey(info_hash)

    def get(self, info_hash: bytes) -> List[TorrentPeer]:
        compact_peers = grouper(self.dbm.get(info_hash), 6)
        return [TorrentPeer.from_compact(bytes(compact_peer)) for compact_peer in compact_peers]


try:
    old_filepath = Path(sys.argv[1])
except IndexError:
    exit(f"Usage: {__file__} <path to old database>")

old = OldPeerDatabaseStub(str(old_filepath))
new = TorrentDatabase(filepath=old_filepath.with_suffix(".sqlite"))

num_keys = len(old.dbm.keys())
num_hashes = num_peers = 0
for info_hash, peers in old:
    num_hashes += 1
    for peer in peers:
        num_peers += 1
        new.add_peer(info_hash, peer)
    print(f"{num_hashes} hashes, {num_peers} peers done ({num_hashes / num_keys:.2%})")