import sqlite3
import logging
import os
from lbry.blob.blob_info import BlobInfo
from lbry.stream.descriptor import StreamDescriptor

log = logging.getLogger(__name__)


def do_migration(conf):
    db_path = os.path.join(conf.data_dir, "lbrynet.sqlite")
    blob_dir = os.path.join(conf.data_dir, "blobfiles")
    connection = sqlite3.connect(db_path)
    cursor = connection.cursor()

    query = "select stream_name, stream_key, suggested_filename, sd_hash, stream_hash from stream"
    streams = cursor.execute(query).fetchall()

    blobs = cursor.execute("select s.stream_hash, s.position, s.iv, b.blob_hash, b.blob_length from stream_blob s "
                           "left outer join blob b ON b.blob_hash=s.blob_hash order by s.position").fetchall()
    blobs_by_stream = {}
    for stream_hash, position, iv, blob_hash, blob_length in blobs:
        blobs_by_stream.setdefault(stream_hash, []).append(BlobInfo(position, blob_length or 0, iv, 0, blob_hash))

    for stream_name, stream_key, suggested_filename, sd_hash, stream_hash in streams:
        sd = StreamDescriptor(None, blob_dir, stream_name, stream_key, suggested_filename,
                              blobs_by_stream[stream_hash], stream_hash, sd_hash)
        if sd_hash != sd.calculate_sd_hash():
            log.info("Stream for descriptor %s is invalid, cleaning it up", sd_hash)
            blob_hashes = [blob.blob_hash for blob in blobs_by_stream[stream_hash]]
            delete_stream(cursor, stream_hash, sd_hash, blob_hashes, blob_dir)

    connection.commit()
    connection.close()


def delete_stream(transaction, stream_hash, sd_hash, blob_hashes, blob_dir):
    transaction.execute("delete from content_claim where stream_hash=? ", (stream_hash,))
    transaction.execute("delete from file where stream_hash=? ", (stream_hash, ))
    transaction.execute("delete from stream_blob where stream_hash=?", (stream_hash, ))
    transaction.execute("delete from stream where stream_hash=? ", (stream_hash, ))
    transaction.execute("delete from blob where blob_hash=?", (sd_hash, ))
    for blob_hash in blob_hashes:
        transaction.execute("delete from blob where blob_hash=?", (blob_hash, ))
        file_path = os.path.join(blob_dir, blob_hash)
        if os.path.isfile(file_path):
            os.unlink(file_path)