import logging
import os
import time
import sqlite3
import traceback
from decimal import Decimal
from twisted.internet import defer, task, reactor, threads
from twisted.enterprise import adbapi

from lbryschema.claim import ClaimDict
from lbryschema.decode import smart_decode
from lbrynet import conf
from lbrynet.cryptstream.CryptBlob import CryptBlobInfo
from lbryum.constants import COIN

log = logging.getLogger(__name__)


def _get_next_available_file_name(download_directory, file_name):
    base_name, ext = os.path.splitext(file_name or "_")
    if ext:
        ext = ".%s" % ext
    i = 0
    while os.path.isfile(os.path.join(download_directory, file_name)):
        i += 1
        file_name = "%s_%i%s" % (base_name, i, ext)
    return os.path.join(download_directory, file_name)


def _open_file_for_writing(download_directory, suggested_file_name):
    file_path = _get_next_available_file_name(download_directory, suggested_file_name)
    try:
        file_handle = open(file_path, 'wb')
        file_handle.close()
    except IOError:
        log.error(traceback.format_exc())
        raise ValueError(
            "Failed to open %s. Make sure you have permission to save files to that location." % file_path
        )
    return os.path.basename(file_path)


def open_file_for_writing(download_directory, suggested_file_name):
    """
    Used to touch the path of a file to be downloaded

    :param download_directory: (str)
    :param suggested_file_name: (str)
    :return: (str) basename
    """
    return threads.deferToThread(_open_file_for_writing, download_directory, suggested_file_name)


def get_next_announce_time(hash_announcer, num_hashes_to_announce=1, min_reannounce_time=60*60,
                           single_announce_duration=5):
    """
    Hash reannounce time is set to current time + MIN_HASH_REANNOUNCE_TIME,
    unless we are announcing a lot of hashes at once which could cause the
    the announce queue to pile up.  To prevent pile up, reannounce
    only after a conservative estimate of when it will finish
    to announce all the hashes.

    Args:
        num_hashes_to_announce: number of hashes that will be added to the queue
    Returns:
        timestamp for next announce time
    """
    queue_size = hash_announcer.hash_queue_size() + num_hashes_to_announce
    reannounce = max(min_reannounce_time,
                     queue_size * single_announce_duration)
    return time.time() + reannounce


def rerun_if_locked(f):
    max_attempts = 3

    def rerun(err, rerun_count, *args, **kwargs):
        log.debug("Failed to execute (%s): %s", err, args)
        if err.check(sqlite3.OperationalError) and err.value.message == "database is locked":
            log.warning("database was locked. rerunning %s with args %s, kwargs %s",
                        str(f), str(args), str(kwargs))
            if rerun_count < max_attempts:
                return task.deferLater(reactor, 0, inner_wrapper, rerun_count + 1, *args, **kwargs)
        raise err

    def inner_wrapper(rerun_count, *args, **kwargs):
        d = f(*args, **kwargs)
        d.addErrback(rerun, rerun_count, *args, **kwargs)
        return d

    def wrapper(*args, **kwargs):
        return inner_wrapper(0, *args, **kwargs)

    return wrapper


class SqliteConnection(adbapi.ConnectionPool):
    def __init__(self, db_path):
        adbapi.ConnectionPool.__init__(self, 'sqlite3', db_path, check_same_thread=False)

    @rerun_if_locked
    def runInteraction(self, interaction, *args, **kw):
        return adbapi.ConnectionPool.runInteraction(self, interaction, *args, **kw)


class SQLiteStorage(object):
    CREATE_TABLES_QUERY = """
            pragma foreign_keys=on;
            pragma journal_mode=WAL;
    
            create table if not exists blob (
                blob_hash char(96) primary key not null,
                blob_length integer not null,
                next_announce_time integer not null,
                should_announce integer not null default 0,
                status text not null
            );
            
            create table if not exists stream (
                stream_hash char(96) not null primary key,
                sd_hash char(96) not null references blob,
                stream_key text not null,
                stream_name text not null,
                suggested_filename text not null
            );
            
            create table if not exists stream_blob (
                stream_hash char(96) not null references stream,
                blob_hash char(96) references blob,
                position integer not null,
                iv char(32) not null,
                primary key (stream_hash, blob_hash)
            );
            
            create table if not exists claim (
                claim_outpoint text not null primary key,
                claim_id char(40) not null,
                claim_name text not null,
                amount integer not null,
                height integer not null,
                serialized_metadata blob not null,
                channel_claim_id text,
                address text not null,
                claim_sequence integer not null
            );

            create table if not exists file (
                stream_hash text primary key not null references stream,
                file_name text not null,
                download_directory text not null,
                blob_data_rate real not null,
                status text not null
            );
            
            create table if not exists content_claim (
                stream_hash text unique not null references file,
                claim_outpoint text not null references claim,
                primary key (stream_hash, claim_outpoint)
            );
            
            create table if not exists support (
                support_outpoint text not null primary key,
                claim_id text not null,
                amount integer not null,
                address text not null
            );
    """

    def __init__(self, db_dir):
        self.db_dir = db_dir
        self._db_path = os.path.join(db_dir, "lbrynet.sqlite")
        log.info("connecting to database: %s", self._db_path)
        self.db = SqliteConnection(self._db_path)

    def setup(self):
        def _create_tables(transaction):
            transaction.executescript(self.CREATE_TABLES_QUERY)
        return self.db.runInteraction(_create_tables)

    @defer.inlineCallbacks
    def run_and_return_one_or_none(self, query, *args):
        result = yield self.db.runQuery(query, args)
        if result:
            defer.returnValue(result[0][0])
        else:
            defer.returnValue(None)

    @defer.inlineCallbacks
    def run_and_return_list(self, query, *args):
        result = yield self.db.runQuery(query, args)
        if result:
            defer.returnValue([i[0] for i in result])
        else:
            defer.returnValue([])

    def stop(self):
        self.db.close()
        return defer.succeed(True)

    # # # # # # # # # blob functions # # # # # # # # #

    @defer.inlineCallbacks
    def add_completed_blob(self, blob_hash, length, next_announce_time, should_announce):
        log.debug("Adding a completed blob. blob_hash=%s, length=%i", blob_hash, length)
        yield self.add_known_blob(blob_hash, length)
        yield self.set_blob_status(blob_hash, "finished")
        yield self.set_should_announce(blob_hash, next_announce_time, should_announce)
        yield self.db.runOperation(
            "update blob set blob_length=? where blob_hash=?", (length, blob_hash)
        )

    def set_should_announce(self, blob_hash, next_announce_time, should_announce):
        should_announce = 1 if should_announce else 0
        return self.db.runOperation(
            "update blob set next_announce_time=?, should_announce=? where blob_hash=?",
            (next_announce_time, should_announce, blob_hash)
        )

    def set_blob_status(self, blob_hash, status):
        return self.db.runOperation(
            "update blob set status=? where blob_hash=?", (status, blob_hash)
        )

    def get_blob_status(self, blob_hash):
        return self.run_and_return_one_or_none(
            "select status from blob where blob_hash=?", blob_hash
        )

    @defer.inlineCallbacks
    def add_known_blob(self, blob_hash, length):
        status = yield self.get_blob_status(blob_hash)
        if status is None:
            status = "pending"
            yield self.db.runOperation("insert into blob values (?, ?, ?, ?, ?)",
                                       (blob_hash, length, 0, 0, status))
        defer.returnValue(status)

    def should_announce(self, blob_hash):
        return self.run_and_return_one_or_none(
            "select should_announce from blob where blob_hash=?", blob_hash
        )

    def count_should_announce_blobs(self):
        return self.run_and_return_one_or_none(
            "select count(*) from blob where should_announce=1 and status=?", "finished"
        )

    def get_all_should_announce_blobs(self):
        return self.run_and_return_list(
            "select blob_hash from blob where should_announce=1 and status=?", "finished"
        )

    def get_blobs_to_announce(self, hash_announcer):
        def get_and_update(transaction):
            timestamp = time.time()
            if conf.settings['announce_head_blobs_only']:
                r = transaction.execute(
                    "select blob_hash from blob "
                    "where blob_hash is not null and should_announce=1 and next_announce_time<?",
                    (timestamp,)
                )
            else:
                r = transaction.execute(
                    "select blob_hash from blob where blob_hash is not null and next_announce_time<?", (timestamp,)
                )

            blobs = [b for b, in r.fetchall()]
            next_announce_time = get_next_announce_time(hash_announcer, len(blobs))
            transaction.execute(
                "update blob set next_announce_time=? where next_announce_time<?", (next_announce_time, timestamp)
            )
            log.debug("Got %s blobs to announce, next announce time is in %s seconds", len(blobs),
                      next_announce_time-time.time())
            return blobs

        return self.db.runInteraction(get_and_update)

    def delete_blobs_from_db(self, blob_hashes):
        def delete_blobs(transaction):
            for blob_hash in blob_hashes:
                transaction.execute("delete from blob where blob_hash=?;", (blob_hash,))
        return self.db.runInteraction(delete_blobs)

    def get_all_blob_hashes(self):
        return self.run_and_return_list("select blob_hash from blob")

    # # # # # # # # # stream blob functions # # # # # # # # #

    def add_blobs_to_stream(self, stream_hash, blob_infos):
        def _add_stream_blobs(transaction):
            for blob_info in blob_infos:
                transaction.execute("insert into stream_blob values (?, ?, ?, ?)",
                                    (stream_hash, blob_info.get('blob_hash', None),
                                     blob_info['blob_num'], blob_info['iv']))
        return self.db.runInteraction(_add_stream_blobs)

    @defer.inlineCallbacks
    def add_known_blobs(self, blob_infos):
        for blob_info in blob_infos:
            if blob_info.get('blob_hash') and blob_info['length']:
                yield self.add_known_blob(blob_info['blob_hash'], blob_info['length'])

    # # # # # # # # # stream functions # # # # # # # # #

    def store_stream(self, stream_hash, sd_hash, stream_name, stream_key, suggested_file_name,
                     stream_blob_infos):
        """
        Add a stream to the stream table

        :param stream_hash: hash of the assembled stream
        :param sd_hash: hash of the sd blob
        :param stream_key: blob decryption key
        :param stream_name: the name of the file the stream was generated from
        :param suggested_file_name: (str) suggested file name for stream
        :param stream_blob_infos: (list) of blob info dictionaries
        :return: (defer.Deferred)
        """

        def _store_stream(transaction):
            transaction.execute("insert into stream values (?, ?, ?, ?, ?);",
                                 (stream_hash, sd_hash, stream_key, stream_name,
                                  suggested_file_name))

            for blob_info in stream_blob_infos:
                transaction.execute("insert into stream_blob values (?, ?, ?, ?)",
                                    (stream_hash, blob_info.get('blob_hash', None),
                                     blob_info['blob_num'], blob_info['iv']))

        return self.db.runInteraction(_store_stream)

    @defer.inlineCallbacks
    def delete_stream(self, stream_hash):
        sd_hash = yield self.get_sd_blob_hash_for_stream(stream_hash)
        stream_blobs = yield self.get_blobs_for_stream(stream_hash)
        blob_hashes = [b.blob_hash for b in stream_blobs]

        def _delete_stream(transaction):
            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, ))
        yield self.db.runInteraction(_delete_stream)

    def get_all_streams(self):
        return self.run_and_return_list("select stream_hash from stream")

    def get_stream_info(self, stream_hash):
        d = self.db.runQuery("select stream_name, stream_key, suggested_filename, sd_hash from stream "
                             "where stream_hash=?", (stream_hash, ))
        d.addCallback(lambda r: None if not r else r[0])
        return d

    def check_if_stream_exists(self, stream_hash):
        d = self.db.runQuery("select stream_hash from stream where stream_hash=?", (stream_hash, ))
        d.addCallback(lambda r: True if len(r) else False)
        return d

    def get_blob_num_by_hash(self, stream_hash, blob_hash):
        return self.run_and_return_one_or_none(
            "select position from stream_blob where stream_hash=? and blob_hash=?",
            stream_hash, blob_hash
        )

    def get_stream_blob_by_position(self, stream_hash, blob_num):
        return self.run_and_return_one_or_none(
            "select blob_hash from stream_blob where stream_hash=? and position=?",
            stream_hash, blob_num
        )

    def get_blobs_for_stream(self, stream_hash):
        def _get_blobs_for_stream(transaction):
            crypt_blob_infos = []
            stream_blobs = transaction.execute("select blob_hash, position, iv from stream_blob "
                                               "where stream_hash=?", (stream_hash, )).fetchall()
            if stream_blobs:
                for blob_hash, position, iv in stream_blobs:
                    if blob_hash is not None:
                        blob_length = transaction.execute("select blob_length from blob "
                                                          "where blob_hash=?",
                                                          (blob_hash,)).fetchone()
                        blob_length = 0 if not blob_length else blob_length[0]
                        crypt_blob_infos.append(CryptBlobInfo(blob_hash, position, blob_length, iv))
                    else:
                        crypt_blob_infos.append(CryptBlobInfo(None, position, 0, iv))
                crypt_blob_infos = sorted(crypt_blob_infos, key=lambda info: info.blob_num)
            return crypt_blob_infos
        return self.db.runInteraction(_get_blobs_for_stream)

    def get_stream_of_blob(self, blob_hash):
        return self.run_and_return_one_or_none(
            "select stream_hash from stream_blob where blob_hash=?", blob_hash
        )

    def get_sd_blob_hash_for_stream(self, stream_hash):
        return self.run_and_return_one_or_none(
            "select sd_hash from stream where stream_hash=?", stream_hash
        )

    def get_stream_hash_for_sd_hash(self, sd_blob_hash):
        return self.run_and_return_one_or_none(
            "select stream_hash from stream where sd_hash = ?", sd_blob_hash
        )

    # # # # # # # # # file stuff # # # # # # # # #

    @defer.inlineCallbacks
    def save_downloaded_file(self, stream_hash, file_name, download_directory, data_payment_rate):
        # touch the closest available file to the file name
        file_name = yield open_file_for_writing(download_directory.decode('hex'), file_name.decode('hex'))
        result = yield self.save_published_file(
            stream_hash, file_name.encode('hex'), download_directory, data_payment_rate
        )
        defer.returnValue(result)

    def save_published_file(self, stream_hash, file_name, download_directory, data_payment_rate, status="stopped"):
        def do_save(db_transaction):
            db_transaction.execute(
                "insert into file values (?, ?, ?, ?, ?)",
                (stream_hash, file_name, download_directory, data_payment_rate, status)
            )
            file_rowid = db_transaction.lastrowid
            return file_rowid
        return self.db.runInteraction(do_save)

    def get_filename_for_rowid(self, rowid):
        return self.run_and_return_one_or_none("select file_name from file where rowid=?", rowid)

    def get_all_lbry_files(self):
        def _lbry_file_dict(rowid, stream_hash, file_name, download_dir, data_rate, status, _, sd_hash, stream_key,
                            stream_name, suggested_file_name):
            return {
                "row_id": rowid,
                "stream_hash": stream_hash,
                "file_name": file_name,
                "download_directory": download_dir,
                "blob_data_rate": data_rate,
                "status": status,
                "sd_hash": sd_hash,
                "key": stream_key,
                "stream_name": stream_name,
                "suggested_file_name": suggested_file_name
            }

        def _get_all_files(transaction):
            return [
                _lbry_file_dict(*file_info) for file_info in transaction.execute(
                    "select file.rowid, file.*, stream.* "
                    "from file inner join stream on file.stream_hash=stream.stream_hash"
                ).fetchall()
            ]

        d = self.db.runInteraction(_get_all_files)
        return d

    def change_file_status(self, rowid, new_status):
        d = self.db.runQuery("update file set status=? where rowid=?", (new_status, rowid))
        d.addCallback(lambda _: new_status)
        return d

    def get_lbry_file_status(self, rowid):
        return self.run_and_return_one_or_none(
            "select status from file where rowid = ?", rowid
        )

    def get_rowid_for_stream_hash(self, stream_hash):
        return self.run_and_return_one_or_none(
            "select rowid from file where stream_hash=?", stream_hash
        )

    # # # # # # # # # support functions # # # # # # # # #

    def save_supports(self, claim_id, supports):
        # TODO: add 'address' to support items returned for a claim from lbrycrdd and lbryum-server
        def _save_support(transaction):
            transaction.execute("delete from support where claim_id=?", (claim_id, ))
            for support in supports:
                transaction.execute(
                    "insert into support values (?, ?, ?, ?)",
                    ("%s:%i" % (support['txid'], support['nout']), claim_id, int(support['amount'] * COIN),
                     support.get('address', ""))
                )
        return self.db.runInteraction(_save_support)

    def get_supports(self, claim_id):
        def _format_support(outpoint, supported_id, amount, address):
            return {
                "txid": outpoint.split(":")[0],
                "nout": int(outpoint.split(":")[1]),
                "claim_id": supported_id,
                "amount": float(Decimal(amount) / Decimal(COIN)),
                "address": address,
            }

        def _get_supports(transaction):
            return [
                _format_support(*support_info)
                for support_info in transaction.execute(
                    "select * from support where claim_id=?", (claim_id, )
                ).fetchall()
            ]

        return self.db.runInteraction(_get_supports)

    # # # # # # # # # claim functions # # # # # # # # #

    @defer.inlineCallbacks
    def save_claim(self, claim_info, claim_dict=None):
        outpoint = "%s:%i" % (claim_info['txid'], claim_info['nout'])
        claim_id = claim_info['claim_id']
        name = claim_info['name']
        amount = int(COIN * claim_info['amount'])
        height = claim_info['height']
        address = claim_info['address']
        sequence = claim_info['claim_sequence']
        claim_dict = claim_dict or smart_decode(claim_info['value'])
        serialized = claim_dict.serialized.encode('hex')

        def _save_claim(transaction):
            transaction.execute(
                "insert or replace into claim values (?, ?, ?, ?, ?, ?, ?, ?, ?)",
                (outpoint, claim_id, name, amount, height, serialized, claim_dict.certificate_id, address, sequence)
            )
        yield self.db.runInteraction(_save_claim)

        if 'supports' in claim_info:  # if this response doesn't have support info don't overwrite the existing
                                      # support info
            yield self.save_supports(claim_id, claim_info['supports'])

    def save_content_claim(self, stream_hash, claim_outpoint):
        def _save_content_claim(transaction):
            # get the claim id and serialized metadata
            claim_info = transaction.execute(
                "select claim_id, serialized_metadata from claim where claim_outpoint=?", (claim_outpoint, )
            ).fetchone()
            if not claim_info:
                raise Exception("claim not found")
            new_claim_id, claim = claim_info[0], ClaimDict.deserialize(claim_info[1].decode('hex'))

            # certificate claims should not be in the content_claim table
            if not claim.is_stream:
                raise Exception("claim does not contain a stream")

            # get the known sd hash for this stream
            known_sd_hash = transaction.execute(
                "select sd_hash from stream where stream_hash=?", (stream_hash, )
            ).fetchone()
            if not known_sd_hash:
                raise Exception("stream not found")
            # check the claim contains the same sd hash
            if known_sd_hash[0] != claim.source_hash:
                raise Exception("stream mismatch")

            # if there is a current claim associated to the file, check that the new claim is an update to it
            current_associated_content = transaction.execute(
                "select claim_outpoint from content_claim where stream_hash=?", (stream_hash, )
            ).fetchone()
            if current_associated_content:
                current_associated_claim_id = transaction.execute(
                    "select claim_id from claim where claim_outpoint=?", current_associated_content
                ).fetchone()[0]
                if current_associated_claim_id != new_claim_id:
                    raise Exception("invalid stream update")

            # update the claim associated to the file
            transaction.execute("insert or replace into content_claim values (?, ?)", (stream_hash, claim_outpoint))
        return self.db.runInteraction(_save_content_claim)

    @defer.inlineCallbacks
    def get_content_claim(self, stream_hash, include_supports=True):
        def _get_content_claim(transaction):
            claim_id = transaction.execute(
                "select claim.claim_id from content_claim "
                "inner join claim on claim.claim_outpoint=content_claim.claim_outpoint and content_claim.stream_hash=? "
                "order by claim.rowid desc", (stream_hash, )
            ).fetchone()
            if not claim_id:
                return None
            return claim_id[0]

        content_claim_id = yield self.db.runInteraction(_get_content_claim)
        result = None
        if content_claim_id:
            result = yield self.get_claim(content_claim_id, include_supports)
        defer.returnValue(result)

    @defer.inlineCallbacks
    def get_claim(self, claim_id, include_supports=True):
        def _claim_response(outpoint, claim_id, name, amount, height, serialized, channel_id, address, claim_sequence):
            r = {
                "name": name,
                "claim_id": claim_id,
                "address": address,
                "claim_sequence": claim_sequence,
                "value": ClaimDict.deserialize(serialized.decode('hex')).claim_dict,
                "height": height,
                "amount": float(Decimal(amount) / Decimal(COIN)),
                "nout": int(outpoint.split(":")[1]),
                "txid": outpoint.split(":")[0],
                "channel_claim_id": channel_id,
                "channel_name": None
            }
            return r

        def _get_claim(transaction):
            claim_info = transaction.execute(
                "select * from claim where claim_id=? order by height, rowid desc", (claim_id, )
            ).fetchone()
            result = _claim_response(*claim_info)
            if result['channel_claim_id']:
                channel_name_result = transaction.execute(
                    "select claim_name from claim where claim_id=?", (result['channel_claim_id'], )
                ).fetchone()
                if channel_name_result:
                    result['channel_name'] = channel_name_result[0]
            return result

        result = yield self.db.runInteraction(_get_claim)
        if include_supports:
            supports = yield self.get_supports(result['claim_id'])
            result['supports'] = supports
            result['effective_amount'] = float(
                sum([support['amount'] for support in supports]) + result['amount']
            )
        defer.returnValue(result)

    def get_unknown_certificate_ids(self):
        def _get_unknown_certificate_claim_ids(transaction):
            return [
                claim_id for (claim_id,) in transaction.execute(
                    "select distinct c1.channel_claim_id from claim as c1 "
                    "where c1.channel_claim_id!='' "
                    "and c1.channel_claim_id not in "
                    "(select c2.claim_id from claim as c2)"
                ).fetchall()
            ]
        return self.db.runInteraction(_get_unknown_certificate_claim_ids)