from .utils import *
import elasticsearch
import time
import logging
logger = logging.getLogger(__name__)

def optimize_index(client, index_name, max_num_segments=None, delay=0,
                request_timeout=21600):
    """
    Optimize (Lucene forceMerge) index to `max_num_segments` per shard

    :arg client: The Elasticsearch client connection
    :arg index_name: The index name
    :arg max_num_segments: Merge to this number of segments per shard.
    :arg delay: A number of seconds to delay after successfully optimizing
    :arg request_timeout: Number of seconds before the connection should timeout
    :rtype: bool
    """
    if optimized(client, index_name, max_num_segments):
        return True
    else:
        logger.info('Optimizing index {0} to {1} segments per shard.  Please wait...'.format(index_name, max_num_segments))
        try:
            client.indices.optimize(
                index=index_name, max_num_segments=max_num_segments,
                request_timeout=request_timeout
            )
            if delay > 0:
                logger.info("Pausing for {0} seconds before continuing...".format(delay))
                time.sleep(delay)
            return True
        except Exception:
            logger.error("Error optimizing index {0}.  Run with --debug flag and/or check Elasticsearch logs for more information.".format(index_name))
            return False

def optimize(client, indices, max_num_segments=None, delay=0, request_timeout=21600):
    """
    Helper method called by the CLI.

    :arg client: The Elasticsearch client connection
    :arg indices: A list of indices to act on
    :arg max_num_segments: Merge to this number of segments per shard.
    :arg delay: A number of seconds to delay after successfully optimizing
    :arg request_timeout: Number of seconds before the connection should timeout
    :rtype: bool
    """
    retval = True
    for i in ensure_list(indices):
        # If we fail once, we fail completely
        success = optimize_index(
                    client, i, max_num_segments=max_num_segments, delay=delay,
                    request_timeout=request_timeout
                  )
        if not success:
            retval = False
    return retval
