#!/usr/libexec/platform-python

import sys
from collections import defaultdict

import htcondor2 as htcondor
import classad2 as classad


def main(requested_clusterID):

    constraint = None
    if requested_clusterID is not None:
        constraint = f'clusterID == {requested_clusterID}'
    schedd = htcondor.Schedd()
    results = schedd.jobEpochHistory(
        ad_type=['epoch', 'common'],
        constraint=constraint,
    )


    #
    # Because the shadow can fall back to using normal input transfer for jobs
    # which specify common files, we have to record either (a) that we fell
    # back for a given epoch or (b) that we successfully mapped a catalog for
    # this epoch.  (Otherwise, that is, we can't be sure that if an epoch skipped
    # a transfer because of the common files functionality or not.)
    #
    # So we record (1), each epoch whose job ad defines at least one common
    # file catalog; and (2), each epoch which indicates a succesful mapping.
    #
    # For extra credit, we can correlate COMMON entries to epochs for sizes.
    #


    # For each cluster ID, how many epochs had at least one common file catalog?
    EpochsByClusterID = defaultdict(lambda: 0)
    # For each cluster ID, how many epochs had a common file catalog mapped?
    CommonFilesMappedByClusterID = defaultdict(lambda: 0)
    # For each cluster ID, how many common transfers occurred?
    CommonTransfersByClusterID = defaultdict(lambda: 0)
    # For each cluster ID, how many catalogs were defined?
    CommonCatalogsByClusterID = defaultdict(lambda: 0)
    # For each cluster ID, how many common bytes were transferred?
    CommonBytesByClusterID = defaultdict(lambda: 0)

    for entry in results:
        clusterID = entry['ClusterID']
        epoch_ad_type = entry['EpochAdType']

        if epoch_ad_type == "COMMON":
            CommonTransfersByClusterID[clusterID] += 1

            stats_ad = entry.get('TransferCommonStats')
            if stats_ad is not None:
                protocols = stats_ad['Protocols']
                for protocol in protocols.split(','):
                    bytes = stats_ad[f"{protocol}SizeBytes"]
                    CommonBytesByClusterID[clusterID] += bytes
            else:
                CommonBytesByClusterID[clusterID] += entry['CedarSizeBytes']
        elif epoch_ad_type == "EPOCH":
            old_style = False;
            if 'CommonInputFiles' in entry:
                old_style = True
                CommonCatalogsByClusterID[clusterID] += 1

            new_style = False
            if 'CommonInputCatalogs' in entry:
                new_style = True
                string_list = entry['CommonInputCatalogs']
                # This isn't quite right, but it's probably close enough.
                list = string_list.split(',')
                CommonCatalogsByClusterID[clusterID] += len(list)

            if old_style or new_style:
                EpochsByClusterID[clusterID] += 1


            if 'CommonFilesMappedTime' in entry:
                CommonFilesMappedByClusterID[clusterID] += 1


    if len(CommonTransfersByClusterID) == 0:
        if requested_clusterID is None:
            print("Found no common file transfers.")
        else:
            print(f"Found no common file transfer for cluster ID {requested_clusterID}.")
        sys.exit(0)


    # We could record the number of succesful mappings, but for now let's just
    # assume that if any mapping in an epoch succeeded, that they all did.
    WholeTransfersByClusterID = defaultdict(lambda: 0)
    BytesPerWholeTransferByClusterID = defaultdict(lambda: 0)
    for clusterID, transfers in CommonTransfersByClusterID.items():
        transfers_per_cluster = CommonCatalogsByClusterID[clusterID]/EpochsByClusterID[clusterID]
        whole_transfers = transfers / transfers_per_cluster
        if float(int(whole_transfers)) != whole_transfers:
            print(
                f"Ignoring partial transfers in cluster ID {clusterID}: "
                f"{transfers} transfers / "
                f"(({CommonCatalogsByClusterID[clusterID]} common catalogs / "
                f"{EpochsByClusterID[clusterID]} epochs) = "
                f"{transfers_per_cluster} transfers_per_cluster) = "
                f"{whole_transfers} whole_transfers"
            )
        whole_transfers = int(whole_transfers)
        WholeTransfersByClusterID[clusterID] = whole_transfers

        bytes_per_whole_transfer = int(
            CommonBytesByClusterID[clusterID] / whole_transfers
        )
        BytesPerWholeTransferByClusterID[clusterID] = bytes_per_whole_transfer

        # And for the money...
        common_epochs = CommonFilesMappedByClusterID[clusterID]
        total_bytes = common_epochs * bytes_per_whole_transfer
        bytes_actually_transferred = whole_transfers * bytes_per_whole_transfer
        pct_a = int(
            ((total_bytes - bytes_actually_transferred)/total_bytes) * 100
        )
        print(
            f"Cluster {clusterID}: required {total_bytes} total bytes in common files "
            f"(as {bytes_per_whole_transfer} bytes per epoch * {common_epochs} epochs, "
            f"not including fall-back epochs), but only transferred "
            f"{bytes_actually_transferred} bytes, skipping "
            f"{total_bytes - bytes_actually_transferred} bytes, or "
            f"{pct_a}% of the total."
        )

    if requested_clusterID is not None:
        return 0


    total_epochs = 0
    for clusterID, count in EpochsByClusterID.items():
        total_epochs += count

    total_common_mappings = 0
    for clusterID, count in CommonFilesMappedByClusterID.items():
        total_common_mappings += count

    total_whole_transfers = 0
    for clusterID, count in WholeTransfersByClusterID.items():
        total_whole_transfers += count


    pct_a = int(
        ((total_common_mappings - total_whole_transfers)/total_common_mappings) * 100
    )
    pct_b = int(
        ((total_epochs - total_whole_transfers)/total_epochs) * 100
    )
    print(
        f"Of {total_epochs} total epochs, "
        f"{total_common_mappings} successfuly mapped common files "
        f"after performing {total_whole_transfers} whole transfers, "
        f"skipping {pct_a}% of those transfers, "
        f"or {pct_b}% of all possible transfers."
    )

    return 0


if __name__ == '__main__':
    clusterID = None
    if len(sys.argv) == 1:
        pass
    elif len(sys.argv) == 2:
        clusterID = int(sys.argv[1])
    else:
        print(f"Usage: {sys.argv[0]} [clusterID]")
        sys.exit(1)
    sys.exit(main(clusterID))
