#!/usr/bin/python

import sys
import argparse
import json
import os
import shutil
import random
import time
import tempfile

import conf
import ems_util


def do_download_sw(sw_info, sw_download_dir):
    """
    return err, reason, file_location_in_nes
    """

    sw_location = sw_info['swLocation']

    # Use copy file from SW_SERVER_SIMULATOR to simulate download file
    sw_file_name = sw_location.split('/')[-1]

    file_location_in_server = conf.SW_SERVER_SIMULATOR + '/' + sw_file_name
    file_location_in_ne = sw_download_dir + '/' + sw_file_name

    try:
        shutil.copy(file_location_in_server, sw_download_dir)
    except IOError as e:
        return True, "Download %s to %s error: %s" % (sw_file_name, sw_download_dir, str(e)), file_location_in_ne

    return False, None, file_location_in_ne


def generate_notification(download_process_id, download_status, downloaded_ne_sw_info, failed_sw_info):
    notification = {
        "objectClass": "EMSClass",
        "objectInstance": "EMSInstance",
        "notificationId": random.randint(1, conf.MAX_INT),
        "eventTime": time.asctime(),
        "systemDN": "emssimulator",
        "notificationType": "notifyDownloadNESwStatusChanged",
        "downloadProcessId": download_process_id,
        "downloadOperationStatus": download_status
    }

    if downloaded_ne_sw_info:
        notification["downloadedNESwInfo"] = downloaded_ne_sw_info

    if failed_sw_info:
        notification["failedSwInfo"] = failed_sw_info

    return notification


def download_ne_sw(sw_to_be_downloaded, ne_id):
    ne_info = ems_util.get_ne_info_from_db_by_id(ne_id)

    download_process_id = random.randint(1, conf.MAX_INT)
    result = conf.REQ_SUCCESS
    ret_value = {
        "downloadProcessId": download_process_id,
        "result": result
    }

    if not ne_info:
        ret_value["result"] = conf.REQ_FAILURE
        ret_value["reason"] = "Can not find NE %s" % ne_id
        return ret_value

    ne_info["status"] = conf.STATUS_DOWNLOADING
    ems_util.update_ne_info(ne_info)

    num_sw_to_be_downloaded = len(sw_to_be_downloaded)

    downloaded_ne_sw_info = []
    failed_sw_info = []

    sw_download_parent_dir = conf.PNF_SIMULATORS_DIR + '/' + ne_info['omIP'] + conf.PNF_SW_DOWNLOAD_DIR
    sw_download_dir = ne_info.get("downloadedSwLocation", "")
    try:
        if not os.path.isdir(sw_download_parent_dir):
            os.makedirs(sw_download_parent_dir)

        if sw_download_dir and not os.path.isdir(sw_download_dir):
            os.makedirs(sw_download_dir)
    except OSError as e:
        ret_value["result"] = conf.REQ_FAILURE
        ret_value["reason"] = str(e)
        return ret_value

    if not sw_download_dir:
        sw_download_dir = tempfile.mkdtemp(dir=sw_download_parent_dir)

    for sw_info in sw_to_be_downloaded:
        err, reason, file_location = do_download_sw(sw_info, sw_download_dir)
        if not err:
            downloaded_ne_sw_info.append(file_location)
        else:
            result = conf.REQ_FAILURE
            failed_sw_entry = {
                "failedSw": file_location,
                "failureReason": reason
            }
            failed_sw_info.append(failed_sw_entry)

    num_downloaded_ne_sw = len(downloaded_ne_sw_info)

    if num_downloaded_ne_sw == num_sw_to_be_downloaded:
        download_status = "NE_SWDOWNLOAD_SUCCESSFUL"
    elif num_downloaded_ne_sw == 0:
        download_status = "NE_SWDOWNLOAD_FAILED"
    else:
        download_status = "NE_SWDOWNLOAD_PARTIALLY_SUCCESSFUL"

    notification = generate_notification(download_process_id, download_status, downloaded_ne_sw_info, failed_sw_info)
    ems_util.send_notification(notification, download_process_id)

    if result == conf.REQ_SUCCESS:
        ne_info["downloadedSwLocation"] = sw_download_dir
        ems_util.update_ne_info(ne_info)
    else:
        shutil.rmtree(sw_download_dir, ignore_errors=True)

        ret_value["result"] = result
        ret_value["reason"] = json.dumps(failed_sw_info)

    # for automated software management, there is no listOfStepNumbersAndDurations
    return ret_value


def main():
    parser = argparse.ArgumentParser()

    parser.add_argument("--swToBeDownloaded", help="The NE software to be downloaded", required=True)
    parser.add_argument("--neIdentifier", help="The NE where the software can be downloaded", required=True)

    args = parser.parse_args()

    sw_to_be_downloaded = json.loads(args.swToBeDownloaded)

    ret_value = download_ne_sw(sw_to_be_downloaded, args.neIdentifier)
    print json.dumps(ret_value)

    if ret_value["result"] == conf.REQ_SUCCESS:
        sys.exit(conf.RET_CODE_SUCCESS)
    else:
        sys.exit(conf.RET_CODE_FAILURE)


if __name__ == '__main__':
    main()