Nebula rundown as json export plugin

from nebula import *

class Plugin(APIPlugin):
    def main(self, **kwargs):
        try:
            id_channel = int(kwargs.get("id_channel"))
            channel_config = config["playout_channels"][id_channel]
        except:
            log_traceback()
            return NebulaResponse(400, "No such channel")

        try:
            start_time = datestr2ts(kwargs.get("date"), *channel_config["day_start"])
        except Exception:
            log_traceback()
            return NebulaResponse(400, "Wrong date specified")


        event_keys = ["start", "title", "subtitle", "description"]
        asset_keys = ["title", "subtitle", "description", "genre", "id_folder", "intention", "editorial_format"]

        result = []
        for event in get_rundown(id_channel, start_time, start_time+(3600*24)):
            edata = {}
            for k in event_keys:
                if event[k]:
                    edata[k] = event[k]


            edata["items"] = []
            for item in event.items:
                idata = {
                    "title" : item["title"],
                    "scheduled_time" : item["rundown_scheduled"],
                    "broadcast_time" : item["rundown_broadcast"],
                }
                if item.asset:
                    idata["asset"] = {k : item.asset[k] for k in asset_keys if item.asset[k]}

                edata["items"].append(idata)
            result.append(edata)

        return NebulaResponse(200, data=result)