import glob
import hashlib
import json
import logging
import os
import uuid
from datetime import datetime

from sqlalchemy import Column, Integer, String, DateTime, JSON, event
from sqlalchemy.ext.declarative import declarative_base

from .render_workers.render_worker import RenderStatus, RenderWorkerFactory

logger = logging.getLogger()
Base = declarative_base()


class ScheduledJob(Base):
    __tablename__ = 'scheduled_jobs'
    id = Column(String, primary_key=True)

    renderer = Column(String)
    input_path = Column(String)
    output_path = Column(String)
    priority = Column(Integer)
    owner = Column(String)
    client = Column(String)
    notify = Column(String)
    date_created = Column(DateTime)
    scheduled_start = Column(DateTime)
    name = Column(String)
    file_hash = Column(String)
    worker_data_store = Column(JSON)

    def __init__(self, renderer, input_path, output_path, args, priority=2, owner=None, client=None, notify=None,
                 custom_id=None, name=None):
        self.id = custom_id or self.generate_id()

        self.renderer = renderer
        self.input_path = input_path
        self.output_path = output_path
        self.priority = priority
        self.owner = owner
        self.client = client
        self.notify = notify
        self.date_created = datetime.now()
        self.scheduled_start = None
        self.name = name or os.path.basename(input_path) + '_' + self.date_created.strftime("%Y.%m.%d_%H.%M.%S")

        self.worker_object = RenderWorkerFactory.create_worker(renderer, input_path, output_path, args)
        self.worker_object.log_path = self.log_path()
        self.worker_object.validate()

        self.file_hash = None
        if not self.file_hash and os.path.exists(input_path):
            self.file_hash = hashlib.md5(open(input_path, 'rb').read()).hexdigest()

    def worker_data(self):
        if hasattr(self, 'worker_object'):
            fetched = self.worker_object.json()
            if fetched != self.worker_data_store:
                self.worker_data_store = fetched
        return self.worker_data_store

    @staticmethod
    def before_insert(mapper, connection, target):
        logger.debug(f"Before insert: {target.name}")
        if hasattr(target, 'worker_object'):
            target.worker_data_store = target.worker_object.json()

    @staticmethod
    def before_update(mapper, connection, target):
        logger.debug(f"Before update: {target.name}")
        if hasattr(target, 'worker_object'):
            target.worker_data_store = target.worker_object.json()

    @classmethod
    def register_user_events(cls):
        event.listen(cls, 'before_insert', cls.before_insert)
        event.listen(cls, 'before_update', cls.before_update)

    def render_status(self):
        try:
            worker_status = RenderStatus(self.worker_data()['status'])
            if hasattr(self, 'worker_object'):
                if self.scheduled_start and worker_status == RenderStatus.NOT_STARTED:
                    return RenderStatus.SCHEDULED
            else:
                if worker_status == RenderStatus.RUNNING:
                    return RenderStatus.ERROR
        except Exception as e:
            logger.error(f"Exception fetching render status: {e}")
            worker_status = RenderStatus.UNDEFINED
        return worker_status

    def json(self):
        """Converts RenderJob into JSON-friendly dict"""
        job_dict = None
        try:
            job_dict = {
                'id': self.id,
                'name': self.name,
                'input_path': self.input_path,
                'output_path': self.output_path,
                'priority': self.priority,
                'owner': self.owner,
                'client': self.client,
                'notify': self.notify,
                'date_created': self.date_created,
                'scheduled_start': self.scheduled_start,
                'status': self.render_status().value,
                'time_elapsed': self.worker_data().get('time_elapsed', None),
                'file_hash': self.file_hash,
                'percent_complete': self.worker_data().get('percent_complete', None),
                'file_list': self.file_list(),
                'renderer': self.renderer,
                'worker': self.worker_data(),
            }

            # convert to json and back to auto-convert dates to iso format
            def date_serializer(o):
                if isinstance(o, datetime):
                    return o.isoformat()
            json_convert = json.dumps(job_dict, default=date_serializer)
            job_dict = json.loads(json_convert)
        except Exception as e:
            logger.exception(e)
            logger.error("Error converting to JSON: {}".format(e))
        return job_dict

    def start(self):
        if hasattr(self, 'worker_object'):
            self.worker_object.start()

    def stop(self):
        if hasattr(self, 'worker_object'):
            self.worker_object.stop()

    def work_path(self):
        return os.path.dirname(self.output_path)

    def file_list(self):
        job_dir = os.path.dirname(self.output_path)
        return glob.glob(os.path.join(job_dir, '*'))

    def log_path(self):
        return os.path.join(os.path.dirname(self.input_path), self.name + '.log')

    @classmethod
    def generate_id(cls):
        return str(uuid.uuid4()).split('-')[0]