from django.db import models
from django.urls import reverse
from django.utils import timezone
from django.utils.timezone import datetime, timedelta
from django.conf import settings
import json
import logging
from enum import Enum

from .services import calculated_qualities as qualities

logger = logging.getLogger(__name__)

# constants

class State(Enum):
    DEFINED = "defined"
    STAGED = "staged"
    FETCHED = "fetched"
    PROCESSED = "processed"
    STORED = 'stored'
    VALIDATED = "validated"
    SCRUBBED = "scrubbed"
    ARCHIVED = "archived"
    FINISHED = "finished"
    SUSPENDED = "suspended"
    DISCARDED = "discarded"
    FAILED = "failed"

datetime_format_string = '%Y-%m-%dT%H:%M:%SZ'
verified_statusses = ['stored','validated','scrubbed','archived','finished','suspended','discarded']

class Workflow(models.Model):
    description = models.CharField(max_length=500, blank=True, null=True)
    tag = models.CharField(max_length=30, blank=True, null=True)
    workflow_uri = models.CharField(unique=True, max_length=30, blank=True, null=True)
    repository = models.CharField(max_length=100, blank=True, null=True)
    commit_id = models.CharField(max_length=100, blank=True, null=True)
    path = models.CharField(max_length=100, blank=True, null=True)
    oi_size_fraction = models.FloatField(blank=True, null=True)
    meta_scheduling = models.JSONField(null=True, blank=True)
    default_parameters = models.JSONField(null=True, blank=True)
    prefetch = models.BooleanField(null=True, default=True)

    def __str__(self):
        return str(self.id) + ' - ' + str(self.workflow_uri)


# convert the quality information from the JSONfield into a easy parsable list for the template
def convert_quality_to_list_for_template(task):
    list = []

    try:
        list.append(str(task.quality_json['uv-coverage']))
        list.append(str(task.quality_json['sensitivity']))
        list.append(str(task.quality_json['observing-conditions']))
        #list.append("-")

    except Exception as err:
        pass

    return list


def convert_quality_to_shortlist_for_template(task):
    list = []

    try:
        list.append(str(task.quality_json['uv-coverage']))
        list.append(str(task.quality_json['sensitivity']))
        list.append(str(task.quality_json['observing-conditions']))
    except Exception as err:
        pass

    return list

def convert_summary_to_list_for_template(task):
    list = []

    try:
        summary = task.quality_json['summary']

    except Exception as err:
        pass

    return list



class Task(models.Model):

    # Task control properties
    task_type = models.CharField(max_length=20, default="regular")
    filter = models.CharField(max_length=30, blank=True, null=True)
    environment = models.CharField(max_length=255, blank=True, null=True)
    new_status = models.CharField(max_length=50, default="defining", null=True)
    status = models.CharField(db_index=True, default="unknown", max_length=50,blank=True, null=True)
    quality = models.CharField(max_length=10,blank=True, null=True)
    calculated_qualities = models.JSONField(null=True, blank=True)
    resume = models.BooleanField(verbose_name="Resume", default=True)
    creationTime = models.DateTimeField(verbose_name="CreationTime",default=timezone.now, blank=True)

    priority = models.IntegerField(default=100, null=True)
    purge_policy = models.CharField(max_length=5, default="no", blank=True, null=True)
    cleanup_policy = models.CharField(max_length=30, blank=True, null=True)
    stage_request_id = models.IntegerField(null=True)

    # LOFAR properties
    project = models.CharField(max_length=100, blank=True, null=True, default="unknown")
    sas_id = models.CharField(verbose_name="SAS_ID",max_length=15, blank=True, null=True)
    inputs = models.JSONField(null=True, blank=True)
    outputs = models.JSONField(null=True, blank=True)
    metrics = models.JSONField(null=True, blank=True)
    remarks = models.JSONField(null=True, blank=True)
    meta_scheduling = models.JSONField(null=True, blank=True)
    archive = models.JSONField(null=True, blank=True)

    size_to_process = models.PositiveBigIntegerField(default=0, null=True, blank=True)
    size_processed = models.PositiveBigIntegerField(default=0, null=True, blank=True)
    total_processing_time = models.IntegerField(default=0, null=True, blank=True)

    # relationships
    workflow = models.ForeignKey(Workflow, related_name='tasks', on_delete=models.CASCADE, null=True, blank=True)
    predecessor = models.ForeignKey('self', related_name='successors', on_delete=models.SET_NULL, null=True, blank=True)
    joined_output_task = models.ForeignKey('self', related_name='joined_input_tasks', on_delete=models.SET_NULL, null=True, blank=True)

    def __str__(self):
        return str(self.id) + ' - (' + self.task_type + ') - ' + str(self.sas_id)

    def save(self, *args, **kwargs):
        # nv:1mar2023, temporary hack, set tasks 'on hold' as soon they get to 'scrubbed'
        # (users forget to do that manually, causing unwanted ingests)
        if (self.status != State.SCRUBBED.value) & (self.new_status == State.SCRUBBED.value):
            self.resume = False

        # nv:19jun2023, calculate the qualities for this task
        if (self.status != State.STORED.value) & (self.new_status == State.STORED.value):

            # read the quality_thresholds from the Configuration table
            try:
                quality_thresholds = json.loads(Configuration.objects.get(key='quality_thresholds').value)
            except:
                quality_thresholds = {
                    "moderate": 20,
                    "poor": 50,
                    "overall_poor": 50,
                    "overall_good": 90,
                }

            tasks_for_this_sasid = Task.objects.filter(sas_id=self.sas_id)
            self.calculated_qualities = qualities.calculate_qualities(self, tasks_for_this_sasid, quality_thresholds)

        super(Task, self).save(*args, **kwargs)


    # this translates a view-name (from urls.py) back to a url, to avoid hardcoded url's in the html templates
    # bad : <td><a href="/atdb/tasks/{{ task.id }}/" target="_blank">{{ task.taskID }} </a> </td>
    # good: <td><a href="{{ task.get_absolute_url }}" target="_blank">{{ task.taskID }} </a> </td>
    def get_absolute_url(self):
        return reverse('task-detail-view-api', kwargs={'pk': self.pk})

    def get_jobs_statusses(self):
        statusses = {}

        # check the statusses of all the jobs of this id
        jobs = Job.objects.filter(task_id=self.id)
        for job in jobs:

            try:
                key = job.metadata['status'].lower()
                # if key doesn't exist, add a new one
                try:
                    statusses[key] = statusses[key] + 1
                except:
                    statusses.update({ key : 0 })
                    statusses[key] = statusses[key] + 1

            except:
                pass

        return statusses


    @property
    def predecessor_status(self):
        try:
            return self.predecessor.status
        except:
            return "no_predecessor"

    @property
    def has_quality(self):
        try:
            quality = self.outputs['quality']
            return True
        except:
            return False

    @property
    def has_plots(self):
        try:
            quality = self.outputs['quality']
            plots = quality['plots']
            if len(plots) > 0:
                return True
            else:
                return False

        except:
            return False

    @property
    def has_summary(self):
        try:
            summary = self.outputs['quality']['summary']
            return True
        except:
            return False


    @property
    def quality_json(self):
        try:
            return self.outputs['quality']
        except:
            return None

    @property
    def get_quality_remarks(self):
        try:
            return self.remarks['quality']
        except:
            return None

    @property
    def get_quality_remarks_taskid(self):
        try:
            return self.remarks['quality_taskid']
        except:
            return None

    @property
    def get_quality_remarks_sasid(self):
        try:
            return self.remarks['quality_sasid']
        except:
            return None

    @property
    def quality_as_list(self):
        try:
            q = convert_quality_to_list_for_template(self)
            return q
        except:
            return None

    @property
    def quality_as_shortlist(self):
        try:
            q = convert_quality_to_shortlist_for_template(self)
            return q
        except:
            return None

    @property
    def summary_as_list(self):
        try:
            q = convert_summary_to_list_for_template(self)
            return q
        except:
            return None

    @property
    def sas_id_archived(self):
        try:
            return self.archive['sas_id_archived']
        except:
            return None


    @property
    def path_to_lta(self):
        try:
            return self.archive['path_to_lta']
        except:
            return None

    @property
    def sasid_is_verified(self):
        for task in Task.objects.filter(sas_id=self.sas_id):
           if task.status not in verified_statusses:
               return False
        return True

    @property
    def sasid_finished_fraction(self):
        size_archived = 0
        size_remaining = 0
        total_size = 0

        tasks = Task.objects.filter(sas_id=self.sas_id)

        for task in tasks:
           if task.status == State.FINISHED.value:
               size_archived = size_archived + task.size_to_process
           else:
               size_remaining = size_remaining + task.size_to_process
           total_size = total_size + task.size_to_process

        finished = {}
        try:
            finished['fraction'] = round((size_archived / (size_remaining + size_archived)) * 100)
        except:
            finished['fraction'] = -1

        finished['total_size'] = total_size
        finished['remaining'] = size_remaining

        return finished

    @property
    def joined_status(self):
        # if a task has joined_input_tasks, then check their status
        try:
            joined_input_tasks = self.joined_input_tasks.all()
            status = None
            for task in joined_input_tasks:
                if status and task.status != status:
                    return None
                status = task.status

            # all statusses are the same, return it
            return status
        except Exception as e:
            print(e)

        return "unknown"

    @property
    def stageit_url(self):
        stage_request_id = self.stage_request_id
        if stage_request_id:
            stager_api = Configuration.objects.get(key='stager:api').value
            url = f"{stager_api}/requests/{self.stage_request_id}/"
            return url
        else:
            return None

    # NV: this shows the latest status change, but because it is a derived property it cannot be sorted.
    # This functionality was not requested, and to avoid additional requests about 'sort' functionalty
    # it is currently commented out. Could be of use later though, so I leave it in for now.
    # @property
    # def latest_change(self):
    #     qs = Status.objects.filter(task__id=self.id).order_by('-timestamp')
    #     if len(qs) > 0:
    #         status = qs[0]
    #         timestamp = status.timestamp
    #
    #     return timestamp


class LogEntry(models.Model):
    cpu_cycles = models.IntegerField(null=True,blank=True)
    wall_clock_time = models.IntegerField(null=True,blank=True)
    url_to_log_file = models.CharField(max_length=100, blank=True, null=True)
    service = models.CharField(max_length=30, blank=True, null=True)
    step_name = models.CharField(max_length=30, blank=True, null=True)
    timestamp = models.DateTimeField(blank=True, null=True)
    status = models.CharField(max_length=50,default="defined", blank=True, null=True)
    description = models.CharField(max_length=255, blank=True, null=True)
    size_processed = models.PositiveBigIntegerField(default=0, null=True, blank=True)
    # relationships
    task = models.ForeignKey(Task, related_name='log_entries', on_delete=models.CASCADE, null=False)

    def __str__(self):
        return str(self.id)+ ' - '+ str(self.task)+' - '+self.status +' ('+self.step_name+')'

    def save(self, *args, **kwargs):
        #override save to check how long this task has been in this state.
        try:

            # if this logentry already has a wall_clock_time, then don't change it.
            if not self.wall_clock_time:

                # gather all entries for this task, to discover the previous one.
                entries_for_this_task = LogEntry.objects.filter(task=self.task).order_by("-timestamp")
                # remove entries from the list, including 'this', so that the latest remaining is the previous entry.
                for entry in entries_for_this_task:
                    entries_for_this_task = entries_for_this_task.exclude(id=entry.id)
                    if entry == self:
                        break

                try:
                    latest_entry_before_self = entries_for_this_task.latest('timestamp')
                    previous_timestamp = latest_entry_before_self.timestamp
                except:
                    # if no previous entry exists, then use the timestamp from the task.
                    previous_timestamp = self.task.creationTime

                dt = (self.timestamp - previous_timestamp).seconds
                message = "logentry for task "+str(self.task.id)+", to "+self.status + " took " + str(dt) + " seconds"
                logger.info(message)

                self.wall_clock_time = dt
        except Exception as e:
            print(e)

        finally:
            # finally save the Monitor info itself also
            super(LogEntry, self).save(*args, **kwargs)



class Status(models.Model):
    name = models.CharField(max_length=50, default="unknown")
    timestamp = models.DateTimeField(default=timezone.now, blank=True)

    # relationships
    task = models.ForeignKey(Task, related_name='status_history', on_delete=models.CASCADE, null=False)

    # the representation of the value in the REST API
    def __str__(self):
        formatedDate = self.timestamp.strftime(datetime_format_string)
        return str(self.name)+' ('+str(formatedDate)+')'


class Configuration(models.Model):
    filter = models.CharField(max_length=30, blank=True, null=True)
    key = models.CharField(max_length=50)
    # large value needed to hold the dcache token
    value = models.CharField(max_length=5120)

    # the representation of the value in the REST API
    def __str__(self):
        return str(self.key)


class Job(models.Model):
    type = models.CharField(db_index=True, max_length=20, default=None,null=True, blank=True)
    task_id = models.IntegerField(null=True, blank=True)
    job_id = models.IntegerField(null=True, blank=True)
    timestamp = models.DateTimeField(default=timezone.now, blank=True)
    metadata = models.JSONField(null=True, blank=True)

    # the representation of the value in the REST API
    def __str__(self):
        return 'task_id:'+str(self.task_id)+', job_id:'+str(self.job_id)

    @property
    def webdav_url(self):
        try:
            path = self.metadata['stdout_path']

            # form the webdav url
            s = path.rsplit('/', 1)
            l = s[0].split('/run')
            webdav_url = "https://public.spider.surfsara.nl/project/ldv/run" + l[1]

            return webdav_url
        except:
            return "N/A"


class PostProcessingRule(models.Model):
    aggregation_key = models.CharField(db_index=True, max_length=20, default=None,null=True, blank=True)
    trigger_status = models.CharField(db_index=True, default="unknown", max_length=50, blank=True, null=True)

    # relationships
    workflow_to_process = models.ForeignKey(Workflow, related_name='to_process', on_delete=models.SET_NULL, null=True, blank=True)
    workflow_to_apply = models.ForeignKey(Workflow, related_name='to_apply',on_delete=models.SET_NULL, null=True, blank=True)

    # the representation of the value in the REST API
    def __str__(self):
        return str(self.aggregation_key)+' - '+str(self.trigger_status)


class LatestMonitor(models.Model):
    name = models.CharField(max_length=50, default="unknown")
    type = models.CharField(max_length=20, default="ldv-service", null=True, blank=True)
    timestamp = models.DateTimeField(default=datetime.utcnow, blank=True)
    hostname = models.CharField(max_length=50, default="unknown")
    process_id = models.IntegerField(null=True, blank=True)
    description = models.CharField(max_length=255, blank=True, null=True)
    status = models.CharField(max_length=50, default="ok", null=True)
    metadata = models.JSONField(null=True, blank=True)

    @property
    def enabled(self):
        try:
            enabled = self.metadata['enabled']
            return enabled
        except:
            # only when metadata['enabled']=False' this will be register as false.
            # to make sure that services are enabled by default
            return "True"

    # the representation of the value in the REST API
    def __str__(self):
        return str(self.name) + ' - ('+ self.hostname+') - '+str(self.timestamp) + ' - ' + self.status


def purge_old_records():
    current_time = timezone.now()  # change this
    try:
        time_threshold = current_time - timedelta(hours=settings.MAX_MONITORING_HISTORY_HOURS)
        records_to_delete = Monitor.objects.filter(timestamp__lt=time_threshold).delete()
    except Exception as e:
        # if MAX_MONITORING_HISTORY_HOURS is not set, then do nothing and continue
        pass


class Monitor(models.Model):
    name = models.CharField(max_length=50, default="unknown")
    type = models.CharField(max_length=20, default="ldv-service", null=True, blank=True)
    timestamp = models.DateTimeField(default=datetime.utcnow, blank=True)
    hostname = models.CharField(max_length=50, default="unknown")
    process_id = models.IntegerField(null=True, blank=True)
    description = models.CharField(max_length=255, blank=True, null=True)
    status = models.CharField(max_length=50, default="ok", null=True)
    metadata = models.JSONField(null=True, blank=True)

    def save(self, *args, **kwargs):
        # check if this combination of service name + hostname already exists
        # in the LatestMonitor, and update if it is newer.
        try:
            latestMonitor = LatestMonitor.objects.get(name=self.name,hostname=self.hostname)
            # carry over the metadata, if possible
            latest_metadata = latestMonitor.metadata
            latestMonitor.delete()
        except:
            pass

        # this combination of name and hostname didn't yet exist, create it.
        metadata = self.metadata
        try:
            if latest_metadata:
                metadata = latest_metadata
        except:
            pass

        latestMonitor = LatestMonitor(
            name=self.name,
            type=self.type,
            timestamp=self.timestamp,
            hostname = self.hostname,
            process_id = self.process_id,
            description = self.description,
            status = self.status,
            metadata = metadata
        )
        latestMonitor.save()

        # finally save the Monitor info itself also
        super(Monitor, self).save(*args, **kwargs)

        # and purge the monitoring table to its max
        purge_old_records()

    # the representation of the value in the REST API
    def __str__(self):
        return str(self.name) + ' - ('+ self.hostname+') - '+str(self.timestamp) + ' - ' + self.status