# Python import
from uuid import uuid4

# Django imports
from django.db import models
from django.conf import settings
from django.db.models.signals import post_save
from django.dispatch import receiver
from django.core.validators import MinValueValidator, MaxValueValidator
from django.core.exceptions import ValidationError
from django.utils import timezone

# Module imports
from . import ProjectBaseModel
from plane.utils.html_processor import strip_tags


def get_default_properties():
    return {
        "assignee": True,
        "start_date": True,
        "due_date": True,
        "labels": True,
        "key": True,
        "priority": True,
        "state": True,
        "sub_issue_count": True,
        "link": True,
        "attachment_count": True,
        "estimate": True,
        "created_on": True,
        "updated_on": True,
    }


def get_default_filters():
    return {
        "priority": None,
        "state": None,
        "state_group": None,
        "assignees": None,
        "created_by": None,
        "labels": None,
        "start_date": None,
        "target_date": None,
        "subscriber": None,
    }


def get_default_display_filters():
    return {
        "group_by": None,
        "order_by": "-created_at",
        "type": None,
        "sub_issue": True,
        "show_empty_groups": True,
        "layout": "list",
        "calendar_date_range": "",
    }


def get_default_display_properties():
    return {
        "assignee": True,
        "attachment_count": True,
        "created_on": True,
        "due_date": True,
        "estimate": True,
        "key": True,
        "labels": True,
        "link": True,
        "priority": True,
        "start_date": True,
        "state": True,
        "sub_issue_count": True,
        "updated_on": True,
    }


# TODO: Handle identifiers for Bulk Inserts - nk
class IssueManager(models.Manager):
    def get_queryset(self):
        return (
            super()
            .get_queryset()
            .filter(
                models.Q(issue_inbox__status=1)
                | models.Q(issue_inbox__status=-1)
                | models.Q(issue_inbox__status=2)
                | models.Q(issue_inbox__isnull=True)
            )
            .exclude(archived_at__isnull=False)
            .exclude(project__archived_at__isnull=False)
            .exclude(is_draft=True)
        )


class Issue(ProjectBaseModel):
    PRIORITY_CHOICES = (
        ("urgent", "Urgent"),
        ("high", "High"),
        ("medium", "Medium"),
        ("low", "Low"),
        ("none", "None"),
    )
    parent = models.ForeignKey(
        "self",
        on_delete=models.CASCADE,
        null=True,
        blank=True,
        related_name="parent_issue",
    )
    state = models.ForeignKey(
        "db.State",
        on_delete=models.CASCADE,
        null=True,
        blank=True,
        related_name="state_issue",
    )
    estimate_point = models.IntegerField(
        validators=[MinValueValidator(0), MaxValueValidator(7)],
        null=True,
        blank=True,
    )
    name = models.CharField(max_length=255, verbose_name="Issue Name")
    description = models.JSONField(blank=True, default=dict)
    description_html = models.TextField(blank=True, default="<p></p>")
    description_stripped = models.TextField(blank=True, null=True)
    priority = models.CharField(
        max_length=30,
        choices=PRIORITY_CHOICES,
        verbose_name="Issue Priority",
        default="none",
    )
    start_date = models.DateField(null=True, blank=True)
    target_date = models.DateField(null=True, blank=True)
    assignees = models.ManyToManyField(
        settings.AUTH_USER_MODEL,
        blank=True,
        related_name="assignee",
        through="IssueAssignee",
        through_fields=("issue", "assignee"),
    )
    sequence_id = models.IntegerField(
        default=1, verbose_name="Issue Sequence ID"
    )
    labels = models.ManyToManyField(
        "db.Label", blank=True, related_name="labels", through="IssueLabel"
    )
    sort_order = models.FloatField(default=65535)
    completed_at = models.DateTimeField(null=True)
    archived_at = models.DateField(null=True)
    is_draft = models.BooleanField(default=False)
    external_source = models.CharField(max_length=255, null=True, blank=True)
    external_id = models.CharField(max_length=255, blank=True, null=True)

    objects = models.Manager()
    issue_objects = IssueManager()

    class Meta:
        verbose_name = "Issue"
        verbose_name_plural = "Issues"
        db_table = "issues"
        ordering = ("-created_at",)

    def save(self, *args, **kwargs):
        # This means that the model isn't saved to the database yet
        if self.state is None:
            try:
                from plane.db.models import State

                default_state = State.objects.filter(
                    ~models.Q(name="Triage"),
                    project=self.project,
                    default=True,
                ).first()
                # if there is no default state assign any random state
                if default_state is None:
                    random_state = State.objects.filter(
                        ~models.Q(name="Triage"), project=self.project
                    ).first()
                    self.state = random_state
                else:
                    self.state = default_state
            except ImportError:
                pass
        else:
            try:
                from plane.db.models import State

                # Check if the current issue state group is completed or not
                if self.state.group == "completed":
                    self.completed_at = timezone.now()
                else:
                    self.completed_at = None
            except ImportError:
                pass

        if self._state.adding:
            # Get the maximum display_id value from the database
            last_id = IssueSequence.objects.filter(
                project=self.project
            ).aggregate(largest=models.Max("sequence"))["largest"]
            # aggregate can return None! Check it first.
            # If it isn't none, just use the last ID specified (which should be the greatest) and add one to it
            if last_id:
                self.sequence_id = last_id + 1
            else:
                self.sequence_id = 1

            largest_sort_order = Issue.objects.filter(
                project=self.project, state=self.state
            ).aggregate(largest=models.Max("sort_order"))["largest"]
            if largest_sort_order is not None:
                self.sort_order = largest_sort_order + 10000

        # Strip the html tags using html parser
        self.description_stripped = (
            None
            if (self.description_html == "" or self.description_html is None)
            else strip_tags(self.description_html)
        )
        super(Issue, self).save(*args, **kwargs)

    def __str__(self):
        """Return name of the issue"""
        return f"{self.name} <{self.project.name}>"


class IssueBlocker(ProjectBaseModel):
    block = models.ForeignKey(
        Issue, related_name="blocker_issues", on_delete=models.CASCADE
    )
    blocked_by = models.ForeignKey(
        Issue, related_name="blocked_issues", on_delete=models.CASCADE
    )

    class Meta:
        verbose_name = "Issue Blocker"
        verbose_name_plural = "Issue Blockers"
        db_table = "issue_blockers"
        ordering = ("-created_at",)

    def __str__(self):
        return f"{self.block.name} {self.blocked_by.name}"


class IssueRelation(ProjectBaseModel):
    RELATION_CHOICES = (
        ("duplicate", "Duplicate"),
        ("relates_to", "Relates To"),
        ("blocked_by", "Blocked By"),
    )

    issue = models.ForeignKey(
        Issue, related_name="issue_relation", on_delete=models.CASCADE
    )
    related_issue = models.ForeignKey(
        Issue, related_name="issue_related", on_delete=models.CASCADE
    )
    relation_type = models.CharField(
        max_length=20,
        choices=RELATION_CHOICES,
        verbose_name="Issue Relation Type",
        default="blocked_by",
    )

    class Meta:
        unique_together = ["issue", "related_issue"]
        verbose_name = "Issue Relation"
        verbose_name_plural = "Issue Relations"
        db_table = "issue_relations"
        ordering = ("-created_at",)

    def __str__(self):
        return f"{self.issue.name} {self.related_issue.name}"


class IssueMention(ProjectBaseModel):
    issue = models.ForeignKey(
        Issue, on_delete=models.CASCADE, related_name="issue_mention"
    )
    mention = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        on_delete=models.CASCADE,
        related_name="issue_mention",
    )

    class Meta:
        unique_together = ["issue", "mention"]
        verbose_name = "Issue Mention"
        verbose_name_plural = "Issue Mentions"
        db_table = "issue_mentions"
        ordering = ("-created_at",)

    def __str__(self):
        return f"{self.issue.name} {self.mention.email}"


class IssueAssignee(ProjectBaseModel):
    issue = models.ForeignKey(
        Issue, on_delete=models.CASCADE, related_name="issue_assignee"
    )
    assignee = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        on_delete=models.CASCADE,
        related_name="issue_assignee",
    )

    class Meta:
        unique_together = ["issue", "assignee"]
        verbose_name = "Issue Assignee"
        verbose_name_plural = "Issue Assignees"
        db_table = "issue_assignees"
        ordering = ("-created_at",)

    def __str__(self):
        return f"{self.issue.name} {self.assignee.email}"


class IssueLink(ProjectBaseModel):
    title = models.CharField(max_length=255, null=True, blank=True)
    url = models.TextField()
    issue = models.ForeignKey(
        "db.Issue", on_delete=models.CASCADE, related_name="issue_link"
    )
    metadata = models.JSONField(default=dict)

    class Meta:
        verbose_name = "Issue Link"
        verbose_name_plural = "Issue Links"
        db_table = "issue_links"
        ordering = ("-created_at",)

    def __str__(self):
        return f"{self.issue.name} {self.url}"


def get_upload_path(instance, filename):
    return f"{instance.workspace.id}/{uuid4().hex}"


def file_size(value):
    # File limit check is only for cloud hosted
    if value.size > settings.FILE_SIZE_LIMIT:
        raise ValidationError("File too large. Size should not exceed 5 MB.")

class IssueActivity(ProjectBaseModel):
    issue = models.ForeignKey(
        Issue,
        on_delete=models.SET_NULL,
        null=True,
        related_name="issue_activity",
    )
    verb = models.CharField(
        max_length=255, verbose_name="Action", default="created"
    )
    field = models.CharField(
        max_length=255, verbose_name="Field Name", blank=True, null=True
    )
    old_value = models.TextField(
        verbose_name="Old Value", blank=True, null=True
    )
    new_value = models.TextField(
        verbose_name="New Value", blank=True, null=True
    )

    comment = models.TextField(verbose_name="Comment", blank=True)
    issue_comment = models.ForeignKey(
        "db.IssueComment",
        on_delete=models.SET_NULL,
        related_name="issue_comment",
        null=True,
    )
    actor = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        on_delete=models.SET_NULL,
        null=True,
        related_name="issue_activities",
    )
    old_identifier = models.UUIDField(null=True)
    new_identifier = models.UUIDField(null=True)
    epoch = models.FloatField(null=True)

    class Meta:
        verbose_name = "Issue Activity"
        verbose_name_plural = "Issue Activities"
        db_table = "issue_activities"
        ordering = ("-created_at",)

    def __str__(self):
        """Return issue of the comment"""
        return str(self.issue)


class IssueComment(ProjectBaseModel):
    comment_stripped = models.TextField(verbose_name="Comment", blank=True)
    comment_json = models.JSONField(blank=True, default=dict)
    comment_html = models.TextField(blank=True, default="<p></p>")
    issue = models.ForeignKey(
        Issue, on_delete=models.CASCADE, related_name="issue_comments"
    )
    # System can also create comment
    actor = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        on_delete=models.CASCADE,
        related_name="comments",
        null=True,
    )
    access = models.CharField(
        choices=(
            ("INTERNAL", "INTERNAL"),
            ("EXTERNAL", "EXTERNAL"),
        ),
        default="INTERNAL",
        max_length=100,
    )
    external_source = models.CharField(max_length=255, null=True, blank=True)
    external_id = models.CharField(max_length=255, blank=True, null=True)

    def save(self, *args, **kwargs):
        self.comment_stripped = (
            strip_tags(self.comment_html) if self.comment_html != "" else ""
        )
        return super(IssueComment, self).save(*args, **kwargs)

    class Meta:
        verbose_name = "Issue Comment"
        verbose_name_plural = "Issue Comments"
        db_table = "issue_comments"
        ordering = ("-created_at",)

    def __str__(self):
        """Return issue of the comment"""
        return str(self.issue)


class IssueProperty(ProjectBaseModel):
    user = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        on_delete=models.CASCADE,
        related_name="issue_property_user",
    )
    filters = models.JSONField(default=get_default_filters)
    display_filters = models.JSONField(default=get_default_display_filters)
    display_properties = models.JSONField(
        default=get_default_display_properties
    )

    class Meta:
        verbose_name = "Issue Property"
        verbose_name_plural = "Issue Properties"
        db_table = "issue_properties"
        ordering = ("-created_at",)
        unique_together = ["user", "project"]

    def __str__(self):
        """Return properties status of the issue"""
        return str(self.user)


class Label(ProjectBaseModel):
    parent = models.ForeignKey(
        "self",
        on_delete=models.CASCADE,
        null=True,
        blank=True,
        related_name="parent_label",
    )
    name = models.CharField(max_length=255)
    description = models.TextField(blank=True)
    color = models.CharField(max_length=255, blank=True)
    sort_order = models.FloatField(default=65535)
    external_source = models.CharField(max_length=255, null=True, blank=True)
    external_id = models.CharField(max_length=255, blank=True, null=True)

    class Meta:
        unique_together = ["name", "project"]
        verbose_name = "Label"
        verbose_name_plural = "Labels"
        db_table = "labels"
        ordering = ("-created_at",)

    def save(self, *args, **kwargs):
        if self._state.adding:
            # Get the maximum sequence value from the database
            last_id = Label.objects.filter(project=self.project).aggregate(
                largest=models.Max("sort_order")
            )["largest"]
            # if last_id is not None
            if last_id is not None:
                self.sort_order = last_id + 10000

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

    def __str__(self):
        return str(self.name)


class IssueLabel(ProjectBaseModel):
    issue = models.ForeignKey(
        "db.Issue", on_delete=models.CASCADE, related_name="label_issue"
    )
    label = models.ForeignKey(
        "db.Label", on_delete=models.CASCADE, related_name="label_issue"
    )

    class Meta:
        verbose_name = "Issue Label"
        verbose_name_plural = "Issue Labels"
        db_table = "issue_labels"
        ordering = ("-created_at",)

    def __str__(self):
        return f"{self.issue.name} {self.label.name}"


class IssueSequence(ProjectBaseModel):
    issue = models.ForeignKey(
        Issue,
        on_delete=models.SET_NULL,
        related_name="issue_sequence",
        null=True,
    )
    sequence = models.PositiveBigIntegerField(default=1)
    deleted = models.BooleanField(default=False)

    class Meta:
        verbose_name = "Issue Sequence"
        verbose_name_plural = "Issue Sequences"
        db_table = "issue_sequences"
        ordering = ("-created_at",)


class IssueSubscriber(ProjectBaseModel):
    issue = models.ForeignKey(
        Issue, on_delete=models.CASCADE, related_name="issue_subscribers"
    )
    subscriber = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        on_delete=models.CASCADE,
        related_name="issue_subscribers",
    )

    class Meta:
        unique_together = ["issue", "subscriber"]
        verbose_name = "Issue Subscriber"
        verbose_name_plural = "Issue Subscribers"
        db_table = "issue_subscribers"
        ordering = ("-created_at",)

    def __str__(self):
        return f"{self.issue.name} {self.subscriber.email}"


class IssueReaction(ProjectBaseModel):
    actor = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        on_delete=models.CASCADE,
        related_name="issue_reactions",
    )
    issue = models.ForeignKey(
        Issue, on_delete=models.CASCADE, related_name="issue_reactions"
    )
    reaction = models.CharField(max_length=20)

    class Meta:
        unique_together = ["issue", "actor", "reaction"]
        verbose_name = "Issue Reaction"
        verbose_name_plural = "Issue Reactions"
        db_table = "issue_reactions"
        ordering = ("-created_at",)

    def __str__(self):
        return f"{self.issue.name} {self.actor.email}"


class CommentReaction(ProjectBaseModel):
    actor = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        on_delete=models.CASCADE,
        related_name="comment_reactions",
    )
    comment = models.ForeignKey(
        IssueComment,
        on_delete=models.CASCADE,
        related_name="comment_reactions",
    )
    reaction = models.CharField(max_length=20)

    class Meta:
        unique_together = ["comment", "actor", "reaction"]
        verbose_name = "Comment Reaction"
        verbose_name_plural = "Comment Reactions"
        db_table = "comment_reactions"
        ordering = ("-created_at",)

    def __str__(self):
        return f"{self.issue.name} {self.actor.email}"


class IssueVote(ProjectBaseModel):
    issue = models.ForeignKey(
        Issue, on_delete=models.CASCADE, related_name="votes"
    )
    actor = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        on_delete=models.CASCADE,
        related_name="votes",
    )
    vote = models.IntegerField(
        choices=(
            (-1, "DOWNVOTE"),
            (1, "UPVOTE"),
        ),
        default=1,
    )

    class Meta:
        unique_together = [
            "issue",
            "actor",
        ]
        verbose_name = "Issue Vote"
        verbose_name_plural = "Issue Votes"
        db_table = "issue_votes"
        ordering = ("-created_at",)

    def __str__(self):
        return f"{self.issue.name} {self.actor.email}"


# TODO: Find a better method to save the model
@receiver(post_save, sender=Issue)
def create_issue_sequence(sender, instance, created, **kwargs):
    if created:
        IssueSequence.objects.create(
            issue=instance,
            sequence=instance.sequence_id,
            project=instance.project,
        )