# Copyright (c) 2023-present Pi Dash Software, Inc. and contributors
# SPDX-License-Identifier: AGPL-3.0-only
# See the LICENSE file for details.

# Third party imports
from rest_framework import serializers

# Module imports
from pi_dash.app.serializers import IssueSerializer


class IssueExportSerializer(IssueSerializer):
    """
    Export-optimized serializer that extends IssueSerializer with human-readable fields.

    Converts UUIDs to readable values for CSV/JSON export.
    """

    identifier = serializers.SerializerMethodField()
    project_name = serializers.CharField(source='project.name', read_only=True, default="")
    project_identifier = serializers.CharField(source='project.identifier', read_only=True, default="")
    state_name = serializers.CharField(source='state.name', read_only=True, default="")
    created_by_name = serializers.CharField(source='created_by.full_name', read_only=True, default="")

    assignees = serializers.SerializerMethodField()
    parent = serializers.SerializerMethodField()
    labels = serializers.SerializerMethodField()
    cycles = serializers.SerializerMethodField()
    modules = serializers.SerializerMethodField()
    comments = serializers.SerializerMethodField()
    estimate = serializers.SerializerMethodField()
    links = serializers.SerializerMethodField()
    relations = serializers.SerializerMethodField()
    subscribers = serializers.SerializerMethodField()

    class Meta(IssueSerializer.Meta):
        fields = [
            "project_name",
            "project_identifier",
            "parent",
            "identifier",
            "sequence_id",
            "name",
            "state_name",
            "priority",
            "assignees",
            "subscribers",
            "created_by_name",
            "start_date",
            "target_date",
            "completed_at",
            "created_at",
            "updated_at",
            "archived_at",
            "estimate",
            "labels",
            "cycles",
            "modules",
            "links",
            "relations",
            "comments",
            "sub_issues_count",
            "link_count",
            "attachment_count",
            "is_draft",
        ]

    def get_identifier(self, obj):
        return f"{obj.project.identifier}-{obj.sequence_id}"

    def get_assignees(self, obj):
        return [u.full_name for u in obj.assignees.all() if u.is_active]

    def get_subscribers(self, obj):
        """Return list of subscriber names."""
        return [sub.subscriber.full_name for sub in obj.issue_subscribers.all() if sub.subscriber]

    def get_parent(self, obj):
        if not obj.parent:
            return ""
        return f"{obj.parent.project.identifier}-{obj.parent.sequence_id}"

    def get_labels(self, obj):
        return [
            il.label.name
            for il in obj.label_issue.all()
            if il.deleted_at is None
        ]

    def get_cycles(self, obj):
        return [ic.cycle.name for ic in obj.issue_cycle.all()]

    def get_modules(self, obj):
        return [im.module.name for im in obj.issue_module.all()]

    def get_estimate(self, obj):
        """Return estimate point value."""
        if obj.estimate_point:
            return obj.estimate_point.value if hasattr(obj.estimate_point, 'value') else str(obj.estimate_point)
        return ""

    def get_links(self, obj):
        """Return list of issue links with titles."""
        return [
            {
                "url": link.url,
                "title": link.title if link.title else link.url,
            }
            for link in obj.issue_link.all()
        ]

    def get_relations(self, obj):
        """Return list of related issues."""
        relations = []

        # Outgoing relations (this issue relates to others)
        for rel in obj.issue_relation.all():
            if rel.related_issue:
                relations.append({
                    "type": rel.relation_type if hasattr(rel, 'relation_type') else "related",
                    "issue": f"{rel.related_issue.project.identifier}-{rel.related_issue.sequence_id}",
                    "direction": "outgoing"
                })

        # Incoming relations (other issues relate to this one)
        for rel in obj.issue_related.all():
            if rel.issue:
                relations.append({
                    "type": rel.relation_type if hasattr(rel, 'relation_type') else "related",
                    "issue": f"{rel.issue.project.identifier}-{rel.issue.sequence_id}",
                    "direction": "incoming"
                })

        return relations

    def get_comments(self, obj):
        """Return list of comments with author and timestamp."""
        return [
            {
                "comment": comment.comment_stripped if hasattr(comment, 'comment_stripped') else comment.comment_html,
                "created_by": comment.actor.full_name if comment.actor else "",
                "created_at": comment.created_at.strftime("%Y-%m-%d %H:%M:%S") if comment.created_at else "",
            }
            for comment in obj.issue_comments.all()
        ]
