from __future__ import annotations

from django.db import models

from control_plane.common import TimestampedModel


class KnowledgeNode(TimestampedModel):
    project = models.ForeignKey("projects.Project", on_delete=models.CASCADE, related_name="knowledge_nodes")
    node_type = models.CharField(max_length=80)
    external_id = models.CharField(max_length=500)
    title = models.CharField(max_length=500, blank=True)
    properties = models.JSONField(default=dict, blank=True)

    class Meta:
        constraints = [models.UniqueConstraint(fields=["project", "node_type", "external_id"], name="unique_knowledge_node")]


class KnowledgeEdge(TimestampedModel):
    project = models.ForeignKey("projects.Project", on_delete=models.CASCADE, related_name="knowledge_edges")
    source = models.ForeignKey(KnowledgeNode, on_delete=models.CASCADE, related_name="outgoing_edges")
    target = models.ForeignKey(KnowledgeNode, on_delete=models.CASCADE, related_name="incoming_edges")
    edge_type = models.CharField(max_length=80)
    evidence = models.JSONField(default=list, blank=True)

    class Meta:
        constraints = [models.UniqueConstraint(fields=["source", "target", "edge_type"], name="unique_knowledge_edge")]