from django.db import migrations
from django.utils import timezone


KNOWLEDGE_FIELDS = (
    "knowledge_base_id",
    "title",
    "problem",
    "applicable_scope",
    "category_code",
    "related_system",
    "environment_scope",
    "error_code",
    "root_cause",
    "troubleshooting_steps",
    "solution",
    "risk_note",
    "source_type",
    "source_ticket_id",
)

PLAN_FIELDS = (
    "knowledge_base_id",
    "title",
    "problem_pattern",
    "applicable_scope",
    "category_code",
    "related_system",
    "environment_scope",
    "decision_rules",
    "troubleshooting_steps",
    "risk_note",
    "source_ticket_id",
)

SOLUTION_FIELDS = (
    "title",
    "problem_signature",
    "related_system",
    "environment_scope",
    "category_id",
    "root_cause",
    "solution",
    "risk_note",
    "allow_auto_resolve",
    "requires_human_action",
    "requires_external_confirmation",
    "requires_production_change",
)


def backfill_governed_assets(apps, schema_editor):
    GovernedAsset = apps.get_model("knowledge", "GovernedAsset")
    GovernedAssetVersion = apps.get_model("knowledge", "GovernedAssetVersion")
    KnowledgeItem = apps.get_model("knowledge", "KnowledgeItem")
    TroubleshootingPlan = apps.get_model("knowledge", "TroubleshootingPlan")
    Solution = apps.get_model("solutions", "Solution")
    now = timezone.now()
    definitions = (
        ("knowledge_item", KnowledgeItem, KNOWLEDGE_FIELDS),
        ("troubleshooting_plan", TroubleshootingPlan, PLAN_FIELDS),
        ("solution", Solution, SOLUTION_FIELDS),
    )
    for asset_type, model, fields in definitions:
        for instance in model.objects.all().iterator():
            asset, _ = GovernedAsset.objects.get_or_create(
                asset_type=asset_type,
                object_id=instance.id,
                defaults={"created_by_id": instance.created_by_id},
            )
            if asset.versions.exists():
                continue
            original_status = instance.status
            if original_status == "published":
                version_status = "published"
            elif original_status in {"offline", "disabled"}:
                version_status = "offline"
                if original_status == "disabled":
                    instance.status = "offline"
                    instance.save(update_fields=["status"])
            else:
                version_status = "draft"
            version = GovernedAssetVersion.objects.create(
                asset=asset,
                version=1,
                status=version_status,
                content={field: getattr(instance, field) for field in fields},
                created_by_id=instance.created_by_id,
                published_at=now if version_status == "published" else None,
                offline_at=now if version_status == "offline" else None,
            )
            if version_status == "published":
                asset.current_published_version = version
                asset.save(update_fields=["current_published_version"])


class Migration(migrations.Migration):
    dependencies = [
        ("knowledge", "0005_alter_knowledgechunk_options_governedasset_and_more"),
        ("solutions", "0003_solution_allow_auto_resolve_and_more"),
    ]

    operations = [
        migrations.RunPython(backfill_governed_assets, migrations.RunPython.noop),
    ]