from django.db import transaction
from django.utils import timezone

from content.models import ContentInteraction, ContentItem
from math_life.models import (
    MathBTIAssessment,
    MathBTIResult,
    MathIdentity,
    Story,
    StoryRun,
    StoryVersion,
)
from math_life.services import score_mathbti
from progression.models import Card, UserCard
from progression.services import initialize_math_identity

from .models import VisitorMigration


def migration_summary(payload):
    mathbti = 1 if isinstance(payload.get("mathbti"), dict) else 0
    return {
        "mathbti_results": mathbti,
        "story_saves": min(len(payload.get("story_saves", [])), 20),
        "favorites": min(len(payload.get("favorites", [])), 200),
        "cards": min(len(payload.get("cards", [])), 100),
    }


@transaction.atomic
def apply_visitor_migration(user):
    migration = VisitorMigration.objects.select_for_update().get(user=user)
    if migration.status == VisitorMigration.Status.APPLIED:
        return migration

    payload = migration.payload
    mathbti = payload.get("mathbti")
    if isinstance(mathbti, dict):
        assessment = MathBTIAssessment.objects.filter(
            version=mathbti.get("version"),
            is_published=True,
        ).first()
        if assessment:
            code, scores = score_mathbti(assessment.definition, mathbti.get("answers", []))
            identity = MathIdentity.objects.get(code=code)
            MathBTIResult.objects.create(
                user=user,
                assessment=assessment,
                identity=identity,
                answers=mathbti["answers"],
                axis_scores=scores,
            )
            initialize_math_identity(user, identity)

    for item in payload.get("story_saves", [])[:20]:
        if not isinstance(item, dict):
            continue
        story = Story.objects.filter(slug=item.get("story_slug")).first()
        if story is None:
            continue
        version = StoryVersion.objects.filter(
            story=story,
            version=item.get("version"),
            is_published=True,
        ).first()
        node_id = item.get("current_node")
        if version is None or node_id not in version.content.get("nodes", {}):
            continue
        StoryRun.objects.get_or_create(
            user=user,
            story_version=version,
            status=StoryRun.Status.ACTIVE,
            defaults={
                "current_node": node_id,
                "state": item.get("state", {}) if isinstance(item.get("state"), dict) else {},
            },
        )

    favorites = ContentItem.objects.filter(
        slug__in=payload.get("favorites", [])[:200],
        is_published=True,
    )
    ContentInteraction.objects.bulk_create(
        [
            ContentInteraction(
                user=user,
                content=item,
                action=ContentInteraction.Action.FAVORITE,
            )
            for item in favorites
        ],
        ignore_conflicts=True,
    )

    cards = Card.objects.filter(slug__in=payload.get("cards", [])[:100])
    UserCard.objects.bulk_create(
        [UserCard(user=user, card=card, source="visitor_migration") for card in cards],
        ignore_conflicts=True,
    )

    migration.status = VisitorMigration.Status.APPLIED
    migration.applied_at = timezone.now()
    migration.save(update_fields=["status", "applied_at"])
    return migration