from django.db import transaction
from django.utils import timezone
from rest_framework.exceptions import ValidationError

from progression.models import RewardTransaction, UserAbility

from .models import ContentInteraction, ContentItem, VideoProgress

ABILITY_TO_DIMENSION = {
    ContentItem.Ability.VISION: UserAbility.Dimension.VISION,
    ContentItem.Ability.HUMANITIES: UserAbility.Dimension.HUMANITIES,
    ContentItem.Ability.DETECTION: UserAbility.Dimension.DETECTION,
    ContentItem.Ability.MODELING: UserAbility.Dimension.MODELING,
    ContentItem.Ability.CONNECTION: UserAbility.Dimension.CONNECTION,
}


@transaction.atomic
def complete_video(user, content):
    if content.kind != ContentItem.Kind.VIDEO:
        raise ValidationError("只有视频内容可以提交观看完成")

    progress, _ = VideoProgress.objects.select_for_update().get_or_create(
        user=user,
        content=content,
    )
    progress.position_seconds = max(progress.position_seconds, content.duration_seconds)
    progress.completed = True
    progress.completed_at = progress.completed_at or timezone.now()

    reward = None
    dimension = ABILITY_TO_DIMENSION.get(content.ability_dimension)
    if dimension and not progress.reward_granted:
        transaction_key = f"video-complete:{content.id}"
        reward_tx, created = RewardTransaction.objects.get_or_create(
            user=user,
            idempotency_key=transaction_key,
            defaults={
                "source": "video_complete",
                "rewards": {"ability": dimension, "fragments": 1},
            },
        )
        if created:
            ability, _ = UserAbility.objects.select_for_update().get_or_create(
                user=user,
                dimension=dimension,
            )
            ability.fragments += 1
            ability.save(update_fields=["fragments"])
        progress.reward_granted = True
        reward = reward_tx.rewards

    progress.save(
        update_fields=[
            "position_seconds",
            "completed",
            "completed_at",
            "reward_granted",
            "updated_at",
        ]
    )
    ContentInteraction.objects.get_or_create(
        user=user,
        content=content,
        action=ContentInteraction.Action.COMPLETE,
    )
    return progress, reward