import { getUserIdFromSession } from '../../../utils/auth';
import { OBSTACLE_CLEAR_COST } from '../../../utils/village';

export default defineEventHandler(async (event) => {
    // 1. Get objectId from params
    const objectId = parseInt(event.context.params?.id || '', 10);
    if (isNaN(objectId)) {
        throw createError({ statusCode: 400, statusMessage: 'Invalid object ID.' });
    }

    const userId = await getUserIdFromSession(event);

    // 2. Find village + objects
    const village = await prisma.village.findUnique({
        where: { userId },
        include: { objects: true }
    });

    if (!village) {
        // This case is unlikely if user has ever fetched their village, but is a good safeguard.
        throw createError({ statusCode: 404, statusMessage: 'Village not found.' });
    }

    // 3. Find the object
    const objectToDelete = village.objects.find(o => o.id === objectId);

    // 4. If not found -> 404
    if (!objectToDelete) {
        throw createError({ statusCode: 404, statusMessage: 'Object not found.' });
    }

    // 5. If OBSTACLE
    if (objectToDelete.type === 'OBSTACLE') {
        const cost = OBSTACLE_CLEAR_COST[objectToDelete.obstacleMetadata || 'DEFAULT'] ?? OBSTACLE_CLEAR_COST.DEFAULT;
        
        try {
            // Atomically check coins, deduct, and delete
            await prisma.$transaction([
                prisma.user.update({
                    where: { id: userId, coins: { gte: cost } },
                    data: { coins: { decrement: cost } },
                }),
                prisma.villageObject.delete({ where: { id: objectId } }),
            ]);
        } catch (e) {
            // The transaction fails if the user update fails due to insufficient coins
            throw createError({ statusCode: 402, statusMessage: 'Insufficient coins to clear obstacle.' });
        }

    // 6. If HOUSE
    } else if (objectToDelete.type === 'HOUSE') {
        const houseCount = village.objects.filter(o => o.type === 'HOUSE').length;
        const fieldCount = village.objects.filter(o => o.type === 'FIELD').length;

        // Check if removing this house violates the worker rule
        if (fieldCount > (houseCount - 1)) {
            throw createError({ 
                statusCode: 400, 
                statusMessage: `Cannot remove house. You have ${fieldCount} fields and need at least ${fieldCount} workers.` 
            });
        }
        
        // Delete the house (no cost)
        await prisma.villageObject.delete({ where: { id: objectId } });

    // 7. Otherwise (FIELD, ROAD, FENCE)
    } else {
        // Delete the object (no cost)
        await prisma.villageObject.delete({ where: { id: objectId } });
    }

    // 8. Return success message
    return { message: "Object removed successfully" };
});