const cloud = require('wx-server-sdk');

cloud.init({ env: cloud.DYNAMIC_CURRENT_ENV });

const VALID_FIELDS = new Set(['likes', 'downloads']);

exports.main = async (event) => {
    try {
        const db = cloud.database();
        const command = db.command;
        const collection = db.collection('worksheets');

        const id = String(event.id || '').trim();
        const field = String(event.field || '').trim();

        if (!id) throw new Error('worksheet id 不能为空');
        if (!VALID_FIELDS.has(field)) throw new Error('统计字段不合法');

        await collection.doc(id).update({
            data: {
                [field]: command.inc(1),
                updatedAt: db.serverDate(),
            },
        });

        return {
            success: true,
            data: { _id: id, field },
        };
    } catch (error) {
        return {
            success: false,
            message:
                error instanceof Error ? error.message : '更新统计失败',
        };
    }
};