module.exports = Self => {
    Self.remoteMethod('makeMulti', {
        description: 'Add a record or update it if it already exists.',
        accessType: 'WRITE',
        accepts: [{
            arg: 'shelvingFk',
            type: 'number',
            required: true,
        },
        {
            arg: 'items',
            type: ['number'],
            required: true,
            description: 'array of item foreign keys'
        },
        {
            arg: 'warehouseFk',
            type: 'number',
            required: true
        }],

        http: {
            path: `/makeMulti`,
            verb: 'POST'
        }
    });

    Self.makeMulti = async(shelvingFk, items, warehouseFk, options) => {
        const myOptions = {};
        let tx;

        if (typeof options == 'object')
            Object.assign(myOptions, options);

        if (!myOptions.transaction) {
            tx = await Self.beginTransaction({});
            myOptions.transaction = tx;
        }

        const discardItems = [];

        try {
            for (let item of items) {
                if (!discardItems.includes(item)) {
                    let quantity = items.reduce((acc, cur) => {
                        return acc + (cur === item ? 1 : 0);
                    }, 0);
                    discardItems.push(item);

                    let [result] = await Self.rawSql('SELECT vn.itemPacking(?, ?)', [item, warehouseFk]);
                    let packing;

                    if (result) packing = Object.values(result)[0];
                    if (!packing) packing = 1;

                    quantity = quantity * packing;

                    await Self.rawSql('CALL vn.itemShelving_add(?, ?, ?, NULL, NULL, ?, ?)',
                        [shelvingFk,
                            item,
                            quantity,
                            packing,
                            warehouseFk]
                    );
                }
            }

            if (tx) await tx.commit();
        } catch (e) {
            if (tx) await tx.rollback();
            throw e;
        }
    };
};