const ParameterizedSQL = require('loopback-connector').ParameterizedSQL;
const mergeFilters = require('vn-loopback/util/filter').mergeFilters;

module.exports = Self => {
    Self.remoteMethod('lastItemBuys', {
        description: 'Returns a list of items from last buys',
        accepts: [
            {
                arg: 'id',
                type: 'number',
                required: true,
                description: 'origin itemId',
                http: {source: 'path'}
            },
            {
                arg: 'filter',
                type: 'object',
                description: `Filter defining where, order, offset, and limit - must be a JSON-encoded string`
            }
        ],
        returns: {
            type: ['object'],
            root: true
        },
        http: {
            path: `/:id/lastItemBuys`,
            verb: 'GET'
        }
    });

    Self.lastItemBuys = async(id, filter, options) => {
        const conn = Self.dataSource.connector;
        const models = Self.app.models;
        const where = {isActive: true};
        const myOptions = {};
        if (typeof options == 'object')
            Object.assign(myOptions, options);

        filter = mergeFilters(filter, {where});

        const entry = await models.Entry.findById(id, {
            include: [{
                relation: 'travel',
                scope: {
                    fields: ['warehouseInFk', 'landed'],
                }
            }]
        }, myOptions);
        const travel = entry.travel();

        const stmts = [];
        let stmt;
        stmt = new ParameterizedSQL(`CALL buy_getUltimate(?, ?, ?)`, [
            null,
            travel.warehouseInFk,
            travel.landed
        ]);
        stmts.push(stmt);
        stmts.push('DROP TEMPORARY TABLE IF EXISTS tmp.item');
        stmt = new ParameterizedSQL(
            `CREATE TEMPORARY TABLE tmp.item
            (PRIMARY KEY (id))
            SELECT
                    i.*,
                    p.name AS producerName,
                    nk.name AS inkName
                FROM item i
                    LEFT JOIN producer p ON p.id = i.producerFk
                    LEFT JOIN ink nk ON nk.id = i.inkFk
                    JOIN tmp.buyUltimate bu ON i.id = bu.itemFk
                        AND bu.warehouseFk = ?
        `, [travel.warehouseInFk]);
        stmts.push(stmt);
        stmt = new ParameterizedSQL('SELECT * FROM tmp.item');
        stmt.merge(conn.makeSuffix(filter));

        const itemsIndex = stmts.push(stmt) - 1;

        stmts.push('DROP TEMPORARY TABLE tmp.item');

        const sql = ParameterizedSQL.join(stmts, ';');
        const result = await conn.executeStmt(sql, myOptions);
        return result[itemsIndex];
    };
};