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

module.exports = Self => {
    Self.remoteMethodCtx('getSerial', {
        description: 'Return invoiceIn serial',
        accessType: 'READ',
        accepts: [{
            arg: 'filter',
            type: 'object'
        }, {
            arg: 'daysAgo',
            type: 'number',
            required: true
        }, {
            arg: 'serial',
            type: 'string'
        }],
        returns: {
            type: 'object',
            root: true
        },
        http: {
            path: '/getSerial',
            verb: 'GET'
        }
    });

    Self.getSerial = async(ctx, options) => {
        const conn = Self.dataSource.connector;
        const args = ctx.args;
        const myOptions = {};

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

        const issued = Date.vnNew();
        const where = buildFilter(args, (param, value) => {
            switch (param) {
            case 'daysAgo':
                issued.setDate(issued.getDate() - value);
                return {'i.issued': {gte: issued}};
            case 'serial':
                return {'i.serial': {like: `%${value}%`}};
            }
        });

        const filter = mergeFilters(args.filter, {where});

        const stmt = new ParameterizedSQL(
            `SELECT i.serial, SUM(IF(i.isBooked, 0,1)) pending, COUNT(*) total
                FROM vn.invoiceIn i`
        );

        stmt.merge(conn.makeWhere(filter.where));
        stmt.merge(`GROUP BY i.serial`);
        stmt.merge(conn.makeOrderBy(filter.order));
        stmt.merge(conn.makeLimit(filter));

        const result = await conn.executeStmt(stmt, myOptions);

        return result;
    };
};