<?php

namespace App\Database;

use Illuminate\Database\DatabaseManager;
use Illuminate\Database\Query\Expression;

class UpdateMassive
{

    /**
     * UPDATE transactions
     * SET updated_at = CASE id
     * WHEN 1 THEN '2019-01-15 10:00:00'::date
     * WHEN 2 THEN '2019-01-16 11:00:00'::date
     * WHEN 3 THEN '2019-01-17 12:00:00'::date
     * END
     * WHERE id IN (1, 2, 3);
     *
     * update transactions set updated_at = '2019-01-15 10:00:00' where id = 1
     * update transactions set updated_at = '2019-01-16 10:00:00' where id = 2
     * update transactions set updated_at = '2019-01-17 10:00:00' where id = 3
     *
     * @param string $table
     * @param string $primaryKeyName
     * @param $config
     *
     * Config:
     * [
     *  [
     *    "primary_key" => 200576
     *    "columns" => array:1 [
     *      "transactions_banks.coupon_code" => "2001462387"
     *     ]
     *  ]
     * ]
     *
     * @return void
     */
    public function apply(string $table, string $primaryKeyName, $config): void
    {
        /** @var DatabaseManager $db */
        $db = app('db');

        $primaryKeyValues = [];
        $whenGroup = [];

        foreach ($config as $configItem) {
            $primaryKey = $configItem['primary_key'];

            $primaryKeyValues[] = $primaryKey;
            foreach ($configItem['columns'] as $columnName => $columnValue) {
                if (!isset($whenGroup[$columnName])) {
                    $whenGroup[$columnName] = [];
                }

                $whenGroup[$columnName][] = vsprintf('WHEN %s THEN %s', [
                    $primaryKey,
                    $columnValue
                ]);
            }
        }
        $values = [];
        foreach ($whenGroup as $column => $whenArr) {
            /** @var Expression[] $whenArr */
            $case = $db->raw(vsprintf('CASE %s %s END', [$primaryKeyName, implode(' ', $whenArr)]));
            $values[$column] = $case;
        }

        if (empty($values)) {
            return;
        }

//        $db->enableQueryLog();
        $db->table($table)
            ->whereIn($primaryKeyName, $primaryKeyValues)
            ->update($values);

//        dd($db->getQueryLog());
    }
}