<?php

/**
 * ChartGeneration.php
 * Copyright (c) 2019 james@firefly-iii.org
 *
 * This file is part of Firefly III (https://github.com/firefly-iii).
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

declare(strict_types=1);

namespace FireflyIII\Support\Http\Controllers;

use Carbon\Carbon;
use FireflyIII\Exceptions\FireflyException;
use FireflyIII\Generator\Chart\Basic\GeneratorInterface;
use FireflyIII\Models\Account;
use FireflyIII\Repositories\Account\AccountRepositoryInterface;
use FireflyIII\Support\CacheProperties;
use Illuminate\Support\Collection;

/**
 * Trait ChartGeneration
 */
trait ChartGeneration
{
    /**
     * Shows an overview of the account balances for a set of accounts.
     *
     * @throws FireflyException
     */
    protected function accountBalanceChart(Collection $accounts, Carbon $start, Carbon $end): array // chart helper method.
    {
        // chart properties for cache:
        $cache        = new CacheProperties();
        $cache->addProperty($start);
        $cache->addProperty($end);
        $cache->addProperty('chart.account.account-balance-chart');
        $cache->addProperty($accounts);
        $convertToNative =app('preferences')->get('convert_to_native', false)->data;
        if ($cache->has()) {
            // return $cache->get();
        }
        app('log')->debug('Regenerate chart.account.account-balance-chart from scratch.');
        $locale       = app('steam')->getLocale();

        /** @var GeneratorInterface $generator */
        $generator    = app(GeneratorInterface::class);

        /** @var AccountRepositoryInterface $accountRepos */
        $accountRepos = app(AccountRepositoryInterface::class);

        $default      = app('amount')->getDefaultCurrency();
        $chartData    = [];

        /** @var Account $account */
        foreach ($accounts as $account) {
            // TODO we can use getAccountCurrency instead.
            $currency     = $accountRepos->getAccountCurrency($account);
            if (null === $currency) {
                $currency = $default;
            }
            // if the user prefers the native currency, overrule the currency of the account.
            if($currency->id !== $default->id && $convertToNative) {
                $currency = $default;
            }

            $currentSet   = [
                'label'           => $account->name,
                'currency_symbol' => $currency->symbol,
                'entries'         => [],
            ];

            $currentStart = clone $start;
            $range        = $convertToNative ? app('steam')->balanceInRangeNative($account, $start, clone $end) : app('steam')->balanceInRange($account, $start, clone $end);
            $previous     = array_values($range)[0];
            while ($currentStart <= $end) {
                $format                        = $currentStart->format('Y-m-d');
                $label                         = trim($currentStart->isoFormat((string) trans('config.month_and_day_js', [], $locale)));
                $balance                       = $range[$format] ?? $previous;
                $previous                      = $balance;
                $currentStart->addDay();
                $currentSet['entries'][$label] = $balance;
            }
            $chartData[]  = $currentSet;
        }
        $data         = $generator->multiSet($chartData);
        $cache->store($data);

        return $data;
    }
}