<?php

/**
 * UpdatedGroupEventHandler.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\Handlers\Events;

use FireflyIII\Enums\TransactionTypeEnum;
use FireflyIII\Enums\WebhookTrigger;
use FireflyIII\Events\RequestedSendWebhookMessages;
use FireflyIII\Events\UpdatedTransactionGroup;
use FireflyIII\Generator\Webhook\MessageGeneratorInterface;
use FireflyIII\Models\Account;
use FireflyIII\Models\Transaction;
use FireflyIII\Models\TransactionJournal;
use FireflyIII\Repositories\PeriodStatistic\PeriodStatisticRepositoryInterface;
use FireflyIII\Repositories\RuleGroup\RuleGroupRepositoryInterface;
use FireflyIII\Services\Internal\Support\CreditRecalculateService;
use FireflyIII\Support\Models\AccountBalanceCalculator;
use FireflyIII\TransactionRules\Engine\RuleEngineInterface;
use Illuminate\Support\Collection;
use Illuminate\Support\Facades\Log;

/**
 * Class UpdatedGroupEventHandler
 */
class UpdatedGroupEventHandler
{
    public function runAllHandlers(UpdatedTransactionGroup $event): void
    {
        $this->unifyAccounts($event);
        $this->processRules($event);
        $this->recalculateCredit($event);
        $this->triggerWebhooks($event);
        $this->removePeriodStatistics($event);
        if ($event->runRecalculations) {
            $this->updateRunningBalance($event);
        }


    }

    /**
     * TODO duplicate
     */
    private function removePeriodStatistics(UpdatedTransactionGroup $event): void
    {
        /** @var PeriodStatisticRepositoryInterface $repository */
        $repository = app(PeriodStatisticRepositoryInterface::class);

        /** @var TransactionJournal $journal */
        foreach ($event->transactionGroup->transactionJournals as $journal) {
            $source     = $journal->transactions()->where('amount', '<', '0')->first();
            $dest       = $journal->transactions()->where('amount', '>', '0')->first();
            $repository->deleteStatisticsForModel($source->account, $journal->date);
            $repository->deleteStatisticsForModel($dest->account, $journal->date);

            $categories = $journal->categories;
            $tags       = $journal->tags;
            $budgets    = $journal->budgets;

            foreach ($categories as $category) {
                $repository->deleteStatisticsForModel($category, $journal->date);
            }
            foreach ($tags as $tag) {
                $repository->deleteStatisticsForModel($tag, $journal->date);
            }
            foreach ($budgets as $budget) {
                $repository->deleteStatisticsForModel($budget, $journal->date);
            }
            if (0 === $categories->count()) {
                $repository->deleteStatisticsForPrefix($journal->userGroup, 'no_category', $journal->date);
            }
            if (0 === $budgets->count()) {
                $repository->deleteStatisticsForPrefix($journal->userGroup, 'no_budget', $journal->date);
            }
        }
    }

    /**
     * This method will make sure all source / destination accounts are the same.
     */
    public function unifyAccounts(UpdatedTransactionGroup $updatedGroupEvent): void
    {
        $group         = $updatedGroupEvent->transactionGroup;
        if (1 === $group->transactionJournals->count()) {
            return;
        }

        // first journal:
        /** @var null|TransactionJournal $first */
        $first         = $group->transactionJournals()
            ->orderBy('transaction_journals.date', 'DESC')
            ->orderBy('transaction_journals.order', 'ASC')
            ->orderBy('transaction_journals.id', 'DESC')
            ->orderBy('transaction_journals.description', 'DESC')
            ->first()
        ;

        if (null === $first) {
            Log::warning(sprintf('Group #%d has no transaction journals.', $group->id));

            return;
        }

        $all           = $group->transactionJournals()->get()->pluck('id')->toArray();

        /** @var Account $sourceAccount */
        $sourceAccount = $first->transactions()->where('amount', '<', '0')->first()->account;

        /** @var Account $destAccount */
        $destAccount   = $first->transactions()->where('amount', '>', '0')->first()->account;

        $type          = $first->transactionType->type;
        if (TransactionTypeEnum::TRANSFER->value === $type || TransactionTypeEnum::WITHDRAWAL->value === $type) {
            // set all source transactions to source account:
            Transaction::whereIn('transaction_journal_id', $all)
                ->where('amount', '<', 0)->update(['account_id' => $sourceAccount->id])
            ;
        }
        if (TransactionTypeEnum::TRANSFER->value === $type || TransactionTypeEnum::DEPOSIT->value === $type) {
            // set all destination transactions to destination account:
            Transaction::whereIn('transaction_journal_id', $all)
                ->where('amount', '>', 0)->update(['account_id' => $destAccount->id])
            ;
        }
    }

    /**
     * This method will check all the rules when a journal is updated.
     */
    private function processRules(UpdatedTransactionGroup $updatedGroupEvent): void
    {
        if (false === $updatedGroupEvent->applyRules) {
            Log::info(sprintf('Will not run rules on group #%d', $updatedGroupEvent->transactionGroup->id));

            return;
        }

        $journals            = $updatedGroupEvent->transactionGroup->transactionJournals;
        $array               = [];

        /** @var TransactionJournal $journal */
        foreach ($journals as $journal) {
            $array[] = $journal->id;
        }
        $journalIds          = implode(',', $array);
        Log::debug(sprintf('Add local operator for journal(s): %s', $journalIds));

        // collect rules:
        $ruleGroupRepository = app(RuleGroupRepositoryInterface::class);
        $ruleGroupRepository->setUser($updatedGroupEvent->transactionGroup->user);

        $groups              = $ruleGroupRepository->getRuleGroupsWithRules('update-journal');

        // file rule engine.
        $newRuleEngine       = app(RuleEngineInterface::class);
        $newRuleEngine->setUser($updatedGroupEvent->transactionGroup->user);
        $newRuleEngine->addOperator(['type' => 'journal_id', 'value' => $journalIds]);
        $newRuleEngine->setRuleGroups($groups);
        $newRuleEngine->fire();
    }

    private function recalculateCredit(UpdatedTransactionGroup $event): void
    {
        $group  = $event->transactionGroup;

        /** @var CreditRecalculateService $object */
        $object = app(CreditRecalculateService::class);
        $object->setGroup($group);
        $object->recalculate();
    }

    private function triggerWebhooks(UpdatedTransactionGroup $updatedGroupEvent): void
    {
        Log::debug(__METHOD__);
        $group  = $updatedGroupEvent->transactionGroup;
        if (false === $updatedGroupEvent->fireWebhooks) {
            Log::info(sprintf('Will not fire webhooks for transaction group #%d', $group->id));

            return;
        }
        $user   = $group->user;

        /** @var MessageGeneratorInterface $engine */
        $engine = app(MessageGeneratorInterface::class);
        $engine->setUser($user);
        $engine->setObjects(new Collection()->push($group));
        $engine->setTrigger(WebhookTrigger::UPDATE_TRANSACTION);
        $engine->generateMessages();

        Log::debug(sprintf('send event RequestedSendWebhookMessages from %s', __METHOD__));
        event(new RequestedSendWebhookMessages());
    }

    private function updateRunningBalance(UpdatedTransactionGroup $event): void
    {
        Log::debug(__METHOD__);
        $group = $event->transactionGroup;
        foreach ($group->transactionJournals as $journal) {
            AccountBalanceCalculator::recalculateForJournal($journal);
        }
    }
}
