<?php

/*
 * FixTransactionTypes.php
 * Copyright (c) 2021 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\Console\Commands\Correction;

use FireflyIII\Console\Commands\ShowsFriendlyMessages;
use FireflyIII\Exceptions\FireflyException;
use FireflyIII\Models\Account;
use FireflyIII\Models\Transaction;
use FireflyIII\Models\TransactionJournal;
use FireflyIII\Models\TransactionType;
use Illuminate\Console\Command;
use Illuminate\Support\Collection;
use Illuminate\Support\Facades\Log;

class CorrectsTransactionTypes extends Command
{
    use ShowsFriendlyMessages;

    protected $description = 'Make sure all transactions are of the correct type, based on source + dest.';
    protected $signature   = 'correction:transaction-types';

    /**
     * Execute the console command.
     */
    public function handle(): int
    {
        $count    = 0;
        $journals = $this->collectJournals();
        Log::debug(sprintf('In FixTransactionTypes, found %d journals.', $journals->count()));

        /** @var TransactionJournal $journal */
        foreach ($journals as $journal) {
            $fixed = $this->fixJournal($journal);
            if ($fixed) {
                ++$count;
            }
        }
        if ($count > 0) {
            $this->friendlyInfo(sprintf('Corrected transaction type of %d transaction journals.', $count));

            return 0;
        }
        $this->friendlyPositive('All transaction journals are of the correct transaction type');

        return 0;
    }

    private function changeJournal(TransactionJournal $journal, string $expectedType): void
    {
        $type = TransactionType::whereType($expectedType)->first();
        if (null !== $type) {
            $journal->transaction_type_id = $type->id;
            $journal->save();
        }
    }

    /**
     * Collect all transaction journals.
     */
    private function collectJournals(): Collection
    {
        return TransactionJournal::with(['transactionType', 'transactions', 'transactions.account', 'transactions.account.accountType'])->get();
    }

    private function fixJournal(TransactionJournal $journal): bool
    {
        $type         = $journal->transactionType->type;

        try {
            $source      = $this->getSourceAccount($journal);
            $destination = $this->getDestinationAccount($journal);
        } catch (FireflyException $e) {
            $this->friendlyError($e->getMessage());

            return false;
        }
        $expectedType = (string) config(sprintf('firefly.account_to_transaction.%s.%s', $source->accountType->type, $destination->accountType->type));
        if ($expectedType !== $type) {
            $this->friendlyWarning(sprintf(
                'Transaction journal #%d was of type "%s" but is corrected to "%s" (%s -> %s)',
                $journal->id,
                $type,
                $expectedType,
                $source->accountType->type,
                $destination->accountType->type
            ));
            $this->changeJournal($journal, $expectedType);

            return true;
        }

        return false;
    }

    /**
     * @throws FireflyException
     */
    private function getDestinationAccount(TransactionJournal $journal): Account
    {
        $collection  = $journal->transactions->filter(static fn (Transaction $transaction): bool => $transaction->amount > 0);
        if (0 === $collection->count()) {
            throw new FireflyException(sprintf('300004: Journal #%d has no destination transaction.', $journal->id));
        }
        if (1 !== $collection->count()) {
            throw new FireflyException(sprintf('300005: Journal #%d has multiple destination transactions.', $journal->id));
        }

        /** @var Transaction $transaction */
        $transaction = $collection->first();

        /** @var null|Account $account */
        $account     = $transaction->account;
        if (null === $account) {
            throw new FireflyException(sprintf('300006: Journal #%d, transaction #%d has no destination account.', $journal->id, $transaction->id));
        }

        return $account;
    }

    /**
     * @throws FireflyException
     */
    private function getSourceAccount(TransactionJournal $journal): Account
    {
        $collection  = $journal->transactions->filter(static fn (Transaction $transaction): bool => $transaction->amount < 0);
        if (0 === $collection->count()) {
            throw new FireflyException(sprintf('300001: Journal #%d has no source transaction.', $journal->id));
        }
        if (1 !== $collection->count()) {
            throw new FireflyException(sprintf('300002: Journal #%d has multiple source transactions.', $journal->id));
        }

        /** @var Transaction $transaction */
        $transaction = $collection->first();

        /** @var null|Account $account */
        $account     = $transaction->account;
        if (null === $account) {
            throw new FireflyException(sprintf('300003: Journal #%d, transaction #%d has no source account.', $journal->id, $transaction->id));
        }

        return $account;
    }
}
