<?php
/**
 * BudgetRepository.php
 * Copyright (C) 2016 thegrumpydictator@gmail.com
 *
 * This software may be modified and distributed under the terms of the
 * Creative Commons Attribution-ShareAlike 4.0 International License.
 *
 * See the LICENSE file for details.
 */

declare(strict_types = 1);

namespace FireflyIII\Repositories\Budget;

use Carbon\Carbon;
use FireflyIII\Events\StoredBudgetLimit;
use FireflyIII\Events\UpdatedBudgetLimit;
use FireflyIII\Models\Budget;
use FireflyIII\Models\BudgetLimit;
use FireflyIII\Models\LimitRepetition;
use FireflyIII\Models\Transaction;
use FireflyIII\Models\TransactionJournal;
use FireflyIII\Models\TransactionType;
use FireflyIII\User;
use Illuminate\Database\Eloquent\Builder;
use Illuminate\Database\Query\JoinClause;
use Illuminate\Support\Collection;
use Log;

/**
 * Class BudgetRepository
 *
 * @package FireflyIII\Repositories\Budget
 */
class BudgetRepository implements BudgetRepositoryInterface
{
    /** @var User */
    private $user;

    /**
     * BudgetRepository constructor.
     *
     * @param User $user
     */
    public function __construct(User $user)
    {
        $this->user = $user;
    }

    /**
     * @return bool
     */
    public function cleanupBudgets(): bool
    {
        // delete limits with amount 0:
        BudgetLimit::where('amount', 0)->delete();

        return true;

    }

    /**
     * @param Budget $budget
     *
     * @return bool
     */
    public function destroy(Budget $budget): bool
    {
        $budget->delete();

        return true;
    }

    /**
     * Find a budget.
     *
     * @param int $budgetId
     *
     * @return Budget
     */
    public function find(int $budgetId): Budget
    {
        $budget = $this->user->budgets()->find($budgetId);
        if (is_null($budget)) {
            $budget = new Budget;
        }

        return $budget;
    }

    /**
     * Find a budget.
     *
     * @param string $name
     *
     * @return Budget
     */
    public function findByName(string $name): Budget
    {
        $budgets = $this->user->budgets()->get(['budgets.*']);
        /** @var Budget $budget */
        foreach ($budgets as $budget) {
            if ($budget->name === $name) {
                return $budget;
            }
        }

        return new Budget;
    }

    /**
     * This method returns the oldest journal or transaction date known to this budget.
     * Will cache result.
     *
     * @param Budget $budget
     *
     * @return Carbon
     */
    public function firstUseDate(Budget $budget): Carbon
    {
        $oldest  = Carbon::create()->startOfYear();
        $journal = $budget->transactionJournals()->orderBy('date', 'ASC')->first();
        if (!is_null($journal)) {
            $oldest = $journal->date < $oldest ? $journal->date : $oldest;
        }

        $transaction = $budget
            ->transactions()
            ->leftJoin('transaction_journals', 'transaction_journals.id', '=', 'transactions.id')
            ->orderBy('transaction_journals.date', 'ASC')->first(['transactions.*', 'transaction_journals.date']);
        if (!is_null($transaction)) {
            $carbon = new Carbon($transaction->date);
            $oldest = $carbon < $oldest ? $carbon : $oldest;
        }

        return $oldest;

    }

    /**
     * @return Collection
     */
    public function getActiveBudgets(): Collection
    {
        /** @var Collection $set */
        $set = $this->user->budgets()->where('active', 1)->get();

        $set = $set->sortBy(
            function (Budget $budget) {
                return strtolower($budget->name);
            }
        );

        return $set;
    }

    /**
     * @param Carbon $start
     * @param Carbon $end
     *
     * @return Collection
     */
    public function getAllBudgetLimitRepetitions(Carbon $start, Carbon $end): Collection
    {
        $query = LimitRepetition::
        leftJoin('budget_limits', 'limit_repetitions.budget_limit_id', '=', 'budget_limits.id')
                                ->leftJoin('budgets', 'budgets.id', '=', 'budget_limits.budget_id')
                                ->where('limit_repetitions.startdate', '<=', $end->format('Y-m-d 00:00:00'))
                                ->where('limit_repetitions.startdate', '>=', $start->format('Y-m-d 00:00:00'))
                                ->where('budgets.user_id', $this->user->id);

        $set = $query->get(['limit_repetitions.*', 'budget_limits.budget_id']);

        return $set;
    }

    /**
     * @return Collection
     */
    public function getBudgets(): Collection
    {
        /** @var Collection $set */
        $set = $this->user->budgets()->get();

        $set = $set->sortBy(
            function (Budget $budget) {
                return strtolower($budget->name);
            }
        );

        return $set;
    }

    /**
     * @return Collection
     */
    public function getInactiveBudgets(): Collection
    {
        /** @var Collection $set */
        $set = $this->user->budgets()->where('active', 0)->get();

        $set = $set->sortBy(
            function (Budget $budget) {
                return strtolower($budget->name);
            }
        );

        return $set;
    }

    /**
     * @param Collection $budgets
     * @param Collection $accounts
     * @param Carbon     $start
     * @param Carbon     $end
     *
     * @return string
     */
    public function spentInPeriod(Collection $budgets, Collection $accounts, Carbon $start, Carbon $end) : string
    {
        // collect amount of transaction journals, which is easy:
        $budgetIds  = $budgets->pluck('id')->toArray();
        $accountIds = $accounts->pluck('id')->toArray();

        Log::debug('spentInPeriod: Now in spentInPeriod for these budgets: ', $budgetIds);
        Log::debug('spentInPeriod: and these accounts: ', $accountIds);
        Log::debug(sprintf('spentInPeriod: Start date is "%s", end date is "%s"', $start->format('Y-m-d'), $end->format('Y-m-d')));

        $fromJournalsQuery = TransactionJournal
            ::leftJoin('budget_transaction_journal', 'budget_transaction_journal.transaction_journal_id', '=', 'transaction_journals.id')
            ->leftJoin('transaction_types', 'transaction_types.id', '=', 'transaction_journals.transaction_type_id')
            ->leftJoin(
                'transactions', function (JoinClause $join) {
                $join->on('transactions.transaction_journal_id', '=', 'transaction_journals.id')->where('transactions.amount', '<', '0');
            }
            )
            ->where('transaction_journals.date', '>=', $start->format('Y-m-d'))
            ->where('transaction_journals.date', '<=', $end->format('Y-m-d'))
            ->whereNull('transaction_journals.deleted_at')
            ->whereNull('transactions.deleted_at')
            ->where('transaction_journals.user_id', $this->user->id)
            ->where('transaction_types.type', 'Withdrawal');

        // add budgets:
        if ($budgets->count() > 0) {
            $fromJournalsQuery->whereIn('budget_transaction_journal.budget_id', $budgetIds);
        }

        // add accounts:
        if ($accounts->count() > 0) {
            $fromJournalsQuery->whereIn('transactions.account_id', $accountIds);
        }
        $first = strval($fromJournalsQuery->sum('transactions.amount'));
        Log::debug(sprintf('spentInPeriod: Result from first query: %s', $first));
        unset($fromJournalsQuery);

        // collect amount from transactions:
        /**
         * select transactions.id, budget_transaction.budget_id , transactions.amount
         *
         *
         * and budget_transaction.budget_id in (1,61)
         * and transactions.account_id in (2)
         */
        $fromTransactionsQuery = Transaction
            ::leftJoin('budget_transaction', 'budget_transaction.transaction_id', '=', 'transactions.id')
            ->leftJoin('transaction_journals', 'transaction_journals.id', '=', 'transactions.transaction_journal_id')
            ->leftJoin('transaction_types', 'transaction_types.id', '=', 'transaction_journals.transaction_type_id')
            ->whereNull('transactions.deleted_at')
            ->whereNull('transaction_journals.deleted_at')
            ->where('transactions.amount', '<', 0)
            ->where('transaction_journals.date', '>=', $start->format('Y-m-d'))
            ->where('transaction_journals.date', '<=', $end->format('Y-m-d'))
            ->where('transaction_journals.user_id', $this->user->id)
            ->where('transaction_types.type', 'Withdrawal');

        // add budgets:
        if ($budgets->count() > 0) {
            $fromTransactionsQuery->whereIn('budget_transaction.budget_id', $budgetIds);
        }

        // add accounts:
        if ($accounts->count() > 0) {
            $fromTransactionsQuery->whereIn('transactions.account_id', $accountIds);
        }
        $second = strval($fromTransactionsQuery->sum('transactions.amount'));
        Log::debug(sprintf('spentInPeriod: Result from second query: %s', $second));

        Log::debug(sprintf('spentInPeriod: FINAL: %s', bcadd($first, $second)));

        return bcadd($first, $second);
    }

    /**
     * @param Collection $accounts
     * @param Carbon     $start
     * @param Carbon     $end
     *
     * @return string
     */
    public function spentInPeriodWithoutBudget(Collection $accounts, Carbon $start, Carbon $end): string
    {
        $types = [TransactionType::WITHDRAWAL];
        $query = $this->user->transactionJournals()
                            ->distinct()
                            ->transactionTypes($types)
                            ->leftJoin('budget_transaction_journal', 'budget_transaction_journal.transaction_journal_id', '=', 'transaction_journals.id')
                            ->leftJoin(
                                'transactions as source', function (JoinClause $join) {
                                $join->on('source.transaction_journal_id', '=', 'transaction_journals.id')->where('source.amount', '<', 0);
                            }
                            )
                            ->leftJoin(
                                'transactions as destination', function (JoinClause $join) {
                                $join->on('destination.transaction_journal_id', '=', 'transaction_journals.id')->where('destination.amount', '>', 0);
                            }
                            )
                            ->leftJoin('budget_transaction', 'source.id', '=', 'budget_transaction.transaction_id')
                            ->whereNull('budget_transaction_journal.id')
                            ->whereNull('budget_transaction.id')
                            ->before($end)
                            ->after($start)
                            ->whereNull('source.deleted_at')
                            ->whereNull('destination.deleted_at')
                            ->where('transaction_journals.completed', 1);

        if ($accounts->count() > 0) {
            $accountIds = $accounts->pluck('id')->toArray();
            $query->where(
            // source.account_id in accountIds XOR destination.account_id in accountIds
                function (Builder $sourceXorDestinationQuery) use ($accountIds) {
                    $sourceXorDestinationQuery->where(
                        function (Builder $inSourceButNotDestinationQuery) use ($accountIds) {
                            $inSourceButNotDestinationQuery->whereIn('source.account_id', $accountIds)
                                                           ->whereNotIn('destination.account_id', $accountIds);
                        }
                    )->orWhere(
                        function (Builder $inDestinationButNotSourceQuery) use ($accountIds) {
                            $inDestinationButNotSourceQuery->whereIn('destination.account_id', $accountIds)
                                                           ->whereNotIn('source.account_id', $accountIds);
                        }
                    );
                }
            );
        }
        $ids = $query->get(['transaction_journals.id'])->pluck('id')->toArray();
        $sum = '0';
        if (count($ids) > 0) {
            $sum = strval(
                $this->user->transactions()
                           ->whereIn('transaction_journal_id', $ids)
                           ->where('amount', '<', '0')
                           ->whereNull('transactions.deleted_at')
                           ->sum('amount')
            );
        }

        return $sum;
    }

    /**
     * @param array $data
     *
     * @return Budget
     */
    public function store(array $data): Budget
    {
        $newBudget = new Budget(
            [
                'user_id' => $this->user->id,
                'name'    => $data['name'],
            ]
        );
        $newBudget->save();

        return $newBudget;
    }

    /**
     * @param Budget $budget
     * @param array  $data
     *
     * @return Budget
     */
    public function update(Budget $budget, array $data): Budget
    {
        // update the account:
        $budget->name   = $data['name'];
        $budget->active = $data['active'];
        $budget->save();

        return $budget;
    }

    /**
     * @param Budget $budget
     * @param Carbon $start
     * @param Carbon $end
     * @param string $range
     * @param int    $amount
     *
     * @return BudgetLimit
     */
    public function updateLimitAmount(Budget $budget, Carbon $start, Carbon $end, string $range, int $amount) : BudgetLimit
    {
        // there might be a budget limit for this startdate:
        $repeatFreq = config('firefly.range_to_repeat_freq.' . $range);
        /** @var BudgetLimit $limit */
        $limit = $budget->budgetlimits()
                        ->where('budget_limits.startdate', $start)
                        ->where('budget_limits.repeat_freq', $repeatFreq)->first(['budget_limits.*']);

        // delete if amount is zero.
        if (!is_null($limit) && $amount <= 0.0) {
            $limit->delete();

            return new BudgetLimit;
        }
        // update if exists:
        if (!is_null($limit)) {
            $limit->amount = $amount;
            $limit->save();

            // fire event to create or update LimitRepetition.
            event(new UpdatedBudgetLimit($limit, $end));

            return $limit;
        }

        // create one and return it.
        $limit = new BudgetLimit;
        $limit->budget()->associate($budget);
        $limit->startdate   = $start;
        $limit->amount      = $amount;
        $limit->repeat_freq = $repeatFreq;
        $limit->repeats     = 0;
        $limit->save();
        event(new StoredBudgetLimit($limit, $end));


        // likewise, there should be a limit repetition to match the end date
        // (which is always the end of the month) but that is caught by an event.
        // so handled automatically.

        return $limit;
    }
}