<?php
/**
 * ReportController.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\Http\Controllers\Chart;


use Carbon\Carbon;
use FireflyIII\Generator\Chart\Report\ReportChartGeneratorInterface;
use FireflyIII\Http\Controllers\Controller;
use FireflyIII\Repositories\Account\AccountTaskerInterface;
use FireflyIII\Support\CacheProperties;
use Illuminate\Support\Collection;
use Navigation;
use Response;
use Steam;

/**
 * Class ReportController
 *
 * @package FireflyIII\Http\Controllers\Chart
 */
class ReportController extends Controller
{

    /** @var ReportChartGeneratorInterface */
    protected $generator;

    /**
     *
     */
    public function __construct()
    {
        parent::__construct();
        // create chart generator:
        $this->generator = app(ReportChartGeneratorInterface::class);
    }

    /**
     * This chart, by default, is shown on the multi-year and year report pages,
     * which means that giving it a 2 week "period" should be enough granularity.
     *
     * @param Collection $accounts
     * @param Carbon $start
     * @param Carbon     $end
     * @return \Illuminate\Http\JsonResponse
     */
    public function netWorth(Collection $accounts, Carbon $start, Carbon $end)
    {
        // chart properties for cache:
        $cache = new CacheProperties;
        $cache->addProperty('netWorth');
        $cache->addProperty($start);
        $cache->addProperty($accounts);
        $cache->addProperty($end);
        if ($cache->has()) {
            return Response::json($cache->get());
        }
        $ids     = $accounts->pluck('id')->toArray();
        $current = clone $start;
        $entries = new Collection;
        while ($current < $end) {
            $balances = Steam::balancesById($ids, $current);
            $sum      = $this->arraySum($balances);
            $entries->push(
                [
                    'date'      => clone $current,
                    'net-worth' => $sum,
                ]
            );

            $current->addDays(7);
        }
        $data = $this->generator->netWorth($entries);

        $cache->store($data);

        return Response::json($data);
    }


    /**
     * Shows income and expense, debet/credit: operations
     *
     * @param Collection $accounts
     * @param Carbon     $start
     * @param Carbon     $end
     *
     *
     * @return \Illuminate\Http\JsonResponse
     */
    public function operations(Collection $accounts, Carbon $start, Carbon $end)
    {
        // chart properties for cache:
        $cache = new CacheProperties;
        $cache->addProperty('yearInOut');
        $cache->addProperty($start);
        $cache->addProperty($accounts);
        $cache->addProperty($end);
        if ($cache->has()) {
            return Response::json($cache->get());
        }

        $chartSource = $this->getYearData($accounts, $start, $end);

        if ($start->diffInMonths($end) > 12) {
            // data = method X
            $data = $this->multiYearOperations($chartSource['earned'], $chartSource['spent'], $start, $end);
            $cache->store($data);

            return Response::json($data);
        }

        // data = method Y
        $data = $this->singleYearOperations($chartSource['earned'], $chartSource['spent'], $start, $end);
        $cache->store($data);

        return Response::json($data);


    }

    /**
     * Shows sum income and expense, debet/credit: operations
     * @param Carbon     $start
     * @param Carbon     $end
     * @param Collection $accounts
     *
     * @return \Illuminate\Http\JsonResponse
     */
    public function sum(Collection $accounts, Carbon $start, Carbon $end)
    {

        // chart properties for cache:
        $cache = new CacheProperties;
        $cache->addProperty('yearInOutSummarized');
        $cache->addProperty($start);
        $cache->addProperty($end);
        $cache->addProperty($accounts);
        if ($cache->has()) {
            return Response::json($cache->get());
        }
        $chartSource = $this->getYearData($accounts, $start, $end);

        if ($start->diffInMonths($end) > 12) {
            // per year
            $data = $this->multiYearSum($chartSource['earned'], $chartSource['spent'], $start, $end);
            $cache->store($data);

            return Response::json($data);
        }
        // per month!
        $data = $this->singleYearSum($chartSource['earned'], $chartSource['spent'], $start, $end);
        $cache->store($data);

        return Response::json($data);

    }

    /**
     * @param array  $earned
     * @param array  $spent
     * @param Carbon $start
     * @param Carbon $end
     *
     * @return array
     */
    protected function multiYearOperations(array $earned, array $spent, Carbon $start, Carbon $end)
    {
        $entries = new Collection;
        while ($start < $end) {

            $incomeSum  = $this->pluckFromArray($start->year, $earned);
            $expenseSum = $this->pluckFromArray($start->year, $spent);

            $entries->push([clone $start, $incomeSum, $expenseSum]);
            $start->addYear();
        }

        $data = $this->generator->multiYearOperations($entries);

        return $data;
    }

    /**
     * @param array  $earned
     * @param array  $spent
     * @param Carbon $start
     * @param Carbon $end
     *
     * @return array
     */
    protected function multiYearSum(array $earned, array $spent, Carbon $start, Carbon $end)
    {
        $income  = '0';
        $expense = '0';
        $count   = 0;
        while ($start < $end) {

            $currentIncome  = $this->pluckFromArray($start->year, $earned);
            $currentExpense = $this->pluckFromArray($start->year, $spent);
            $income         = bcadd($income, $currentIncome);
            $expense        = bcadd($expense, $currentExpense);

            $count++;
            $start->addYear();
        }

        $data = $this->generator->multiYearSum($income, $expense, $count);

        return $data;
    }

    /**
     * @param int   $year
     * @param array $set
     *
     * @return string
     */
    protected function pluckFromArray($year, array $set)
    {
        $sum = '0';
        foreach ($set as $date => $amount) {
            if (substr($date, 0, 4) == $year) {
                $sum = bcadd($sum, $amount);
            }
        }

        return $sum;

    }

    /**
     * @param array  $earned
     * @param array  $spent
     * @param Carbon $start
     * @param Carbon $end
     *
     * @return array
     */
    protected function singleYearOperations(array $earned, array $spent, Carbon $start, Carbon $end)
    {
        // per month? simply use each month.

        $entries = new Collection;
        while ($start < $end) {
            // total income and total expenses:
            $date       = $start->format('Y-m');
            $incomeSum  = isset($earned[$date]) ? $earned[$date] : 0;
            $expenseSum = isset($spent[$date]) ? $spent[$date] : 0;

            $entries->push([clone $start, $incomeSum, $expenseSum]);
            $start->addMonth();
        }

        $data = $this->generator->yearOperations($entries);

        return $data;
    }

    /**
     * @param array  $earned
     * @param array  $spent
     * @param Carbon $start
     * @param Carbon $end
     *
     * @return array
     */
    protected function singleYearSum(array $earned, array $spent, Carbon $start, Carbon $end)
    {
        $income  = '0';
        $expense = '0';
        $count   = 0;
        while ($start < $end) {
            $date           = $start->format('Y-m');
            $currentIncome  = isset($earned[$date]) ? $earned[$date] : 0;
            $currentExpense = isset($spent[$date]) ? $spent[$date] : 0;
            $income         = bcadd($income, $currentIncome);
            $expense        = bcadd($expense, $currentExpense);

            $count++;
            $start->addMonth();
        }

        $data = $this->generator->yearSum($income, $expense, $count);

        return $data;
    }

    /**
     * @param $array
     *
     * @return string
     */
    private function arraySum($array) : string
    {
        $sum = '0';
        foreach ($array as $entry) {
            $sum = bcadd($sum, $entry);
        }

        return $sum;
    }

    /**
     * @param Collection $accounts
     * @param Carbon     $start
     * @param Carbon     $end
     *
     * @return array
     */
    private function getYearData(Collection $accounts, Carbon $start, Carbon $end): array
    {
        $tasker       = app(AccountTaskerInterface::class);
        $currentStart = clone $start;
        $spentArray   = [];
        $earnedArray  = [];
        while ($currentStart <= $end) {
            $currentEnd         = Navigation::endOfPeriod($currentStart, '1M');
            $date               = $currentStart->format('Y-m');
            $spent              = $tasker->amountOutInPeriod($accounts, $accounts, $currentStart, $currentEnd);
            $earned             = $tasker->amountInInPeriod($accounts, $accounts, $currentStart, $currentEnd);
            $spentArray[$date]  = bcmul($spent, '-1');
            $earnedArray[$date] = $earned;
            $currentStart       = Navigation::addPeriod($currentStart, '1M', 0);
        }

        return [
            'spent'  => $spentArray,
            'earned' => $earnedArray,
        ];
    }
}