<?php
declare(strict_types = 1);

namespace FireflyIII\Http\Controllers\Chart;


use Carbon\Carbon;
use FireflyIII\Generator\Chart\Category\CategoryChartGeneratorInterface;
use FireflyIII\Http\Controllers\Controller;
use FireflyIII\Models\Category;
use FireflyIII\Repositories\Category\CategoryRepositoryInterface as CRI;
use FireflyIII\Support\CacheProperties;
use Illuminate\Support\Collection;
use Log;
use Navigation;
use Preferences;
use Response;
use stdClass;

/**
 * Class CategoryController
 *
 * @package FireflyIII\Http\Controllers\Chart
 */
class CategoryController extends Controller
{
    const MAKE_POSITIVE = -1;
    const KEEP_POSITIVE = 1;


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

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


    /**
     * Show an overview for a category for all time, per month/week/year.
     *
     * @param CRI      $repository
     * @param Category $category
     *
     * @return \Symfony\Component\HttpFoundation\Response
     */
    public function all(CRI $repository, Category $category)
    {
        $start              = $repository->firstUseDate($category, new Collection);
        $range              = Preferences::get('viewRange', '1M')->data;
        $start              = Navigation::startOfPeriod($start, $range);
        $categoryCollection = new Collection([$category]);
        $end                = new Carbon;
        $entries            = new Collection;
        $cache              = new CacheProperties;
        $cache->addProperty($start);
        $cache->addProperty($end);
        $cache->addProperty('all');
        $cache->addProperty('categories');
        if ($cache->has()) {
            //return Response::json($cache->get());
        }

        while ($start <= $end) {
            $currentEnd = Navigation::endOfPeriod($start, $range);
            Log::debug('Searching for expenses from ' . $start . ' to ' . $currentEnd);
            $spent  = $repository->spentInPeriod($categoryCollection, new Collection, $start, $currentEnd);
            $earned = $repository->earnedInPeriod($categoryCollection, new Collection, $start, $currentEnd);
            $date   = Navigation::periodShow($start, $range);
            $entries->push([clone $start, $date, $spent, $earned]);
            $start = Navigation::addPeriod($start, $range, 0);
        }
        $entries = $entries->reverse();
        $entries = $entries->slice(0, 48);
        $entries = $entries->reverse();
        $data    = $this->generator->all($entries);
        $cache->store($data);

        return ' ' . json_encode($data);

        return Response::json($data);

    }

    /**
     * @param CRI      $repository
     * @param Category $category
     *
     * @return \Symfony\Component\HttpFoundation\Response
     */
    public function currentPeriod(CRI $repository, Category $category)
    {
        $start = clone session('start', Carbon::now()->startOfMonth());
        $end   = session('end', Carbon::now()->endOfMonth());
        $data  = $this->makePeriodChart($repository, $category, $start, $end);

        return Response::json($data);
    }

    /**
     * Returns a chart of what has been earned in this period in each category
     * grouped by month.
     *
     * @param CRI                         $repository
     * @param                             $reportType
     * @param Carbon                      $start
     * @param Carbon                      $end
     * @param Collection                  $accounts
     *
     * @return \Illuminate\Http\JsonResponse
     */
    public function earnedInPeriod(CRI $repository, string $reportType, Carbon $start, Carbon $end, Collection $accounts)
    {
        /**
         * $cache = new CacheProperties; // chart properties for cache:
         * $cache->addProperty($start);
         * $cache->addProperty($end);
         * $cache->addProperty($reportType);
         * $cache->addProperty($accounts);
         * $cache->addProperty('category');
         * $cache->addProperty('earned-in-period');
         * if ($cache->has()) {
         * return Response::json($cache->get());
         * }
         *
         * $set        = $repository->earnedForAccountsPerMonth($accounts, $start, $end);
         * $categories = $set->unique('id')->sortBy(
         * function (Category $category) {
         * return $category->name;
         * }
         * );
         * $entries    = $this->filterCollection($start, $end, $set, $categories);
         * $data       = $this->generator->earnedInPeriod($categories, $entries);
         * $cache->store($data);
         *
         * return $data;
         **/
    }

    /**
     * Show this month's category overview.
     *
     * @param CRI $repository
     *
     * @return \Symfony\Component\HttpFoundation\Response
     */
    public function frontpage(CRI $repository)
    {
        $start = session('start', Carbon::now()->startOfMonth());
        $end   = session('end', Carbon::now()->endOfMonth());
        // chart properties for cache:
        $cache = new CacheProperties;
        $cache->addProperty($start);
        $cache->addProperty($end);
        $cache->addProperty('category');
        $cache->addProperty('frontpage');
        if ($cache->has()) {
            //return Response::json($cache->get());
        }
        $categories = $repository->getCategories();
        $set        = new Collection;
        /** @var Category $category */
        foreach ($categories as $category) {
            $spent = $repository->spentInPeriod(new Collection([$category]), new Collection, $start, $end);
            Log::debug('Spent for ' . $category->name . ' is ' . $spent . ' (' . bccomp($spent, '0') . ')');
            if (bccomp($spent, '0') === -1) {
                $category->spent = $spent;
                $set->push($category);
            }
        }
        // this is a "fake" entry for the "no category" entry.
        $entry        = new stdClass;
        $entry->name  = trans('firefly.no_category');
        $entry->spent = $repository->spentInPeriodWithoutCategory(new Collection, $start, $end);
        $set->push($entry);

        $set  = $set->sortBy('spent');
        $data = $this->generator->frontpage($set);
        $cache->store($data);

        return Response::json($data);

    }

    /**
     * @param                             $reportType
     * @param Carbon                      $start
     * @param Carbon                      $end
     * @param Collection                  $accounts
     * @param Collection                  $categories
     *
     * @return \Illuminate\Http\JsonResponse
     */
    public function multiYear(string $reportType, Carbon $start, Carbon $end, Collection $accounts, Collection $categories)
    {
        /**
         * // /** @var CRI $repository
         * // $repository = app(CRI::class);
         *
         * // chart properties for cache:
         * $cache = new CacheProperties();
         * $cache->addProperty($reportType);
         * $cache->addProperty($start);
         * $cache->addProperty($end);
         * $cache->addProperty($accounts);
         * $cache->addProperty($categories);
         * $cache->addProperty('multiYearCategory');
         *
         * if ($cache->has()) {
         * return Response::json($cache->get());
         * }
         *
         * $entries = new Collection;
         * $set     = $repository->listMultiYear($categories, $accounts, $start, $end);
         *
         * /** @var Category $category
         * foreach ($categories as $category) {
         * $entry = ['name' => '', 'spent' => [], 'earned' => []];
         *
         * $currentStart = clone $start;
         * while ($currentStart < $end) {
         * // fix the date:
         * $year       = $currentStart->year;
         * $currentEnd = clone $currentStart;
         * $currentEnd->endOfYear();
         *
         *
         * // get data:
         * if (is_null($category->id)) {
         * $name   = trans('firefly.noCategory');
         * $spent  = $repository->sumSpentNoCategory($accounts, $currentStart, $currentEnd);
         * $earned = $repository->sumEarnedNoCategory($accounts, $currentStart, $currentEnd);
         * } else {
         * // get from set:
         * $entrySpent  = $set->filter(
         * function (Category $cat) use ($year, $category) {
         * return ($cat->type == 'Withdrawal' && $cat->dateFormatted == $year && $cat->id == $category->id);
         * }
         * )->first();
         * $entryEarned = $set->filter(
         * function (Category $cat) use ($year, $category) {
         * return ($cat->type == 'Deposit' && $cat->dateFormatted == $year && $cat->id == $category->id);
         * }
         * )->first();
         *
         * $name   = $category->name;
         * $spent  = !is_null($entrySpent) ? $entrySpent->sum : 0;
         * $earned = !is_null($entryEarned) ? $entryEarned->sum : 0;
         * }
         *
         * // save to array:
         * $entry['name']          = $name;
         * $entry['spent'][$year]  = ($spent * -1);
         * $entry['earned'][$year] = $earned;
         *
         * // jump to next year.
         * $currentStart = clone $currentEnd;
         * $currentStart->addDay();
         * }
         * $entries->push($entry);
         * }
         * // generate chart with data:
         * $data = $this->generator->multiYear($entries);
         * $cache->store($data);
         *
         * return Response::json($data);
         *
         */

    }

    /**
     * @param Category   $category
     * @param string     $reportType
     * @param Carbon     $start
     * @param Carbon     $end
     * @param Collection $accounts
     *
     * @return \Illuminate\Http\JsonResponse
     */
    public function period(Category $category, string $reportType, Carbon $start, Carbon $end, Collection $accounts)
    {
        /**
         * // chart properties for cache:
         * $cache = new CacheProperties();
         * $cache->addProperty($start);
         * $cache->addProperty($end);
         * $cache->addProperty($reportType);
         * $cache->addProperty($accounts);
         * $cache->addProperty($category->id);
         * $cache->addProperty('category');
         * $cache->addProperty('period');
         * if ($cache->has()) {
         * return Response::json($cache->get());
         * }
         *
         * /** @var CategoryRepositoryInterface $repository
         * $repository = app(CategoryRepositoryInterface::class);
         * // loop over period, add by users range:
         * $current   = clone $start;
         * $viewRange = Preferences::get('viewRange', '1M')->data;
         * $format    = strval(trans('config.month'));
         * $set       = new Collection;
         * while ($current < $end) {
         * $currentStart = clone $current;
         * $currentEnd   = Navigation::endOfPeriod($currentStart, $viewRange);
         *
         * $spent  = strval(array_sum($repository->spentPerDay($category, $currentStart, $currentEnd, $accounts)));
         * $earned = strval(array_sum($repository->earnedPerDay($category, $currentStart, $currentEnd, $accounts)));
         *
         * $entry = [
         * $category->name,
         * $currentStart->formatLocalized($format),
         * $spent,
         * $earned,
         *
         * ];
         * $set->push($entry);
         * $currentEnd->addDay();
         * $current = clone $currentEnd;
         * }
         * $data = $this->generator->period($set);
         * $cache->store($data);
         *
         * return Response::json($data);
         * **/

    }

    /**
     * @param CRI                         $repository
     * @param Category                    $category
     *
     * @param                             $date
     *
     * @return \Symfony\Component\HttpFoundation\Response
     */
    public function specificPeriod(CRI $repository, Category $category, $date)
    {
        $carbon = new Carbon($date);
        $range  = Preferences::get('viewRange', '1M')->data;
        $start  = Navigation::startOfPeriod($carbon, $range);
        $end    = Navigation::endOfPeriod($carbon, $range);
        $data   = $this->makePeriodChart($repository, $category, $start, $end);

        return Response::json($data);
    }

    /**
     * Returns a chart of what has been spent in this period in each category
     * grouped by month.
     *
     * @param CRI                         $repository
     * @param                             $reportType
     * @param Carbon                      $start
     * @param Carbon                      $end
     * @param Collection                  $accounts
     *
     *
     * @return \Illuminate\Http\JsonResponse
     */
    public function spentInPeriod(CRI $repository, $reportType, Carbon $start, Carbon $end, Collection $accounts)
    {
        /**
         * $cache = new CacheProperties; // chart properties for cache:
         * $cache->addProperty($start);
         * $cache->addProperty($end);
         * $cache->addProperty($reportType);
         * $cache->addProperty($accounts);
         * $cache->addProperty('category');
         * $cache->addProperty('spent-in-period');
         * if ($cache->has()) {
         * return Response::json($cache->get());
         * }
         *
         *
         * $set        = $repository->spentForAccountsPerMonth($accounts, $start, $end);
         * $categories = $set->unique('id')->sortBy(
         * function (Category $category) {
         * return $category->name;
         * }
         * );
         * $entries    = $this->filterCollection($start, $end, $set, $categories);
         * $entries    = $this->invertSelection($entries);
         * $data       = $this->generator->spentInPeriod($categories, $entries);
         * $cache->store($data);
         *
         * return $data;
         * */
    }

    /**
     * @param Carbon     $start
     * @param Carbon     $end
     * @param Collection $set
     * @param Collection $categories
     *
     * @return Collection
     */
    private function filterCollection(Carbon $start, Carbon $end, Collection $set, Collection $categories): Collection
    {
        /**
         * $entries = new Collection;
         *
         * while ($start < $end) { // filter the set:
         * $row        = [clone $start];
         * $currentSet = $set->filter( // get possibly relevant entries from the big $set
         * function (Category $category) use ($start) {
         * return $category->dateFormatted == $start->format('Y-m');
         * }
         * );
         * /** @var Category $category
         * foreach ($categories as $category) { // check for each category if its in the current set.
         * $entry = $currentSet->filter( // if its in there, use the value.
         * function (Category $cat) use ($category) {
         * return ($cat->id == $category->id);
         * }
         * )->first();
         * if (!is_null($entry)) {
         * $row[] = $entry->earned ? round($entry->earned, 2) : round($entry->spent, 2);
         * } else {
         * $row[] = 0;
         * }
         * }
         * $entries->push($row);
         * $start->addMonth();
         * }
         *
         * return $entries;
         * */
    }

    /**
     * Not the most elegant solution but it works.
     *
     * @param Collection $entries
     *
     * @return Collection
     */
    private function invertSelection(Collection $entries): Collection
    {
        /**
         * $result = new Collection;
         * foreach ($entries as $entry) {
         * $new   = [$entry[0]];
         * $count = count($entry);
         * for ($i = 1; $i < $count; $i++) {
         * $new[$i] = ($entry[$i] * -1);
         * }
         * $result->push($new);
         * }
         *
         * return $result;
         * **/

    }

    /**
     * @param CRI      $repository
     * @param Category $category
     * @param Carbon   $start
     * @param Carbon   $end
     *
     * @return array
     */
    private function makePeriodChart(CRI $repository, Category $category, Carbon $start, Carbon $end)
    {
        $categoryCollection = new Collection([$category]);
        $cache              = new CacheProperties;
        $cache->addProperty($start);
        $cache->addProperty($end);
        $cache->addProperty($category->id);
        $cache->addProperty('specific-period');

        if ($cache->has()) {
            // return $cache->get();
        }
        $entries = new Collection;
        Log::debug('Start is ' . $start . ' en end is ' . $end);
        while ($start <= $end) {
            Log::debug('Now at ' . $start);
            $spent = $repository->spentInPeriod($categoryCollection, new Collection, $start, $start);
            Log::debug('spent: ' . $spent);
            $earned = $repository->earnedInPeriod($categoryCollection, new Collection, $start, $start);
            Log::debug('earned: ' . $earned);
            $date = Navigation::periodShow($start, '1D');
            $entries->push([clone $start, $date, $spent, $earned]);
            $start->addDay();
        }

        $data = $this->generator->period($entries);
        $cache->store($data);

        return $data;

        /**
         * // get amount earned in period, grouped by day.
         * // get amount spent in period, grouped by day.
         * $spentArray  = $repository->spentPerDay($category, $start, $end, new Collection);
         * $earnedArray = $repository->earnedPerDay($category, $start, $end, new Collection);
         *
         * while ($start <= $end) {
         * $str    = $start->format('Y-m-d');
         * $spent  = $spentArray[$str] ?? '0';
         * $earned = $earnedArray[$str] ?? '0';
         * $date   = Navigation::periodShow($start, '1D');
         * $entries->push([clone $start, $date, $spent, $earned]);
         * $start->addDay();
         * }
         *
         * $data = $this->generator->period($entries);
         * $cache->store($data);
         *
         * return $data;
         */
    }

}