<?php

namespace App\Services;

use App\Exceptions\TabulationException;
use App\Models\Entry;
use App\Models\Event;
use App\Models\Student;
use Illuminate\Support\Collection;
use Illuminate\Support\Facades\Cache;

class DoublerService
{
    protected EntryService $entryService;

    protected AuditionService $auditionService;

    public function __construct(EntryService $entryService, AuditionService $auditionService)
    {
        $this->entryService = $entryService;
        $this->auditionService = $auditionService;
    }

    /**
     * returns a collection of doublers for the event in the form of
     * [studentId => [student=>student, entries=>[entries]]
     */
    public function doublersForEvent(Event $event, string $mode = 'seating')
    {
        $cacheKey = 'event'.$event->id.'doublers-'.$mode;

        return Cache::remember($cacheKey, 60, function () use ($event, $mode) {
            return $this->findDoublersForEvent($event, $mode);
        });
    }

    /**
     * @throws TabulationException
     */
    protected function findDoublersForEvent(Event $event, string $mode = 'seating'): array
    {
        // TODO add scoped entry queries to the event model
        $this->validateEvent($event);
        $entries = $event->entries()->with('audition')->with('student')->get();
        $entries = match ($mode) {
            'seating' => $entries->filter(fn ($entry) => $entry->for_seating === 1),
            'advancement' => $entries->filter(fn ($entry) => $entry->for_advance === 1),
        };

        $grouped = $entries->groupBy('student_id');
        // Filter out student groups with only one entry in the event
        $grouped = $grouped->filter(fn ($s) => $s->count() > 1);
        $doubler_array = [];
        foreach ($grouped as $student_id => $entries) {
            $doubler_array[$student_id] = [
                'student_id' => $student_id,
                'entries' => $entries,
            ];
        }

        return $doubler_array;
    }

    public function simpleDoubleInfo(Entry $primaryEntry)
    {
        if (! isset($this->findDoublersForEvent($primaryEntry->audition->event)[$primaryEntry->student_id])) {
            return false;
        }

        return $this->findDoublersForEvent($primaryEntry->audition->event)[$primaryEntry->student_id]['entries'];
    }

    public function entryDoublerData(Entry $primaryEntry)
    {
        if (! isset($this->doublersForEvent($primaryEntry->audition->event)[$primaryEntry->student_id])) {
            return false;
        }
        $entries = $this->doublersForEvent($primaryEntry->audition->event)[$primaryEntry->student_id]['entries'];
        $entryData = collect([]);
        /** @var Collection $entries */
        foreach ($entries as $entry) {
            $status = 'undecided';
            if ($entry->hasFlag('declined')) {
                $status = 'declined';
            }
            if ($entry->hasFlag('no_show')) {
                $status = 'no_show';
            }

            $lims = $this->auditionService->getSeatingLimits($entry->audition);
            $limits = [];
            foreach ($lims as $lim) {
                $limits[] = [
                    'ensemble_name' => $lim['ensemble']->name,
                    'accepts' => $lim['limit'],
                    'ensemble' => $lim['ensemble'],
                ];
            }

            $entryData[$entry->id] = [
                'entry' => $entry,
                'audition' => $entry->audition,
                'auditionName' => $entry->audition->name,
                'status' => $status,
                'rank' => $this->entryService->rankOfEntry('seating', $entry),
                'unscored_entries' => $entry->audition->unscored_entries_count,
                'seating_limits' => $limits,
            ];
        }
        // find out how many items in the collection $entryData have a status of 'undecided'
        $undecided_count = $entryData->filter(fn ($entry) => $entry['status'] === 'undecided')->count();
        // if $undecided_count is 1 set the item where status is 'undecided' to 'accepted'
        if ($undecided_count === 1) {
            $entryData->transform(function ($entry) {
                if ($entry['status'] === 'undecided') {
                    $entry['status'] = 'accepted';
                }

                return $entry;
            });
        }

        return $entryData;
    }

    /**
     * @throws TabulationException
     */
    protected function validateEvent(Event $event)
    {
        if (! $event->exists) {
            throw new TabulationException('Invalid event provided');
        }
    }
}