<?php

namespace App\Services;

use App\Models\Entry;
use App\Models\Student;
use Illuminate\Contracts\Database\Eloquent\Builder;
use Illuminate\Support\Facades\Cache;

class DoublerService
{
    protected $doublersCacheKey = 'doublers';

    protected $auditionService;

    protected $tabulationService;

    protected $seatingService;

    /**
     * Create a new class instance.
     */
    public function __construct(AuditionService $auditionService, TabulationService $tabulationService, SeatingService $seatingService)
    {
        $this->auditionService   = $auditionService;
        $this->tabulationService = $tabulationService;
        $this->seatingService = $seatingService;
    }

    /**
     * Returns a collection of students that have more than one entry
     */
    public function getDoublers(): \Illuminate\Database\Eloquent\Collection
    {
        // TODO creating or destroying an entry should refresh the doubler cache
        // TODO needs to split by event so that a doubler may enter jazz and concert events for example
        $doublers = Cache::remember($this->doublersCacheKey, 60, function () {
            return Student::withCount(['entries' => function (Builder $query) {
                $query->where('for_seating', true);
            }])
                ->with(['entries' => function (Builder $query) {
                    $query->where('for_seating', true);
                }])
                ->havingRaw('entries_count > ?', [1])
                ->get();
        });

        return $doublers;
    }

    public function refreshDoublerCache()
    {
        Cache::forget($this->doublersCacheKey);
        $this->getDoublers();
    }

    /**
     * Returns an array of information about each entry for a specific doubler. Info for each entry includes
     * entryID
     * auditionID
     * auditionName
     * rank => This student's rank in the given audition
     * unscored => How many entries remain to be scored in this audition
     * limits => acceptance limits for this audition
     * status => accepted, declined, or undecided
     *
     * @param  int  $studentId  The ID of the doubler
     */
    public function getDoublerInfo($studentId): array
    {
        $doubler = $this->getDoublers()->firstWhere('id', $studentId);

        // Split $doubler->entries into two arrays based on the result of hasFlag('declined')
        $undecidedEntries = $doubler->entries->filter(function ($entry) {
            return ! $entry->hasFlag('declined');
        });
        $acceptedEntry = null;
        if ($undecidedEntries->count() == 1) {
            $acceptedEntry = $undecidedEntries->first();
        }
        // TODO can I rewrite this?

        // When getting a doubler we need to know
        // 1) What their entries are
        // 2) For each audition they're entered in, what is their rank
        // 3) For each audition they're entered in, how many entries are unscored
        // 4) How many are accepted on that instrument
        // 5) Status - accepted, declined or undecided

        $info = [];

        foreach ($doubler->entries as $entry) {
            if ($entry->hasFlag('declined')) {
                $status = 'declined';
            } elseif ($entry === $acceptedEntry) {
                $status = 'accepted';
            } else {
                $status = 'undecided';
            }
            $info[$entry->id] = [
                'entryID' => $entry->id,
                'auditionID' => $entry->audition_id,
                'auditionName' => $this->auditionService->getAudition($entry->audition_id)->name,
                'rank' => $this->tabulationService->entryRank($entry),
                'unscored' => $this->tabulationService->remainingEntriesForAudition($entry->audition_id),
                'limits' => $this->seatingService->getLimitForAudition($entry->audition_id),
                'status' => $status,
            ];
            $entry->audition = $this->auditionService->getAudition($entry->audition_id);
        }

        return $info;
    }

    /**
     * Checks if a student is a doubler based on the given student ID
     *
     * @param  int  $studentId  The ID of the student to check
     * @return bool Returns true if the student is a doubler, false otherwise
     */
    public function studentIsDoubler($studentId): bool
    {
        return $this->getDoublers()->contains('id', $studentId);
    }
}