<?php

namespace App\Services\Ppm;

use App\Models\Position;
use App\Models\PositionQuota;
use App\Models\PusatMengundi;
use App\Models\SaluranMengundi;
use App\Models\StaffAssignment;
use Illuminate\Support\Collection;

class AssignmentVacancyService
{
    public function hasPusatVacancy(PusatMengundi $pusatMengundi, string $roleCode): bool
    {
        $position = Position::query()->where('code', $roleCode)->first();

        if ($position === null) {
            return false;
        }

        $quota = PositionQuota::query()
            ->where('election_id', $pusatMengundi->election_id)
            ->where('pusat_mengundi_id', $pusatMengundi->id)
            ->whereNull('saluran_mengundi_id')
            ->where('position_id', $position->id)
            ->value('quota');

        if ($quota === null) {
            return false;
        }

        $used = StaffAssignment::query()
            ->where('election_id', $pusatMengundi->election_id)
            ->where('pusat_mengundi_id', $pusatMengundi->id)
            ->whereNull('saluran_mengundi_id')
            ->where('position_id', $position->id)
            ->where('status', 'active')
            ->count();

        return $used < (int) $quota;
    }

    public function hasSaluranVacancy(PusatMengundi $pusatMengundi, int $saluranMengundiId, string $roleCode): bool
    {
        $position = Position::query()->where('code', $roleCode)->first();

        if ($position === null) {
            return false;
        }

        $saluran = SaluranMengundi::query()
            ->where('id', $saluranMengundiId)
            ->where('pusat_mengundi_id', $pusatMengundi->id)
            ->first();

        if (! $saluran instanceof SaluranMengundi) {
            return false;
        }

        $quota = PositionQuota::query()
            ->where('election_id', $pusatMengundi->election_id)
            ->where('pusat_mengundi_id', $pusatMengundi->id)
            ->where('saluran_mengundi_id', $saluran->id)
            ->where('position_id', $position->id)
            ->value('quota');

        if ($quota === null) {
            return false;
        }

        $used = StaffAssignment::query()
            ->where('election_id', $pusatMengundi->election_id)
            ->where('pusat_mengundi_id', $pusatMengundi->id)
            ->where('saluran_mengundi_id', $saluran->id)
            ->where('position_id', $position->id)
            ->where('status', 'active')
            ->count();

        return $used < (int) $quota;
    }

    /**
     * @return Collection<int, SaluranMengundi>
     */
    public function availableSaluransForRole(PusatMengundi $pusatMengundi, string $roleCode): Collection
    {
        /** @var Collection<int, SaluranMengundi> $salurans */
        $salurans = $pusatMengundi->saluranMengundis()
            ->orderBy('number')
            ->get()
            ->filter(fn (mixed $saluran): bool => $saluran instanceof SaluranMengundi
                && $this->hasSaluranVacancy($pusatMengundi, $saluran->id, $roleCode))
            ->values();

        return $salurans;
    }
}