<?php

namespace App\Domains\Ticket\Models;

use App\Domains\Ticket\Enums\ValidityTimeType;
use Carbon\CarbonInterface;
use Illuminate\Database\Eloquent\Attributes\Fillable;
use Illuminate\Database\Eloquent\Collection as EloquentCollection;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\BelongsTo;
use Illuminate\Database\Eloquent\Relations\BelongsToMany;

#[Fillable(['ticket_id'])]
class TicketValidityGroup extends Model
{
    public $timestamps = false;

    /** @return BelongsTo<Ticket, $this> */
    public function ticket(): BelongsTo
    {
        return $this->belongsTo(Ticket::class);
    }

    /** @return BelongsToMany<ValidityTime, $this> */
    public function validityTimes(): BelongsToMany
    {
        return $this->belongsToMany(
            ValidityTime::class,
            'ticket_validity_group_times',
            'ticket_validity_group_id',
            'validity_time_id',
        );
    }

    public function isValid(?CarbonInterface $at = null): bool
    {
        $at ??= now();
        $validityTimes = $this->resolvedValidityTimes();

        return $validityTimes->isNotEmpty()
            && $validityTimes->every(
                fn (ValidityTime $validityTime): bool => $validityTime->isValid($at)
            );
    }

    public function isExpired(?CarbonInterface $at = null): bool
    {
        $at ??= now();
        $expiresAt = $this->effectiveExpiresAt($at);

        return $expiresAt !== null && $expiresAt->lessThanOrEqualTo($at);
    }

    public function effectiveStartsAt(?CarbonInterface $at = null): ?CarbonInterface
    {
        $at ??= now();
        $anchor = $this->dateAnchor() ?? $at;

        return $this->resolvedValidityTimes()
            ->map(fn (ValidityTime $validityTime): ?CarbonInterface => $validityTime->startsAt($anchor))
            ->filter()
            ->sortByDesc(fn (CarbonInterface $startsAt): int => $startsAt->getTimestamp())
            ->first();
    }

    public function effectiveExpiresAt(?CarbonInterface $at = null): ?CarbonInterface
    {
        $at ??= now();
        $anchor = $this->dateAnchor() ?? $at;

        return $this->resolvedValidityTimes()
            ->map(function (ValidityTime $validityTime) use ($anchor): ?CarbonInterface {
                $startsAt = $validityTime->startsAt($anchor);
                $expiresAt = $validityTime->expiresAt($anchor);

                if (
                    $startsAt !== null
                    && $expiresAt !== null
                    && $expiresAt->lessThanOrEqualTo($startsAt)
                ) {
                    return $expiresAt->addDay();
                }

                return $expiresAt;
            })
            ->filter()
            ->sortBy(fn (CarbonInterface $expiresAt): int => $expiresAt->getTimestamp())
            ->first();
    }

    /** @return EloquentCollection<int, ValidityTime> */
    public function resolvedValidityTimes(): EloquentCollection
    {
        if ($this->relationLoaded('validityTimes')) {
            return $this->getRelation('validityTimes');
        }

        if (! $this->exists) {
            return new EloquentCollection;
        }

        $validityTimes = $this->validityTimes()->get();
        $this->setRelation('validityTimes', $validityTimes);

        return $validityTimes;
    }

    private function dateAnchor(): ?CarbonInterface
    {
        return $this->resolvedValidityTimes()
            ->filter(fn (ValidityTime $validityTime): bool => $validityTime->type === ValidityTimeType::FixedWindow)
            ->map(fn (ValidityTime $validityTime): ?CarbonInterface => $validityTime->fixed_starts_at)
            ->filter()
            ->sortByDesc(fn (CarbonInterface $startsAt): int => $startsAt->getTimestamp())
            ->first();
    }
}