<?php

namespace App\Models;

use Carbon\CarbonInterface;
use Illuminate\Database\Eloquent\Builder;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\BelongsTo;
use Illuminate\Database\Eloquent\Relations\HasMany;

class Transfer extends Model
{
    public const STATUS_ACTIVE = 'active';

    public const STATUS_GRACE = 'grace';

    public const STATUS_EXPIRED = 'expired';

    public const STATUS_DELETED = 'deleted';

    protected $fillable = [
        'user_id',
        'qr_code_id',
        'title',
        'message',
        'password_hash',
        'retention_days',
        'expires_at',
        'paid_until',
        'grace_ends_at',
        'last_billed_at',
        'status',
        'downloads_total',
        'storage_bytes',
    ];

    protected $casts = [
        'retention_days' => 'integer',
        'expires_at' => 'datetime',
        'paid_until' => 'datetime',
        'grace_ends_at' => 'datetime',
        'last_billed_at' => 'datetime',
        'downloads_total' => 'integer',
        'storage_bytes' => 'integer',
    ];

    public function user(): BelongsTo
    {
        return $this->belongsTo(User::class);
    }

    public function qrCode(): BelongsTo
    {
        return $this->belongsTo(QrCode::class);
    }

    public function files(): HasMany
    {
        return $this->hasMany(TransferFile::class);
    }

    public function downloadEvents(): HasMany
    {
        return $this->hasMany(TransferDownloadEvent::class);
    }

    /** Files are available to recipients while paid or within the unpaid grace window. */
    public function isAccessible(): bool
    {
        if ($this->status === self::STATUS_DELETED) {
            return false;
        }

        if ($this->isPaid()) {
            return true;
        }

        return $this->isInGracePeriod();
    }

    /** @deprecated Use isAccessible() — kept for existing call sites. */
    public function isActive(): bool
    {
        return $this->isAccessible();
    }

    public function isPaid(): bool
    {
        if (! in_array($this->status, [self::STATUS_ACTIVE, self::STATUS_GRACE], true)) {
            return false;
        }

        return $this->paid_until instanceof CarbonInterface && $this->paid_until->isFuture();
    }

    public function isInGracePeriod(): bool
    {
        if ($this->status !== self::STATUS_GRACE) {
            return false;
        }

        return $this->grace_ends_at instanceof CarbonInterface && $this->grace_ends_at->isFuture();
    }

    public function isPastGracePeriod(): bool
    {
        return $this->grace_ends_at instanceof CarbonInterface && $this->grace_ends_at->isPast();
    }

    public function billingPeriodEndsAt(): ?CarbonInterface
    {
        return $this->paid_until;
    }

    public function isPasswordProtected(): bool
    {
        return $this->password_hash !== null && $this->password_hash !== '';
    }

    public function storageGb(): float
    {
        return round($this->storage_bytes / (1024 * 1024 * 1024), 3);
    }

    public function monthlyCostGhs(): float
    {
        return round($this->storageGb() * (float) config('transfer.price_per_gb_month', 0.30), 2);
    }

    public function billingStatusLabel(): string
    {
        if ($this->isPaid()) {
            return 'Active';
        }

        if ($this->isInGracePeriod()) {
            return 'Payment due';
        }

        return 'Unavailable';
    }

    public function scopeAccessible(Builder $query): Builder
    {
        return $query
            ->whereIn('status', [self::STATUS_ACTIVE, self::STATUS_GRACE])
            ->where(function (Builder $inner) {
                $inner->where('paid_until', '>', now())
                    ->orWhere('grace_ends_at', '>', now());
            });
    }
}