<?php

namespace Longyi\FreeGift\Models;

use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\BelongsTo;
use Illuminate\Support\Facades\Storage;
use Longyi\FreeGift\Config\Gift;
use Longyi\FreeGift\Contracts\FreeGiftRule as FreeGiftRuleContract;
use Webkul\CartRule\Models\CartRule;

/**
 * 赠品规则配置，1:1 挂在 `cart_rules` 上。
 */
class FreeGiftRule extends Model implements FreeGiftRuleContract
{
    /**
     * The table associated with the model.
     *
     * @var string
     */
    protected $table = 'free_gift_rules';

    /**
     * The attributes that are mass assignable.
     *
     * @var array
     */
    protected $fillable = [
        'cart_rule_id',
        'sku',
        'type',
        'items_discount',
        'minimal_items_price',
        'apply_tax',
        'apply_shipping',
        'auto_add',
        'show_banner',
        'banner_image',
        'banner_alt',
    ];

    /**
     * The attributes that should be cast.
     *
     * @var array
     */
    protected $casts = [
        'cart_rule_id'        => 'integer',
        'type'                => 'integer',
        'minimal_items_price' => 'float',
        'apply_tax'           => 'boolean',
        'apply_shipping'      => 'boolean',
        'auto_add'            => 'boolean',
        'show_banner'         => 'boolean',
    ];

    /**
     * 关联的营销规则。
     */
    public function cart_rule(): BelongsTo
    {
        return $this->belongsTo(CartRule::class, 'cart_rule_id');
    }

    /**
     * Banner 图片的公开访问地址。
     */
    public function bannerImageUrl(): ?string
    {
        if (empty($this->banner_image)) {
            return null;
        }

        return Storage::url($this->banner_image);
    }

    /**
     * 赠品 SKU 列表。
     *
     * @return string[]
     */
    public function skuList(): array
    {
        if (empty($this->sku)) {
            return [];
        }

        return array_values(array_filter(array_map('trim', explode(',', $this->sku))));
    }

    /**
     * 是否是「一组合计送 N 个」。
     */
    public function isOneOf(): bool
    {
        return (int) $this->type === Gift::TYPE_ONE;
    }

    /**
     * 是否是「每个 SKU 各送 N 个」。
     */
    public function isAllOf(): bool
    {
        return (int) $this->type === Gift::TYPE_ALL;
    }
}