<?php

// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the GNU Affero General Public License v3.0.
// See the LICENCE file in the repository root for full licence text.

namespace App\Models\Store;

use App\Exceptions\InsufficientStockException;
use Carbon\Carbon;

/**
 * @property bool $allow_multiple
 * @property \Carbon\Carbon|null $available_until
 * @property float $base_shipping
 * @property float|null $cost
 * @property \Carbon\Carbon $created_at
 * @property string|null $custom_class
 * @property \Carbon\Carbon|null $deleted_at
 * @property string|null $description
 * @property int $display_order
 * @property bool $enabled
 * @property string|null $header_description
 * @property string|null $header_image
 * @property string|null $image
 * @property string|null $images_json
 * @property self $masterProduct
 * @property int|null $master_product_id
 * @property int $max_quantity
 * @property string $name
 * @property float $next_shipping
 * @property \Illuminate\Database\Eloquent\Collection $notificationRequests NotificationRequest
 * @property int $product_id
 * @property bool $promoted
 * @property string|null $shopify_id
 * @property int|null $stock
 * @property string|null $type_mappings_json
 * @property \Carbon\Carbon|null $updated_at
 * @property \Illuminate\Database\Eloquent\Collection $variations static
 * @property int|null $weight
 */
class Product extends Model
{
    const BUTTON_DISABLED = [self::SUPPORTER_TAG_NAME, self::USERNAME_CHANGE];
    const REDIRECT_PLACEHOLDER = 'redirect';
    const SUPPORTER_TAG_NAME = 'supporter-tag';
    const USERNAME_CHANGE = 'username-change';

    protected $primaryKey = 'product_id';

    protected $casts = [
        'available_until' => 'datetime',
        'cost' => 'float',
        'base_shipping' => 'float',
        'next_shipping' => 'float',
        'promoted' => 'boolean',
        'enabled' => 'boolean',
        'allow_multiple' => 'boolean',
    ];

    private $images;
    private $types;

    public function masterProduct()
    {
        return $this->belongsTo(static::class, 'master_product_id');
    }

    public function variations()
    {
        return $this->hasMany(static::class, 'master_product_id');
    }

    public function notificationRequests()
    {
        return $this->hasMany(NotificationRequest::class);
    }

    public function isRedirectPlaceholder()
    {
        return $this->custom_class === static::REDIRECT_PLACEHOLDER;
    }

    public function inStock($quantity = 1, $includeVariations = false)
    {
        $inStock = $this->stock === null || $this->stock >= $quantity;

        if ($inStock === false && $includeVariations === true) {
            $inStock = ($this->masterProduct ?? $this)
                ->variations
                ->contains(function ($variation) use ($quantity) {
                    return $variation->inStock($quantity);
                });
        }

        return $inStock;
    }

    public function getHeaderImageAttribute($value)
    {
        if ($this->masterProduct) {
            return $this->masterProduct->header_image;
        } else {
            return $value;
        }
    }

    public function getHeaderDescriptionAttribute($value)
    {
        if ($this->masterProduct) {
            return $this->masterProduct->header_description;
        } else {
            return $value;
        }
    }

    public function getDescriptionAttribute($value)
    {
        return presence($value) ?? $this->masterProduct?->description;
    }

    public function isAvailable(): bool
    {
        return $this->enabled
            && ($this->available_until === null ? true : $this->available_until->isFuture());
    }

    public function typeMappings()
    {
        if ($this->masterProduct) {
            return $this->masterProduct->typeMappings();
        } else {
            return json_decode($this->type_mappings_json, true);
        }
    }

    public function images()
    {
        if (!$this->images_json && $this->masterProduct) {
            return $this->masterProduct->images();
        } else {
            if (!$this->images && $this->images_json) {
                $this->images = json_decode($this->images_json, true);
            }

            return $this->images ?? [];
        }
    }

    public function requiresShipping()
    {
        return $this->weight !== null;
    }

    public function scopeAvailable($query)
    {
        return $query
            ->where('enabled', true)
            ->where(function ($q) {
                return $q->whereNull('available_until')->orWhere('available_until', '>=', Carbon::now());
            });
    }

    public function scopeNotAvailable($query)
    {
        return $query->where('available_until', '<', Carbon::now());
    }

    public function scopeListing($query)
    {
        return $query
            ->available()
            ->where('master_product_id', null)
            ->with('masterProduct')
            ->with('variations')
            ->orderBy('promoted', 'desc')
            ->orderBy('display_order', 'desc');
    }

    public function scopeCustomClass($query, $name)
    {
        return $query
            ->where('custom_class', $name);
    }

    public function scopeEnabled($query)
    {
        return $query->where('enabled', true);
    }

    public function scopeHasShipping($query)
    {
        return $query->whereNotNull('weight');
    }

    /**
     * Returns the Shopify product variant GraphQL gid for this Product, null if it is not a Shopify item.
     * This is currently implemented as convenience for checking the gid matches the one from the Storefront API.
     *
     * @return string|null
     */
    public function getShopifyVariantGid(): ?string
    {
        return $this->isShopify() ? base64_encode("gid://shopify/ProductVariant/{$this->shopify_id}") : null;
    }

    public function isShopify(): bool
    {
        return $this->shopify_id !== null;
    }

    public function productsInRange()
    {
        if (!($mappings = $this->typeMappings())) {
            return [];
        }

        return self::whereIn('product_id', array_keys($mappings))->get();
    }

    public function release($quantity)
    {
        if (
            $this->stock === null
            // stock may have been directly updated to 0.
            // TODO: should count reservations and available stock separately or something.
            || $this->stock <= 0
        ) {
            return;
        }

        $this->incrementInstance('stock', $quantity);
    }

    public function reserve($quantity)
    {
        if ($this->stock === null) {
            return;
        }

        $this->decrementInstance('stock', $quantity);

        // operating under the assumtion that the caller will prevent concurrent updates.
        if ($this->stock < 0) {
            throw new InsufficientStockException();
        }
    }

    public function types()
    {
        $mappings = $this->typeMappings();
        if ($mappings === null) {
            return;
        }

        if ($this->types !== null) {
            return $this->types;
        }

        $currentMapping = $mappings[strval($this->product_id)];
        $this->types = [];

        foreach ($mappings as $product_id => $mapping) {
            foreach ($mapping as $type => $value) {
                if (!isset($this->types[$type])) {
                    $this->types[$type] = [];
                }
                $mappingDiff = array_diff_assoc($mapping, $currentMapping);
                if ((count($mappingDiff) === 0) || (count($mappingDiff) === 1 && isset($mappingDiff[$type]))) {
                    $this->types[$type][$value] = intval($product_id);
                }
            }
        }

        return $this->types;
    }

    public function url(): string
    {
        return $this->isRedirectPlaceholder()
            ? $this->description
            : route('store.products.show', $this);
    }
}