<?php

namespace FluentCart\App\Models;

use FluentCart\Api\ModuleSettings;
use FluentCart\App\App;
use FluentCart\App\Helpers\AttributeHelper;
use FluentCart\App\Helpers\Helper;
use FluentCart\App\Helpers\Status;
use FluentCart\App\Models\Concerns\CanSearch;
use FluentCart\App\Models\Concerns\CanUpdateBatch;
use FluentCart\App\Models\Relations\BundleChildrenRelation;
use FluentCart\App\Services\PlanUpgradeService;
use FluentCart\App\Services\URL;
use FluentCart\Framework\Database\Orm\Builder;
use FluentCart\Framework\Support\Arr;

/**
 *  Product Details Model - DB Model for Product Details
 *
 *  Database Model
 *
 *
 * @package FluentCart\App\Models
 *
 * @version 1.0.0
 */
class ProductVariation extends Model
{

    use CanSearch, CanUpdateBatch;

    protected $table = 'fct_product_variations';

    protected $fillable = [
        'post_id',
        'media_id',
        'serial_index',
        'sold_individually',
        'variation_title',
        'variation_identifier',
        'sku',
        'manage_stock',
        'payment_type',
        'stock_status',
        'backorders',
        'total_stock',
        'available',
        'committed',
        'on_hold',
        'fulfillment_type',
        'item_status',
        'manage_cost',
        'item_price',
        'item_cost',
        'compare_price',
        'other_info',
        'downloadable',
        'shipping_class'
    ];


    /**
     * The attributes that should be cast.
     *
     * @var array
     */
    protected $casts = [
        'post_id'           => 'integer',
        'media_id'          => 'integer',
        'item_cost'         => 'double',
        'item_price'        => 'double',
        'compare_price'     => 'double',
        'backorders'        => 'integer',
        'total_stock'       => 'integer',
        'available'         => 'integer',
        'committed'         => 'integer',
        'on_hold'           => 'integer',
        'sold_individually' => 'integer',
        'serial_index'      => 'integer',
        'other_info'        => 'array',
    ];

    protected $appends = ['thumbnail'];


    public function getOtherInfoAttribute($value)
    {
        $value = !empty($value) ? json_decode($value, true) : [];

        if($this->payment_type === 'subscription'){
            $isInstallment = (Arr::get($value, 'installment', 'no') === 'yes' && App::isProActive())?
                'yes':'no';
            $value['payment_type'] = 'subscription';
            $value['installment'] = $isInstallment;
            $value['repeat_interval'] = Arr::get($value, 'repeat_interval', 'yearly');
            $value['times'] = Arr::get($value, 'times', 0);
            $value['trial_days'] = Arr::get($value, 'trial_days', 0);
            $value['manage_setup_fee'] = Arr::get($value, 'manage_setup_fee', 'no');
        }
        return $value;
    }


    protected static function booted()
    {
        static::retrieved(function ($product) {
            $product->append('formatted_total');
        });
    }

    protected function getFormattedTotalAttribute()
    {
        return Helper::toDecimal($this->item_price);
    }


    /**
     * One2One: Product Variation belongs to one Product
     *
     * @return \FluentCart\Framework\Database\Orm\Relations\BelongsTo
     */
    public function product(): \FluentCart\Framework\Database\Orm\Relations\BelongsTo
    {
        return $this->belongsTo(Product::class, 'post_id', 'ID');
    }

    public function shippingClass(): \FluentCart\Framework\Database\Orm\Relations\BelongsTo
    {
        return $this->belongsTo(ShippingClass::class, 'shipping_class', 'id');
    }

    /**
     * Labeled attribute combination for this variation, e.g. "Color: Red | Size: XS".
     *
     * Uses the batched `variation_display_title` when
     * AttributeHelper::attachVariationDisplayTitles() has already resolved it,
     * and otherwise resolves on demand — so callers get a correct value either
     * way, and a correctly batched caller costs no extra queries.
     *
     * @return string Falls back to the stored variation title.
     */
    public function getVariationLabel(): string
    {
        $resolved = (string) ($this->variation_display_title ?? '');

        if ($resolved !== '') {
            return $resolved;
        }

        $variationType = $this->product_detail ? $this->product_detail->variation_type : '';

        $label = AttributeHelper::getDisplayAttributesString(
            AttributeHelper::getProductItemAttributes($this->id, $this->post_id),
            [
                'title'          => $this->variation_title,
                'variation_type' => $variationType,
                'other_info'     => ['variation_type' => $variationType],
            ],
            'order_item'
        );

        return $label !== '' ? $label : (string) $this->variation_title;
    }

    /**
     * Full display title for this variation: "<product> - <attribute combination>".
     *
     * The catalogue-side counterpart to OrderItem::getDisplayTitle(), which
     * composes the same shape from a frozen line item. Product feeds, plan
     * names and CLI output all need the product name alongside the variation,
     * and each was concatenating it themselves.
     *
     * @return string
     */
    public function getDisplayTitle(): string
    {
        $label        = $this->getVariationLabel();
        $productTitle = $this->product ? (string) $this->product->post_title : '';

        if ($productTitle === '' || $productTitle === $label) {
            return $label;
        }

        if ($label === '') {
            return $productTitle;
        }

        return $productTitle . ' - ' . $label;
    }

    /**
     * One2One: Product Variation belongs to one Product detail
     *
     * @return \FluentCart\Framework\Database\Orm\Relations\BelongsTo
     */
    public function product_detail()
    {
        return $this->belongsTo(ProductDetail::class, 'post_id', 'post_id');
    }

    public function media()
    {
        return $this->hasOne(ProductMeta::class, 'object_id', 'id')->select('id', 'object_id', 'meta_value')->where('meta_key', 'product_thumbnail');
    }

    public function product_downloads(): \FluentCart\Framework\Database\Orm\Relations\HasMany
    {
        return $this
            ->hasMany(ProductDownload::class, 'post_id', 'post_id')
            ->where('product_variation_id', 'like', '%' . $this->id . '%')
            ->orWhereNull('product_variation_id')
            ->orWhere('product_variation_id', '[]');

    }

    public function attrRelations(): \FluentCart\Framework\Database\Orm\Relations\HasMany
    {
        return $this->hasMany(AttributeRelation::class, 'object_id', 'id');
    }

    public function order_items()
    {
        return $this->hasMany(OrderItem::class, 'object_id', 'id');
    }

    public function downloadable_files()
    {
        return $this->hasMany(ProductDownload::class, 'product_variation_id', 'id');
    }

    public function upgrade_paths(): \FluentCart\Framework\Database\Orm\Relations\HasMany
    {
        return $this->hasMany(Meta::class, 'object_id', 'id')
            ->where('object_type', PlanUpgradeService::$metaType)
            ->where('meta_key', PlanUpgradeService::$metaKey);
    }

    public function attrMap()
    {
        return $this->hasMany(AttributeRelation::class, 'object_id', 'id');
    }

    public function getThumbnailAttribute()
    {
        if (empty($this->media) || !is_array($this->media->meta_value)) {
            return null;
        }
        // Ensure the first element exists and has a non-empty 'url' key
        if (empty($this->media->meta_value[0]['url'])) {
            return null;
        }

        return $this->media->meta_value[0]['url'];
    }

    public function scopeGetWithShippingClass(Builder $query)
    {
        $variations = $query->get();

        $shippingMethodIds = $variations->pluck('other_info.shipping_class')->filter(function ($item) {
            return !empty($item);
        })->toArray();


        $shippingMethods = ShippingMethod::query()->whereIn('id', $shippingMethodIds)->get()->keyBy('id');

        $variations->map(function ($variation) use ($shippingMethods) {
            $shippingClassId = Arr::get($variation, 'other_info.shipping_class');
            if (!$shippingClassId) {
                return $variation;
            }
            $method = $shippingMethods->get($shippingClassId);

            if (!$method) {
                return $variation;
            }
            $variation->attributes['shipping_method'] = $method;
            return $variation;
        });


        return $query->get();
    }


    public static function boot()
    {
        parent::boot();
        static::deleting(function ($model) {
            \FluentCart\Api\Meta::deleteVariationMedia($model->id);
            $model->attrMap()->delete();
        });
    }

    /**
     * Check if the product variation can be purchased
     *
     * @param int $quantity
     * @return bool|\WP_Error
     */
    public function canPurchase($quantity = 1)
    {
        if ($this->item_status !== 'active' || !in_array($this->product->post_status, ['publish', 'private'])) {
            return new \WP_Error('unpublished', __('This product is not available for purchase.', 'fluent-cart'));
        }

        if ($this->payment_type === 'subscription' && $quantity > 1) {
            return new \WP_Error('invalid_subscription_quantity', __('You cannot purchase more than one subscription at a time.', 'fluent-cart'));
        }

        $productDetail = $this->product_detail;
        if (!$productDetail) {
            return new \WP_Error('unpublished', __('This product is not available for purchase', 'fluent-cart'));
        }

        if (ModuleSettings::isActive('stock_management')) {
            if (($productDetail->manage_stock && $this->manage_stock) && $quantity > $this->available) {
                return new \WP_Error('insufficient_stock', __('Sorry, this product is currently out of stock.', 'fluent-cart'));
            }
        }


        if ($this->product->isBundleProduct() && !App::isProActive()) {
            return new \WP_Error('invalid_bundle_product', __('Sorry, this product is not available for purchase.', 'fluent-cart'));

        }

        $bundleCheck = apply_filters('fluent_cart/variation/can_purchase_bundle', null, [
            'variation' => $this,
            'quantity'  => (int)$quantity
        ]);
        if (is_wp_error($bundleCheck)) {
            return $bundleCheck;
        } elseif ($bundleCheck === false) {
            return new \WP_Error('insufficient_stock', __('Sorry, this product is currently out of stock.', 'fluent-cart'));
        }

        return true;
    }

    public function getSubscriptionTermsText($withComparePrice = false)
    {
        if ($this->payment_type !== 'subscription') {
            return '';
        }

        $otherInfo = $this->other_info;

        $formattedData = [
            'trial_days'       => Arr::get($otherInfo, 'trial_days', 0),
            'interval'         => Arr::get($otherInfo, 'repeat_interval', 'yearly'),
            'times'            => Arr::get($otherInfo, 'times', 0), // 0 means infinite
            'signup_fee'       => Arr::get($otherInfo, 'signup_fee', 0) ? Helper::toDecimal(Arr::get($otherInfo, 'signup_fee', 0)) : 0,
            'signup_fee_label' => Arr::get($otherInfo, 'signup_fee_name', ''),
            'price'            => Helper::toDecimal($this->item_price),
            'compare_price'    => ($withComparePrice && $this->compare_price > $this->item_price) ? Helper::toDecimal($this->compare_price) : 0,
        ];

        return Helper::getSubscriptionTermText($formattedData);
    }

    public function getPurchaseUrl()
    {
        return site_url('?fluent-cart=instant_checkout&item_id=' . $this->id . '&quantity=1');
    }

    public function soldIndividually()
    {
        if ($this->product) {
            return $this->product->soldIndividually();
        }
        return false;
    }

    public function isStock(): bool
    {
        // Check if variation is active
        if ($this->item_status !== 'active') {
            return false;
        }

        // Check if this is a bundle product variation
        $isBundleProduct = $this->product && $this->product->isBundleProduct();

        // If stock management is disabled for this variation
        if (!$this->manage_stock) {
            // For bundle products, still check child items
            if ($isBundleProduct) {
                return $this->isBundleChildrenInStock();
            }
            // For regular products without stock management, check status
            return $this->stock_status === Helper::IN_STOCK;
        }

        // Stock management is enabled - check availability and status
        $hasStock = ($this->available > 0 && $this->stock_status === Helper::IN_STOCK);

        // For non-bundle products, return stock status
        if (!$isBundleProduct) {
            return $hasStock;
        }

        // For bundle products, parent must be in stock AND all children must be in stock
        if (!$hasStock) {
            return false;
        }

        return $this->isBundleChildrenInStock();
    }

    /**
     * Check if all bundle children are in stock
     *
     * @return bool
     */
    protected function isBundleChildrenInStock(): bool
    {
        $childIds = Arr::get($this->other_info, 'bundle_child_ids', []);

        // No bundle children, consider as in stock
        if (empty($childIds) || !is_array($childIds)) {
            return true;
        }

        // Get all bundle children variations
        $children = static::query()
            ->whereIn('id', $childIds)
            ->get(['id', 'manage_stock', 'available', 'stock_status', 'item_status', 'post_id', 'other_info']);

        // Check each child
        foreach ($children as $child) {
            // Child must be active
            if ($child->item_status !== 'active') {
                return false;
            }

            // Only check stock for children that manage inventory.
            // Children without stock management (e.g. digital products) are always considered in stock.
            if ((int)$child->manage_stock === 1) {
                if ((int)$child->available <= 0 || $child->stock_status !== Helper::IN_STOCK) {
                    return false;
                }
            }

            // Nested bundle check commented out: bundle_child_ids live on the bundle's own variation,
            // not on the leaf child variation referenced here. Each bundle's isStock() handles its own
            // children independently, so this recursive call is redundant and causes N+1 queries.
            // if ($child->product && $child->product->isBundleProduct()) {
            //     $nestedChildIds = Arr::get($child->other_info, 'bundle_child_ids', []);
            //     if (!empty($nestedChildIds)) {
            //         if (!$child->isBundleChildrenInStock()) {
            //             return false;
            //         }
            //     }
            // }
        }

        return true;
    }

    public function bundleChildren(): BundleChildrenRelation
    {
        return new BundleChildrenRelation(
            $this->newQuery(),
            $this,
            'other_info',           // JSON column name
            'bundle_child_ids'      // JSON key name
        );
    }
}