<?php

namespace App\Domains\Purchase\Resources;

use App\Domains\Cart\Models\CartItem;
use App\Domains\Purchase\Models\PurchaseItem;
use Illuminate\Http\Request;
use Illuminate\Http\Resources\Json\JsonResource;

/**
 * @mixin \App\Domains\Purchase\Models\PurchaseItem|\App\Domains\Cart\Models\CartItem
 */
class PurchaseItemResource extends JsonResource
{
    /**
     * @return array<string, mixed>
     */
    public function toArray(Request $request): array
    {
        $variant = $this->variant;
        $product = $variant?->product;
        $quantity = (int) ($this->cantidad ?? 0);
        $unitPrice = $this->resolveUnitPrice();
        $lineTotal = $this->resolveLineTotal($unitPrice, $quantity);

        return [
            'id' => $this->id,
            'quantity' => $quantity,
            'unit_price' => $this->formatMoney($unitPrice),
            'line_total' => $this->formatMoney($lineTotal),
            'product' => $product === null ? null : [
                'id' => $product->id,
                'nombre' => $product->nombre,
                'slug' => $product->slug,
                'imagen' => $this->resolveImageUrl(),
            ],
            'variant' => $variant === null ? null : [
                'id' => $variant->id,
                'attributes' => $this->resolveAttributes(),
            ],
        ];
    }

    protected function resolveUnitPrice(): float
    {
        if ($this->resource instanceof PurchaseItem) {
            return (float) ($this->precio_unitario ?? 0);
        }

        if ($this->resource instanceof CartItem) {
            return (float) ($this->variant?->product?->precio ?? 0);
        }

        return 0.0;
    }

    protected function resolveLineTotal(float $unitPrice, int $quantity): float
    {
        if ($this->resource instanceof PurchaseItem) {
            return (float) ($this->total ?? 0);
        }

        return $unitPrice * $quantity;
    }

    protected function resolveImageUrl(): ?string
    {
        $variant = $this->variant;

        if ($variant === null || ! $variant->relationLoaded('attachments')) {
            return null;
        }

        $attachment = $variant->attachments->first();

        if ($attachment === null) {
            return null;
        }

        return $attachment->getTemporaryUrl(1440);
    }

    /**
     * @return array<int, array{name: string, value: mixed}>
     */
    protected function resolveAttributes(): array
    {
        $variant = $this->variant;

        if ($variant === null || ! $variant->relationLoaded('definitions')) {
            return [];
        }

        return $variant->definitions
            ->map(function ($definition): array {
                return [
                    'name' => (string) ($definition->productAttribute?->attribute?->nombre ?? ''),
                    'value' => $definition->value,
                ];
            })
            ->filter(fn (array $attribute): bool => $attribute['name'] !== '' || $attribute['value'] !== null)
            ->values()
            ->all();
    }

    protected function formatMoney(float|int|string|null $amount): ?string
    {
        if ($amount === null) {
            return null;
        }

        return number_format((float) $amount, 2, '.', '');
    }
}