<?php

namespace App\Domains\FiestaFutbolInfantil\Services;

use App\Domains\Catalog\Enums\InventoryPolicy;
use App\Domains\Catalog\Models\Attribute;
use App\Domains\Catalog\Models\AttributeOption;
use App\Domains\Catalog\Models\CatalogItem;
use App\Domains\Catalog\Models\Category;
use App\Domains\Catalog\Models\Inventory;
use App\Domains\Catalog\Models\ItemAttribute;
use App\Domains\Catalog\Models\Variant;
use App\Domains\Catalog\Services\CatalogService;
use App\Domains\Tenant\Models\Tenant;
use Illuminate\Support\Collection;
use Illuminate\Support\Facades\DB;
use Illuminate\Validation\ValidationException;

class AccommodationService
{
    private const ATTRIBUTE_CODE = 'tipo_alojamiento';

    public function __construct(private readonly CatalogService $catalogService) {}

    public function current(Tenant $tenant): ?CatalogItem
    {
        return CatalogItem::query()
            ->where('tenant_code', $tenant->codigo)
            ->where('slug', 'alojamiento')
            ->with([
                'itemAttributes.attribute.options',
                'variants.catalogItem',
                'variants.inventory',
                'variants.definitions',
            ])
            ->first();
    }

    /**
     * @param  array<int, array<string, mixed>>  $variants
     */
    public function upsertMany(Tenant $tenant, array $variants): CatalogItem
    {
        return DB::transaction(function () use ($tenant, $variants): CatalogItem {
            $attribute = $this->attribute($tenant);
            $accommodation = $this->accommodation($tenant, $variants);
            $itemAttribute = $accommodation->itemAttributes()->firstOrCreate(
                ['attribute_id' => $attribute->id],
                ['allow_multi_select' => false],
            );
            $existingVariants = $accommodation->variants()
                ->with(['inventory', 'definitions'])
                ->lockForUpdate()
                ->get();
            $resolvedVariants = $this->resolveVariants($variants);

            $this->validateValues($resolvedVariants, $existingVariants, $itemAttribute);

            foreach ($resolvedVariants as $index => $data) {
                $variant = isset($data['id'])
                    ? $existingVariants->firstWhere('id', (int) $data['id'])
                    : null;

                if (isset($data['id']) && $variant === null) {
                    throw ValidationException::withMessages([
                        "variants.{$index}.id" => ['La variante no pertenece al producto Alojamiento.'],
                    ]);
                }

                if ($variant === null) {
                    $this->createVariant($attribute, $accommodation, $itemAttribute, $data);
                } else {
                    $this->updateVariant($attribute, $variant, $itemAttribute, $data, $index);
                }
            }

            $minimumPrice = $accommodation->variants()->min('precio');
            if ($minimumPrice !== null) {
                $accommodation->update(['precio' => $minimumPrice]);
            }

            return $accommodation->fresh()->load([
                'itemAttributes.attribute.options',
                'variants.catalogItem',
                'variants.inventory',
                'variants.definitions',
            ]);
        });
    }

    public function delete(Tenant $tenant, int $accommodationId): void
    {
        $variant = Variant::query()
            ->whereKey($accommodationId)
            ->whereHas('catalogItem', fn ($query) => $query
                ->where('tenant_code', $tenant->codigo)
                ->where('slug', 'alojamiento'))
            ->firstOrFail();

        $this->catalogService->deleteVariant($variant);
    }

    private function attribute(Tenant $tenant): Attribute
    {
        $attribute = Attribute::query()
            ->where('tenant_codigo', $tenant->codigo)
            ->where('codigo', self::ATTRIBUTE_CODE)
            ->with('options')
            ->lockForUpdate()
            ->first();

        if ($attribute === null) {
            throw ValidationException::withMessages([
                'variants' => ['Falta el atributo requerido tipo_alojamiento.'],
            ]);
        }

        return $attribute;
    }

    /** @param array<int, array<string, mixed>> $variants */
    private function accommodation(Tenant $tenant, array $variants): CatalogItem
    {
        $category = Category::query()->firstOrCreate([
            'tenant_code' => $tenant->codigo,
            'nombre' => 'Alojamientos',
        ]);
        $accommodation = CatalogItem::withTrashed()
            ->where('tenant_code', $tenant->codigo)
            ->where('slug', 'alojamiento')
            ->lockForUpdate()
            ->first();

        if ($accommodation !== null) {
            if ($accommodation->trashed()) {
                $accommodation->restore();
            }

            $accommodation->update([
                'category_id' => $category->id,
                'inventory_policy' => InventoryPolicy::Tracked->value,
                'has_tickets' => true,
            ]);

            return $accommodation;
        }

        return CatalogItem::query()->create([
            'tenant_code' => $tenant->codigo,
            'slug' => 'alojamiento',
            'nombre' => 'Alojamiento',
            'descripcion' => 'Alojamiento',
            'category_id' => $category->id,
            'precio' => collect($variants)->min('price') ?? 0,
            'inventory_policy' => InventoryPolicy::Tracked->value,
            'has_tickets' => true,
            'inventory_id' => null,
        ]);
    }

    /**
     * @param  array<int, array<string, mixed>>  $variants
     * @return array<int, array<string, mixed>>
     */
    private function resolveVariants(array $variants): array
    {
        return collect($variants)->map(fn (array $variant): array => [
            ...$variant,
            'title' => trim($variant['title']),
            'value' => $this->valueCode($variant['title']),
            'description' => $variant['description'] ?? null,
            'stock' => (int) $variant['stock'],
        ])->all();
    }

    /**
     * @param  array<int, array<string, mixed>>  $incoming
     * @param  Collection<int, Variant>  $existing
     */
    private function validateValues(array $incoming, Collection $existing, ItemAttribute $itemAttribute): void
    {
        $incomingIds = collect($incoming)->pluck('id')->filter()->map(fn ($id): int => (int) $id);
        $seen = [];

        foreach ($existing->whereNotIn('id', $incomingIds) as $variant) {
            $value = $variant->definitions->firstWhere('item_attribute_id', $itemAttribute->id)?->value;
            if ($value !== null) {
                $seen[mb_strtolower(trim($value))] = true;
            }
        }

        foreach ($incoming as $index => $variant) {
            $value = $variant['value'];

            if (isset($seen[$value])) {
                throw ValidationException::withMessages([
                    "variants.{$index}.title" => ['Ya existe un tipo de alojamiento con ese título.'],
                ]);
            }

            $seen[$value] = true;
        }
    }

    /** @param array<string, mixed> $data */
    private function createVariant(
        Attribute $attribute,
        CatalogItem $accommodation,
        ItemAttribute $itemAttribute,
        array $data,
    ): void {
        $this->createOption($attribute, $data['value'], $data['title']);

        $inventory = Inventory::query()->create(['real_stock' => $data['stock']]);
        $variant = $accommodation->variants()->create([
            'inventory_id' => $inventory->id,
            'descripcion' => $data['description'],
            'precio' => $data['price'],
        ]);
        $variant->definitions()->create([
            'item_attribute_id' => $itemAttribute->id,
            'value' => $data['value'],
        ]);
    }

    /** @param array<string, mixed> $data */
    private function updateVariant(
        Attribute $attribute,
        Variant $variant,
        ItemAttribute $itemAttribute,
        array $data,
        int $index,
    ): void {
        $inventory = Inventory::query()
            ->whereKey($variant->inventory_id)
            ->lockForUpdate()
            ->firstOrFail();

        if ($data['stock'] < $inventory->reserved_stock) {
            throw ValidationException::withMessages([
                "variants.{$index}.stock" => [
                    'El stock no puede ser menor que la cantidad actualmente reservada.',
                ],
            ]);
        }

        $definition = $variant->definitions
            ->firstWhere('item_attribute_id', $itemAttribute->id);
        $option = $definition === null
            ? null
            : $attribute->options->firstWhere('value', $definition->value);

        if ($option === null) {
            $this->createOption($attribute, $data['value'], $data['title']);
        } else {
            $option->update([
                'value' => $data['value'],
                'label' => $data['title'],
            ]);
        }

        $variant->update([
            'descripcion' => $data['description'],
            'precio' => $data['price'],
        ]);
        $inventory->update(['real_stock' => $data['stock']]);
        $variant->definitions()->updateOrCreate(
            ['item_attribute_id' => $itemAttribute->id],
            ['value' => $data['value']],
        );
    }

    private function createOption(Attribute $attribute, string $value, string $label): AttributeOption
    {
        $existing = $attribute->options->first(
            fn (AttributeOption $option): bool => mb_strtolower($option->value) === $value
        );

        if ($existing !== null) {
            $existing->update(['label' => $label]);

            return $existing;
        }

        $option = $attribute->options()->create([
            'value' => $value,
            'label' => $label,
            'sort_order' => ((int) $attribute->options->max('sort_order')) + 1,
        ]);
        $attribute->options->push($option);

        return $option;
    }

    private function valueCode(string $title): string
    {
        return mb_strtolower((string) preg_replace('/\s+/u', '_', trim($title)));
    }
}