<?php

namespace App\Domains\FiestaFutbolInfantil\Services;

use App\Domains\Catalog\Enums\EventProductType;
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 FoodService
{
    private const ATTRIBUTE_CODES = ['event_date', 'horario', 'servicio'];

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

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

    /**
     * @param  array<int, array<string, mixed>>  $variants
     */
    public function upsertMany(Tenant $tenant, array $variants): CatalogItem
    {
        return DB::transaction(function () use ($tenant, $variants): CatalogItem {
            $attributes = $this->attributes($tenant);
            $food = $this->food($tenant, $variants);
            $itemAttributes = $this->itemAttributes($food, $attributes);

            $food->variants()->whereNull('precio')->update(['precio' => $food->precio]);
            $existingVariants = $food->variants()
                ->with(['inventory', 'eventDate', 'eventDates', 'definitions.itemAttribute.attribute'])
                ->lockForUpdate()
                ->get();
            $resolvedVariants = $this->resolveVariants($variants, $attributes);

            $this->validateCombinations($resolvedVariants, $existingVariants);

            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 Comida.'],
                    ]);
                }

                if ($variant === null) {
                    $this->createVariant($food, $itemAttributes, $data);
                } else {
                    $this->updateVariant($variant, $itemAttributes, $data, $index);
                }
            }

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

            return $food->fresh()->load([
                'variants.catalogItem',
                'variants.inventory',
                'variants.eventDate',
                'variants.eventDates',
                'variants.definitions.itemAttribute.attribute',
            ]);
        });
    }

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

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

    /** @return Collection<string, Attribute> */
    private function attributes(Tenant $tenant): Collection
    {
        $attributes = Attribute::query()
            ->where('tenant_codigo', $tenant->codigo)
            ->whereIn('codigo', self::ATTRIBUTE_CODES)
            ->with('options')
            ->get()
            ->keyBy('codigo');

        $missingCodes = collect(self::ATTRIBUTE_CODES)->diff($attributes->keys());
        if ($missingCodes->isNotEmpty()) {
            throw ValidationException::withMessages([
                'variants' => [
                    'Faltan atributos requeridos para Comida: '.$missingCodes->implode(', ').'.',
                ],
            ]);
        }

        return $attributes;
    }

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

        if ($food !== null) {
            $food->update([
                'category_id' => $category->id,
                'event_product_type' => EventProductType::Product->value,
                'inventory_policy' => InventoryPolicy::Tracked->value,
                'has_tickets' => false,
            ]);

            return $food;
        }

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

    /**
     * @param  Collection<string, Attribute>  $attributes
     * @return Collection<string, ItemAttribute>
     */
    private function itemAttributes(CatalogItem $food, Collection $attributes): Collection
    {
        return $attributes->mapWithKeys(function (Attribute $attribute, string $code) use ($food): array {
            $itemAttribute = $food->itemAttributes()->firstOrCreate(
                ['attribute_id' => $attribute->id],
                ['allow_multi_select' => false],
            );

            return [$code => $itemAttribute];
        });
    }

    /**
     * @param  array<int, array<string, mixed>>  $variants
     * @param  Collection<string, Attribute>  $attributes
     * @return array<int, array<string, mixed>>
     */
    private function resolveVariants(array $variants, Collection $attributes): array
    {
        return collect($variants)->map(function (array $variant, int $index) use ($attributes): array {
            $schedule = $this->option($attributes['horario'], $variant['schedule'], "variants.{$index}.schedule");
            $service = $this->option($attributes['servicio'], $variant['service'], "variants.{$index}.service");

            return [
                ...$variant,
                'event_date_id' => (int) $variant['event_date_id'],
                'schedule' => $schedule->value,
                'service' => $service->value,
                'description' => (string) ($variant['description'] ?? ''),
                'stock' => (int) $variant['stock'],
            ];
        })->all();
    }

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

        if ($option === null) {
            throw ValidationException::withMessages([
                $validationKey => ["El valor seleccionado no es válido para {$attribute->nombre}."],
            ]);
        }

        return $option;
    }

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

        foreach ($existing->whereNotIn('id', $incomingIds) as $variant) {
            $values = $variant->selectionValues();
            $seen[$this->combinationKey(
                (int) $variant->selectedEventDates()->first()?->id,
                (string) $values->get('horario'),
                (string) $values->get('servicio'),
            )] = true;
        }

        foreach ($incoming as $index => $variant) {
            $key = $this->combinationKey(
                $variant['event_date_id'],
                $variant['schedule'],
                $variant['service'],
            );

            if (isset($seen[$key])) {
                throw ValidationException::withMessages([
                    "variants.{$index}" => ['La combinación de fecha, horario y servicio ya existe.'],
                ]);
            }

            $seen[$key] = true;
        }
    }

    /** @param Collection<string, ItemAttribute> $itemAttributes */
    private function createVariant(CatalogItem $food, Collection $itemAttributes, array $data): void
    {
        $inventory = Inventory::query()->create(['real_stock' => $data['stock']]);
        $variant = $food->variants()->create([
            'event_date_id' => $data['event_date_id'],
            'inventory_id' => $inventory->id,
            'descripcion' => $data['description'],
            'precio' => $data['price'],
        ]);
        $variant->eventDates()->sync([$data['event_date_id']]);
        $this->syncDefinitions($variant, $itemAttributes, $data);
    }

    /** @param Collection<string, ItemAttribute> $itemAttributes */
    private function updateVariant(
        Variant $variant,
        Collection $itemAttributes,
        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.',
                ],
            ]);
        }

        $variant->update([
            'event_date_id' => $data['event_date_id'],
            'descripcion' => $data['description'],
            'precio' => $data['price'],
        ]);
        $variant->eventDates()->sync([$data['event_date_id']]);
        $inventory->update(['real_stock' => $data['stock']]);
        $this->syncDefinitions($variant, $itemAttributes, $data);
    }

    /** @param Collection<string, ItemAttribute> $itemAttributes */
    private function syncDefinitions(Variant $variant, Collection $itemAttributes, array $data): void
    {
        $definitionAttributes = $itemAttributes->toBase()->only(['horario', 'servicio']);
        $variant->definitions()->whereIn('item_attribute_id', $definitionAttributes->pluck('id'))->delete();
        $variant->definitions()->createMany([
            [
                'item_attribute_id' => $definitionAttributes['horario']->id,
                'value' => $data['schedule'],
            ],
            [
                'item_attribute_id' => $definitionAttributes['servicio']->id,
                'value' => $data['service'],
            ],
        ]);
    }

    private function combinationKey(int $eventDateId, string $schedule, string $service): string
    {
        return implode('|', [
            $eventDateId,
            mb_strtolower(trim($schedule)),
            mb_strtolower(trim($service)),
        ]);
    }
}