<?php

namespace App\Services;

use Illuminate\Database\Eloquent\Model;
use Illuminate\Support\Str;

/**
 * Generic CRUD/clone helpers for the Pavão/Irrecusável pricing blocks, reused
 * across the 4 tables (base/unit level x Pavão/Irrecusável) since they all
 * share the same column shape (Matrícula, Aulas, Materiais, Valor Total).
 */
class ProposalPricingService
{
    private const VALUE_FIELDS = [
        'registration_value',
        'registration_included_in_course',
        'registration_installments_allowed',
        'registration_max_installments',
        'classes_value',
        'classes_included_in_course',
        'classes_installments_allowed',
        'classes_max_installments',
        'classes_discount_percentage',
        'materials_included_in_course',
        'materials_installments_allowed',
        'materials_max_installments',
        'total_value',
        'total_max_installments',
    ];

    /**
     * Create or update the pricing block owned by $ownerId (a class_package or
     * class_package_unit row), plus its material lines.
     */
    public function upsert(
        string $modelClass,
        string $productModelClass,
        string $ownerColumn,
        int $ownerId,
        array $data,
        bool $withCondition = false,
    ): Model {
        $materials  = $data['materials'] ?? [];
        $attributes = array_intersect_key($data, array_flip($this->fields($withCondition)));

        $attributes['materials_total_value'] = $this->calcMaterialValue($materials);

        /** @var Model $proposal */
        $proposal = $modelClass::updateOrCreate([$ownerColumn => $ownerId], $attributes);

        $this->syncMaterials($proposal, $productModelClass, $materials);

        return $proposal->fresh('products.product');
    }

    /**
     * Clone a base-level Pavão/Irrecusável proposal (with materials) into a
     * unit-level copy. Only called at replication time (new unit, or new
     * proposal replicated to existing units) — unit copies are independent
     * afterwards and are never overwritten by later base updates.
     */
    public function cloneToUnit(
        ?Model $baseProposal,
        string $unitModelClass,
        string $unitProductModelClass,
        string $unitOwnerColumn,
        int $unitOwnerId,
        string $baseForeignKeyColumn,
        bool $withCondition = false,
    ): void {
        if (!$baseProposal) return;

        $attributes = $baseProposal->only($this->fields($withCondition));

        $attributes['materials_total_value']  = $baseProposal->materials_total_value;
        $attributes[$unitOwnerColumn]         = $unitOwnerId;
        $attributes[$baseForeignKeyColumn]    = $baseProposal->id;

        /** @var Model $unitProposal */
        $unitProposal = $unitModelClass::create($attributes);

        $baseProposal->products->each(function ($product) use ($unitProposal, $unitProductModelClass) {
            $unitProductModelClass::create([
                $this->foreignKeyFor($unitProposal) => $unitProposal->id,
                'product_id'                        => $product->product_id,
                'quantity'                           => $product->quantity,
                'price'                              => $product->price,
            ]);
        });
    }

    /**
     * Remove the pricing block for $ownerId, if one exists — used when the
     * user turns a Pavão/Irrecusável section off. Only ever touches the
     * owner's own row (base or unit); never cascades to already-cloned copies.
     */
    public function deleteFor(string $modelClass, string $ownerColumn, int $ownerId): void
    {
        $modelClass::where($ownerColumn, $ownerId)->delete();
    }

    private function fields(bool $withCondition): array
    {
        return $withCondition ? [...self::VALUE_FIELDS, 'condition'] : self::VALUE_FIELDS;
    }

    private function syncMaterials(Model $proposal, string $productModelClass, array $materials): void
    {
        $proposal->products()->delete();

        foreach ($materials as $material) {
            $productModelClass::create([
                $this->foreignKeyFor($proposal) => $proposal->id,
                'product_id'                    => $material['product_id'],
                'quantity'                       => $material['quantity'],
                'price'                          => $material['price'],
            ]);
        }
    }

    private function foreignKeyFor(Model $model): string
    {
        return Str::snake(class_basename($model)) . '_id';
    }

    private function calcMaterialValue(array $materials): float
    {
        return array_reduce($materials, fn($carry, $m) => $carry + ($m['quantity'] * $m['price']), 0.0);
    }
}