<?php
/**
 * Provider input: the shopper photo, the product's image and the prompt for its type.
 *
 * @package Fitzaro
 */

namespace Fitzaro\Job;

use Fitzaro\Image\InvalidImage;
use Fitzaro\Image\Sanitizer;
use Fitzaro\Prompt\ProductType;
use Fitzaro\Prompt\PromptBuilder;
use Fitzaro\Prompt\VariantText;
use Fitzaro\Provider\ReferenceImage;
use Fitzaro\Provider\TryOnInput;
use Fitzaro\Storage\FileStore;

defined( 'ABSPATH' ) || exit;

// Exception messages are never printed; the REST layer maps codes to escaped text.
// phpcs:disable WordPress.Security.EscapeOutput.ExceptionNotEscaped

/**
 * Image 1 is the stored shopper photo, image 2 the product image normalised like an upload
 * (smaller input means fewer tokens, so lower cost). The prompt depends on the product type and
 * names the selected variant.
 */
final class ProductInputBuilder implements InputBuilder {

	public const QUALITY = 'medium';

	/**
	 * Where uploads are stored.
	 *
	 * @var FileStore
	 */
	private $files;

	/**
	 * Receives ( product ID, variation ID ), returns the product image bytes or null.
	 *
	 * @var callable
	 */
	private $product_image;

	/**
	 * Receives a product ID, returns a ProductType constant or null.
	 *
	 * @var callable
	 */
	private $product_type;

	/**
	 * Receives a variation ID, returns its attribute names and values.
	 *
	 * @var callable
	 */
	private $variant_attributes;

	/**
	 * Normalises the product image.
	 *
	 * @var Sanitizer
	 */
	private $sanitizer;

	/**
	 * Creates the builder.
	 *
	 * @param FileStore $files              Where uploads are stored.
	 * @param callable  $product_image      Receives ( product ID, variation ID ), returns image bytes or null.
	 * @param callable  $product_type       Receives a product ID, returns a ProductType constant or null.
	 * @param callable  $variant_attributes Receives a variation ID, returns array( name => value ).
	 * @param Sanitizer $sanitizer          Normalises the product image.
	 */
	public function __construct( FileStore $files, callable $product_image, callable $product_type, callable $variant_attributes, Sanitizer $sanitizer ) {
		$this->files              = $files;
		$this->product_image      = $product_image;
		$this->product_type       = $product_type;
		$this->variant_attributes = $variant_attributes;
		$this->sanitizer          = $sanitizer;
	}

	/**
	 * Input for one request row.
	 *
	 * @param array<string, mixed> $row Request row.
	 * @throws InputUnavailable When the photo, the product image or a supported type is missing.
	 */
	public function build( array $row ): TryOnInput {
		$person = $this->files->read( (string) ( $row['upload_path'] ?? '' ) );
		if ( null === $person ) {
			throw new InputUnavailable( JobError::MISSING_UPLOAD );
		}

		$product_id = (int) ( $row['product_id'] ?? 0 );
		$type       = ProductType::valid( ( $this->product_type )( $product_id ) );
		if ( null === $type ) {
			throw new InputUnavailable( JobError::UNSUPPORTED_TYPE );
		}

		$variation_id = (int) ( $row['variation_id'] ?? 0 );
		$bytes        = ( $this->product_image )( $product_id, $variation_id );
		if ( ! is_string( $bytes ) || '' === $bytes ) {
			throw new InputUnavailable( JobError::NO_PRODUCT_IMAGE );
		}

		try {
			$product = $this->sanitizer->sanitize( $bytes );
		} catch ( InvalidImage $e ) {
			throw new InputUnavailable( JobError::NO_PRODUCT_IMAGE );
		}

		$attributes = $variation_id > 0 ? ( $this->variant_attributes )( $variation_id ) : array();
		$variant    = VariantText::line( is_array( $attributes ) ? $attributes : array() );

		return new TryOnInput( $person, array( new ReferenceImage( $product, $type ) ), PromptBuilder::build( $type, $variant ), self::QUALITY );
	}
}