<?php
/**
 * Per-product and per-variation sample fields, plus swatch-pack fields.
 *
 * All values are stored as product meta through the WC_Product object
 * (HPOS-safe). Nothing here writes to posts or options directly.
 *
 * Meta keys:
 *   _tryv_sample_enabled       'yes' | 'no'
 *   _tryv_sample_price         decimal string, blank = regular price
 *   _tryv_sample_free          int, blank = global default
 *   _tryv_sample_max_order     int, blank = global default
 *   _tryv_sample_max_customer  int, blank = global default
 *   _tryv_is_pack              'yes' | 'no'
 *   _tryv_pack_products        array of product IDs
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

function tryv_product_init() {
	add_action( 'woocommerce_product_options_general_product_data', 'tryv_render_product_fields' );
	add_action( 'woocommerce_admin_process_product_object', 'tryv_save_product_fields' );
	add_action( 'woocommerce_product_after_variable_attributes', 'tryv_render_variation_fields', 10, 3 );
	add_action( 'woocommerce_save_product_variation', 'tryv_save_variation_fields', 10, 2 );
}

/**
 * Is this product eligible for sampling at all?
 *
 * @param WC_Product $product Product object.
 * @return bool
 */
function tryv_product_sample_enabled( $product ) {
	if ( ! $product instanceof WC_Product ) {
		return false;
	}
	if ( 'yes' !== $product->get_meta( '_tryv_sample_enabled', true ) ) {
		return false;
	}
	if ( tryv_product_is_pack( $product ) ) {
		// QC fixes B2 + M7: a pack is only sampleable when the pack
		// itself is purchasable and in stock AND it has at least one
		// valid component at order time. An empty pack, or a pack
		// whose components are all unpublished / out of stock /
		// not purchasable / themselves packs, is not sampleable, so
		// no button renders and no sample add validates. A component
		// that is temporarily out of stock stays stored on the pack
		// and becomes valid again when it is back in stock, because
		// validity is checked live here, not by deleting it on save.
		return $product->is_purchasable() && $product->is_in_stock()
			&& ! empty( tryv_pack_valid_component_ids( $product ) );
	}
	return $product->is_purchasable() && $product->is_in_stock();
}

/**
 * Is this product a swatch pack?
 *
 * @param WC_Product $product Product object.
 * @return bool
 */
function tryv_product_is_pack( $product ) {
	if ( ! $product instanceof WC_Product ) {
		return false;
	}
	return 'yes' === $product->get_meta( '_tryv_is_pack', true );
}

/**
 * Component product IDs for a pack, excluding the pack itself.
 *
 * @param WC_Product $product Product object.
 * @return int[]
 */
function tryv_pack_product_ids( $product ) {
	if ( ! $product instanceof WC_Product ) {
		return array();
	}
	$raw = $product->get_meta( '_tryv_pack_products', true );
	if ( ! is_array( $raw ) ) {
		return array();
	}
	$ids = array();
	foreach ( $raw as $id ) {
		$id = absint( $id );
		if ( $id > 0 && $id !== $product->get_id() ) {
			$ids[] = $id;
		}
	}
	return array_values( array_unique( $ids ) );
}

/**
 * Valid component IDs for a pack, checked live at order time (M7):
 * the component must exist, be published, be purchasable, be in
 * stock, and must not itself be a pack (nested packs are rejected).
 * A component's own "Allow samples" flag is NOT required: pack
 * sampling is governed by the pack's flag, so a swatch material can
 * be sampled as part of a pack without being offered as a single
 * sample. Stored components that fail this check are hidden from
 * ordering but are not deleted, so they return when eligible again.
 * Use this list for all runtime decisions; tryv_pack_product_ids()
 * returns the stored list for display/editing.
 *
 * @param WC_Product $product Pack product object.
 * @return int[]
 */
function tryv_pack_valid_component_ids( $product ) {
	if ( ! $product instanceof WC_Product ) {
		return array();
	}
	$ids = array();
	foreach ( tryv_pack_product_ids( $product ) as $id ) {
		$component = wc_get_product( $id );
		if ( ! $component ) {
			continue;
		}
		if ( 'publish' !== $component->get_status() ) {
			continue;
		}
		if ( tryv_product_is_pack( $component ) ) {
			continue;
		}
		if ( ! $component->is_purchasable() || ! $component->is_in_stock() ) {
			continue;
		}
		$ids[] = absint( $id );
	}
	return array_values( array_unique( $ids ) );
}

/**
 * Is one product a valid pack component at save time? Save-time
 * filtering is deliberately narrower than the live check above:
 * only self-reference, nested packs, and non-existent products are
 * dropped on save. Publish/stock/purchasability are NOT dropped on
 * save, because those change over time and a temporarily
 * out-of-stock component should not be permanently deleted from
 * the pack. The live check handles those at order time.
 *
 * @param int $component_id Candidate component ID.
 * @param int $pack_id Pack product ID.
 * @return bool
 */
function tryv_is_saveable_pack_component( $component_id, $pack_id ) {
	$component_id = absint( $component_id );
	if ( $component_id <= 0 || $component_id === absint( $pack_id ) ) {
		return false;
	}
	$component = wc_get_product( $component_id );
	if ( ! $component ) {
		return false;
	}
	if ( tryv_product_is_pack( $component ) ) {
		return false;
	}
	return true;
}

/**
 * Sample price for a product or variation. Blank falls back to the
 * product's regular price; a stored 0 is a genuinely free sample price.
 * For a variation, the full fallback chain lives in
 * tryv_sample_price_for() in cart.php: variation sample, variation
 * regular, parent sample, parent regular. This helper on its own
 * only does sample-then-regular for the object given to it.
 *
 * @param WC_Product $product Product or variation object.
 * @return float
 */
function tryv_get_sample_price( $product ) {
	$raw = $product->get_meta( '_tryv_sample_price', true );
	if ( '' === $raw || null === $raw ) {
		return (float) $product->get_regular_price();
	}
	return max( 0, (float) $raw );
}

/**
 * Resolve a per-product numeric limit, falling back to the global default.
 *
 * @param WC_Product $product Product object.
 * @param string     $meta_key Meta key for the per-product value.
 * @param string     $setting_key Global setting key.
 * @return int 0 means no limit, except for the free allowance where 0 means no free samples.
 */
function tryv_resolve_limit( $product, $meta_key, $setting_key ) {
	$raw = $product->get_meta( $meta_key, true );
	if ( '' === $raw || null === $raw ) {
		$settings = tryv_get_settings();
		return absint( $settings[ $setting_key ] );
	}
	return absint( $raw );
}

/**
 * The sampled identity for a cart/order line: variation ID when a
 * variation was chosen, otherwise the product ID.
 *
 * @param int $product_id Product ID.
 * @param int $variation_id Variation ID, 0 for simple products.
 * @return int
 */
function tryv_sampled_id( $product_id, $variation_id ) {
	return $variation_id > 0 ? absint( $variation_id ) : absint( $product_id );
}

/**
 * Render the sample fields on the simple-product edit screen.
 */
function tryv_render_product_fields() {
	global $post;
	if ( ! $post ) {
		return;
	}
	$product = wc_get_product( $post->ID );
	if ( ! $product ) {
		return;
	}
	echo '<div class="options_group show_if_simple show_if_variable">';
	woocommerce_wp_checkbox(
		array(
			'id'          => '_tryv_sample_enabled',
			'label'       => __( 'Allow samples', 'tryvertising' ),
			'description' => __( 'Show the sample button on this product page.', 'tryvertising' ),
			'value'       => 'yes' === $product->get_meta( '_tryv_sample_enabled', true ) ? 'yes' : 'no',
		)
	);
	woocommerce_wp_text_input(
		array(
			'id'                => '_tryv_sample_price',
			'label'             => __( 'Sample price', 'tryvertising' ),
			'description'       => __( 'Leave blank to charge the regular price. Enter 0 for a free sample price (the free allowance still applies first). For a variation, the price order is: variation sample price, variation regular price, parent sample price, parent regular price.', 'tryvertising' ),
			'desc_tip'          => true,
			'type'              => 'number',
			'custom_attributes' => array( 'min' => '0', 'step' => '0.01' ),
			'value'             => $product->get_meta( '_tryv_sample_price', true ),
		)
	);
	woocommerce_wp_text_input(
		array(
			'id'                => '_tryv_sample_free',
			'label'             => __( 'Free samples (override)', 'tryvertising' ),
			'description'       => __( 'Leave blank to use the shop default. Counted per variation when a variation is sampled; a pack counts against every component. Pending, on-hold, processing and completed orders all count.', 'tryvertising' ),
			'desc_tip'          => true,
			'type'              => 'number',
			'custom_attributes' => array( 'min' => '0', 'step' => '1' ),
			'value'             => $product->get_meta( '_tryv_sample_free', true ),
		)
	);
	woocommerce_wp_text_input(
		array(
			'id'                => '_tryv_sample_max_order',
			'label'             => __( 'Max samples per order (override)', 'tryvertising' ),
			'description'       => __( 'Leave blank to use the shop default. 0 means no limit. Counted per variation when a variation is sampled; a pack counts against every component.', 'tryvertising' ),
			'desc_tip'          => true,
			'type'              => 'number',
			'custom_attributes' => array( 'min' => '0', 'step' => '1' ),
			'value'             => $product->get_meta( '_tryv_sample_max_order', true ),
		)
	);
	woocommerce_wp_text_input(
		array(
			'id'                => '_tryv_sample_max_customer',
			'label'             => __( 'Max samples per customer (override)', 'tryvertising' ),
			'description'       => __( 'Leave blank to use the shop default. 0 means no limit. Counted per variation when a variation is sampled; a pack counts against every component. Pending, on-hold, processing and completed orders all count.', 'tryvertising' ),
			'desc_tip'          => true,
			'type'              => 'number',
			'custom_attributes' => array( 'min' => '0', 'step' => '1' ),
			'value'             => $product->get_meta( '_tryv_sample_max_customer', true ),
		)
	);
	woocommerce_wp_checkbox(
		array(
			'id'          => '_tryv_is_pack',
			'label'       => __( 'This product is a swatch pack', 'tryvertising' ),
			'description' => __( 'Ordering a sample of this product counts as sampling each component product below.', 'tryvertising' ),
			'value'       => tryv_product_is_pack( $product ) ? 'yes' : 'no',
		)
	);
	woocommerce_wp_select(
		array(
			// QC fix M6: WooCommerce's select renderer uses the
			// 'name' as given and does NOT append [] for a multiple
			// select on its own. Without the [] here, a multi-select
			// posts as a single string in PHP (last value only) and
			// the old array-only save code dropped it. With [] the
			// field posts as an array and 3+ components save.
			'id'          => '_tryv_pack_products',
			'name'        => '_tryv_pack_products[]',
			'label'       => __( 'Pack components', 'tryvertising' ),
			'description' => __( 'Hold Ctrl/Cmd to select several products. Only used when the swatch-pack box above is checked. Packs cannot be components of another pack — a pack selected here is dropped on save. Components must be published, purchasable and in stock at order time; a component that fails that check is not sampled, but stays stored on the pack.', 'tryvertising' ),
			'desc_tip'    => true,
			'class'       => 'wc-enhanced-select',
			'style'       => 'width:100%',
			'custom_attributes' => array( 'multiple' => 'multiple' ),
			'options'     => tryv_product_options_for_pack( $product->get_id() ),
			'value'       => tryv_pack_product_ids( $product ),
		)
	);
	echo '</div>';
}

/**
 * Product options for the pack multi-select: published simple and
 * variable products, excluding the pack itself.
 *
 * @param int $exclude_id Product ID to exclude.
 * @return array id => title
 */
function tryv_product_options_for_pack( $exclude_id ) {
	$options = array();
	$products = wc_get_products(
		array(
			'limit'  => -1,
			'status' => 'publish',
			'type'   => array( 'simple', 'variable' ),
		)
	);
	foreach ( $products as $p ) {
		if ( $p->get_id() === absint( $exclude_id ) ) {
			continue;
		}
		$options[ $p->get_id() ] = $p->get_name() . ' (#' . $p->get_id() . ')';
	}
	return $options;
}

/**
 * Save the product fields. Runs inside WooCommerce's product-save flow,
 * which already verifies its own nonce; the capability check here is
 * an extra guard, and the save is abandoned if it fails.
 *
 * @param WC_Product $product Product object being saved.
 */
function tryv_save_product_fields( $product ) {
	if ( ! current_user_can( 'edit_post', $product->get_id() ) ) {
		return;
	}
	// phpcs:ignore WordPress.Security.NonceVerification -- WooCommerce verifies the product-save nonce.
	$posted = isset( $_POST['_tryv_sample_enabled'] ) ? sanitize_text_field( wp_unslash( $_POST['_tryv_sample_enabled'] ) ) : 'no';
	$product->update_meta_data( '_tryv_sample_enabled', 'yes' === $posted ? 'yes' : 'no' );

	$product->update_meta_data( '_tryv_sample_price', tryv_posted_decimal( '_tryv_sample_price' ) );
	$product->update_meta_data( '_tryv_sample_free', tryv_posted_int_or_blank( '_tryv_sample_free' ) );
	$product->update_meta_data( '_tryv_sample_max_order', tryv_posted_int_or_blank( '_tryv_sample_max_order' ) );
	$product->update_meta_data( '_tryv_sample_max_customer', tryv_posted_int_or_blank( '_tryv_sample_max_customer' ) );

	// phpcs:ignore WordPress.Security.NonceVerification -- WooCommerce verifies the product-save nonce.
	$is_pack = isset( $_POST['_tryv_is_pack'] ) && 'yes' === sanitize_text_field( wp_unslash( $_POST['_tryv_is_pack'] ) );
	$product->update_meta_data( '_tryv_is_pack', $is_pack ? 'yes' : 'no' );

	$pack_ids = array();
	// phpcs:ignore WordPress.Security.NonceVerification -- WooCommerce verifies the product-save nonce.
	if ( isset( $_POST['_tryv_pack_products'] ) ) {
		// QC fix M6, backward compatible: the fixed field name posts
		// an array, but an old form (or a single selection) posts a
		// string. Treat a string as a one-element list instead of
		// dropping it, so a one-component pack can never be lost.
		$posted_pack = wp_unslash( $_POST['_tryv_pack_products'] ); // phpcs:ignore WordPress.Security.ValidatedSanitizedInput
		if ( ! is_array( $posted_pack ) ) {
			$posted_pack = array( $posted_pack );
		}
		foreach ( $posted_pack as $id ) {
			// QC fix M7: nested packs are rejected on save, as is
			// the pack itself and any non-existent product. Stock /
			// publish status is NOT filtered here (see
			// tryv_is_saveable_pack_component): that is checked live
			// at order time, so a temporarily out-of-stock
			// component is not permanently deleted from the pack.
			if ( tryv_is_saveable_pack_component( $id, $product->get_id() ) ) {
				$pack_ids[] = absint( $id );
			}
		}
	}
	$product->update_meta_data( '_tryv_pack_products', array_values( array_unique( $pack_ids ) ) );
}

/**
 * Read a posted decimal field, returning '' when blank.
 *
 * @param string $key Field name.
 * @return string
 */
function tryv_posted_decimal( $key ) {
	// phpcs:ignore WordPress.Security.NonceVerification -- Caller verifies the product-save nonce.
	if ( ! isset( $_POST[ $key ] ) || '' === $_POST[ $key ] ) {
		return '';
	}
	$raw = sanitize_text_field( wp_unslash( $_POST[ $key ] ) );
	if ( ! is_numeric( $raw ) ) {
		return '';
	}
	return (string) max( 0, (float) $raw );
}

/**
 * Read a posted integer field, returning '' when blank.
 *
 * @param string $key Field name.
 * @return string
 */
function tryv_posted_int_or_blank( $key ) {
	// phpcs:ignore WordPress.Security.NonceVerification -- Caller verifies the product-save nonce.
	if ( ! isset( $_POST[ $key ] ) || '' === $_POST[ $key ] ) {
		return '';
	}
	return (string) max( 0, absint( $_POST[ $key ] ) );
}

/**
 * Render per-variation sample fields. Only the price is per-variation:
 * whether sampling is allowed is set on the parent product, so a
 * variation is never silently disabled by an unticked box.
 *
 * @param int $loop Variation index in the form.
 * @param array $variation_data Variation data.
 * @param WP_Post $variation Variation post object.
 */
function tryv_render_variation_fields( $loop, $variation_data, $variation ) {
	$product = wc_get_product( $variation->ID );
	if ( ! $product ) {
		return;
	}
	woocommerce_wp_text_input(
		array(
			'id'                => '_tryv_sample_price[' . $loop . ']',
			'label'             => __( 'Sample price', 'tryvertising' ),
			'description'       => __( 'Leave blank to use, in order: this variation\'s regular price, then the parent product\'s sample price, then the parent regular price.', 'tryvertising' ),
			'desc_tip'          => true,
			'type'              => 'number',
			'custom_attributes' => array( 'min' => '0', 'step' => '0.01' ),
			'value'             => $product->get_meta( '_tryv_sample_price', true ),
			'wrapper_class'     => 'form-row form-row-full',
		)
	);
}

/**
 * Save per-variation sample fields (price only).
 *
 * @param int $variation_id Variation ID.
 * @param int $loop Variation index in the form.
 */
function tryv_save_variation_fields( $variation_id, $loop ) {
	if ( ! current_user_can( 'edit_post', $variation_id ) ) {
		return;
	}
	$product = wc_get_product( $variation_id );
	if ( ! $product ) {
		return;
	}
	// phpcs:ignore WordPress.Security.NonceVerification -- WooCommerce verifies the product-save nonce.
	$price_raw = isset( $_POST['_tryv_sample_price'][ $loop ] ) ? sanitize_text_field( wp_unslash( $_POST['_tryv_sample_price'][ $loop ] ) ) : '';
	$product->update_meta_data( '_tryv_sample_price', ( '' === $price_raw || ! is_numeric( $price_raw ) ) ? '' : (string) max( 0, (float) $price_raw ) );
	$product->save();
}