<?php
/**
 * Unit tests for wc-stock-functions.php.
 *
 * @package WooCommerce\Tests\Functions\Stock
 */

/**
 * Class WC_Stock_Functions_Tests.
 */
class WC_Stock_Functions_Tests extends \WC_Unit_Test_Case {

	/**
	 * @var array List of statuses which reduces stock from inventory.
	 */
	public $order_stock_reduce_statuses = array(
		'wc-processing',
		'wc-completed',
		'wc-on-hold',
	);

	/**
	 * @var array List of statuses which restores stock back into inventory.
	 */
	public $order_stock_restore_statuses = array(
		'wc-cancelled',
		'wc-pending',
	);

	/**
	 * @var array List of statuses which have no impact on inventory.
	 */
	public $order_stock_no_effect_statuses = array(
		'wc-failed',
		'wc-refunded',
	);

	/**
	 * Helper function to simulate creating order from cart.
	 *
	 * @param string $status Status for the newly created order.
	 */
	private function create_order_from_cart_with_status( $status ) {
		$product = WC_Helper_Product::create_simple_product(
			true,
			array(
				'manage_stock'   => true,
				'stock_quantity' => 10,
			)
		);
		WC()->cart->empty_cart();
		WC()->cart->add_to_cart( $product->get_id(), 1 );
		WC()->cart->calculate_totals();

		$checkout = WC_Checkout::instance();
		$order    = new WC_Order();
		$checkout->set_data_from_cart( $order );
		$order->set_status( $status );
		$order->save();
		return $order;
	}

	/**
	 * Helper function to change order status and assert product inventory values.
	 *
	 * @param string $status_from       Initial status of the order.
	 * @param string $status_to         Status to transition the order to.
	 * @param int    $before_transition Inventory value before order status is changed.
	 * @param int    $after_transition  Inventory value after order status change.
	 */
	private function transition_order_status_and_assert_stock_quantity( $status_from, $status_to, $before_transition, $after_transition ) {
		$order      = $this->create_order_from_cart_with_status( $status_from );
		$order_item = array_values( $order->get_items( 'line_item' ) )[0];

		$product = new WC_Product( $order_item->get_product_id() );
		$this->assertEquals( $before_transition, $product->get_stock_quantity() );

		// Changing status from UI also calls this method in metadata save hook. This has impact on stock levels, so simulate it here as well.
		wc_save_order_items( $order, $order->get_items() );

		$order->set_status( $status_to );
		$order->save();
		$product = new WC_Product( $order_item->get_product_id() );
		$this->assertEquals( $after_transition, $product->get_stock_quantity(), "Stock levels unexpected when transitioning from $status_from to $status_to." );
	}

	/**
	 * Test inventory count after order status transitions which reduces stock to another status which also reduces stock.
	 * Stock should have reduced once already, and should not reduce again.
	 */
	public function test_status_transition_stock_reduce_to_stock_reduce() {
		foreach ( $this->order_stock_reduce_statuses as $order_status_from ) {
			foreach ( $this->order_stock_reduce_statuses as $order_status_to ) {
				$this->transition_order_status_and_assert_stock_quantity( $order_status_from, $order_status_to, 9, 9 );
			}
		}
	}

	/**
	 * Test inventory count after order status transitions which reduces stock to another status which restores stock.
	 * Should should have already reduced once, and will increase again after transitioning.
	 */
	public function test_status_transition_stock_reduce_to_stock_restore() {
		foreach ( $this->order_stock_reduce_statuses as $order_status_from ) {
			foreach ( $this->order_stock_restore_statuses as $order_status_to ) {
				$this->transition_order_status_and_assert_stock_quantity( $order_status_from, $order_status_to, 9, 10 );
			}
		}
	}

	/**
	 * Test inventory count after order status transitions which reduces stock to another status which don't affect inventory.
	 * Stock should have already reduced, and will not change on transitioning.
	 */
	public function test_status_transition_stock_reduce_to_stock_no_effect() {
		foreach ( $this->order_stock_reduce_statuses as $order_status_from ) {
			foreach ( $this->order_stock_no_effect_statuses as $order_status_to ) {
				$this->transition_order_status_and_assert_stock_quantity( $order_status_from, $order_status_to, 9, 9 );
			}
		}
	}

	/**
	 * Test inventory count after order status transtions which restores stock to another status which reduces stock.
	 * Stock should not have reduced, but will reduce after transition.
	 */
	public function test_status_transition_stock_restore_to_stock_reduce() {
		foreach ( $this->order_stock_restore_statuses as $order_status_from ) {
			foreach ( $this->order_stock_reduce_statuses as $order_status_to ) {
				$this->transition_order_status_and_assert_stock_quantity( $order_status_from, $order_status_to, 10, 9 );
			}
		}
	}

	/**
	 * Test inventory count after order status transitions which restores stock to another status which also restores stock.
	 * Stock should not have reduced, and will remain the same even after transition (i.e. should not be restocked again).
	 */
	public function test_status_transition_stock_restore_to_stock_restore() {
		foreach ( $this->order_stock_restore_statuses as $order_status_from ) {
			foreach ( $this->order_stock_restore_statuses as $order_status_to ) {
				$this->transition_order_status_and_assert_stock_quantity( $order_status_from, $order_status_to, 10, 10 );
			}
		}
	}

	/**
	 * Test inventory count after order status transitions which restores stock to another status which don't affect inventory.
	 * Stock should not have reduced, and will remain the same even after transition.
	 */
	public function test_status_transition_stock_restore_to_stock_no_effect() {
		foreach ( $this->order_stock_restore_statuses as $order_status_from ) {
			foreach ( $this->order_stock_no_effect_statuses as $order_status_to ) {
				$this->transition_order_status_and_assert_stock_quantity( $order_status_from, $order_status_to, 10, 10 );
			}
		}
	}

	/**
	 * Test inventory count after order status transitions which don't affect inventory stock to another status which reduces stock.
	 * Stock would not have been affected, but will reduce after transition.
	 */
	public function test_status_transition_stock_no_effect_to_stock_reduce() {
		foreach ( $this->order_stock_no_effect_statuses as $order_status_from ) {
			foreach ( $this->order_stock_reduce_statuses as $order_status_to ) {
				$this->transition_order_status_and_assert_stock_quantity( $order_status_from, $order_status_to, 10, 9 );
			}
		}
	}

	/**
	 * Test inventory count after order status transitions which don't affect inventory stock to another status which restores stock.
	 * Stock would not have been affected, and will not be restored after transition (since it was not reduced to begin with).
	 */
	public function test_status_transition_stock_no_effect_to_stock_restore() {
		foreach ( $this->order_stock_no_effect_statuses as $order_status_from ) {
			foreach ( $this->order_stock_restore_statuses as $order_status_to ) {
				$this->transition_order_status_and_assert_stock_quantity( $order_status_from, $order_status_to, 10, 10 );
			}
		}
	}

	/**
	 * Test inventory count after order status transitions which don't affect inventory stock to another status which also don't affect inventory.
	 * Stock levels will not change before or after the transition.
	 */
	public function test_status_transition_stock_no_effect_to_stock_no_effect() {
		foreach ( $this->order_stock_no_effect_statuses as $order_status_from ) {
			foreach ( $this->order_stock_no_effect_statuses as $order_status_to ) {
				$this->transition_order_status_and_assert_stock_quantity( $order_status_from, $order_status_to, 10, 10 );
			}
		}
	}

	/**
	 * Assert that a value is equal to another one and is of integer type.
	 *
	 * @param mixed $expected The value $actual must be equal to.
	 * @param mixed $actual The value to check for equality to $expected and for type.
	 */
	private function assertIsIntAndEquals( $expected, $actual ) {
		$this->assertEquals( $expected, $actual );
		self::assertIsInteger( $actual );
	}

	/**
	 * Test wc_get_low_stock_amount with a simple product which has low stock amount set.
	 */
	public function test_wc_get_low_stock_amount_simple_set() {
		$product_low_stock_amount   = 5;
		$site_wide_low_stock_amount = 3;

		// Set the store-wide default.
		update_option( 'woocommerce_notify_low_stock_amount', strval( $site_wide_low_stock_amount ) );

		// Simple product, set low stock amount.
		$product = WC_Helper_Product::create_simple_product(
			true,
			array(
				'manage_stock'     => true,
				'stock_quantity'   => 10,
				'low_stock_amount' => $product_low_stock_amount,
			)
		);

		$this->assertIsIntAndEquals( $product_low_stock_amount, wc_get_low_stock_amount( $product ) );
	}

	/**
	 * Test wc_get_low_stock_amount with a simple product which doesn't have low stock amount set.
	 */
	public function test_wc_get_low_stock_amount_simple_unset() {
		$site_wide_low_stock_amount = 3;

		// Set the store-wide default.
		update_option( 'woocommerce_notify_low_stock_amount', strval( $site_wide_low_stock_amount ) );

		// Simple product, don't set low stock amount.
		$product = WC_Helper_Product::create_simple_product(
			true,
			array(
				'manage_stock'   => true,
				'stock_quantity' => 10,
			)
		);

		$this->assertIsIntAndEquals( $site_wide_low_stock_amount, wc_get_low_stock_amount( $product ) );
	}

	/**
	 * Test wc_get_low_stock_amount with a variable product which has low stock amount set on the variation level,
	 * but not on the parent level. Should use the value from the variation.
	 */
	public function test_wc_get_low_stock_amount_variation_set_parent_unset() {
		$site_wide_low_stock_amount = 3;
		$variation_low_stock_amount = 7;

		// Set the store-wide default.
		update_option( 'woocommerce_notify_low_stock_amount', strval( $site_wide_low_stock_amount ) );

		// Parent low stock amount NOT set.
		$variable_product = WC_Helper_Product::create_variation_product();
		$variable_product->set_manage_stock( false );
		$variable_product->save();

		// Set the variation low stock amount.
		$variations = $variable_product->get_available_variations( 'objects' );
		$var1       = $variations[0];
		$var1->set_manage_stock( true );
		$var1->set_low_stock_amount( $variation_low_stock_amount );
		$var1->save();

		$this->assertIsIntAndEquals( $variation_low_stock_amount, wc_get_low_stock_amount( $var1 ) );

		// Even after turning on manage stock on the parent, but with no value.
		$variable_product->set_manage_stock( true );
		$variable_product->save();
		$this->assertIsIntAndEquals( $variation_low_stock_amount, wc_get_low_stock_amount( $var1 ) );

		// Ans also after turning the manage stock off again on the parent.
		$variable_product->set_manage_stock( false );
		$variable_product->save();
		$this->assertIsIntAndEquals( $variation_low_stock_amount, wc_get_low_stock_amount( $var1 ) );
	}

	/**
	 * Test wc_get_low_stock_amount with a variable product which has low stock amount set on the variation level,
	 * and also on the parent level. Should use the value from the variation.
	 */
	public function test_wc_get_low_stock_amount_variation_set_parent_set() {
		$site_wide_low_stock_amount = 3;
		$parent_low_stock_amount    = 5;
		$variation_low_stock_amount = 7;

		// Set the store-wide default.
		update_option( 'woocommerce_notify_low_stock_amount', strval( $site_wide_low_stock_amount ) );

		// Set the parent low stock amount.
		$variable_product = WC_Helper_Product::create_variation_product();
		$variable_product->set_manage_stock( true );
		$variable_product->set_low_stock_amount( $parent_low_stock_amount );
		$variable_product->save();

		// Set the variation low stock amount.
		$variations = $variable_product->get_available_variations( 'objects' );
		$var1       = $variations[0];
		$var1->set_manage_stock( true );
		$var1->set_low_stock_amount( $variation_low_stock_amount );
		$var1->save();

		$this->assertIsIntAndEquals( $variation_low_stock_amount, wc_get_low_stock_amount( $var1 ) );
	}

	/**
	 * Test wc_get_low_stock_amount with a variable product which has low stock amount set on the parent level,
	 * but NOT on the variation level. Should use the value from the parent.
	 */
	public function test_wc_get_low_stock_amount_variation_unset_parent_set() {
		$site_wide_low_stock_amount = 3;
		$parent_low_stock_amount    = 5;

		// Set the store-wide default.
		update_option( 'woocommerce_notify_low_stock_amount', strval( $site_wide_low_stock_amount ) );

		// Set the parent low stock amount.
		$variable_product = WC_Helper_Product::create_variation_product();
		$variable_product->set_manage_stock( true );
		$variable_product->set_low_stock_amount( $parent_low_stock_amount );
		$variable_product->save();

		// Don't set the variation low stock amount.
		$variations = $variable_product->get_available_variations( 'objects' );
		$var1       = $variations[0];

		$this->assertIsIntAndEquals( $parent_low_stock_amount, wc_get_low_stock_amount( $var1 ) );
	}

	/**
	 * Test wc_get_low_stock_amount with a variable product which *doesn't have* low stock amount set either on the parent level,
	 * or on the variation level. Should use the value from the site-wide setting.
	 */
	public function test_wc_get_low_stock_amount_variation_unset_parent_unset() {
		$site_wide_low_stock_amount = 3;

		// Set the store-wide default.
		update_option( 'woocommerce_notify_low_stock_amount', strval( $site_wide_low_stock_amount ) );

		// Set the parent low stock amount.
		$variable_product = WC_Helper_Product::create_variation_product();
		$variable_product->set_manage_stock( false );

		// Don't set the variation low stock amount.
		$variations = $variable_product->get_available_variations( 'objects' );
		$var1       = $variations[0];
		$var1->set_manage_stock( false );

		$this->assertIsIntAndEquals( $site_wide_low_stock_amount, wc_get_low_stock_amount( $var1 ) );
	}

}