<?php

// require_once(DIR_ALVEOLATA . '/definitions.php');
require_once(DIR_ALVEOLATA . '/term/substitution.php');


\alveolata\test\add(
	[
		'name' => 'alveolata',
		'sections' => [
			[
				'name' => 'term',
				'setup' => function (&$environment) {
					// foo(x,y)
					$environment['x'] = new \alveolata\term\class_function(
						'foo',
						[
							new \alveolata\term\class_variable('x'),
							new \alveolata\term\class_variable('y'),
						]
					);
					// foo(bar(),z)
					$environment['y'] = new \alveolata\term\class_function(
						'foo',
						[
							new \alveolata\term\class_function('bar', []),
							// new \alveolata\term\class_function('baz', []),
							new \alveolata\term\class_variable('z'),
						]
					);
				},
				'sections' => [
					[
						'name' => 'substitution-instance',
						'cases' => [
							[
								'name' => 'test',
								'procedure' => function ($assert, &$environment) {
									$substitution = new \alveolata\term\struct_substitution(
										[
											'x' => new \alveolata\term\class_function('qux', []),
										]
									);
									$x_actual = \alveolata\term\substitution_instance($substitution, $environment['x']);
									$x_expected = new \alveolata\term\class_function(
										'foo',
										[
											new \alveolata\term\class_function('qux', []),
											new \alveolata\term\class_variable('y'),
										]
									);
									$assert->is(\alveolata\term\equal($x_expected, $x_actual));
								},
							],
						],
					],
					[
						'name' => 'unifiers',
						'cases' => [
							[
								'name' => 'test',
								'procedure' => function ($assert, &$environment) {
									$substitutions = \alveolata\term\unifiers(
										[
											[
												'first' => $environment['x'],
												'second' => $environment['y'],
											]
										]
									);
									$assert->equal(count($substitutions), 2);
									foreach ($substitutions as $substitution) {
										$assert->equal(count($substitution->mapping), 2);
										$assert->is(
											\alveolata\term\equal(
												$substitution->mapping['x'],
												new \alveolata\term\class_function('bar', []),
											)
										);
										if (array_key_exists('y', $substitution->mapping)) {
											$assert->is(
												\alveolata\term\equal(
													$substitution->mapping['y'],
													new \alveolata\term\class_variable('z', []),
												)
											);
										}
										if (array_key_exists('z', $substitution->mapping)) {
											$assert->is(
												\alveolata\term\equal(
													$substitution->mapping['z'],
													new \alveolata\term\class_variable('y', []),
												)
											);
										}
									}
								},
							],
						],
					],
				],
			]
		]
	]
);