From 4d860ba9bd0d24fbd572db99f5ea338a21b42b33 Mon Sep 17 00:00:00 2001
From: Markus Heck <markus.heck@hs-kempten.de>
Date: Tue, 2 Apr 2024 14:27:33 +0200
Subject: [PATCH] add class to properly work with moodles course category path

---
 classes/local/course_category_path.php    | 115 ++++++++++++
 tests/local/course_category_path_test.php | 212 ++++++++++++++++++++++
 2 files changed, 327 insertions(+)
 create mode 100644 classes/local/course_category_path.php
 create mode 100644 tests/local/course_category_path_test.php

diff --git a/classes/local/course_category_path.php b/classes/local/course_category_path.php
new file mode 100644
index 0000000..52e8f55
--- /dev/null
+++ b/classes/local/course_category_path.php
@@ -0,0 +1,115 @@
+<?php
+
+namespace local_adler\local;
+
+use core_course_category;
+use Countable;
+use invalid_parameter_exception;
+use moodle_exception;
+
+class course_category_path implements Countable {
+    private array $path;
+
+    /**
+     * @param string|null $path the path in moodle (with spaces around the /) or UNIX format (without spaces), can be empty string or null
+     */
+    public function __construct(string|null $path) {
+        if ($path === null || strlen($path) === 0) {
+            $this->path = [];
+        } else {
+            $this->path = $this->split_and_trim_path($path);
+        }
+    }
+
+    /**
+     * @return string the path in moodle format (with spaces around the /)
+     */
+    public function __toString(): string {
+        return implode(' / ', $this->path);
+    }
+
+    public function get_path(): array {
+        return $this->path;
+    }
+
+    public function count(): int {
+        return count($this->path);
+    }
+
+    public function exists(): bool {
+        try {
+            $this->get_category_id();
+            return true;
+        } catch (moodle_exception $e) {
+            return false;
+        }
+    }
+
+    /**
+     * @throws moodle_exception if the category already exists
+     * @throws invalid_parameter_exception if the path is empty
+     */
+    public function create(): int {
+        if(count($this) === 0) {
+            throw new invalid_parameter_exception('path must not be empty');
+        }
+
+        if($this->exists()) {
+            throw new moodle_exception('category_already_exists', 'local_adler');
+        }
+
+        $current_category_id = 0;  // top level category
+        $current_category_path = new course_category_path('');  // this will be used to check if the category already exists
+
+        foreach ($this->get_path() as $category_path_part) {
+            // update current category path
+            $current_category_path->append_to_path($category_path_part);
+
+            // check if category already exists
+            if ($current_category_path->exists()) {
+                $current_category_id = $current_category_path->get_category_id();
+            } else {
+                $current_category_id = core_course_category::create([
+                    'name' => (string)$category_path_part,
+                    'parent' => $current_category_id,
+                    'visible' => 1,
+                ])->id;
+            }
+        }
+
+        return $current_category_id;
+    }
+
+
+    /**
+     * @throws moodle_exception if the category does not exist
+     */
+    public function get_category_id(): int {
+        $categories = core_course_category::make_categories_list();
+        $key = array_search((string)$this, $categories);
+        if ($key === false) {
+            throw new moodle_exception('category_not_found', 'local_adler');
+        }
+        return $key;
+    }
+
+    /**
+     * Append a path part to the end of the path.
+     * @throws invalid_parameter_exception if $path_part is empty
+     */
+    public function append_to_path(string $path_part): void {
+        if (strlen($path_part) === 0) {
+            throw new invalid_parameter_exception('path_part must not be empty');
+        }
+        $this->path = array_merge($this->path, $this->split_and_trim_path($path_part));
+    }
+
+    private function split_and_trim_path(string $path): array {
+        // remove preceding and trailing /
+        $path = trim($path, ' /');
+
+        $path_parts = explode('/', $path);
+        return array_map('trim', $path_parts);
+    }
+
+}
diff --git a/tests/local/course_category_path_test.php b/tests/local/course_category_path_test.php
new file mode 100644
index 0000000..798620f
--- /dev/null
+++ b/tests/local/course_category_path_test.php
@@ -0,0 +1,212 @@
+<?php
+
+namespace local_adler\local;
+
+global $CFG;
+
+use invalid_parameter_exception;
+use local_adler\lib\adler_testcase;
+use Mockery;
+use moodle_exception;
+
+require_once($CFG->dirroot . '/local/adler/tests/lib/adler_testcase.php');
+
+class course_category_path_test extends adler_testcase {
+    public function test_constructor_with_null() {
+        $path = new course_category_path(null);
+        $this->assertEquals(0, count($path));
+    }
+
+    public function test_constructor_with_empty_string() {
+        $path = new course_category_path('');
+        $this->assertEquals(0, count($path));
+    }
+
+    public function test_constructor_with_spaces() {
+        $path = new course_category_path('category1 / category2');
+        $this->assertEquals(2, count($path));
+    }
+
+    public function test_constructor_without_spaces() {
+        $path = new course_category_path('category1/category2');
+        $this->assertEquals(2, count($path));
+    }
+
+    public function test_constructor_with_single_element() {
+        $path = new course_category_path('category1');
+        $this->assertEquals(1, count($path));
+    }
+
+    public function test_constructor_with_preceding_and_trailing_slashes() {
+        $path = new course_category_path('/category1/category2/');
+        $this->assertEquals(2, count($path));
+    }
+
+    public function test_constructor_with_spaces_around_slashes() {
+        $path = new course_category_path(' category1 / category2 ');
+        $this->assertEquals(2, count($path));
+    }
+
+    public function test_to_string_method() {
+        $path = new course_category_path('category1/category2');
+        $this->assertEquals('category1 / category2', $path->__toString());
+    }
+
+    public function test_get_path_method() {
+        $path = new course_category_path('category1/category2');
+        $this->assertEquals(['category1', 'category2'], $path->get_path());
+    }
+
+    public function test_count_method() {
+        $path = new course_category_path('category1/category2');
+        $this->assertEquals(2, $path->count());
+    }
+
+    private function setup_make_categories_list_mock() {
+        $mock = Mockery::mock('alias:core_course_category');
+        $mock->shouldReceive('make_categories_list')->andReturn([
+            1 => 'category1 / category2',
+            2 => 'category3 / category4',
+        ]);
+    }
+
+    /**
+     * @runInSeparateProcess
+     */
+    public function test_get_category_id_method_category_exists() {
+        $this->setup_make_categories_list_mock();
+
+        $path = new course_category_path('category1/category2');
+        $this->assertEquals(1, $path->get_category_id());
+    }
+
+    /**
+     * @runInSeparateProcess
+     */
+    public function test_get_category_id_method_category_does_not_exists() {
+        $this->setup_make_categories_list_mock();
+
+        $path = new course_category_path('category5/category6');
+        $this->expectException(moodle_exception::class);
+        $path->get_category_id();
+    }
+
+    /**
+     * @runInSeparateProcess
+     */
+    public function test_exists_method_category_exists() {
+        $this->setup_make_categories_list_mock();
+
+        $path = new course_category_path('category1/category2');
+        $this->assertTrue($path->exists());
+    }
+
+    /**
+     * @runInSeparateProcess
+     */
+    public function test_exists_method_category_does_not_exist() {
+        $this->setup_make_categories_list_mock();
+
+        $path = new course_category_path('category5/category6');
+        $this->assertFalse($path->exists());
+    }
+
+    public function test_append_to_path_with_valid_path_part(): void {
+        $path = new course_category_path('test/path');
+        $path->append_to_path('new_part');
+        $this->assertEquals('test / path / new_part', (string)$path);
+    }
+
+    public function test_append_to_path_with_empty_path_part(): void {
+        $this->expectException(invalid_parameter_exception::class);
+        $path = new course_category_path('test/path');
+        $path->append_to_path('');
+    }
+
+
+    public function test_append_to_path_with_spaces_around_path_part(): void {
+        $path = new course_category_path('test/path');
+        $path->append_to_path(' new_part ');
+        $this->assertEquals('test / path / new_part', (string)$path);
+    }
+
+    public function test_append_to_path_with_multiple_parts_in_path_part(): void {
+        $path = new course_category_path('test/path');
+        $path->append_to_path('new_part1/new_part2');
+        $this->assertEquals('test / path / new_part1 / new_part2', (string)$path);
+        $this->assertEquals(4, $path->count());
+    }
+
+    public function test_count_zero_exists_false(): void {
+        $path = new course_category_path('');
+        $this->assertEquals(0, $path->count());
+        $this->assertFalse($path->exists());
+    }
+
+    public function test_create_with_count_zero(): void {
+        $this->expectException(invalid_parameter_exception::class);
+        $path = new course_category_path('');
+        $path->create();
+    }
+
+    public function test_create_with_empty_path(): void {
+        $this->expectException(invalid_parameter_exception::class);
+        $path = new course_category_path('');
+        $path->create();
+    }
+
+    /**
+     * @runInSeparateProcess
+     */
+    public function test_create_category_already_exists(): void {
+        $this->setup_make_categories_list_mock();
+
+        $path = new course_category_path('category1/category2');
+        $this->expectException(moodle_exception::class);
+        $this->expectExceptionMessage('category_already_exists');
+        $path->create();
+    }
+
+
+    /**
+     * @runInSeparateProcess
+     */
+    public function test_create_with_one_segment(): void {
+        $mock = Mockery::mock('alias:core_course_category');
+        $mock->shouldReceive('make_categories_list')->andReturn([]);
+        $mock->shouldReceive('create')->andReturn((object) ['id' => 1]);
+
+        $path = new course_category_path('segment1');
+        $this->assertEquals(1, $path->count());
+        $this->assertFalse($path->exists());
+        $this->assertIsInt($path->create());
+    }
+
+    /**
+     * @runInSeparateProcess
+     */
+    public function test_create_with_two_segments_first_exists(): void {
+        $mock = Mockery::mock('alias:core_course_category');
+        $mock->shouldReceive('make_categories_list')->andReturn([42 => 'segment1']);
+        $mock->shouldReceive('create')->andReturn((object) ['id' => 1]);
+
+        $path = new course_category_path('segment1/segment2');
+        $this->assertEquals(2, $path->count());
+        $this->assertFalse($path->exists());
+        $this->assertIsInt($path->create());
+    }
+
+    /**
+     * @runInSeparateProcess
+     */
+    public function test_create_with_two_segments_none_exists(): void {
+        $mock = Mockery::mock('alias:core_course_category');
+        $mock->shouldReceive('make_categories_list')->andReturn([]);
+        $mock->shouldReceive('create')->andReturn((object) ['id' => 1]);
+
+        $path = new course_category_path('segment1/segment2');
+        $this->assertEquals(2, $path->count());
+        $this->assertFalse($path->exists());
+        $this->assertIsInt($path->create());
+    }
+}
\ No newline at end of file