class ContentTranslationSyncUnitTest

class ContentTranslationSyncUnitTest extends KernelTestBase {
    
    /**
     * The synchronizer class to be tested.
     *
     * @var \Drupal\content_translation\FieldTranslationSynchronizer
     */
    protected $synchronizer;
    
    /**
     * The columns to be synchronized.
     *
     * @var array
     */
    protected $synchronized;
    
    /**
     * All the field columns.
     *
     * @var array
     */
    protected $columns;
    
    /**
     * The available language codes.
     *
     * @var array
     */
    protected $langcodes;
    
    /**
     * The field cardinality.
     *
     * @var int
     */
    protected $cardinality;
    
    /**
     * The unchanged field values.
     *
     * @var array
     */
    protected $unchangedFieldValues;
    
    /**
     * {@inheritdoc}
     */
    protected static $modules = [
        'language',
        'content_translation',
    ];
    
    /**
     * {@inheritdoc}
     */
    protected function setUp() : void {
        parent::setUp();
        $this->synchronizer = new FieldTranslationSynchronizer($this->container
            ->get('entity_type.manager'), $this->container
            ->get('plugin.manager.field.field_type'));
        $this->synchronized = [
            'sync1',
            'sync2',
        ];
        $this->columns = array_merge($this->synchronized, [
            'var1',
            'var2',
        ]);
        $this->langcodes = [
            'en',
            'it',
            'fr',
            'de',
            'es',
        ];
        $this->cardinality = 4;
        $this->unchangedFieldValues = [];
        // Set up an initial set of values in the correct state, that is with
        // "synchronized" values being equal.
        foreach ($this->langcodes as $langcode) {
            for ($delta = 0; $delta < $this->cardinality; $delta++) {
                foreach ($this->columns as $column) {
                    $sync = in_array($column, $this->synchronized) && $langcode != $this->langcodes[0];
                    $value = $sync ? $this->unchangedFieldValues[$this->langcodes[0]][$delta][$column] : $langcode . '-' . $delta . '-' . $column;
                    $this->unchangedFieldValues[$langcode][$delta][$column] = $value;
                }
            }
        }
    }
    
    /**
     * Tests the field synchronization algorithm.
     */
    public function testFieldSync() : void {
        // Add a new item to the source items and check that its added to all the
        // translations.
        $sync_langcode = $this->langcodes[2];
        $unchanged_items = $this->unchangedFieldValues[$sync_langcode];
        $field_values = $this->unchangedFieldValues;
        $item = [];
        foreach ($this->columns as $column) {
            $item[$column] = $this->randomMachineName();
        }
        $field_values[$sync_langcode][] = $item;
        $this->synchronizer
            ->synchronizeItems($field_values, $unchanged_items, $sync_langcode, $this->langcodes, $this->synchronized);
        $result = TRUE;
        foreach ($this->unchangedFieldValues as $langcode => $items) {
            // Check that the old values are still in place.
            for ($delta = 0; $delta < $this->cardinality; $delta++) {
                foreach ($this->columns as $column) {
                    $result = $result && $this->unchangedFieldValues[$langcode][$delta][$column] == $field_values[$langcode][$delta][$column];
                }
            }
            // Check that the new item is available in all languages.
            foreach ($this->columns as $column) {
                $result = $result && $field_values[$langcode][$delta][$column] == $field_values[$sync_langcode][$delta][$column];
            }
        }
        $this->assertTrue($result, 'A new item has been correctly synchronized.');
        // Remove an item from the source items and check that its removed from all
        // the translations.
        $sync_langcode = $this->langcodes[1];
        $unchanged_items = $this->unchangedFieldValues[$sync_langcode];
        $field_values = $this->unchangedFieldValues;
        $sync_delta = mt_rand(0, count($field_values[$sync_langcode]) - 1);
        unset($field_values[$sync_langcode][$sync_delta]);
        // Renumber deltas to start from 0.
        $field_values[$sync_langcode] = array_values($field_values[$sync_langcode]);
        $this->synchronizer
            ->synchronizeItems($field_values, $unchanged_items, $sync_langcode, $this->langcodes, $this->synchronized);
        $result = TRUE;
        foreach ($this->unchangedFieldValues as $langcode => $items) {
            $new_delta = 0;
            // Check that the old values are still in place.
            for ($delta = 0; $delta < $this->cardinality; $delta++) {
                // Skip the removed item.
                if ($delta != $sync_delta) {
                    foreach ($this->columns as $column) {
                        $result = $result && $this->unchangedFieldValues[$langcode][$delta][$column] == $field_values[$langcode][$new_delta][$column];
                    }
                    $new_delta++;
                }
            }
        }
        $this->assertTrue($result, 'A removed item has been correctly synchronized.');
        // Move the items around in the source items and check that they are moved
        // in all the translations.
        $sync_langcode = $this->langcodes[3];
        $unchanged_items = $this->unchangedFieldValues[$sync_langcode];
        $field_values = $this->unchangedFieldValues;
        $field_values[$sync_langcode] = [];
        // Scramble the items.
        foreach ($unchanged_items as $delta => $item) {
            $new_delta = ($delta + 1) % $this->cardinality;
            $field_values[$sync_langcode][$new_delta] = $item;
        }
        // Renumber deltas to start from 0.
        ksort($field_values[$sync_langcode]);
        $this->synchronizer
            ->synchronizeItems($field_values, $unchanged_items, $sync_langcode, $this->langcodes, $this->synchronized);
        $result = TRUE;
        foreach ($field_values as $langcode => $items) {
            for ($delta = 0; $delta < $this->cardinality; $delta++) {
                foreach ($this->columns as $column) {
                    $value = $field_values[$langcode][$delta][$column];
                    if (in_array($column, $this->synchronized)) {
                        // If we are dealing with a synchronize column the current value is
                        // supposed to be the same of the source items.
                        $result = $result && $field_values[$sync_langcode][$delta][$column] == $value;
                    }
                    else {
                        // Otherwise the values should be unchanged.
                        $old_delta = ($delta > 0 ? $delta : $this->cardinality) - 1;
                        $result = $result && $this->unchangedFieldValues[$langcode][$old_delta][$column] == $value;
                    }
                }
            }
        }
        $this->assertTrue($result, 'Scrambled items have been correctly synchronized.');
    }
    
    /**
     * Tests that items holding the same values are correctly synchronized.
     */
    public function testMultipleSyncedValues() : void {
        $sync_langcode = $this->langcodes[1];
        $unchanged_items = $this->unchangedFieldValues[$sync_langcode];
        // Determine whether the unchanged values should be altered depending on
        // their delta.
        $delta_callbacks = [
            // Continuous field values: all values are equal.
function ($delta) {
                return TRUE;
            },
            // Alternated field values: only the even ones are equal.
function ($delta) {
                return $delta % 2 !== 0;
            },
            // Sparse field values: only the "middle" ones are equal.
function ($delta) {
                return $delta === 1 || $delta === 2;
            },
            // Sparse field values: only the "extreme" ones are equal.
function ($delta) {
                return $delta === 0 || $delta === 3;
            },
        ];
        foreach ($delta_callbacks as $delta_callback) {
            $field_values = $this->unchangedFieldValues;
            for ($delta = 0; $delta < $this->cardinality; $delta++) {
                if ($delta_callback($delta)) {
                    foreach ($this->columns as $column) {
                        if (in_array($column, $this->synchronized)) {
                            $field_values[$sync_langcode][$delta][$column] = $field_values[$sync_langcode][0][$column];
                        }
                    }
                }
            }
            $changed_items = $field_values[$sync_langcode];
            $this->synchronizer
                ->synchronizeItems($field_values, $unchanged_items, $sync_langcode, $this->langcodes, $this->synchronized);
            foreach ($this->unchangedFieldValues as $langcode => $unchanged_items) {
                for ($delta = 0; $delta < $this->cardinality; $delta++) {
                    foreach ($this->columns as $column) {
                        // The first item is always unchanged hence it is retained by the
                        // synchronization process. The other ones are retained or synced
                        // depending on the logic implemented by the delta callback and
                        // whether it is a sync column or not.
                        $value = $delta > 0 && $delta_callback($delta) && in_array($column, $this->synchronized) ? $changed_items[0][$column] : $unchanged_items[$delta][$column];
                        $this->assertEquals($field_values[$langcode][$delta][$column], $value, "Item {$delta} column {$column} for langcode {$langcode} synced correctly");
                    }
                }
            }
        }
    }
    
    /**
     * Tests that one change in a synchronized column triggers a change in all columns.
     */
    public function testDifferingSyncedColumns() : void {
        $sync_langcode = $this->langcodes[2];
        $unchanged_items = $this->unchangedFieldValues[$sync_langcode];
        $field_values = $this->unchangedFieldValues;
        for ($delta = 0; $delta < $this->cardinality; $delta++) {
            $index = $delta % 2 + 1;
            $field_values[$sync_langcode][$delta]['sync' . $index] .= '-updated';
        }
        $changed_items = $field_values[$sync_langcode];
        $this->synchronizer
            ->synchronizeItems($field_values, $unchanged_items, $sync_langcode, $this->langcodes, $this->synchronized);
        foreach ($this->unchangedFieldValues as $langcode => $unchanged_items) {
            for ($delta = 0; $delta < $this->cardinality; $delta++) {
                foreach ($this->columns as $column) {
                    // If the column is synchronized, the value should have been synced,
                    // for columns that are not synchronized, the value must not change.
                    $expected_value = in_array($column, $this->synchronized) ? $changed_items[$delta][$column] : $this->unchangedFieldValues[$langcode][$delta][$column];
                    $this->assertEquals($expected_value, $field_values[$langcode][$delta][$column], "Differing Item {$delta} column {$column} for langcode {$langcode} synced correctly");
                }
            }
        }
    }

}