diff --git a/core/modules/locale/lib/Drupal/locale/ProjectTranslationState.php b/core/modules/locale/lib/Drupal/locale/ProjectTranslationState.php
new file mode 100644
index 0000000..894e4c5
--- /dev/null
+++ b/core/modules/locale/lib/Drupal/locale/ProjectTranslationState.php
@@ -0,0 +1,405 @@
+<?php
+
+/**
+ * @file
+ * Contains Drupal\locale\ProjectTranslationState.
+ */
+
+namespace Drupal\locale;
+
+/**
+ * @todo
+ */
+class ProjectTranslationState {
+
+  /**
+   * Machine readable project name.
+   */
+  protected $projectName = '';
+
+  /**
+   * Human readable project name.
+   */
+  protected $projectHumanName = '';
+
+  /**
+   * Project release version. e.g. "8.x-1.0"
+   */
+  protected $projectVersion = '';
+
+  /**
+   * Project core version. e.g. "8.x"
+   */
+  protected $projectCore = '';
+
+  /**
+   * Translation file uri pattern. May contain placeholders.
+   */
+  protected $serverPattern = '';
+
+  /**
+   * Array of project states keyed by language.
+   */
+  protected $stateByLanguage = array();
+
+  /**
+   * The time the current project translation was updated.
+   * Zero if unknown or not translated.
+   */
+  protected $timestamp;
+
+  /**
+   * The time the current translation was last checked or updated.
+   */
+  protected $lastChecked;
+
+  /**
+   * The source which holds the most up to date translation.
+   */
+  protected $latestSource;
+
+  /**
+   * The timestamp of the most up to date translation source.
+   */
+  protected $latestSourceTimestamp;
+
+  /**
+   * Local translation source object.
+   */
+  protected $localSource;
+
+  /**
+   * Remote translation source object.
+   */
+  protected $remoteSource;
+
+  /**
+   * @var string
+   */
+  protected $langcode = '';
+
+  public function __construct($project_name) {
+    $this->projectName = $project_name;
+  }
+
+  public function __destruct() {
+    foreach ($this->stateByLanguage as $langcode => $state) {
+      // @todo Need to check if changed?
+      $this->saveState($langcode);
+    }
+  }
+
+  /**
+   * Returns the machine name of the project.
+   */
+  public function getName() {
+    return $this->projectName;
+  }
+
+  /**
+   * Returns the human readable name of the project.
+   */
+  public function getHumanName() {
+    return $this->projectHumanName;
+  }
+
+  /**
+   * Sets the language this project is translated to.
+   *
+   * @param $langcode
+   */
+  public function setLangcode($langcode) {
+    // @todo Need to check if language is translatable?
+    $this->langcode = $langcode;
+    if (!isset($this->stateByLanguage[$langcode])) {
+      $this->initState();
+    }
+    $this->timestamp = &$this->stateByLanguage[$langcode]->timestamp;
+    $this->lastChecked = &$this->stateByLanguage[$langcode]->lastChecked;
+    $this->latestSource = &$this->stateByLanguage[$langcode]->latestSource;
+    $this->latestSourceTimestamp = &$this->stateByLanguage[$langcode]->latestSourceTimestamp;
+    $this->localSource = &$this->stateByLanguage[$langcode]->localSource;
+    $this->remoteSource = &$this->stateByLanguage[$langcode]->remoteSource;
+  }
+
+  /**
+   * Deletes stored data of specified language.
+   */
+  public function deleteLangcode($langcode) {
+    \Drupal::state()->delete('locale.translation_status.' . $this->projectName . '.' . $langcode);
+  }
+
+  /**
+   * Returns the local source state.
+   */
+  public function getLocalSource() {
+    if (!empty($this->localSource)) {
+      return $this->localSource;
+    }
+    return FALSE;
+  }
+
+  /**
+   * Returns the remote source state.
+   */
+  public function getRemoteSource() {
+    if (!empty($this->remoteSource)) {
+      return $this->remoteSource;
+    }
+    return FALSE;
+  }
+
+  public function getLatestSourceTimestamp() {
+    return $this->latestSourceTimestamp;
+  }
+
+  public function getVersion() {
+    return $this->projectVersion;
+  }
+
+  /**
+   * Whether the remote source is valid and can be checked or downloaded.
+   *
+   * @return bool
+   *   Returns FALSE if the project version is a dev release. No translations
+   *   are available for dev releases.
+   */
+  public function remoteIsValid() {
+    // @todo Return FALSE if file was not found (404) less than x time ago.
+    if ($this->projectVersion && strpos('dev', $this->projectVersion) !== FALSE) {
+      return FALSE;
+    }
+    return TRUE;
+  }
+
+  /**
+   * Whether a remote source file is available and can be downloaded.
+   *
+   * @return bool
+   *   Returns FALSE if the project version is a dev release. No translations
+   *   are available for dev releases.
+   */
+  public function remoteIsAvailable() {
+    return $this->remoteIsValid() && $this->latestSource == 'remote';
+  }
+
+  /**
+   * Whether the local source is available and can be imported.
+   *
+   * @return bool
+   *   Returns FALSE if the project version is a dev release. No translations
+   *   are available for dev releases.
+   */
+  public function localIsAvailable() {
+    return $this->latestSource == 'local';
+  }
+
+  public function remoteIsLatest() {
+    return $this->latestSource == 'remote';
+  }
+
+  public function localIsLatest() {
+    return $this->latestSource == 'local';
+  }
+
+  /**
+   * Updates the translation state with local source data.
+   *
+   * @param $data
+   */
+  public function updateLocalSource($data) {
+    $this->localSource = $data;
+    $this->localSource->lastChecked = REQUEST_TIME;
+
+    // If the local translation is the most recent, we update the latestSource
+    // status. Otherwise only mark the current translation as checked. If remote
+    // and local have the same timestamp, the local source is chosen.
+    if ($data->timestamp > $this->latestSourceTimestamp || ($data->timestamp >= $this->latestSourceTimestamp && $this->latestSource == 'remote')) {
+      $this->latestSource = 'local';
+      $this->latestSourceTimestamp = $data->timestamp;
+    }
+    else {
+      $this->lastChecked = REQUEST_TIME;
+    }
+  }
+
+  /**
+   * Updates the translation state with remote source data.
+   *
+   * @param $data
+   */
+  public function updateRemoteSource($data) {
+    $this->remoteSource = $data;
+    $this->remoteSource->lastChecked = REQUEST_TIME;
+
+    // If the remote translation is the most recent, we update the latestSource
+    // status. Otherwise mark the current translation as checked.
+    if ($data->timestamp > $this->latestSourceTimestamp) {
+      $this->latestSource = 'remote';
+      $this->latestSourceTimestamp = $data->timestamp;
+    }
+    else {
+      $this->lastChecked = REQUEST_TIME;
+    }
+  }
+
+  /**
+   * Updates the translation state with the timestamp of a newly imported translation.
+   *
+   * @param $timestamp
+   */
+  public function updateTimestamp($timestamp) {
+    $this->timestamp = $timestamp;
+    $this->lastChecked = REQUEST_TIME;
+
+    $this->latestSource = 'current';
+    $this->latestSourceTimestamp = $timestamp;
+  }
+
+  /**
+   * Whether this project is translated in language $langcode.
+   *
+   * @return bool
+   *   Returns TRUE if this project is translated.
+   */
+  public function isTranslated() {
+    return $this->timestamp > 0;
+  }
+
+  /**
+   * Whether translation updates are available for this language.
+   *
+   * @return bool
+   *   Returns TRUE if a local or remote translation update is available.
+   */
+  public function hasUpdates() {
+    return $this->latestSource == 'local' || $this->latestSource == 'remote' ;
+  }
+
+  /*
+   * Initializes the translation state by loading from cache or building a new one.
+   */
+  protected function initState() {
+    if (empty($this->projectCore)) {
+      $this->loadProject();
+    }
+    $this->loadState();
+    if (empty($this->stateByLanguage[$this->langcode])) {
+      $this->stateByLanguage[$this->langcode] = $this->buildState();
+    }
+  }
+
+  /**
+   * Loads the project data.
+   */
+  protected function loadProject() {
+    module_load_include('translation.inc', 'locale');
+    // @todo Make a singular function based on locale_translation_get_projects()
+    //$project = locale_translation_get_project($this->projectName);
+    // @todo Follow-up issue to convert project into an object, so we don't have
+    //   to call a procedural function here. https://drupal.org/node/1832946
+    $project = locale_translation_get_projects(array($this->projectName));
+    $project = $project[$this->projectName];
+    if (empty($project)) {
+      // @todo Throw exception.
+    }
+    $this->projectHumanName = $this->projectName . ' (TODO)';
+    $this->projectVersion = $project->version;
+    $this->projectCore = $project->core;
+    $this->serverPattern = $project->server_pattern;
+  }
+
+  /**
+   * Builds a new translation state.
+   */
+  protected function buildState() {
+    $state = new \stdClass();
+    $state->timestamp = 0;
+    $state->lastChecked = 0;
+    $state->latestSource = '';
+    $state->latestSourceTimestamp = 0;
+    $state->localSource = $this->buildLocalSource();
+    $state->remoteSource = $this->buildRemoteSource();
+
+    return $state;
+  }
+
+  /**
+   * Builds a local translation source object.
+   */
+  protected function buildLocalSource() {
+    $filename = config('locale.settings')->get('translation.default_filename');
+    $source = new \stdClass();
+    if ($this->fileIsRemote($this->serverPattern)) {
+      $source->filename = $this->buildServerPattern($filename);
+      $source->directory = 'translations://';
+      $source->uri = $source->directory . $source->filename;
+    }
+    else {
+      $source->filename = $this->buildServerPattern(basename($this->serverPattern));
+      $source->directory = $this->buildServerPattern(drupal_dirname($this->serverPattern));
+      $source->uri = $source->directory . '/' . $source->filename;
+    }
+    return $source;
+  }
+
+  /**
+   * Builds a local translation source object.
+   */
+  protected function buildRemoteSource() {
+    $source = new \stdClass();
+    if ($this->fileIsRemote($this->serverPattern)) {
+      $source->filename = $this->buildServerPattern(basename($this->serverPattern));
+      $source->uri = $this->buildServerPattern($this->serverPattern);
+    }
+    return $source;
+  }
+
+  /**
+   * Builds uri of a translation file out of a server path replacement pattern.
+   *
+   * @param string $template
+   *   Uri template string containing placeholders. Available placeholders:
+   *   - "%project": Project name.
+   *   - "%version": Project version.
+   *   - "%core": Project core version.
+   *   - "%language": Language code.
+   *
+   * @return string
+   *   File uri with replaced placeholders.
+   */
+  protected function buildServerPattern($template) {
+    $variables = array(
+      '%project' => $this->projectName,
+      '%version' => $this->projectVersion,
+      '%core' => $this->projectCore,
+      '%language' => $this->langcode,
+    );
+    return strtr($template, $variables);
+  }
+
+  /**
+   * Loads the translation state.
+   */
+  protected function loadState() {
+    return $this->stateByLanguage[$this->langcode] = \Drupal::state()->get('locale.translation_status.' . $this->projectName . '.' . $this->langcode, NULL);
+  }
+
+  /**
+   * Saves the translation state.
+   *
+   * @param $langcode
+   */
+  protected function saveState() {
+    // @todo Need to check if data changed? (hash of lastChecked timestamps).
+    \Drupal::state()->set('locale.translation_status.' . $this->projectName . '.' . $this->langcode, $this->stateByLanguage[$this->langcode]);
+  }
+
+  protected function fileIsRemote($uri) {
+    $scheme = file_uri_scheme($uri);
+    if ($scheme) {
+      return !drupal_realpath($scheme . '://');
+    }
+    return FALSE;
+  }
+}
diff --git a/core/modules/locale/locale.batch.inc b/core/modules/locale/locale.batch.inc
index 5085a2b..fee0b93 100644
--- a/core/modules/locale/locale.batch.inc
+++ b/core/modules/locale/locale.batch.inc
@@ -5,6 +5,7 @@
  *   Batch process to check the availability of remote or local po files.
  */
 
+use Drupal\locale\ProjectTranslationState;
 use Guzzle\Http\Exception\BadResponseException;
 use Guzzle\Http\Exception\RequestException;
 
@@ -40,27 +41,27 @@ function locale_translation_batch_status_check($project, $langcode, $options = a
     'finish_feedback' => TRUE,
     'use_remote' => TRUE,
   );
-  $source = locale_translation_get_status(array($project), array($langcode));
-  $source = $source[$project][$langcode];
+  // @todo Class ProjectTranslationState must be overridable.
+  $project_state = new ProjectTranslationState($project);
+  $project_state->setLangcode($langcode);
 
   // Check the status of local translation files.
-  if (isset($source->files[LOCALE_TRANSLATION_LOCAL])) {
-    if ($file = locale_translation_source_check_file($source)) {
-      locale_translation_status_save($source->name, $source->langcode, LOCALE_TRANSLATION_LOCAL, $file);
+  if ($source = $project_state->getLocalSource()) {
+    if ($local_file = locale_translation_source_check_file($source)) {
+      $project_state->updateLocalSource($local_file);
     }
     $checked = TRUE;
   }
 
   // Check the status of remote translation files.
-  if ($options['use_remote'] && isset($source->files[LOCALE_TRANSLATION_REMOTE])) {
-    $remote_file = $source->files[LOCALE_TRANSLATION_REMOTE];
+  if ($options['use_remote'] && $project_state->remoteIsValid() && $remote_file = $project_state->getRemoteSource()) {
     if ($result = locale_translation_http_check($remote_file->uri)) {
       // Update the file object with the result data. In case of a redirect we
       // store the resulting uri.
       if (isset($result['last_modified'])) {
         $remote_file->uri = isset($result['location']) ? $result['location'] : $remote_file->uri;
         $remote_file->timestamp = $result['last_modified'];
-        locale_translation_status_save($source->name, $source->langcode, LOCALE_TRANSLATION_REMOTE, $remote_file);
+        $project_state->updateRemoteSource($remote_file);
       }
       // @todo What to do with when the file is not found (404)? To prevent
       //   re-checking within the TTL (1day, 1week) we can set a last_checked
@@ -75,12 +76,12 @@ function locale_translation_batch_status_check($project, $langcode, $options = a
   // Provide user feedback and record success or failure for reporting at the
   // end of the batch.
   if ($options['finish_feedback'] && $checked) {
-    $context['results']['files'][] = $source->name;
+    $context['results']['files'][] = $project_state->getName();
   }
   if ($failure && !$checked) {
-    $context['results']['failed_files'][] = $source->name;
+    $context['results']['failed_files'][] = $project_state->getName();
   }
-  $context['message'] = t('Checked translation for %project.', array('%project' => $source->project));
+  $context['message'] = t('Checked translation for %project.', array('%project' => $project_state->getHumanName()));
 }
 
 /**
@@ -135,17 +136,17 @@ function locale_translation_batch_status_finished($success, $results) {
  * @see locale_translation_batch_fetch_import()
  */
 function locale_translation_batch_fetch_download($project, $langcode, &$context) {
-  $sources = locale_translation_get_status(array($project), array($langcode));
-  if (isset($sources[$project][$langcode])) {
-    $source = $sources[$project][$langcode];
-    if (isset($source->type) && $source->type == LOCALE_TRANSLATION_REMOTE) {
-      if ($file = locale_translation_download_source($source->files[LOCALE_TRANSLATION_REMOTE], 'translations://')) {
-        $context['message'] = t('Downloaded translation for %project.', array('%project' => $source->project));
-        locale_translation_status_save($source->name, $source->langcode, LOCALE_TRANSLATION_LOCAL, $file);
-      }
-      else {
-        $context['results']['failed_files'][] = $source->files[LOCALE_TRANSLATION_REMOTE];
-      }
+  $project_state = new ProjectTranslationState($project);
+  $project_state->setLangcode($langcode);
+
+  if ($project_state->remoteIsAvailable() && $remote = $project_state->getRemoteSource()) {
+    $t = get_t();
+    if ($result = locale_translation_download_source($remote, 'translations://')) {
+      $context['message'] = $t('Downloaded translation for %project.', array('%project' => $project_state->getHumanName()));
+      $project_state->updateLocalSource($result);
+    }
+    else {
+      $context['results']['failed_files'][] = $remote;
     }
   }
 }
@@ -169,31 +170,28 @@ function locale_translation_batch_fetch_download($project, $langcode, &$context)
  * @see locale_translation_batch_fetch_download()
  */
 function locale_translation_batch_fetch_import($project, $langcode, $options, &$context) {
-  $sources = locale_translation_get_status(array($project), array($langcode));
-  if (isset($sources[$project][$langcode])) {
-    $source = $sources[$project][$langcode];
-    if (isset($source->type)) {
-      if ($source->type == LOCALE_TRANSLATION_REMOTE || $source->type == LOCALE_TRANSLATION_LOCAL) {
-        $file = $source->files[LOCALE_TRANSLATION_LOCAL];
-        module_load_include('bulk.inc', 'locale');
-        $options += array(
-          'message' => t('Importing translation for %project.', array('%project' => $source->project)),
-        );
-        // Import the translation file. For large files the batch operations is
-        // progressive and will be called repeatedly until finished.
-        locale_translate_batch_import($file, $options, $context);
+  $project_state = new ProjectTranslationState($project);
+  $project_state->setLangcode($langcode);
 
-        // The import is finished.
-        if (isset($context['finished']) && $context['finished'] == 1) {
-          // The import is successful.
-          if (isset($context['results']['files'][$file->uri])) {
-            $context['message'] = t('Imported translation for %project.', array('%project' => $source->project));
+  if ($project_state->localIsAvailable() && $local = $project_state->getLocalSource()) {
+    $local->langcode = $langcode;
+    $t = get_t();
+    module_load_include('bulk.inc', 'locale');
+    $options += array(
+      'message' => $t('Importing translation for %project.', array('%project' => $project_state->getHumanName())),
+    );
+    // Import the translation file. For large files the batch operations is
+    // progressive and will be called repeatedly until finished.
+    locale_translate_batch_import($local, $options, $context);
 
-            // Save the data of imported source into the {locale_file} table and
-            // update the current translation status.
-            locale_translation_status_save($project, $langcode, LOCALE_TRANSLATION_CURRENT, $source->files[LOCALE_TRANSLATION_LOCAL]);
-          }
-        }
+    // The import is finished.
+    if (isset($context['finished']) && $context['finished'] == 1) {
+      // The import is successfull.
+      if (isset($context['results']['files'][$local->uri])) {
+        $context['message'] = $t('Imported translation for %project.', array('%project' => $project_state->getHumanName()));
+
+        // Update the current translation timestamp.
+        $project_state->updateTimestamp($local->timestamp);
       }
     }
   }
@@ -284,9 +282,8 @@ function locale_translation_http_check($uri) {
  *   File object if download was successful. FALSE on failure.
  */
 function locale_translation_download_source($source_file, $directory = 'temporary://') {
-  if ($uri = system_retrieve_file($source_file->uri, $directory)) {
+  if ($uri = system_retrieve_file($source_file->uri, $directory, FALSE, FILE_EXISTS_REPLACE)) {
     $file = clone($source_file);
-    $file->type = LOCALE_TRANSLATION_LOCAL;
     $file->uri = $uri;
     $file->directory = $directory;
     $file->timestamp = filemtime($uri);
diff --git a/core/modules/locale/locale.compare.inc b/core/modules/locale/locale.compare.inc
index dad67a8..a89f417 100644
--- a/core/modules/locale/locale.compare.inc
+++ b/core/modules/locale/locale.compare.inc
@@ -335,10 +335,13 @@ function locale_translation_check_projects_local($projects = array(), $langcodes
   // available. When found the source object is updated with the appropriate
   // type and timestamp of the po file.
   foreach ($projects as $name => $project) {
+    // @todo ProjectTranslationState must be overridable.
+    $project_state = new ProjectTranslationState($project);
     foreach ($langcodes as $langcode) {
-      $source = locale_translation_source_build($project, $langcode);
-      $file = locale_translation_source_check_file($source);
-      locale_translation_status_save($name, $langcode, LOCALE_TRANSLATION_LOCAL, $file);
+      $project_state->setLangcode($langcode);
+      $local = $project_state->getLocal();
+      $file = locale_translation_source_check_file($local);
+      $project_state->updateLocalSource($file);
     }
   }
 }
diff --git a/core/modules/locale/locale.module b/core/modules/locale/locale.module
index 7c3f570..b32ed1f 100644
--- a/core/modules/locale/locale.module
+++ b/core/modules/locale/locale.module
@@ -14,6 +14,7 @@
 use Drupal\Core\Cache\Cache;
 use Drupal\Core\Language\Language;
 use Drupal\Component\Utility\Crypt;
+use Drupal\locale\ProjectTranslationState;
 
 /**
  * Regular expression pattern used to localize JavaScript strings.
@@ -114,21 +115,6 @@
 const LOCALE_TRANSLATION_OVERWRITE_NONE = 'none';
 
 /**
- * Translation source is a remote file.
- */
-const LOCALE_TRANSLATION_REMOTE = 'remote';
-
-/**
- * Translation source is a local file.
- */
-const LOCALE_TRANSLATION_LOCAL = 'local';
-
-/**
- * Translation source is the current translation.
- */
-const LOCALE_TRANSLATION_CURRENT = 'current';
-
-/**
  * Implements hook_help().
  */
 function locale_help($path, $arg) {
@@ -911,7 +897,6 @@ function locale_translation_file_history_delete($projects = array(), $langcodes
  */
 function locale_translation_get_status($projects = NULL, $langcodes = NULL) {
   $result = array();
-  $status = \Drupal::state()->get('locale.translation_status');
   module_load_include('translation.inc', 'locale');
   $projects = $projects ? $projects : array_keys(locale_translation_get_projects());
   $langcodes = $langcodes ? $langcodes : array_keys(locale_translatable_language_list());
@@ -920,14 +905,9 @@ function locale_translation_get_status($projects = NULL, $langcodes = NULL) {
   // status was stored, a new translation source is created.
   foreach ($projects as $project) {
     foreach ($langcodes as $langcode) {
-      if (isset($status[$project][$langcode])) {
-        $result[$project][$langcode] = $status[$project][$langcode];
-      }
-      else {
-        $sources = locale_translation_build_sources(array($project), array($langcode));
-        if (isset($sources[$project][$langcode])) {
-          $result[$project][$langcode] = $sources[$project][$langcode];
-        }
+      // @todo ProjectTranslationState object needs a method to clear its own data.
+      if ($status = Drupal::state()->get('locale.translation_status.' . $project . '.' . $langcode, NULL)) {
+        $result[$project][$langcode] = $status;
       }
     }
   }
@@ -935,80 +915,19 @@ function locale_translation_get_status($projects = NULL, $langcodes = NULL) {
 }
 
 /**
- * Saves the status of translation sources in static cache.
- *
- * @param string $project
- *   Machine readable project name.
- * @param string $langcode
- *   Language code.
- * @param string $type
- *   Type of data to be stored.
- * @param array $data
- *   File object also containing timestamp when the translation is last updated.
- */
-function locale_translation_status_save($project, $langcode, $type, $data) {
-  // Followup issue: http://drupal.org/node/1842362
-  // Split status storage per module/language and expire individually. This will
-  // improve performance for large sites.
-
-  // Load the translation status or build it if not already available.
-  module_load_include('translation.inc', 'locale');
-  $status = locale_translation_get_status();
-  if (empty($status)) {
-    $projects = locale_translation_get_projects(array($project));
-    if (isset($projects[$project])) {
-      $status[$project][$langcode] = locale_translation_source_build($projects[$project], $langcode);
-    }
-  }
-
-  // Merge the new status data with the existing status.
-  if (isset($status[$project][$langcode])) {
-    switch ($type) {
-      case LOCALE_TRANSLATION_REMOTE:
-      case LOCALE_TRANSLATION_LOCAL:
-        // Add the source data to the status array.
-        $status[$project][$langcode]->files[$type] = $data;
-
-        // Check if this translation is the most recent one. Set timestamp and
-        // data type of the most recent translation source.
-        if (isset($data->timestamp) && $data->timestamp) {
-          if ($data->timestamp > $status[$project][$langcode]->timestamp) {
-            $status[$project][$langcode]->timestamp = $data->timestamp;
-            $status[$project][$langcode]->last_checked = REQUEST_TIME;
-            $status[$project][$langcode]->type = $type;
-          }
-        }
-        break;
-      case LOCALE_TRANSLATION_CURRENT:
-        $data->last_checked = REQUEST_TIME;
-        $status[$project][$langcode]->timestamp = $data->timestamp;
-        $status[$project][$langcode]->last_checked = $data->last_checked;
-        $status[$project][$langcode]->type = $type;
-        locale_translation_update_file_history($data);
-        break;
-    }
-
-    \Drupal::state()->set('locale.translation_status', $status);
-    \Drupal::state()->set('locale.translation_last_checked', REQUEST_TIME);
-  }
-}
-
-/**
  * Delete language entries from the status cache.
  *
  * @param array $langcodes
  *   Language code(s) to be deleted from the cache.
  */
 function locale_translation_status_delete_languages($langcodes) {
-  if ($status = locale_translation_get_status()) {
-    foreach ($status as $project => $languages) {
-      foreach ($languages as $langcode => $source) {
-        if (in_array($langcode, $langcodes)) {
-          unset($status[$project][$langcode]);
-        }
-      }
+  $projects = locale_translation_get_projects();
+  foreach (array_keys($projects) as $project) {
+    foreach ($langcodes as $langcode) {
+      // @todo ProjectTranslationState object needs a method to clear its own data.
+      Drupal::state()
+        ->delete('locale.translation_status.' . $project . '.' . $langcode);
     }
-    \Drupal::state()->set('locale.translation_status', $status);
   }
 }
 
@@ -1033,7 +952,14 @@ function locale_translation_status_delete_projects($projects) {
  * Clear the translation status cache.
  */
 function locale_translation_clear_status() {
-  \Drupal::state()->delete('locale.translation_status');
+  $projects = locale_translation_get_projects();
+  $langcodes = locale_translatable_language_list();
+  foreach (array_keys($projects) as $project) {
+    foreach (array_keys($langcodes) as $langcode) {
+      Drupal::state()
+        ->delete('locale.translation_status.' . $project . '.' . $langcode);
+    }
+  }
   \Drupal::state()->delete('locale.translation_last_checked');
 }
 
diff --git a/core/modules/locale/locale.pages.inc b/core/modules/locale/locale.pages.inc
index 98f4db9..e4588d9 100644
--- a/core/modules/locale/locale.pages.inc
+++ b/core/modules/locale/locale.pages.inc
@@ -6,11 +6,8 @@
  */
 
 use Drupal\Component\Utility\String;
-use Drupal\Core\Language\Language;
-use Drupal\locale\SourceString;
-use Drupal\locale\TranslationString;
 use Symfony\Component\HttpFoundation\RedirectResponse;
-use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
+use Drupal\locale\ProjectTranslationState;
 
 /**
  * Page callback: Checks for translation updates and displays the status.
@@ -48,7 +45,7 @@ function locale_translation_status_form($form, &$form_state) {
   module_load_include('translation.inc', 'locale');
   module_load_include('compare.inc', 'locale');
   $updates = $options = array();
-  $languages_update = $languages_not_found = array();
+  $languages_update = $languages_not_found = $languages_translated = array();
   $projects_update = array();
 
   // @todo Calling locale_translation_build_projects() is an expensive way to
@@ -56,41 +53,39 @@ function locale_translation_status_form($form, &$form_state) {
   //   the project name will be stored to display use, like here.
   $project_data = locale_translation_build_projects();
   $languages = locale_translatable_language_list();
-  $status = locale_translation_get_status();
+  $projects = locale_translation_get_projects();
 
   // Prepare information about projects which have available translation
   // updates.
-  if ($languages && $status) {
-    foreach ($status as $project) {
-      foreach ($project as $langcode => $project_info) {
-        // No translation file found for this project-language combination.
-        if (empty($project_info->type)) {
-          $updates[$langcode]['not_found'][] = array(
-            'name' => $project_info->name == 'drupal' ? t('Drupal core') : $project_data[$project_info->name]->info['name'],
-            'version' => $project_info->version,
-            'info' => _locale_translation_status_debug_info($project_info),
-          );
-          $languages_not_found[$langcode] = $langcode;
-        }
-        // Translation update found for this project-language combination.
-        elseif ($project_info->type == LOCALE_TRANSLATION_LOCAL || $project_info->type == LOCALE_TRANSLATION_REMOTE ) {
-          $local = isset($project_info->files[LOCALE_TRANSLATION_LOCAL]) ? $project_info->files[LOCALE_TRANSLATION_LOCAL] : NULL;
-          $remote = isset($project_info->files[LOCALE_TRANSLATION_REMOTE]) ? $project_info->files[LOCALE_TRANSLATION_REMOTE] : NULL;
-          $recent = _locale_translation_source_compare($local, $remote) == LOCALE_TRANSLATION_SOURCE_COMPARE_LT ? $remote : $local;
+  if ($languages) {
+    foreach (array_keys($projects) as $project) {
+      $project_status = new ProjectTranslationState($project);
+      foreach (array_keys($languages) as $langcode) {
+        $project_status->setLangcode($langcode);
+
+        if ($project_status->hasUpdates()) {
           $updates[$langcode]['updates'][] = array(
-            'name' => $project_data[$project_info->name]->info['name'],
-            'version' => $project_info->version,
-            'timestamp' => $recent->timestamp,
+            'name' => $project == 'drupal' ? t('Drupal core') : $project_data[$project]->info['name'],
+            'version' => $project_status->getVersion(),
+            'timestamp' => $project_status->getLatestSourceTimestamp(),
           );
           $languages_update[$langcode] = $langcode;
-          $projects_update[$project_info->name] = $project_info->name;
+          $projects_update[$project] = $project;
+        }
+        elseif (!$project_status->isTranslated()) {
+          $updates[$langcode]['not_found'][] = array(
+            'name' => $project == 'drupal' ? t('Drupal core') : $project_data[$project]->info['name'],
+            'version' => $project_status->getVersion(),
+            'info' => _locale_translation_status_debug_info($project_status),
+          );
+          $languages_not_found[$langcode] = $langcode;
         }
       }
     }
     $languages_not_found = array_diff($languages_not_found, $languages_update);
 
     // Build data options for the select table.
-    foreach($updates as $langcode => $update) {
+    foreach ($updates as $langcode => $update) {
       $title = String::checkPlain($languages[$langcode]->name);
       $locale_translation_update_info = array('#theme' => 'locale_translation_update_info');
       foreach (array('updates', 'not_found') as $update_status) {
@@ -106,7 +101,14 @@ function locale_translation_status_form($form, &$form_state) {
             '#markup' => $title
           ),
         ),
-        'status' => array('class' => array('description', 'expand', 'priority-low'), 'data' => drupal_render($locale_translation_update_info)),
+        'status' => array(
+          'class' => array(
+            'description',
+            'expand',
+            'priority-low'
+          ),
+          'data' => drupal_render($locale_translation_update_info)
+        ),
       );
     }
     // Sort the table data on language name.
@@ -135,12 +137,12 @@ function locale_translation_status_form($form, &$form_state) {
   if (!$languages) {
     $empty = t('No translatable languages available. <a href="@add_language">Add a language</a> first.', array('@add_language' => url('admin/config/regional/language')));
   }
-  elseif ($status) {
-    $empty = t('All translations up to date.');
-  }
-  else  {
+  elseif (empty($updates)) {
     $empty = t('No translation status available. <a href="@check">Check manually</a>.', array('@check' => url('admin/reports/translations/check')));
   }
+  else {
+    $empty = t('All translations up to date.');
+  }
 
   // The projects which require an update. Used by the _submit callback.
   $form['projects_update'] = array(
@@ -246,11 +248,13 @@ function locale_translation_language_table($form_element) {
  * @return string
  *   The string which contains debug information.
  */
-function _locale_translation_status_debug_info($source) {
-  $remote_path = isset($source->files['remote']->uri) ? $source->files['remote']->uri : '';
-  $local_path = isset($source->files['local']->uri) ? $source->files['local']->uri : '';
+function _locale_translation_status_debug_info(ProjectTranslationState $project_status) {
+  $local_source = $project_status->getLocalSource();
+  $remote_source = $project_status->getRemoteSource();
+  $remote_path = isset($remote_source->uri) ? $remote_source->uri : '';
+  $local_path = isset($local_source->uri) ? $local_source->uri : '';
 
-  if (strpos($source->version, 'dev') !== FALSE) {
+  if (strpos($project_status->getVersion(), 'dev') !== FALSE) {
     return t('No translation files are provided for development releases.');
   }
   if (locale_translation_use_remote_source() && $remote_path && $local_path) {
diff --git a/core/modules/locale/locale.translation.inc b/core/modules/locale/locale.translation.inc
index fab2a21..713ce46 100644
--- a/core/modules/locale/locale.translation.inc
+++ b/core/modules/locale/locale.translation.inc
@@ -6,30 +6,6 @@
  */
 
 /**
- * Comparison result of source files timestamps.
- *
- * Timestamp of source 1 is less than the timestamp of source 2.
- * @see _locale_translation_source_compare()
- */
-const LOCALE_TRANSLATION_SOURCE_COMPARE_LT = -1;
-
-/**
- * Comparison result of source files timestamps.
- *
- * Timestamp of source 1 is equal to the timestamp of source 2.
- * @see _locale_translation_source_compare()
- */
-const LOCALE_TRANSLATION_SOURCE_COMPARE_EQ = 0;
-
-/**
- * Comparison result of source files timestamps.
- *
- * Timestamp of source 1 is greater than the timestamp of source 2.
- * @see _locale_translation_source_compare()
- */
-const LOCALE_TRANSLATION_SOURCE_COMPARE_GT = 1;
-
-/**
  * Get array of projects which are available for interface translation.
  *
  * This project data contains all projects which will be checked for available
@@ -86,63 +62,6 @@ function locale_translation_clear_cache_projects() {
 }
 
 /**
- * Loads cached translation sources containing current translation status.
- *
- * @param array $projects
- *   Array of project names. Defaults to all translatable projects.
- * @param array $langcodes
- *   Array of language codes. Defaults to all translatable languages.
- *
- * @return array
- *   Array of source objects. Keyed with <project name>:<language code>.
- *
- * @see locale_translation_source_build()
- */
-function locale_translation_load_sources($projects = NULL, $langcodes = NULL) {
-  $sources = array();
-  $projects = $projects ? $projects : array_keys(locale_translation_get_projects());
-  $langcodes = $langcodes ? $langcodes : array_keys(locale_translatable_language_list());
-
-  // Load source data from locale_translation_status cache.
-  $status = locale_translation_get_status();
-
-  // Use only the selected projects and languages for update.
-  foreach($projects as $project) {
-    foreach ($langcodes as $langcode) {
-      $sources[$project][$langcode] = isset($status[$project][$langcode]) ? $status[$project][$langcode] : NULL;
-    }
-  }
-  return $sources;
-}
-
-/**
- * Build translation sources.
- *
- * @param array $projects
- *   Array of project names. Defaults to all translatable projects.
- * @param array $langcodes
- *   Array of language codes. Defaults to all translatable languages.
- *
- * @return array
- *   Array of source objects. Keyed by project name and language code.
- *
- * @see locale_translation_source_build()
- */
-function locale_translation_build_sources($projects = array(), $langcodes = array()) {
-  $sources = array();
-  $projects = locale_translation_get_projects($projects);
-  $langcodes = $langcodes ? $langcodes : array_keys(locale_translatable_language_list());
-
-  foreach ($projects as $project) {
-    foreach ($langcodes as $langcode) {
-      $source = locale_translation_source_build($project, $langcode);
-      $sources[$source->name][$source->langcode] = $source;
-    }
-  }
-  return $sources;
-}
-
-/**
  * Checks whether a po file exists in the local filesystem.
  *
  * It will search in the directory set in the translation source. Which defaults
@@ -163,136 +82,21 @@ function locale_translation_build_sources($projects = array(), $langcodes = arra
  *   - "uri": File name and path.
  *   - "timestamp": Last updated time of the po file.
  *   FALSE if the file is not found.
- *
- * @see locale_translation_source_build()
  */
-function locale_translation_source_check_file($source) {
-  if (isset($source->files[LOCALE_TRANSLATION_LOCAL])) {
-    $source_file = $source->files[LOCALE_TRANSLATION_LOCAL];
-    $directory = $source_file->directory;
-    $filename = '/' . preg_quote($source_file->filename) . '$/';
+function locale_translation_source_check_file($source_file) {
+  $directory = $source_file->directory;
+  $filename = '/' . preg_quote($source_file->filename) . '$/';
 
-    if ($files = file_scan_directory($directory, $filename, array('key' => 'name', 'recurse' => FALSE))) {
-      $file = current($files);
-      $source_file->uri = $file->uri;
-      $source_file->timestamp = filemtime($file->uri);
-      return $source_file;
-    }
+  if ($files = file_scan_directory($directory, $filename, array('key' => 'name', 'recurse' => FALSE))) {
+    $file = current($files);
+    $source_file->uri = $file->uri;
+    $source_file->timestamp = filemtime($file->uri);
+    return $source_file;
   }
   return FALSE;
 }
 
 /**
- * Builds abstract translation source.
- *
- * @param object $project
- *   Project object.
- * @param string $langcode
- *   Language code.
- * @param string $filename
- *   File name of translation file. May contain placeholders.
- *
- * @return object
- *   Source object:
- *   - "project": Project name.
- *   - "name": Project name (inherited from project).
- *   - "language": Language code.
- *   - "core": Core version (inherited from project).
- *   - "version": Project version (inherited from project).
- *   - "project_type": Project type (inherited from project).
- *   - "files": Array of file objects containing properties of local and remote
- *     translation files.
- *   Other processes can add the following properties:
- *   - "type": Most recent translation source found. LOCALE_TRANSLATION_REMOTE and
- *      LOCALE_TRANSLATION_LOCAL indicate available new translations,
- *      LOCALE_TRANSLATION_CURRENT indicate that the current translation is them
- *      most recent. "type" sorresponds with a key of the "files" array.
- *   - "timestamp": The creation time of the "type" translation (file).
- *   - "last_checked": The time when the "type" translation was last checked.
- *   The "files" array can hold file objects of type:
- *   LOCALE_TRANSLATION_LOCAL, LOCALE_TRANSLATION_REMOTE and
- *   LOCALE_TRANSLATION_CURRENT. Each contains following properties:
- *   - "type": The object type (LOCALE_TRANSLATION_LOCAL,
- *     LOCALE_TRANSLATION_REMOTE, etc. see above).
- *   - "project": Project name.
- *   - "langcode": Language code.
- *   - "version": Project version.
- *   - "uri": Local or remote file path.
- *   - "directory": Directory of the local po file.
- *   - "filename": File name.
- *   - "timestamp": Timestamp of the file.
- *   - "keep": TRUE to keep the downloaded file.
- */
-function locale_translation_source_build($project, $langcode, $filename = NULL) {
-  // Followup issue: http://drupal.org/node/1842380
-  // Convert $source object to a TranslatableProject class and use a typed class
-  // for $source-file.
-
-  // Create a source object with data of the project object.
-  $source = clone $project;
-  $source->project = $project->name;
-  $source->langcode = $langcode;
-  $source->type = '';
-  $source->timestamp = 0;
-  $source->last_checked = 0;
-
-  $filename = $filename ? $filename : \Drupal::config('locale.settings')->get('translation.default_filename');
-
-  // If the server_pattern contains a remote file path we will check for a
-  // remote file. The local version of this file will only be checked if a
-  // translations directory has been defined. If the server_pattern is a local
-  // file path we will only check for a file in the local file system.
-  $files = array();
-  if (_locale_translation_file_is_remote($source->server_pattern)) {
-    $files[LOCALE_TRANSLATION_REMOTE] = (object) array(
-      'project' => $project->name,
-      'langcode' => $langcode,
-      'version' => $project->version,
-      'type' => LOCALE_TRANSLATION_REMOTE,
-      'filename' => locale_translation_build_server_pattern($source, basename($source->server_pattern)),
-      'uri' => locale_translation_build_server_pattern($source, $source->server_pattern),
-    );
-    $files[LOCALE_TRANSLATION_LOCAL] = (object) array(
-      'project' => $project->name,
-      'langcode' => $langcode,
-      'version' => $project->version,
-      'type' => LOCALE_TRANSLATION_LOCAL,
-      'filename' => locale_translation_build_server_pattern($source, $filename),
-      'directory' => 'translations://',
-    );
-    $files[LOCALE_TRANSLATION_LOCAL]->uri = $files[LOCALE_TRANSLATION_LOCAL]->directory . $files[LOCALE_TRANSLATION_LOCAL]->filename;
-  }
-  else {
-    $files[LOCALE_TRANSLATION_LOCAL] = (object) array(
-      'project' => $project->name,
-      'langcode' => $langcode,
-      'version' => $project->version,
-      'type' => LOCALE_TRANSLATION_LOCAL,
-      'filename' => locale_translation_build_server_pattern($source, basename($source->server_pattern)),
-      'directory' => locale_translation_build_server_pattern($source, drupal_dirname($source->server_pattern)),
-    );
-    $files[LOCALE_TRANSLATION_LOCAL]->uri = $files[LOCALE_TRANSLATION_LOCAL]->directory . '/' . $files[LOCALE_TRANSLATION_LOCAL]->filename;
-  }
-  $source->files = $files;
-
-  // If this project+language is already translated, we add its status and
-  // update the current translation timestamp and last_updated time. If the
-  // project+language is not translated before, create a new record.
-  $history = locale_translation_get_file_history();
-  if (isset($history[$project->name][$langcode]) && $history[$project->name][$langcode]->timestamp) {
-    $source->files[LOCALE_TRANSLATION_CURRENT] = $history[$project->name][$langcode];
-    $source->type = LOCALE_TRANSLATION_CURRENT;
-    $source->timestamp = $history[$project->name][$langcode]->timestamp;
-    $source->last_checked = $history[$project->name][$langcode]->last_checked;
-  }
-  else {
-    locale_translation_update_file_history($source);
-  }
-
-  return $source;
-}
-
-/**
  * Build path to translation source, out of a server path replacement pattern.
  *
  * @param object $project
@@ -379,45 +183,6 @@ function _locale_translation_file_is_remote($uri) {
 }
 
 /**
- * Compare two update sources, looking for the newer one.
- *
- * The timestamp property of the source objects are used to determine which is
- * the newer one.
- *
- * @param object $source1
- *   Source object of the first translation source.
- * @param object $source2
- *   Source object of available update.
- *
- * @return integer
- *   - "LOCALE_TRANSLATION_SOURCE_COMPARE_LT": $source1 < $source2 OR $source1
- *     is missing.
- *   - "LOCALE_TRANSLATION_SOURCE_COMPARE_EQ":  $source1 == $source2 OR both
- *     $source1 and $source2 are missing.
- *   - "LOCALE_TRANSLATION_SOURCE_COMPARE_GT":  $source1 > $source2 OR $source2
- *     is missing.
- */
-function _locale_translation_source_compare($source1, $source2) {
-  if (isset($source1->timestamp) && isset($source2->timestamp)) {
-    if ($source1->timestamp == $source2->timestamp) {
-      return LOCALE_TRANSLATION_SOURCE_COMPARE_EQ;
-    }
-    else {
-      return $source1->timestamp > $source2->timestamp ? LOCALE_TRANSLATION_SOURCE_COMPARE_GT : LOCALE_TRANSLATION_SOURCE_COMPARE_LT;
-    }
-  }
-  elseif (isset($source1->timestamp) && !isset($source2->timestamp)) {
-    return LOCALE_TRANSLATION_SOURCE_COMPARE_GT;
-  }
-  elseif (!isset($source1->timestamp) && isset($source2->timestamp)) {
-    return LOCALE_TRANSLATION_SOURCE_COMPARE_LT;
-  }
-  else {
-    return LOCALE_TRANSLATION_SOURCE_COMPARE_EQ;
-  }
-}
-
-/**
  * Returns default import options for translation update.
  *
  * @return array