Support serving of backend translations (#12453)

* Add view to support backend translation fetching

* Load backend translations from component json

* Translations for season sensor

* Scripts to merge and unpack Lokalise translations

* Fix copy paste error

* Serve post-lokalise translations to frontend

* Linting

* Auto-deploy translations with Travis

* Commit post-lokalise translation files

* Split logic into more helper functions

* Fall back to English for missing keys

* Move local translation copies to `.translations`

* Linting

* Initial tests

* Remove unnecessary file check

* Convert translation helper to async/await

* Convert translation helper tests to async/await

* Use set subtraction to find missing_components

* load_translation_files use component->file mapping

* Remove duplicated resources fetching

Get to take advantage of the slick Python 3.5 dict merging here.

* Switch to live project ID

script/translations_download_split.py

@@ -0,0 +1,81 @@
+#!/usr/bin/env python3
+"""Merge all translation sources into a single JSON file."""
+import glob
+import os
+import re
+
+from homeassistant.util import json as json_util
+
+FILENAME_FORMAT = re.compile(r'strings\.(?P<suffix>\w+)\.json')
+
+
+def get_language(path):
+    """Get the language code for the given file path."""
+    return os.path.splitext(os.path.basename(path))[0]
+
+
+def get_component_path(lang, component):
+    """Get the component translation path."""
+    if os.path.isdir(os.path.join("homeassistant", "components", component)):
+        return os.path.join(
+            "homeassistant", "components", component, ".translations",
+            "{}.json".format(lang))
+    else:
+        return os.path.join(
+            "homeassistant", "components", ".translations",
+            "{}.{}.json".format(component, lang))
+
+
+def get_platform_path(lang, component, platform):
+    """Get the platform translation path."""
+    if os.path.isdir(os.path.join(
+            "homeassistant", "components", component, platform)):
+        return os.path.join(
+            "homeassistant", "components", component, platform,
+            ".translations", "{}.json".format(lang))
+    else:
+        return os.path.join(
+            "homeassistant", "components", component, ".translations",
+            "{}.{}.json".format(platform, lang))
+
+
+def get_component_translations(translations):
+    """Get the component level translations."""
+    translations = translations.copy()
+    translations.pop('platform', None)
+
+    return translations
+
+
+def save_language_translations(lang, translations):
+    """Distribute the translations for this language."""
+    components = translations.get('component', {})
+    for component, component_translations in components.items():
+        base_translations = get_component_translations(component_translations)
+        if base_translations:
+            path = get_component_path(lang, component)
+            os.makedirs(os.path.dirname(path), exist_ok=True)
+            json_util.save_json(path, base_translations)
+
+        for platform, platform_translations in component_translations.get(
+                'platform', {}).items():
+            path = get_platform_path(lang, component, platform)
+            os.makedirs(os.path.dirname(path), exist_ok=True)
+            json_util.save_json(path, platform_translations)
+
+
+def main():
+    """Main section of the script."""
+    if not os.path.isfile("requirements_all.txt"):
+        print("Run this from HA root dir")
+        return
+
+    paths = glob.iglob("build/translations-download/*.json")
+    for path in paths:
+        lang = get_language(path)
+        translations = json_util.load_json(path)
+        save_language_translations(lang, translations)
+
+
+if __name__ == '__main__':
+    main()