Add tool to update translations in PRs

Signed-off-by: Knut Ahlers <knut@ahlers.me>

ci/pr-regen-translations.sh

@@ -0,0 +1,65 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+files=(
+  i18n.yaml
+  src/langs/langs.js
+)
+translation_branch=upd-translate
+
+function log() {
+  echo "$@" >&2
+}
+
+PR_REMOTE_URL=${1:-}
+[[ -n $PR_REMOTE_URL ]] || {
+  log "Usage: $(basename $0) <github branch URL i.e. https://github.com/Luzifer/ots/tree/translate-de>"
+  exit 1
+}
+
+remote="$(cut -d '/' -f 1-5 <<<"${PR_REMOTE_URL}").git"
+branch=$(cut -d '/' -f 7 <<<"${PR_REMOTE_URL}")
+
+git diff --exit-code >/dev/null || {
+  log "FATAL: Local changes detected, stopping now."
+  exit 1
+}
+
+switch_back_branch=$(git branch --show-current)
+trap "git switch ${switch_back_branch}" EXIT
+
+log "Updating branch '${branch}' of remote '${remote}'..."
+
+log "+ Fetching remote..."
+git fetch "${remote}" "${branch}"
+
+log "+ Creating work-branch..."
+if git branch | grep -q ${translation_branch}; then
+  git branch -D ${translation_branch}
+fi
+git branch ${translation_branch} FETCH_HEAD
+
+log "+ Switching to work-branch..."
+git switch ${translation_branch}
+
+log "+ Updating translations..."
+make translate
+
+if git diff --exit-code "${files[@]}" >/dev/null; then
+  log "No changed introduced, stopping now."
+fi
+
+log "+ Committing changes..."
+git add "${files[@]}"
+git commit -m 'CI: Update embedded translations'
+
+log "+ Please review these changes:"
+git show
+
+log "[Enter] to continue, [Ctrl+C] to cancel..."
+read
+
+log "+ Updating remote branch..."
+git push ${remote} ${translation_branch}:${branch}
+
+log "Updated remote PR, switching back to previous branch..."