#!/usr/bin/env bash

# See https://zulip.readthedocs.io/en/latest/translating/internationalization.html
# for background on this subsystem.

set -e
set -x

# Check we're on `main` or `\d+\.x`
branch=$(git rev-parse --abbrev-ref HEAD)
if [ "$branch" == "main" ]; then
    suffix=""
elif [[ "$branch" =~ ^[0-9]+\.x$ ]]; then
    suffix="-${branch/./-}"
else
    echo "Unexpected branch name: $branch"
    exit 1
fi

git fetch upstream

local_branch="update-translations-$branch"
if git rev-parse --verify --quiet "origin/$local_branch" >/dev/null; then
    echo "Remote branch origin/$local_branch already exists -- delete it before continuing"
    exit 1
fi
git checkout -b "$local_branch" "upstream/$branch"

# Clear out local any `.mo` files, which cause locale/*/LC_MESSAGES/
# directories to not be empty when their .po files vanish, so git
# doesn't remove the directory.
rm locale/*/LC_MESSAGES/*.mo || true

wlc lock "zulip/frontend$suffix"
wlc lock "zulip/django$suffix"
trap 'wlc unlock "zulip/frontend$suffix" && wlc unlock "zulip/django$suffix"' EXIT

wlc commit "zulip/frontend$suffix"
wlc commit "zulip/django$suffix"

git fetch "https://hosted.weblate.org/git/zulip/django$suffix/"
if [ "$(git rev-list FETCH_HEAD "^upstream/$branch")" == "" ]; then
    echo "No changes from Weblate to commit!"
else
    git cherry-pick FETCH_HEAD "^upstream/$branch"

    git clean -dxf locale/

    # Check that everything is normalized into NFC; if it isn't, we
    # need to fix it in Weblate, or Weblate will fail to rebase the
    # changes out after we push.
    files="$(find locale -type f -name '*.json' -o -name '*.po')"
    mapfile -t files <<<"$files"
    for file in "${files[@]}"; do
        uconv -x any-nfc "$file" | sponge -- "$file"
    done

    git add locale/
    if ! git diff-index --quiet --cached HEAD locale/; then
        echo "Non-NFC translations exist!  Fix them in Weblate first."
        git diff --cached
        exit 1
    fi

    # Update locale/*/legacy_stream_translations.json
    ./tools/i18n/update-for-legacy-translations

    # Trim out any now-empty locale directories
    find locale/ -type d -empty -delete

    git add locale/

    # Double-check that they all compile
    ./manage.py compilemessages --ignore='*'

    git commit --amend -m 'i18n: Sync translations from Weblate.'
fi

./manage.py makemessages --all
git add locale/

if git diff-index --quiet --cached HEAD locale/; then
    echo "No changes to PO files to commit!"
else
    git commit -m 'i18n: Updated .po files for new strings.'
fi

if [ "$(git rev-list HEAD "^upstream/$branch")" == "" ]; then
    echo "No commits to push, aborting!"
    git checkout "$branch"
    git branch -D "$local_branch"
else
    git push origin "HEAD:$local_branch"

    gh_username="$(gh api user --jq '.login')"
    gh pr create --title "Updated translations for $branch from Weblate." --body "" --base "$branch" --head "$gh_username:$local_branch"
    gh pr merge --rebase --auto "$gh_username:$local_branch"
    commit=$(git rev-parse HEAD)

    git checkout "$branch"
    git branch -D "$local_branch"

    echo "Waiting for PR to merge..."
    while [ "$(gh pr list --search "$commit" --state all --json state --jq .[0].state)" != "MERGED" ]; do
        sleep 30
    done

    git push origin --delete "$local_branch"
fi