name: Translation - Update

on:
  schedule:
    - cron: '0 0 * * 3' # every Wednesday at 00:00 UTC
  workflow_dispatch:

permissions:
  contents: write
  pull-requests: write

concurrency:
  group: translation-update
  cancel-in-progress: true

jobs:
  translations-update:
    if: github.repository == 'thunderbird/thunderbird-android'
    runs-on: ubuntu-latest

    env:
      BRANCH_NAME: weblate/update-translations
      BASE_BRANCH: main
      PR_TITLE: "chore(i18n): translations update from Weblate"
      COMMIT_MESSAGE: "chore(i18n): update translations (Weblate)"
      PR_BODY: |
        Automated translation update from [Weblate](https://hosted.weblate.org) for [Thunderbird Mobile - Android](https://hosted.weblate.org/projects/thunderbird/thunderbird-android/app-common/).

        This PR is generated from Weblate's Git export and committed as a single bot commit while preserving contributor attribution via `Co-authored-by` trailers.
      WEBLATE_REMOTE: "https://hosted.weblate.org/git/thunderbird/thunderbird-android/app-common/"
      WEBLATE_BRANCH: main

    steps:
      - name: Checkout the repo
        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
        with:
          fetch-depth: 0

      - name: Configure git and fetch remotes
        run: |
          set -euo pipefail

          git config user.name "Translation Bot"
          git config user.email "translation-bot@thunderbird.net"

          git remote remove weblate 2>/dev/null || true
          git remote add weblate "$WEBLATE_REMOTE"

          git fetch origin "$BASE_BRANCH"
          git fetch weblate "$WEBLATE_BRANCH"

      - name: Detect incoming Weblate changes
        id: changes
        run: |
          if git log --oneline "origin/$BASE_BRANCH..weblate/$WEBLATE_BRANCH" | grep -q .; then
            echo "Incoming changes found between origin/$BASE_BRANCH and weblate/$WEBLATE_BRANCH"
            echo "has_changes=true" >> "$GITHUB_OUTPUT"
          else
            echo "No incoming Weblate changes found"
            echo "has_changes=false" >> "$GITHUB_OUTPUT"
          fi


      - name: Build metadata
        if: steps.changes.outputs.has_changes == 'true'
        run: |
          set -euo pipefail

          {
            printf '%s\n\n' "$PR_BODY"
            printf '### Contributors\n'
            git log --format='%aN' "origin/$BASE_BRANCH..weblate/$WEBLATE_BRANCH" \
              | sort -u \
              | sed 's/^/- /'
          } > .git/pr-body.txt

          git log --format='%aN <%aE>' "origin/$BASE_BRANCH..weblate/$WEBLATE_BRANCH" \
            | grep -Fv 'Hosted Weblate <hosted@weblate.org>' \
            | sort -u \
            | sed 's/^/Co-authored-by: /' > .git/weblate-coauthors.txt

          {
            printf '%s\n\n' "$COMMIT_MESSAGE"
            if [ -s .git/weblate-coauthors.txt ]; then
              cat .git/weblate-coauthors.txt
            fi
          } > .git/commit-message.txt

          echo "Generated PR body:"
          cat .git/pr-body.txt

          echo "Generated co-author trailers:"
          cat .git/weblate-coauthors.txt || true

          echo "Generated commit message:"
          cat .git/commit-message.txt

      - name: Apply Weblate changes
        if: steps.changes.outputs.has_changes == 'true'
        run: |
          set -euo pipefail

          git checkout -B "$BRANCH_NAME" "origin/$BASE_BRANCH"
          git checkout "weblate/$WEBLATE_BRANCH" -- \
            'app-metadata/' \
            ':(glob)**/res/values-*/strings.xml' \
            ':(glob)**/composeResources/values-*/strings.xml'

      - name: Create commit
        if: steps.changes.outputs.has_changes == 'true'
        id: commit
        run: |
          set -euo pipefail

          git add -A

          if git diff --cached --quiet; then
            echo "No staged changes after applying Weblate tree"
            echo "created_commit=false" >> "$GITHUB_OUTPUT"
            exit 0
          fi

          git commit -F .git/commit-message.txt
          echo "created_commit=true" >> "$GITHUB_OUTPUT"

      - name: Push sync branch
        if: steps.commit.outputs.created_commit == 'true'
        run: |
          set -euo pipefail

          git push --force-with-lease origin "$BRANCH_NAME"

      - name: Create or update pull request
        if: steps.commit.outputs.created_commit == 'true'
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          set -euo pipefail

          PR_NUMBER="$(gh pr list \
          --head "$BRANCH_NAME" \
          --base "$BASE_BRANCH" \
          --state open \
          --json number \
          --jq '.[0].number')"

          if [ -n "$PR_NUMBER" ] && [ "$PR_NUMBER" != "null" ]; then
            gh pr edit "$PR_NUMBER" \
              --title "$PR_TITLE" \
              --body-file .git/pr-body.txt
          else
            gh pr create \
            --base "$BASE_BRANCH" \
            --head "$BRANCH_NAME" \
            --title "$PR_TITLE" \
            --body-file .git/pr-body.txt \
            --label "type: translation" \
            --label "report: include"
          fi