branch-apk.yml

name: Branch APK

# On every push to a non-main branch, build a debug APK and replace the
# rolling pre-release tagged `branch-<name>` with the freshly built artifact.
# Testers always get the latest commit by visiting the same release URL.
#
# Pull-request runs build the APK as a workflow artifact (downloadable from
# the Actions tab for ~90 days) but do not touch the release list, so PRs
# from forks can't push tags.

on:
  push:
    branches-ignore:
      - main
    tags-ignore:
      - "**"
  pull_request:
    branches:
      - "**"
  workflow_dispatch:

permissions:
  contents: write

jobs:
  build:
    runs-on: ubuntu-latest

    steps:
      - name: Checkout
        uses: actions/checkout@v4
        with:
          fetch-depth: 0  # full history so we can produce a "since main" log

      - name: Set up JDK 17
        uses: actions/setup-java@v4
        with:
          distribution: temurin
          java-version: "17"

      - name: Set up Gradle
        uses: gradle/actions/setup-gradle@v3

      - name: Make gradlew executable
        run: chmod +x ./gradlew

      - name: Build debug APKs
        # Build the phone APK on every branch. Build the wear APK too when
        # the branch has a wear/ module (currently only wear-os-watch-ultra),
        # so testers can grab both halves from the same rolling release.
        run: |
          targets=":app:assembleDebug"
          if [ -f wear/build.gradle.kts ]; then
            targets="$targets :wear:assembleDebug"
          fi
          ./gradlew $targets --no-daemon --stacktrace
        env:
          GRADLE_OPTS: -Xmx4g -Dorg.gradle.jvmargs=-Xmx4g

      - name: Compute build metadata
        id: meta
        if: github.event_name != 'pull_request'
        run: |
          BRANCH="${GITHUB_REF##*/}"
          SHORT_SHA="$(git rev-parse --short HEAD)"
          TAG="branch-${BRANCH}"
          APK_NAME="EUC-Planet-${BRANCH}-${SHORT_SHA}-phone.apk"
          WEAR_APK_NAME="EUC-Planet-${BRANCH}-${SHORT_SHA}-wear_os.apk"

          # Pull the per-branch description if BRANCH.md exists, otherwise
          # fall back to a generic notice. This becomes the release body header.
          if [ -f BRANCH.md ]; then
            cp BRANCH.md /tmp/branch-notes.md
          else
            cat > /tmp/branch-notes.md <<EOF
          # ${BRANCH}

          No \`BRANCH.md\` found at repo root. Add one to describe what this
          branch is for and who should test it.
          EOF
          fi

          # Recent commits since branching from main, capped to keep the
          # release body readable on big branches.
          git log --pretty=format:'- %h %s' main..HEAD | head -50 > /tmp/commit-log.md || true

          {
            echo "**Pre-release from branch \`${BRANCH}\`** — automatic build at \`${SHORT_SHA}\`."
            echo
            echo "This is a CI-built debug APK. It can't update an existing Play Store install in place — uninstall the Play version first to install this build."
            echo
            cat /tmp/branch-notes.md
            echo
            echo "## Recent commits"
            echo
            cat /tmp/commit-log.md
          } > /tmp/release-body.md

          echo "branch=${BRANCH}" >> "$GITHUB_OUTPUT"
          echo "short_sha=${SHORT_SHA}" >> "$GITHUB_OUTPUT"
          echo "tag=${TAG}" >> "$GITHUB_OUTPUT"
          echo "apk_name=${APK_NAME}" >> "$GITHUB_OUTPUT"
          echo "wear_apk_name=${WEAR_APK_NAME}" >> "$GITHUB_OUTPUT"

      - name: Rename APKs for release
        if: github.event_name != 'pull_request'
        run: |
          cp app/build/outputs/apk/debug/app-debug.apk \
             "/tmp/${{ steps.meta.outputs.apk_name }}"
          # Wear APK only exists on branches that have a wear/ module.
          if [ -f wear/build/outputs/apk/debug/wear-debug.apk ]; then
            cp wear/build/outputs/apk/debug/wear-debug.apk \
               "/tmp/${{ steps.meta.outputs.wear_apk_name }}"
          fi

      - name: Upload phone APK as workflow artifact
        uses: actions/upload-artifact@v4
        with:
          name: app-debug-${{ github.run_id }}
          path: app/build/outputs/apk/debug/app-debug.apk
          retention-days: 90

      - name: Upload wear APK as workflow artifact
        if: hashFiles('wear/build/outputs/apk/debug/wear-debug.apk') != ''
        uses: actions/upload-artifact@v4
        with:
          name: wear-debug-${{ github.run_id }}
          path: wear/build/outputs/apk/debug/wear-debug.apk
          retention-days: 90

      - name: Strip prior APKs from rolling release
        if: github.event_name != 'pull_request'
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          # action-gh-release attaches new files but doesn't remove the previous
          # commit's APK; without this step the rolling pre-release accumulates
          # one APK per push. Delete every existing .apk on the tag before the
          # next step uploads the freshly built one. Tolerate the tag not
          # existing yet (first run on a brand-new branch).
          tag="${{ steps.meta.outputs.tag }}"
          if gh release view "$tag" >/dev/null 2>&1; then
            gh release view "$tag" --json assets \
              --jq '.assets[] | select(.name | endswith(".apk")) | .name' \
            | while read -r asset; do
                [ -n "$asset" ] && gh release delete-asset "$tag" "$asset" --yes || true
              done
          fi

      - name: Replace rolling pre-release with new APK
        if: github.event_name != 'pull_request'
        uses: softprops/action-gh-release@v2
        with:
          tag_name: ${{ steps.meta.outputs.tag }}
          name: ${{ steps.meta.outputs.tag }} (${{ steps.meta.outputs.short_sha }})
          body_path: /tmp/release-body.md
          prerelease: true
          # Replace the existing tag/release on every push so testers can
          # always find the latest at the same URL. The glob picks up both
          # the phone APK and (if the branch has wear/) the watch APK.
          make_latest: "false"
          files: /tmp/EUC-Planet-${{ steps.meta.outputs.branch }}-${{ steps.meta.outputs.short_sha }}*.apk