name: Upstream release

# Watches Modrinth for a new Modrinth App release, rebuilds Modrinth Enhanced
# on top of it, and publishes a release of our own if everything still works.
#
# Nothing is published unless the patches applied, the checks passed and all
# three platforms built, so an upstream change that breaks a patch stops here
# and reports a failure instead of shipping a broken build.

on:
  schedule:
    - cron: '17 6 * * *'
  workflow_dispatch:
    inputs:
      upstream-ref:
        description: Build this upstream tag instead of the newest one
        type: string
        required: false
      revision:
        description: Release the current patches again on the upstream release in upstream.txt, as v1.2.3-2, v1.2.3-3, ...
        type: boolean
        default: false

permissions:
  contents: write

concurrency:
  group: upstream-release
  cancel-in-progress: false

jobs:
  detect:
    name: Detect
    runs-on: ubuntu-latest
    outputs:
      upstream: ${{ steps.check.outputs.upstream }}
      tag: ${{ steps.check.outputs.tag }}
      proceed: ${{ steps.check.outputs.proceed }}
    steps:
      - uses: actions/checkout@v4

      - name: Decide what to release
        id: check
        env:
          GH_TOKEN: ${{ github.token }}
          REQUESTED: ${{ inputs.upstream-ref }}
          REVISION: ${{ inputs.revision }}
        run: |
          set -euo pipefail
          current="$(tr -d '[:space:]' < upstream.txt)"
          if [ "$REVISION" = true ]; then
            # A revision rebuilds what we already ship, not whatever is newest.
            upstream="${REQUESTED:-$current}"
          else
            upstream="${REQUESTED:-$(scripts/latest-upstream.sh)}"
          fi
          echo "upstream=$upstream" >> "$GITHUB_OUTPUT"
          echo "Upstream release: $upstream (we are on $current)"

          if ! gh release view "$upstream" >/dev/null 2>&1; then
            tag="$upstream"
          elif [ "$REVISION" = true ]; then
            # The first release of an upstream version is its plain tag, which
            # counts as revision 1.
            last="$(
              git ls-remote --tags --refs origin "$upstream-*" |
                sed 's#.*refs/tags/##' |
                awk -v prefix="$upstream-" 'index($0, prefix) == 1 {
                  n = substr($0, length(prefix) + 1)
                  if (n ~ /^[0-9]+$/) print n
                }' |
                sort -n |
                tail -1
            )"
            tag="$upstream-$(( ${last:-1} + 1 ))"
          else
            echo "$upstream has already been released; nothing to do."
            echo "proceed=false" >> "$GITHUB_OUTPUT"
            exit 0
          fi

          echo "tag=$tag" >> "$GITHUB_OUTPUT"
          echo "proceed=true" >> "$GITHUB_OUTPUT"
          echo "Releasing $tag"

  build:
    name: Build
    needs: detect
    if: needs.detect.outputs.proceed == 'true'
    uses: ./.github/workflows/build.yml
    with:
      upstream-ref: ${{ needs.detect.outputs.upstream }}

  release:
    name: Release
    needs: [detect, build]
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - name: Record the upstream release we build against
        env:
          UPSTREAM: ${{ needs.detect.outputs.upstream }}
        run: |
          set -euo pipefail
          printf '%s\n' "$UPSTREAM" > upstream.txt
          if git diff --quiet -- upstream.txt; then
            echo "upstream.txt already points at $UPSTREAM"
            exit 0
          fi
          git config user.name 'github-actions[bot]'
          git config user.email '41898282+github-actions[bot]@users.noreply.github.com'
          git commit -m "Track upstream $UPSTREAM" -- upstream.txt
          git push origin HEAD:${{ github.event.repository.default_branch }}

      - name: Download installers
        uses: actions/download-artifact@v4
        with:
          path: artifacts
          merge-multiple: true

      - name: Publish the release
        env:
          GH_TOKEN: ${{ github.token }}
          TAG: ${{ needs.detect.outputs.tag }}
          UPSTREAM: ${{ needs.detect.outputs.upstream }}
        run: |
          set -euo pipefail
          ls -la artifacts
          notes="$(cat <<EOF
          Modrinth Enhanced $TAG, built from [Modrinth App $UPSTREAM](https://github.com/modrinth/code/releases/tag/$UPSTREAM).

          Same app as upstream, with the patches in \`patches/\` applied:

          - no advertising,
          - no telemetry, crash reporting or survey embeds,
          - offline accounts for singleplayer and offline-mode servers,
          - renamed and re-iconed as Modrinth Enhanced.

          It keeps using the same data directory as the official Modrinth App,
          so instances, settings and accounts carry over. Do not run both at
          the same time.

          See the upstream release notes for everything else that changed.
          EOF
          )"
          gh release create "$TAG" \
            --title "Modrinth Enhanced $TAG" \
            --notes "$notes" \
            artifacts/*