name: Merge Upstream Master
on:
  issue_comment:
    types: created

jobs:
  merge-upstream:
    if: |
      github.event.issue.pull_request &&
      (github.event.comment.body == '!merge_upstream') &&
      ((github.event.sender.id == github.event.issue.user.id) ||
      (github.event.comment.author_association == 'COLLABORATOR') ||
      (github.event.comment.author_association == 'MEMBER') ||
      (github.event.comment.author_association == 'OWNER'))

    runs-on: ubuntu-latest
    steps:
      - id: create_token
        uses: actions/create-github-app-token@v3.2.0
        with:
          app-id: ${{ secrets.APP_ID }}
          private-key: ${{ secrets.PRIVATE_KEY }}

      - run: echo "GH_TOKEN=${{ steps.create_token.outputs.token }}" >> "$GITHUB_ENV"
      - run: echo "FAIL_NOTIFIED=false" >> "$GITHUB_ENV"

      - name: Like the comment
        env:
          BASE_REPOSITORY: ${{ github.repository }}
        run: |
          gh api \
            --method POST \
            -H "Accept: application/vnd.github+json" \
            -H "X-GitHub-Api-Version: 2022-11-28" \
            /repos/$BASE_REPOSITORY/issues/comments/${{ github.event.comment.id }}/reactions \
            -f content='+1'

      - name: PR Data
        run: |
          pr_json=$(curl -L -s --fail-with-body -H "Authorization: token ${{ github.token }}" ${{ github.event.issue.pull_request.url }})
          if [ `jq -r '.maintainer_can_modify' <<<$pr_json` == "false" ] ; then
            gh pr comment ${{ github.event.issue.html_url }} --body 'GitHub Actions can not push to the repository without "Allow edits and access to secrets by maintainers" checked.'
            echo "FAIL_NOTIFIED=true" >> "$GITHUB_ENV"
            exit 1
          fi
          echo "PR_REPO=`jq -r '.head.repo.full_name' <<<$pr_json`" >> $GITHUB_ENV
          echo "PR_BRANCH=`jq -r '.head.ref' <<<$pr_json`" >> $GITHUB_ENV
          echo "PR_HEAD_LABEL=`jq -r '.head.label' <<<$pr_json`" >> $GITHUB_ENV

      - uses: actions/checkout@v7.0.0
        with:
          repository: ${{ env.PR_REPO }}
          ref: ${{ env.PR_BRANCH }}
          token: ${{ env.GH_TOKEN }}

      - uses: actions/setup-node@v7.0.0
        with:
          node-version: 20
          cache: 'yarn'
          cache-dependency-path: ./tgui/yarn.lock

      - uses: actions/setup-python@v6.3.0
        with:
          python-version: '3.13'
          cache: 'pip'

      - name: Perform Merge
        env:
          BASE_BRANCH: ${{ github.event.repository.default_branch }}
          BASE_REPOSITORY: ${{ github.repository }}
        run: |
          # Compare head branch and base branch
          compare_result=$(curl -L -s --fail-with-body \
            -H "Accept: application/vnd.github+json" \
            -H "X-GitHub-Api-Version: 2022-11-28" \
            "https://api.github.com/repos/$BASE_REPOSITORY/compare/$BASE_BRANCH...$PR_HEAD_LABEL")
          # Assign multiple variables with one jq execution
          if IFS=$'\n' read -d '' -r behind_by ahead_by <<<$(jq '.behind_by, .ahead_by' <<<$compare_result) ; [ -z "$behind_by" ] || [ -z "$ahead_by" ] ; then
            echo '- Unable to determine the distance between the head branch and the base branch.' | tee -a "$GITHUB_STEP_SUMMARY"
            exit 1
          fi
          if [ "$behind_by" -le 0 ] ; then
            echo '- Skipping merge. Up-to-date with base branch.' | tee -a "$GITHUB_STEP_SUMMARY"
            exit 0
          else
            echo '- Merging base branch. Head branch is behind by '"$behind_by"' commits and ahead by '"$ahead_by"' commits.' | tee -a "$GITHUB_STEP_SUMMARY"
          fi

          # Install Tools
          chmod +x tools/bootstrap/python
          bash tools/hooks/install.sh
          chmod +x tools/hooks/*.merge tgui/bin/tgui

          # Actual Merge
          git config user.name paradisess13[bot]
          git config user.email "165046124+paradisess13[bot]@users.noreply.github.com"
          git remote add upstream "https://github.com/$BASE_REPOSITORY.git"

          git fetch origin "$PR_BRANCH" --depth=$((ahead_by + 1))
          git fetch upstream "$BASE_BRANCH" --depth=$((behind_by + 1))

          # Check if a workflow file would be modified by the merge (permissions prevent pushes if so)
          latest_workflow_commit=$(git log -n 1 --pretty=format:"%H" upstream/$BASE_BRANCH -- .github/workflows)
          if ! git branch --contains $latest_workflow_commit | grep -q "$(git rev-parse --abbrev-ref HEAD)"; then
            gh pr comment ${{ github.event.issue.html_url }} --body "GitHub Actions can not push to this branch as workflow files have been changed since your branch was last updated. Please update your branch past https://github.com/ParadiseSS13/Paradise/commit/$latest_workflow_commit before using this command again."
            echo "FAIL_NOTIFIED=true" >> "$GITHUB_ENV"
            exit 1
          fi

          git merge FETCH_HEAD
          exit_code=0
          merge_conflicts=$(git diff --name-only --diff-filter=U --exit-code) || exit_code=$?
          if [ "$exit_code" -eq 0 ] ; then
            exit 0
          else
            if grep -v ^tgui/public/ <<< "$merge_conflicts" ; then
              gh pr comment ${{ github.event.issue.html_url }} --body "GitHub Actions can not merge upstream into this branch as some conflicted files can not be resolved automatically."
              exit 1
            fi
            if [[ -n "$(grep ^tgui/public/ <<< "$merge_conflicts")" ]] ; then
              echo 'REBUILD_TGUI=true' >>> "$GITHUB_ENV"
            fi
          fi

      - name: Rebuild TGUI
        if: ${{ env.REBUILD_TGUI }}
        run: |
          bash tgui/bin/tgui
          git merge --continue

      - name: Push Changes
        run: |
          if [[ -n "$(git rev-list -1 @{u}..)" ]]; then
            git push origin
          else

      - name: Notify Failure
        if: failure() && env.FAIL_NOTIFIED != 'true'
        run: |
          gh pr comment ${{ github.event.issue.html_url }} -b 'Merging upstream failed, see the action run log for details: https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}'