name: Dashboard Update

on:
  workflow_dispatch:

permissions:
  contents: read

jobs:
  update:
    runs-on: ubuntu-latest
    env:
      UPDATE_SOURCE_REPOSITORY: ${{ vars.UPDATE_SOURCE_REPOSITORY || 'hieunc229/mailflare' }}

    steps:
      - name: Check update token
        env:
          UPDATE_TOKEN: ${{ secrets.MAILFLARE_UPDATE_TOKEN }}
        run: |
          if [ -z "${UPDATE_TOKEN}" ]; then
            echo "::error::Add MAILFLARE_UPDATE_TOKEN as a repository Actions secret."
            exit 1
          fi

      - name: Checkout repository
        uses: actions/checkout@v4
        with:
          fetch-depth: 0
          token: ${{ secrets.MAILFLARE_UPDATE_TOKEN }}

      - name: Replace repository with upstream source
        run: |
          set -euo pipefail
          git config user.name "mailflare-update"
          git config user.email "mailflare-update@users.noreply.github.com"

          upstream_url="https://github.com/${UPDATE_SOURCE_REPOSITORY}.git"
          if git remote get-url upstream >/dev/null 2>&1; then
            git remote set-url upstream "${upstream_url}"
          else
            git remote add upstream "${upstream_url}"
          fi
          git fetch --no-tags upstream

          upstream_branch="$(git remote show upstream | sed -n 's/.*HEAD branch: //p')"
          if [ -z "${upstream_branch}" ]; then
            echo "::error::Could not resolve the default branch of ${UPDATE_SOURCE_REPOSITORY}."
            exit 1
          fi
          upstream_ref="upstream/${upstream_branch}"
          echo "Replacing ${GITHUB_REF_NAME} with ${upstream_ref}."

          # Keep the installation repository's commit history while replacing
          # its complete tracked tree with the current upstream tree.
          git read-tree --reset -u "${upstream_ref}"
          if git diff --cached --quiet; then
            echo "Repository is already up to date."
            exit 0
          fi
          git commit -m "Update Mailflare from ${UPDATE_SOURCE_REPOSITORY}@${upstream_branch}"

      - name: Push update
        run: |
          set -euo pipefail
          if [ -z "$(git log "origin/${GITHUB_REF_NAME}..HEAD" --oneline)" ]; then
            echo "Repository is already up to date."
            exit 0
          fi
          git push origin "HEAD:${GITHUB_REF_NAME}"