# Builds the Docker image and pushes it to Gitea's built-in container registry
# on every push to main. Tags each build as :latest and :<commit-sha>.
#
# PREREQUISITES on your Gitea instance:
#   1. Actions must be enabled (app.ini: [actions] ENABLED = true) and at least
#      one act_runner registered.
#   2. The runner must be able to build images. act_runner needs access to a
#      Docker daemon — either run the runner with the host Docker socket mounted
#      (-v /var/run/docker.sock:/var/run/docker.sock) or in docker-in-docker mode.
#   3. The Package Registry must be enabled (it is by default).
#
# TOKEN: the workflow tries the auto-injected GITHUB_TOKEN first. If your Gitea
# version does not grant it package-write scope, create a Personal Access Token
# with "write:package" scope and add it as a repository secret named
# REGISTRY_TOKEN (Repo > Settings > Actions > Secrets).

name: build-image

on:
  push:
    branches: [main]

jobs:
  build-and-push:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Compute registry host and image name
        id: meta
        run: |
          # Registry host = the Gitea instance host (strip the scheme).
          echo "registry=$(echo '${{ github.server_url }}' | sed -E 's#^https?://##')" >> "$GITHUB_OUTPUT"
          # Image path must be lowercase for OCI registries.
          echo "image=$(echo '${{ github.repository }}' | tr '[:upper:]' '[:lower:]')" >> "$GITHUB_OUTPUT"

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3

      - name: Log in to the Gitea container registry
        uses: docker/login-action@v3
        with:
          registry: ${{ steps.meta.outputs.registry }}
          username: ${{ github.actor }}
          password: ${{ secrets.REGISTRY_TOKEN || secrets.GITHUB_TOKEN }}

      - name: Build and push
        uses: docker/build-push-action@v6
        with:
          context: .
          push: true
          tags: |
            ${{ steps.meta.outputs.registry }}/${{ steps.meta.outputs.image }}:latest
            ${{ steps.meta.outputs.registry }}/${{ steps.meta.outputs.image }}:${{ github.sha }}