name: Build & Push Docker

on:
  push:
    branches: ["main"]
  workflow_dispatch:
  schedule:
    - cron: "@weekly"

jobs:
  build-and-push:
    runs-on: ubuntu-latest

    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Resolve latest Open Stage Control release
        shell: bash
        run: |
          set -euo pipefail

          python3 <<'PY'
          import json
          import urllib.request

          url = "https://framagit.org/api/v4/projects/jean-emmanuel%2Fopen-stage-control/releases"
          with urllib.request.urlopen(url) as response:
              releases = json.load(response)

          if not releases:
              raise SystemExit("No releases returned by upstream API")

          latest = releases[0]
          tag = latest["tag_name"]
          version = tag[1:] if tag.startswith("v") else tag

          with open("release.env", "w", encoding="utf-8") as f:
              f.write(f"OSC_TAG={tag}\n")
              f.write(f"OSC_VERSION={version}\n")
          PY

          cat release.env >> "$GITHUB_ENV"

      - name: Set image names
        shell: bash
        env:
          REPOSITORY: ${{ gitea.repository }}
        run: |
          set -euo pipefail
          OWNER="$(printf '%s' "${REPOSITORY%/*}" | tr '[:upper:]' '[:lower:]')"
          REPO="$(printf '%s' "${REPOSITORY#*/}" | tr '[:upper:]' '[:lower:]')"
          echo "IMAGE_LATEST=git.f-40.com/${OWNER}/${REPO}:latest" >> "$GITHUB_ENV"
          echo "IMAGE_VERSIONED=git.f-40.com/${OWNER}/${REPO}:${OSC_VERSION}" >> "$GITHUB_ENV"

      - name: Login to Gitea Container Registry
        shell: bash
        env:
          REGISTRY_USER: ${{ secrets.USER }}
          REGISTRY_TOKEN: ${{ secrets.TOKEN }}
        run: |
          set -euo pipefail
          echo "$REGISTRY_TOKEN" | docker login git.f-40.com -u "$REGISTRY_USER" --password-stdin

      - name: Decide whether a build is needed
        shell: bash
        env:
          EVENT_NAME: ${{ gitea.event_name }}
        run: |
          set -euo pipefail

          if [ "$EVENT_NAME" = "push" ] || [ "$EVENT_NAME" = "workflow_dispatch" ]; then
            echo "SHOULD_BUILD=true" >> "$GITHUB_ENV"
            echo "BUILD_REASON=repository change or manual run" >> "$GITHUB_ENV"
            exit 0
          fi

          if docker manifest inspect "$IMAGE_VERSIONED" >/dev/null 2>&1; then
            echo "SHOULD_BUILD=false" >> "$GITHUB_ENV"
            echo "BUILD_REASON=version ${OSC_VERSION} already exists in registry" >> "$GITHUB_ENV"
          else
            echo "SHOULD_BUILD=true" >> "$GITHUB_ENV"
            echo "BUILD_REASON=new upstream release ${OSC_TAG}" >> "$GITHUB_ENV"
          fi

      - name: Build
        shell: bash
        run: |
          set -euo pipefail

          if [ "${SHOULD_BUILD}" != "true" ]; then
            echo "Skipping build: ${BUILD_REASON}"
            exit 0
          fi

          echo "Building ${OSC_TAG} because ${BUILD_REASON}"
          docker build \
            --build-arg OPEN_STAGE_CONTROL_VERSION="${OSC_VERSION}" \
            -t "${IMAGE_LATEST}" \
            -t "${IMAGE_VERSIONED}" \
            .

      - name: Push
        shell: bash
        run: |
          set -euo pipefail

          if [ "${SHOULD_BUILD}" != "true" ]; then
            echo "Skipping push: ${BUILD_REASON}"
            exit 0
          fi

          docker push "${IMAGE_VERSIONED}"
          docker push "${IMAGE_LATEST}"